مجتبی ورشاوی2
عضو جدید
حق با دوستمان ebrahimsakht است.
ترجمه مجانی یک صفحه ای برای ساخت وتولیدی
- شروع کننده موضوع مجتبی ورشاوی2
- تاریخ شروع
حق با دوستمان ebrahimsakht است.
alinazarian
عضو جدید
s
s
دوستان با سرچ google translate , ورفتن به آن سايت متني راكه ميخواهيد ترجمه كنيد به انگليس يا هرزبان ديگري قرار دهيد .(يا برعكس)به راحتي كل متن شما ترجمه ميشود.
s
سلام دوست عزيز به جاي ماهي دادن ماهي گيري ياد بديددوستان لینک منبع خود را بگذارید وترجمه را دراین تایپیک دریافت کنیدبا امکانات کامل ترانسلیت درخدمتیم )
دوستان با سرچ google translate , ورفتن به آن سايت متني راكه ميخواهيد ترجمه كنيد به انگليس يا هرزبان ديگري قرار دهيد .(يا برعكس)به راحتي كل متن شما ترجمه ميشود.
مجتبی ورشاوی2
عضو جدید
مجتبی ورشاوی2
عضو جدید
بخش سوم وآخر
بخش سوم وآخر
بخش سوم وآخر
[FONT="]the key benefits of WFMS are: [/FONT]
[FONT="]فواید کلیدی عبارتند از:[/FONT]
[FONT="]
[/FONT][FONT="]• Improved efficiency - automation of many business processes results in the elimination of many unnecessary steps [/FONT][FONT="].[/FONT]
[/FONT][FONT="]• Improved efficiency - automation of many business processes results in the elimination of many unnecessary steps [/FONT][FONT="].[/FONT]
[FONT="]بهبود کارایی –خودکار سازی بسیاری از نتایج پروسه های کسب وکار وزدودن بسیاری از مراحل غیر ضروری. [/FONT]
[FONT="]
[/FONT][FONT="]• Better process control - improved management of business processes achieved through standardizing working methods and the availability of audit trails [/FONT][FONT="].[/FONT]
[/FONT][FONT="]• Better process control - improved management of business processes achieved through standardizing working methods and the availability of audit trails [/FONT][FONT="].[/FONT]
[FONT="]کنترل بهتر پروسه – بهبود مدیریت در مشاغل ,دستیابی به متد کاری استاندارد و رسیدن به حسابرسی های روشن. [/FONT]
[FONT="]
[/FONT][FONT="]• Improved customer service – consistency in the processes leads to greater predictability in levels of response to customers [/FONT][FONT="].[/FONT]
[/FONT][FONT="]• Improved customer service – consistency in the processes leads to greater predictability in levels of response to customers [/FONT][FONT="].[/FONT]
[FONT="]بهبود خدمات به مشتری- منطقی نمودن پروسه هایی که منتهی به پیشگویی کردن درست مراحل پاسخویی به مشتری میگردد.[/FONT]
[FONT="]
[/FONT][FONT="]• Flexibility – software control over processes enables their re-design in line with changing business needs .[/FONT]
[/FONT][FONT="]• Flexibility – software control over processes enables their re-design in line with changing business needs .[/FONT]
[FONT="]تطبیق پذیری- نرم افزاری که به کنترل پروسه می پردازد قادر به طراحی دوباره به همراه تغییرات مورد نیاز کسب وکار خواهد بود.[/FONT]
[FONT="]
[/FONT][FONT="]• Business process improvement - focus on business processes leads to their streamlining and simplification.[/FONT]
[/FONT][FONT="]• Business process improvement - focus on business processes leads to their streamlining and simplification.[/FONT]
[FONT="]بهبود پروسه کسب وکار- تمرکز برروی پروسه کسب وکار منجر به راحتی وساده سازی میگردد.[/FONT]
[FONT="]
[/FONT][FONT="]Proof of the ever-increasing interest in workflow management is the large number of commercial products that have appeared in the last few years including:[/FONT]
[/FONT][FONT="]Proof of the ever-increasing interest in workflow management is the large number of commercial products that have appeared in the last few years including:[/FONT]
[FONT="]اثبات دلیل افزایش یافتن توجهات به مدیریت گردش کار ارقام بزرگی از اقلام تجاری است که در سالهای اخیر ظاهر شده اند شامل: [/FONT]
[FONT="] Action Workflow System, of Action Technologies; IBM’s Flow Mark; Visual WorfFlow from FileNet ; OPEN/workflow, a WANG’s product [4].[/FONT]
مجتبی ورشاوی2
عضو جدید
ترجمه خبری
ترجمه خبری
ترجمه خبری
[FONT="]www.reuters.com[/FONT]
[FONT="]Iran plans to send monkey into space[/FONT]
[FONT="]برنامه ایران برای ارسال میمون به فضا[/FONT]
TEHRAN | Mon Jun 27, 2011 12:12pm EDT TEHRAN (Reuters) - Iran plans to send a live monkey into space next month,
تهران –ریوتر-برنامه ایران برای ارسال یک میمون زنده در ماه آینده
the latest advance in a missile and space program which has alarmed Israel and its western allies that fear the Islamic Republic is seeking nuclear weapons.
آخرین برنامه پیشرفته در موشک وفضا که زنگ خطر را برای اسرائیل وهمپیمانان غربی اش که از برنامه های هسته ای ایران در هراس اند به صدا درآورده است.
The official IRNA news agency on Monday quoted the head of Iran's Space Agency as saying five monkeys were undergoing tests before one is selected for the flight on board a Kavoshgar-5 rocket.
سایت رسمی وخبری ایرنا دردوشنبه نقل کرده است که آژانس فضایی پنج میمون را تحت بررسی قبل از انتخاب برای پرواز با راکت کاوشگر 5 قرار داده است.
President Mahmoud Ahmadinejad said last August that Iran planned to send a man into space by 2017.
رئیس جمهور محمود احمدی نژاد در آگوست گذشته گفت که ایران برنامه ای برای ارسال انسان به فضا تا 2017 را دارد.
Western countries are concerned the long-range ballistic technology used to propel Iranian satellites into orbit could be used to launch atomic warheads.
کشور های غربی توجه خود را معطوف به تکنولوژی موشک های بالستیک دوربرد بکار برده شده در پیشران(موشک حامل) ماهواره های ایران به مدار نموده اند که میتواند برای حمل کلاهک های اتمی نیز بکار رود.
Tehran denies such suggestions and says its nuclear work is purely peaceful.
تهران تمامی این گمانه زنی ها را رد کرده است وگفته است که فعالیت های هسته ای اش کاملاً صلح آمیز است.
Last week, Iran launched its second domestically built satellite into orbit, the Rasad 1 (Observation), which it said was for transmitting images and weather forecasts.
در هفته گذشته ایران دومین ماهواره بومی خود را به مدار پرتاب کرد , که گفته میشود برای ارسال تصاویر وپیشبینی وضع هوا است.
عبدالعلی
عضو جدید
سلام مهندس برام ترجمه میکنی دستت درد نکنه
سلام مهندس برام ترجمه میکنی دستت درد نکنه
سلام مهندس برام ترجمه میکنی دستت درد نکنه
6.2 Dynamic Re-configuration
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]An important use of traceability knowledge is in the reconfiguration of workflows with changed business environment and processes. Recall from our case study that the organization may be forced to move from manufacturing to outsourcing due to changes in the environment. In our example, the change in the validity of the assumption that outsourcing the product may result in losing core competencies and the validity of the assumption that it is cheaper to do so may suggest moving to outsourcing rather than manufacturing. The dynamic reconfiguration of the workflows from that shown in Figure 1 to that shown in Figure 2, in this instance, can be supported by our system with just changes in the validity of these assumptions. Our system uses a reason maintenance system to propagate the effects of changes in one component of process knowledge onto other. In this specific example, the system can suggest that the changed context should involve executing workflows specified in Figure 2. [/FONT]
[/FONT]6.3 Maintaining Integrity
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]Another important problem identified in our analysis is the difficulty in maintaining the integrity of workflows across organizational and task boundaries. For example, in Figure 5, a change in the manufacturing control process to include outsourcing has implications for workflows in other subsystems such as the cost accounting system in the financial module. Recall that the unit cost computation in this module assumes that the product is produced in-house. However, with the changes in the business process to move to outsourcing this assumption gets invalidated. The make/buy decision made in the manufacturing context, in effects, affects the workflows for computing unit costs. Our system provides the ability to manage such dependencies as well. When the workflows in the manufacturing control process change the system will prompt the user about potential conflicts that could arise. In the event that the repercussions can be formally modeled, the system can also suggest a reconfigured workflow for the cost accounting process. [/FONT]
[FONT=Times New Roman,Times New Roman]In the brief scenarios described here, the capabilities of the system to address three key issues associated with workflow specification and maintenance are illustrated. [/FONT]
[/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]An important use of traceability knowledge is in the reconfiguration of workflows with changed business environment and processes. Recall from our case study that the organization may be forced to move from manufacturing to outsourcing due to changes in the environment. In our example, the change in the validity of the assumption that outsourcing the product may result in losing core competencies and the validity of the assumption that it is cheaper to do so may suggest moving to outsourcing rather than manufacturing. The dynamic reconfiguration of the workflows from that shown in Figure 1 to that shown in Figure 2, in this instance, can be supported by our system with just changes in the validity of these assumptions. Our system uses a reason maintenance system to propagate the effects of changes in one component of process knowledge onto other. In this specific example, the system can suggest that the changed context should involve executing workflows specified in Figure 2. [/FONT]
[/FONT]6.3 Maintaining Integrity
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]Another important problem identified in our analysis is the difficulty in maintaining the integrity of workflows across organizational and task boundaries. For example, in Figure 5, a change in the manufacturing control process to include outsourcing has implications for workflows in other subsystems such as the cost accounting system in the financial module. Recall that the unit cost computation in this module assumes that the product is produced in-house. However, with the changes in the business process to move to outsourcing this assumption gets invalidated. The make/buy decision made in the manufacturing context, in effects, affects the workflows for computing unit costs. Our system provides the ability to manage such dependencies as well. When the workflows in the manufacturing control process change the system will prompt the user about potential conflicts that could arise. In the event that the repercussions can be formally modeled, the system can also suggest a reconfigured workflow for the cost accounting process. [/FONT]
[FONT=Times New Roman,Times New Roman]In the brief scenarios described here, the capabilities of the system to address three key issues associated with workflow specification and maintenance are illustrated. [/FONT]
[/FONT]
alinazarian
عضو جدید
ميخواي كه يادت بدم ...واقعاً حرف جالبی زدید باعث شدید کلی بخندم
باتشکر ازشما
مجتبی ورشاوی2
عضو جدید
مجتبی ورشاوی2
عضو جدید
بخش اول
بخش اول
[FONT="]
[/FONT]
بخش اول
[FONT="]6.2 Dynamic Re-configuration [/FONT]
[FONT="]پیکره بندی دینامیک [/FONT][FONT="]
[/FONT][FONT="]An important use of traceability knowledge is in the reconfiguration of workflows with changed business environment and processes.[/FONT]
[/FONT][FONT="]An important use of traceability knowledge is in the reconfiguration of workflows with changed business environment and processes.[/FONT]
[FONT="]یکی از مهمترین کاربردهای استفاده از دانسته های کم اهمیت در پیکره بندی گردشکارها همراه شدن با تغییرات محیط کسب وکار وفرایندها است. [/FONT]
[FONT="] Recall from our case study that the organization may be forced to move from manufacturing to outsourcing due to changes in the environment. [/FONT]
[FONT="]در این مورد مطالعه , ارگانها برای تغییر محیط شاید مجبور به حرکت از خودکفایی محصولات به سمت واردات آن شوند[/FONT]
[FONT="]In our example, the change in the validity of the assumption that outsourcing the product may result in losing core competencies[/FONT]
[FONT="]در این مثال ,ترجیح دربهای آنکه برون سپاری موجب از دست رفت هسته های مهارتی گردد ویا [/FONT]
[FONT="] and the validity of the assumption that it is cheaper to do so may suggest moving to outsourcing rather than manufacturing. [/FONT]
[FONT="]و یا بهای این پندار که برون سپاری برای انجام حرکات موفق خیلی ارزانتر است نسبت به آن که خود تولید کنیم . [/FONT]
[FONT="]The dynamic reconfiguration of the workflows from that shown in Figure 1 to that shown in Figure 2,[/FONT]
[FONT="] in this instance, can be supported by our system with just changes in the validity of these assumptions.[/FONT]
[FONT="]پیکره بندی دینامیک گردشکار در نمای یک ودو نمایش داده شده است .[/FONT]
[FONT="]این مثال میتواند در سیستم ما مورد پشتیبانی قرار بگیرد , با تغییر دربها دادن به پندار درست.[/FONT]
[FONT="] Our system uses a reason maintenance system to propagate the effects of changes in one component of process knowledge onto other.[/FONT]
[FONT="] سیستم ما دلیل تعمیر سیستم را مورد استفاده قرار میدهد تا در پروسه تاثیرات تغییر در یک ساختاردانش را به دیگری منتقل کند. [/FONT]
[FONT="] In this specific example, the system can suggest that the changed context should involve executing workflows specified in Figure 2. [/FONT]
[FONT="]در این مثال , سیستم می تواند حدس بزند تغییرات محتوایی دربرگرفته شده در اجرای گردشکارها در نمای دو. [/FONT]
[/FONT]
مجتبی ورشاوی2
عضو جدید
بخش دوم وپایانی
بخش دوم وپایانی
بخش دوم وپایانی
[FONT="]6.3 Maintaining Integrity [/FONT]
[FONT="]نگهداری یک پارچه [/FONT][FONT="]
[/FONT][FONT="]Another important problem identified in our analysis is the difficulty in maintaining the integrity of workflows [/FONT]
[/FONT][FONT="]Another important problem identified in our analysis is the difficulty in maintaining the integrity of workflows [/FONT]
[FONT="]مسئله مهم دیگر که در آنالیز ما از آن مطلع میشوید سختی های نگهداری یک پارچه گردشکار ها است.[/FONT]
[FONT="]across organizational and task boundaries.[/FONT]
[FONT="]از میان حدود وظایف وسازمان.[/FONT]
[FONT="] For example, in Figure 5, a change in the manufacturing control process to include outsourcing has implications for workflows in other subsystems such as the cost accounting system in the financial module.[/FONT]
[FONT="]بعنوان مثال؛ در نمای 5 یک تغییر در فرایند تولید به منظور در برگرفتن اقلام برونسپاری شده موجب دستیازی برای گردش کارها در دیگر زیر سیستم ها از قیبل سیستم تنخواه در مد های فاینانس است. [/FONT]
[FONT="] Recall that the unit cost computation in this module assumes that the product is produced in-house. However, with the changes in the business process to move to outsourcing this assumption gets invalidated. [/FONT]
[FONT="] به یاد داشته باشید که محاسبات واحدهزینه در این معیار مستلزم آن است که محصول در داخل تولید شده باشد.[/FONT]
[FONT="]به هر حال با تغییر در پروسه کسب وکار در مسیر برونسپاری این معیار از بین می رود. [/FONT]
[FONT="]The make/buy decision made in the manufacturing context, in effects, affects the workflows for computing unit costs. [/FONT]
[FONT="]تصمیم برآنکه تولید کنیم یا وارد کنیم در متن تولید ظاهر می شود ,در تأثیرات , در نتیجه تحلیل هزینه گردشکارهای واحد ها .[/FONT]
[FONT="]Our system provides the ability to manage such dependencies as well. [/FONT]
[FONT="]سیستم ما توانایی مدیریت این وابسته ها را روان فراهم می آورد.[/FONT]
[FONT="]When the workflows in the manufacturing control process change the system will prompt the user about potential conflicts that could arise.[/FONT]
[FONT="]گردشکار در پروسه تولید باعث تغییر می شود وبه کاربر در مورد نیروهایی که باید رشد یابد یاد آور می گردد. [/FONT]
[FONT="] In the event that the repercussions can be formally modeled, the system can also suggest a reconfigured workflow for the cost accounting process. [/FONT]
[FONT="]دررخدادهای که انعکاس ها میتواند از نظر شکل مدل شود, سیستم می تواند پیکره بندی گردش کار را برای اختصاص هزینه ها پیشنهاد بدهد. [/FONT][FONT="]
In the brief scenarios described here, the capabilities of the system to address three key issues associated with workflow specification and maintenance are illustrated[/FONT]
In the brief scenarios described here, the capabilities of the system to address three key issues associated with workflow specification and maintenance are illustrated[/FONT]
[FONT="]بصورت خلاصه سناریو اینگونه شرح داده می شود. توانایی سیستم برای رهنومن سه کلیدمربوط گفته شده همراه با گردش کار و نگهداری نمایش داده شده .[/FONT]
alinazarian
عضو جدید
6.2 پویا دوباره پیکربندی
استفاده مهم از دانش است قابلیت ردیابی در پیکر بندی دوباره از گردش با تغییر محیط کسب و کار و فرایندهای. به یاد بیاورید ، از مطالعه مورد ما که سازمان ممکن است مجبور به حرکت از تولید به علت تغییرات در محیط برون سپاری. در مثال ما ، تغییر در صحت این فرض که برون سپاری این محصول ممکن است در از دست دادن صلاحیتهای اصلی و اعتبار این فرض است که آن را ارزان تر است به انجام این کار ممکن است حرکت را به برون سپاری و نه تولید منجر شود. پیکر بندی دوباره پویا از گردش کار که از آن در شکل 1 نشان داده شده که در شکل 2 ، در این مثال نشان داده شده ، می تواند با سیستم ما تنها با تغییر در اعتبار این فرض پشتیبانی می کند. سیستم ما با استفاده از یک سیستم نگهداری و تعمیرات به دلیل انتشار اثر تغییر در یکی از اجزای فرایند دانش را بر روی دیگر. در این مثال خاص ، سیستم می تواند نشان می دهد که متن تغییر باید شامل اجرای گردش کار مشخص شده در شکل 2.
6.3 حفظ تمامیت
مسئله مهم دیگر که در تحلیل ما مشکل در حفظ یکپارچگی از گردش کار در سراسر مرزهای سازمانی و کار است. به عنوان مثال ، در شکل 5 ، تغییر در فرایند تولید ، کنترل را به برون سپاری شامل مفهوم برای گردش کار در زیر سیستم های دیگر مانند سیستم حسابداری در ماژول مالی. به یاد بیاورید که واحد محاسبه هزینه در این ماژول فرض می کند که این محصول را در خانه تولید می شود. با این حال ، با تغییر در فرآیند کسب و کار را به برون سپاری این فرض باطل می شود حرکت می کند. ساخت / خرید تصمیم گیری ساخته شده در زمینه تولید ، در اثر ، بر گردش کار برای هزینه های واحد محاسبات است. سیستم ما فراهم می کند که توانایی مدیریت وابستگی مانند است. زمانی که گردش کار در فرایند تولید ، کنترل تغییر سیستم به کاربر در مورد درگیری های احتمالی که می تواند بوجود می آیند سریع. در صورتی که عواقب می تواند به طور رسمی مدل ، سیستم همچنین می تواند یک گردش کار را برای پیکربندی مجدد فرایند حسابداری نشان می دهد.
در حالات مختصر در اینجا شرح داده ، از قابلیت های این سیستم را به آدرس سه موضوع کلیدی در ارتباط با مشخصات گردش کار و نگهداری هستند نشان داده شده
مهندس عزیز کلمات پس وپیش دیگه به عهده ی استفاده کننده است.من کارمندم ووقت ندارم ولی کل این ترجمه فک کنم 30 ثانیه وقت بردچون متن رو کلمه به کلمه ترجمه میکنه.استفاده کننده هم یه کم بایس زحمت بکشه
استفاده مهم از دانش است قابلیت ردیابی در پیکر بندی دوباره از گردش با تغییر محیط کسب و کار و فرایندهای. به یاد بیاورید ، از مطالعه مورد ما که سازمان ممکن است مجبور به حرکت از تولید به علت تغییرات در محیط برون سپاری. در مثال ما ، تغییر در صحت این فرض که برون سپاری این محصول ممکن است در از دست دادن صلاحیتهای اصلی و اعتبار این فرض است که آن را ارزان تر است به انجام این کار ممکن است حرکت را به برون سپاری و نه تولید منجر شود. پیکر بندی دوباره پویا از گردش کار که از آن در شکل 1 نشان داده شده که در شکل 2 ، در این مثال نشان داده شده ، می تواند با سیستم ما تنها با تغییر در اعتبار این فرض پشتیبانی می کند. سیستم ما با استفاده از یک سیستم نگهداری و تعمیرات به دلیل انتشار اثر تغییر در یکی از اجزای فرایند دانش را بر روی دیگر. در این مثال خاص ، سیستم می تواند نشان می دهد که متن تغییر باید شامل اجرای گردش کار مشخص شده در شکل 2.
6.3 حفظ تمامیت
مسئله مهم دیگر که در تحلیل ما مشکل در حفظ یکپارچگی از گردش کار در سراسر مرزهای سازمانی و کار است. به عنوان مثال ، در شکل 5 ، تغییر در فرایند تولید ، کنترل را به برون سپاری شامل مفهوم برای گردش کار در زیر سیستم های دیگر مانند سیستم حسابداری در ماژول مالی. به یاد بیاورید که واحد محاسبه هزینه در این ماژول فرض می کند که این محصول را در خانه تولید می شود. با این حال ، با تغییر در فرآیند کسب و کار را به برون سپاری این فرض باطل می شود حرکت می کند. ساخت / خرید تصمیم گیری ساخته شده در زمینه تولید ، در اثر ، بر گردش کار برای هزینه های واحد محاسبات است. سیستم ما فراهم می کند که توانایی مدیریت وابستگی مانند است. زمانی که گردش کار در فرایند تولید ، کنترل تغییر سیستم به کاربر در مورد درگیری های احتمالی که می تواند بوجود می آیند سریع. در صورتی که عواقب می تواند به طور رسمی مدل ، سیستم همچنین می تواند یک گردش کار را برای پیکربندی مجدد فرایند حسابداری نشان می دهد.
در حالات مختصر در اینجا شرح داده ، از قابلیت های این سیستم را به آدرس سه موضوع کلیدی در ارتباط با مشخصات گردش کار و نگهداری هستند نشان داده شده
مهندس عزیز کلمات پس وپیش دیگه به عهده ی استفاده کننده است.من کارمندم ووقت ندارم ولی کل این ترجمه فک کنم 30 ثانیه وقت بردچون متن رو کلمه به کلمه ترجمه میکنه.استفاده کننده هم یه کم بایس زحمت بکشه
مجتبی ورشاوی2
عضو جدید
شد همان حرفی که جناب ebrahimsakht زد .
مگه ما چیزی جز این می گفتیم ؟
alinazarian
عضو جدید
OK =0 KILLD
asus450000
عضو
باسلام و عرض خسته نباشید فراوان
بی زحمت ترجمه ای:
Teflon and other fluorocarbon and "non-stick" type coatings are mainly applied by traditional painting or powder coating techniques, then hot cured in ovens. These products are not easily applied by thermal spray, although they can benefit from a thermal spray metallic or ceramic coating as a base coat
Conventional PTFE coating is consisted of spraying the solved liquid teflon on the surface and heat the coated surface in an oven for several ours like what we do in IRAN in " Leab dadne ceramic va pokhtan dar koore" however you could you spray molten teflon on to the surface which is known as thermal spray or hot spray.
To find more info you could search "teflon spray coating", "non-stick coating", "thermal spray coating", etc.
http://www.syntheticcoatings.ie/Page.asp?PageID=8
here you may find some practical info
I am so sorry for writing in english as I cannot type in persian and need to follow the forum's rules
Thermal Spray
Thermal spray coating involves the use of a torch to heat a material, in powder or wire form, to a molten or near-molten state, and the use of a gas to propel the material to the target substrate, creating a completely new surface. The coating material may be a single element, alloy or compound with unique physical properties that are, in most cases, achievable only through the thermal spray process.
Thermal spray coatings are a highly cost-effective and straight-forward method for adding superior properties and performance qualities to a given engineering surface. The variety of products and coatings that can be enhanced by thermal spray are virtually limitless. The coatings are usually metallic, ceramic, carbides, or a combination of these materials to meet a range of physical criteria.
Thermal Spray Wire
Click here for more information on the properties of Teflon© coatings. Online enquiry form
Synthetic Coatings Ireland's engineers will assist you in determining a suitable coating for your application. Take five minutes to complete our online form and we will respond the next business day - click HERE to go to the enquiry form.
ویدونم پخش پیلیه ولی دمتون گرم سریع تر
بی زحمت ترجمه ای:
Teflon and other fluorocarbon and "non-stick" type coatings are mainly applied by traditional painting or powder coating techniques, then hot cured in ovens. These products are not easily applied by thermal spray, although they can benefit from a thermal spray metallic or ceramic coating as a base coat
Conventional PTFE coating is consisted of spraying the solved liquid teflon on the surface and heat the coated surface in an oven for several ours like what we do in IRAN in " Leab dadne ceramic va pokhtan dar koore" however you could you spray molten teflon on to the surface which is known as thermal spray or hot spray.
To find more info you could search "teflon spray coating", "non-stick coating", "thermal spray coating", etc.
http://www.syntheticcoatings.ie/Page.asp?PageID=8
here you may find some practical info
I am so sorry for writing in english as I cannot type in persian and need to follow the forum's rules
Thermal Spray
Thermal spray coatings are a highly cost-effective and straight-forward method for adding superior properties and performance qualities to a given engineering surface. The variety of products and coatings that can be enhanced by thermal spray are virtually limitless. The coatings are usually metallic, ceramic, carbides, or a combination of these materials to meet a range of physical criteria.
Thermal Spray Wire
[FONT=Arial, sans-serif]Material
[FONT=Arial, sans-serif]Hardness and Bond Strength[/FONT]
[FONT=Arial, sans-serif]Typical Characteristics and Applications[/FONT]
[FONT=Arial, sans-serif]Copper[/FONT]
[FONT=Arial, sans-serif]37 Rb
7324 PSI[/FONT]
7324 PSI[/FONT]
[FONT=Arial, sans-serif]Electric conductivity;
Copper reclamation;
Used as alternate to copper plating[/FONT]
Copper reclamation;
Used as alternate to copper plating[/FONT]
[FONT=Arial, sans-serif]Molybdenum[/FONT]
[FONT=Arial, sans-serif]14-36 Rb
5496 PSI[/FONT]
5496 PSI[/FONT]
[FONT=Arial, sans-serif]Abrasion resistance;
Excellent adhesion to steel;
Excellent in molten metal environment in inert atmospheres[/FONT]
Excellent adhesion to steel;
Excellent in molten metal environment in inert atmospheres[/FONT]
[FONT=Arial, sans-serif]Carbon Steel[/FONT]
[FONT=Arial, sans-serif]97-100 Rb
5700 PSI[/FONT]
5700 PSI[/FONT]
[FONT=Arial, sans-serif]Dimensional restoration of mismachined and worn parts[/FONT]
[FONT=Arial, sans-serif]Tungsten Carbide[/FONT]
[FONT=Arial, sans-serif]52 Rc
6700 PSI[/FONT]
6700 PSI[/FONT]
[FONT=Arial, sans-serif]Excellent bond strength;
Abrasion resistance;
Dredge cutter blades[/FONT]
[/FONT]Abrasion resistance;
Dredge cutter blades[/FONT]
[FONT=Arial, sans-serif]FUNCTION[/FONT]
[FONT=Arial, sans-serif]APPLICATION[/FONT]
[FONT=Arial, sans-serif]COATING[/FONT]
[FONT=Arial, sans-serif]Wear Resistance[/FONT]
[FONT=Arial, sans-serif]Adhesive Wear[/FONT]
[FONT=Arial, sans-serif]Bearings, piston rings, hydraulic press sleeves[/FONT]
[FONT=Arial, sans-serif]Chrome Oxide, Babbit, Carbon Steel[/FONT]
[FONT=Arial, sans-serif]Abrasive Wear[/FONT]
[FONT=Arial, sans-serif]Guide bars, pump seals, concrete mixer screws[/FONT]
[FONT=Arial, sans-serif]Tungsten Carbide, Alumina/Titania, Steel[/FONT]
[FONT=Arial, sans-serif]Surface Fatigue
Wear[/FONT]
Wear[/FONT]
[FONT=Arial, sans-serif]Dead centers, cam followers, fan blades (jet engines), wear rings (land based turbines)[/FONT]
[FONT=Arial, sans-serif]Tungsten Carbide, Copper/Nickel/Indium Alloy, Chrome Carbide[/FONT]
[FONT=Arial, sans-serif]Erosion[/FONT]
[FONT=Arial, sans-serif]Slurry pumps, exhaust fans, dust collectors[/FONT]
[FONT=Arial, sans-serif]Tungsten Carbide, Stellite[/FONT]
[FONT=Arial, sans-serif]Heat Resistance[/FONT]
[FONT=Arial, sans-serif]Burner cans/baskets (gas turbines), exhaust ducts[/FONT]
[FONT=Arial, sans-serif]Partially Stabilized Zirconia[/FONT]
[FONT=Arial, sans-serif]Oxidation Resistance[/FONT]
[FONT=Arial, sans-serif]Exhaust mufflers, heat treating fixtures, exhaust valve stems[/FONT]
[FONT=Arial, sans-serif]Aluminum, Nickel/Chrome Alloy, Hastelloy[/FONT]
[FONT=Arial, sans-serif]Corrosion Resistance[/FONT]
[FONT=Arial, sans-serif]Pump parts, storage tanks, food handling equipment[/FONT]
[FONT=Arial, sans-serif]Stainless Steel (316), Aluminum, Inconel, Hastelloy[/FONT]
[FONT=Arial, sans-serif]Electrical Conductivity[/FONT]
[FONT=Arial, sans-serif]Electrical contacts, ground connectors[/FONT]
[FONT=Arial, sans-serif]Copper[/FONT]
[FONT=Arial, sans-serif]Electrical Resistance[/FONT]
[FONT=Arial, sans-serif]Insulation for heater tubes, soldering tips[/FONT]
[FONT=Arial, sans-serif]Alumina[/FONT]
[FONT=Arial, sans-serif]Restoration of Dim.[/FONT]
[FONT=Arial, sans-serif]Printing rolls, undersize bearings[/FONT]
[FONT=Arial, sans-serif]Carbon Steel, Stainless Steel[/FONT]
Click here for more information on the properties of Teflon© coatings. Online enquiry form
Synthetic Coatings Ireland's engineers will assist you in determining a suitable coating for your application. Take five minutes to complete our online form and we will respond the next business day - click HERE to go to the enquiry form.
ویدونم پخش پیلیه ولی دمتون گرم سریع تر
asus450000
عضو
file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image002.jpg
Teflon® is known for it's amazing non-stick characteristics. The advantages are: improved product quality, less clean up time, and no doctoring.
The On Machine Seaming (OMS) with dryer covers made with Teflon® FEP provide the best release on the first two dryers after the size press and coaters. Dryer covers also reduce unwanted draw between dryers.
The dryer's surface is first cleaned to provide a good surface for bonding. The heat shrinkable film is then rolled around the dryer and the sealer is put in place. The film is then sealed to complete the tube. The seal's strength is as strong as the material itself.
file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image004.jpg
The dryer is then heated up to 250°F shrinking down the sleeve.
The roll cover is bonded to the dryer by injecting the adhesive under the end of the sleeve. It is then cured at maximum temperature.
The complete installation is accomplished in 8-12 hours, leaving a smooth as glass finish.
Common questions and answers on next page
[FONT="]3.[/FONT]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image006.jpg
[FONT="]TEFLON® PEP is a registered Trademark of E. I. du Pont de Nemours Company and is used under license by Fluoron, Inc. [/FONT]
[FONT="]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image008.jpg[/FONT]
[FONT="]
[/FONT] [FONT="] [/FONT]
[FONT="]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg[/FONT]
Frequently Asked Questions
1. What are the advantages of "Tef/on®" on a dryer?
[FONT="]2. [/FONT]Does the dryer need to be removed from the machine for installation?
[FONT="]4. [/FONT]Will there be any picking or build-up, which would require doctoring?
[FONT="]4. [/FONT]Will the sleeve reduces unwanted draw between dryers?
[FONT="]6. [/FONT]How long does it take to install a FLUORON, INC. sleeve?
7. How strong is the seam?
8. How thick is the "Tef/on®" film?
[FONT="]9. [/FONT]Would this cover be satisfactory for resurfacing a dryer that has grooves and pitted areas?
1 [FONT="]O. [/FONT]"Tef/on®" is an insulator. Will this affect drying?
"Tef/on® FEP' is known for it's amazing non-stick characteristics. The advantages are: improved product quality, less clean up time, and no doctoring.
No. With O.M.S. (On Machine Seaming) the dryer remains on the machine.
No. Remember, clay, starch, and coating will not stick to a dryer with a FLUORON, INC. sleeve made with "Tef/on® FEP'. No doctoring is needed.
Yes. A roll cover made with "Tef/on® FEP' will help reduce the sheet's tendency to hang on and follow the dryer.
Yes. Often dryer temperature has been decreased to reduce "picking". With "picking" eliminated, the temperature and speed can be increased.
Once cleaning and preparation of the dryer is complete, a sleeve can be installed in 8 to 12 hours.
FLUORON, INC. seams are virtually undetectable. The seal strength is as strong as the material itself.
A .020" thickness of FEP film is standard. FLUORON, INC. has the capability to make a thinner or thicker sleeves up to .125" for special applications.
The cover made with "Tef/on® FEP" leaves a glass smooth finish, eliminating corrosion while filling grooves and pits with adhesive.
In 1965, the first roll cover of "Tef/on®" was installed on a dryer. There have never been any problems with drying. In fact, drying temperature can be turned up to increase drying capacity.
[FONT="]TEFLON® PEP is a registered Trademark of E. I. du Pont de Nemours Company and is used under license by Fluoron, Inc. [/FONT]
[FONT="]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image008.jpg[/FONT]
Teflon® is known for it's amazing non-stick characteristics. The advantages are: improved product quality, less clean up time, and no doctoring.
The On Machine Seaming (OMS) with dryer covers made with Teflon® FEP provide the best release on the first two dryers after the size press and coaters. Dryer covers also reduce unwanted draw between dryers.
The dryer's surface is first cleaned to provide a good surface for bonding. The heat shrinkable film is then rolled around the dryer and the sealer is put in place. The film is then sealed to complete the tube. The seal's strength is as strong as the material itself.
file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image004.jpg
The dryer is then heated up to 250°F shrinking down the sleeve.
The roll cover is bonded to the dryer by injecting the adhesive under the end of the sleeve. It is then cured at maximum temperature.
The complete installation is accomplished in 8-12 hours, leaving a smooth as glass finish.
Common questions and answers on next page
[FONT="]3.[/FONT]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image006.jpg
[FONT="]TEFLON® PEP is a registered Trademark of E. I. du Pont de Nemours Company and is used under license by Fluoron, Inc. [/FONT]
[FONT="]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image008.jpg[/FONT]
[FONT="]
[/FONT] [FONT="] [/FONT]
[FONT="]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image010.jpg[/FONT]
Frequently Asked Questions
1. What are the advantages of "Tef/on®" on a dryer?
[FONT="]2. [/FONT]Does the dryer need to be removed from the machine for installation?
[FONT="]4. [/FONT]Will there be any picking or build-up, which would require doctoring?
[FONT="]4. [/FONT]Will the sleeve reduces unwanted draw between dryers?
5. Can I increase my dryer temperature without picking or build-up and increase machine speed.
[FONT="]6. [/FONT]How long does it take to install a FLUORON, INC. sleeve?
7. How strong is the seam?
8. How thick is the "Tef/on®" film?
[FONT="]9. [/FONT]Would this cover be satisfactory for resurfacing a dryer that has grooves and pitted areas?
1 [FONT="]O. [/FONT]"Tef/on®" is an insulator. Will this affect drying?
"Tef/on® FEP' is known for it's amazing non-stick characteristics. The advantages are: improved product quality, less clean up time, and no doctoring.
No. With O.M.S. (On Machine Seaming) the dryer remains on the machine.
No. Remember, clay, starch, and coating will not stick to a dryer with a FLUORON, INC. sleeve made with "Tef/on® FEP'. No doctoring is needed.
Yes. A roll cover made with "Tef/on® FEP' will help reduce the sheet's tendency to hang on and follow the dryer.
Yes. Often dryer temperature has been decreased to reduce "picking". With "picking" eliminated, the temperature and speed can be increased.
Once cleaning and preparation of the dryer is complete, a sleeve can be installed in 8 to 12 hours.
FLUORON, INC. seams are virtually undetectable. The seal strength is as strong as the material itself.
A .020" thickness of FEP film is standard. FLUORON, INC. has the capability to make a thinner or thicker sleeves up to .125" for special applications.
The cover made with "Tef/on® FEP" leaves a glass smooth finish, eliminating corrosion while filling grooves and pits with adhesive.
In 1965, the first roll cover of "Tef/on®" was installed on a dryer. There have never been any problems with drying. In fact, drying temperature can be turned up to increase drying capacity.
[FONT="]TEFLON® PEP is a registered Trademark of E. I. du Pont de Nemours Company and is used under license by Fluoron, Inc. [/FONT]
[FONT="]file:///C:/Users/h/AppData/Local/Temp/msohtmlclip1/01/clip_image008.jpg[/FONT]
asus450000
عضو
[FONT="]Making Teflon Stick[/FONT][FONT="][/FONT]
[FONT="](This article appeared in [/FONT][FONT="]Invention & Technology magazine, Summer 2000 [/FONT][FONT="]www.americanheritage.com[/FONT][FONT="] and I highly recommend the magazine[/FONT][FONT="][/FONT]
One of the most versatile and familiar products of American chemical engineering, Teflon, was discovered by accident. There are many such tales to be found in the history of industrial chemistry, from vulcanized rubber to saccharin to Post-Its, all of which were stumbled upon by researchers looking for other things. So common, in fact, are unplanned discoveries of this sort that one might expect would-be inventors to simply mix random chemicals all day long until they come up with something valuable. Yet the circumstances behind the Teflon story show how each step along the way drew on the skills and talents of workers who were trained to nurture such discoveries and take them from the laboratory to the market. Teflon was developed at Du Pont, the source of many twentieth-century chemical innovations. It came about as a byproduct of the firm’s involvement with refrigerants. In the early 1930s a pair of General Motors chemists, A. L. Henne and Thomas Midgley, brought samples of two compounds to the Jackson Laboratory at Du Pont’s Chambers Works in Deepwater, New Jersey. The compounds, called Freon 11 and Freon 12, were chlorofluorocarbons (CFCs)—hydrocarbons in which some or all of the hydrogen was replaced with chlorine or fluorine. GM’s research laboratories had developed the family of Freons for its Frigidaire division, which made refrigeration equipment. They were meant to replace existing refrigerants such as ammonia, sulfur dioxide, and propane, which were less efficient than Freons and either too poisonous or too explosive for residential use.
Having made the basic discovery, GM teamed up with Du Pont to take advantage of the latter’s expertise in manufacturing and research and development. The two companies formed a joint venture called Kinetic Chemicals, which by the mid-1930s had isolated and tested a wide range of CFCs and put the most promising ones into mass production. The best seller was refrigerant 114 (later called Freon 114), or retrafluorodichloroethane (CF2ClCF2Cl). Kinetic had agreed to reserve its entire output of Freon 114 for Frigidaire, so in the late 1930s Du Pont was looking for an equally effective refrigerant that it could sell to other manufacturers. One of the chemists assigned to this project was the 27-year-old Roy J. Plunkett, who had been hired in 1936 after completing his doctorate at Ohio State University.
Plunkett was working on a new CFC that he hoped would be a good refrigerant. He synthesized it by reacting tetrafluoroethylene (TFE), a gas at room conditions, with hydrochloric acid. To further this research, Plunkett and his assistant, Jack Rebok, prepared 100 pounds of TFE and stored it in pressure cylinders, to be dispensed as needed. To prevent an explosion or rupture of the cylinder, they kept the canisters in dry ice.
On the morning of April 6, 1938, Rebok connected a canister of TFE to the reaction apparatus he and Plunkett had been using. His standard procedure was to release some TFE into a heated chamber and then spray in hydrochloric acid, but this time, when he opened the valve on the TFE container, nothing came out. A cursory examination did not reveal anything wrong with the valve. Had the gas somehow leaked out? Rebok and Plunkett weighed the cylinder and discovered that most of the gas was still inside. They fiddled with the valve some more, even using a wire to unclog it, but nothing happened.[/FONT][FONT="][/FONT]
asus450000
عضو
[FONT="]Rebok (left) Plunket (right) and another chemist, Bob McHarness, reenact the discovery of Teflon[/FONT][FONT="] [/FONT]
[FONT="]A frustrated Plunkett removed the valve completely, turned the canister upside down, and shook it. Some flecks of white powder floated out. Plunkett and Rebok sawed open several of the storage canisters and found that their interior walls were lined with a smooth, waxy white coating. In his lab notebook Plunkett wrote, “A white solid material was obtained, which was supposed to be a polymerized product.” This entry shows that he instantly understood what had occurred, even though it was generally believed at the time that a chlorinated or fluorinated ethylene could not be polymerized because previous attempts to do so had failed. Something about the combination of pressure and temperature had forced the TFE molecules to join together in long chains, and the resulting compound turned out to have a most interesting set of properties.
Two days later Plunkett noted some additional characteristics of the intriguing substance: “It is thermoplastic, melts at a temperature approaching red heat, and boils away. It burns without residue; the decompositive products etch glass.” He also observed that it was insoluble in cold and hot water, acetone, Freon 113, ether, petroleum ether, alcohol, pyridine, toluene ethyl acetate, concentrated sulfuric acid, glacial acetic acid, nitrobenzene, isoanyl alcohol, ortho dichlorobenzene, sodium hydroxide, and concentrated nitric acid. Further tests showed that the substance did not char or melt when exposed to a soldering iron or an electric arc. Moisture did not cause it to rot or swell, prolonged exposure to sunlight did not degrade it, and it was impervious to mold and fungus.
Plunkett’s next step was to duplicate the conditions that had produced the first batch of polymerized tetrafluoroethylene (PTFE). After experimentation he succeeded in re-creating what had occurred by chance inside the canisters. On July 1, 1939, he applied for a patent (which he assigned to Kinetic Chemicals) on tetrafluoroethylene polymers. The patent was granted in 1941.
The patent application ended Plunkett’s involvement with his discovery, since at that point the problem shifted from fluorine chemistry, which was his area of expertise, to polymer chemistry and process development. Plunkett was named chemical supervisor of Du Pont’s tetraethyl lead plant and stayed with Du Pont in various positions until his retirement in 1975; he was inducted into the National Inventors Hall of Fame in 1985 and died in 1994.
For about three years Du Pont’s organic chemicals department experimented with ways to produce IFE, also known as TFE monomer, which was the raw material for PTFE. Plunkett and Rebok had produced small batches for laboratory use, but if PTFE was ever going to find a practical use and be produced commercially, the company would have to find a way to turn out TFE monomer in industrial quantities. When the organic group came up with a promising method, Du Pont’s central research and development department began looking into possible polymerization processes.
Spontaneous polymerization of TFE can lead to explosive reactions because heat is released in the process, so it had to be carefully controlled. Experiments by the chemist Robert M. Joyce soon led to a feasible but costly procedure. Meanwhile, Du Pont’s applications group began identifying the properties of PTFE that would be useful in industry, such as its resistance to electric currents and to most chemical reactions. Then came World War II, which gave a large boost to the development of PTFE (and many other technologies).
Scientists working on the Manhattan Project faced the difficult problem of separating the isotope U-235 (which makes up about 0.7 percent of the element uranium in its natural state) from the far more plentiful but inert U-238. The method they settled on was gaseous diffusion, in which a gas is forced through a porous material. Since heavy molecules diffuse more slowly than light ones, multiple repetitions of the diffusion process will yield a gas enriched in the lighter isotopes. Gen. Leslie Groves, director of the Manhattan Project, chose Du Pont to design the separation plant. To make it work, the designers needed equipment that would stand up to the highly corrosive starting material, uranium hexafluoride gas, which destroyed conventional gaskets and seals. PTFE was just what they needed, and Du Pont agreed to reserve its entire output for government use.
For security reasons PTFE was referred to by a code name, K 416, and the small production unit at Arlington, New Jersey, was heavily guarded. Despite the tight security and Du Pont’s efforts to control the polymerization process, the Arlington production unit was wrecked by an explosion one night in 1944. The next morning construction workers stood by while Army and FBI investigators looked for evidence of sabotage. Working with Du Pont chemists, they found that the explosion had been caused by uncontrolled, spontaneous polymerization that was detonated by the exothermic, or heat-releasing, decomposition of TFE to carbon and tetrafluoromethane. When the investigators left, the construction crews took over, working two 12-hour shifts a day. Within two months the unit had been rebuilt with heavy barricades surrounding it.[/FONT][FONT="][/FONT]
[FONT="]A frustrated Plunkett removed the valve completely, turned the canister upside down, and shook it. Some flecks of white powder floated out. Plunkett and Rebok sawed open several of the storage canisters and found that their interior walls were lined with a smooth, waxy white coating. In his lab notebook Plunkett wrote, “A white solid material was obtained, which was supposed to be a polymerized product.” This entry shows that he instantly understood what had occurred, even though it was generally believed at the time that a chlorinated or fluorinated ethylene could not be polymerized because previous attempts to do so had failed. Something about the combination of pressure and temperature had forced the TFE molecules to join together in long chains, and the resulting compound turned out to have a most interesting set of properties.
Two days later Plunkett noted some additional characteristics of the intriguing substance: “It is thermoplastic, melts at a temperature approaching red heat, and boils away. It burns without residue; the decompositive products etch glass.” He also observed that it was insoluble in cold and hot water, acetone, Freon 113, ether, petroleum ether, alcohol, pyridine, toluene ethyl acetate, concentrated sulfuric acid, glacial acetic acid, nitrobenzene, isoanyl alcohol, ortho dichlorobenzene, sodium hydroxide, and concentrated nitric acid. Further tests showed that the substance did not char or melt when exposed to a soldering iron or an electric arc. Moisture did not cause it to rot or swell, prolonged exposure to sunlight did not degrade it, and it was impervious to mold and fungus.
Plunkett’s next step was to duplicate the conditions that had produced the first batch of polymerized tetrafluoroethylene (PTFE). After experimentation he succeeded in re-creating what had occurred by chance inside the canisters. On July 1, 1939, he applied for a patent (which he assigned to Kinetic Chemicals) on tetrafluoroethylene polymers. The patent was granted in 1941.
The patent application ended Plunkett’s involvement with his discovery, since at that point the problem shifted from fluorine chemistry, which was his area of expertise, to polymer chemistry and process development. Plunkett was named chemical supervisor of Du Pont’s tetraethyl lead plant and stayed with Du Pont in various positions until his retirement in 1975; he was inducted into the National Inventors Hall of Fame in 1985 and died in 1994.
For about three years Du Pont’s organic chemicals department experimented with ways to produce IFE, also known as TFE monomer, which was the raw material for PTFE. Plunkett and Rebok had produced small batches for laboratory use, but if PTFE was ever going to find a practical use and be produced commercially, the company would have to find a way to turn out TFE monomer in industrial quantities. When the organic group came up with a promising method, Du Pont’s central research and development department began looking into possible polymerization processes.
Spontaneous polymerization of TFE can lead to explosive reactions because heat is released in the process, so it had to be carefully controlled. Experiments by the chemist Robert M. Joyce soon led to a feasible but costly procedure. Meanwhile, Du Pont’s applications group began identifying the properties of PTFE that would be useful in industry, such as its resistance to electric currents and to most chemical reactions. Then came World War II, which gave a large boost to the development of PTFE (and many other technologies).
Scientists working on the Manhattan Project faced the difficult problem of separating the isotope U-235 (which makes up about 0.7 percent of the element uranium in its natural state) from the far more plentiful but inert U-238. The method they settled on was gaseous diffusion, in which a gas is forced through a porous material. Since heavy molecules diffuse more slowly than light ones, multiple repetitions of the diffusion process will yield a gas enriched in the lighter isotopes. Gen. Leslie Groves, director of the Manhattan Project, chose Du Pont to design the separation plant. To make it work, the designers needed equipment that would stand up to the highly corrosive starting material, uranium hexafluoride gas, which destroyed conventional gaskets and seals. PTFE was just what they needed, and Du Pont agreed to reserve its entire output for government use.
For security reasons PTFE was referred to by a code name, K 416, and the small production unit at Arlington, New Jersey, was heavily guarded. Despite the tight security and Du Pont’s efforts to control the polymerization process, the Arlington production unit was wrecked by an explosion one night in 1944. The next morning construction workers stood by while Army and FBI investigators looked for evidence of sabotage. Working with Du Pont chemists, they found that the explosion had been caused by uncontrolled, spontaneous polymerization that was detonated by the exothermic, or heat-releasing, decomposition of TFE to carbon and tetrafluoromethane. When the investigators left, the construction crews took over, working two 12-hour shifts a day. Within two months the unit had been rebuilt with heavy barricades surrounding it.[/FONT][FONT="][/FONT]
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[FONT="]How Teflon is made from chloroform and hydrogen fluoride[/FONT][FONT="] [/FONT]
[FONT="]The Manhattan Project consumed about two-thirds of Arlington’s PTFE output, and the remainder was used for other military applications. It proved to be ideal for the nose cones of proximity bombs because it was both electrically resistive and transparent to radar. It was also used in airplane engines and in explosives manufacturing, where nitric acid would destroy gaskets made of other materials, and as a lining in liquid-fuel tanks, whose cold temperatures could make other linings brittle. When the Army needed tape two-thousandths of an inch thick to wrap copper wires in the radar systems of night bombers, it was painstakingly shaved off a solid block of PTFE at a cost of $100 per pound. The high cost was justified because PTFE did a job nothing else could do.
When peace returned, Du Pont decided to go ahead with commercializing PTFE, since its manifold military uses had shown its great industrial potential. With its unmatched knowledge of polymers, the company was in a good position to take advantage of the postwar manufacturing boom. In 1944 the company had registered the trademark Teflon, probably suggested by the abbreviation TFE. The new substance was an ideal fit for Du Pont’s traditional marketing strategy, which was to shun the manufacture of commodity plastics and specialize in sophisticated materials that could command premium prices. Other materials with some of Teflon’s properties were available, but none were as comprehensively resistant to corrosion, and none of the lubricants or low-friction materials then in use were anywhere near as durable or maintenance-free.[/FONT][FONT="][/FONT]
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[FONT="]Acid corrodes a rod of ordinary plastic but leaves Teflon unaffected.[/FONT][FONT="] [/FONT]
[FONT="]The company faced significant obstacles before it could produce large amounts of Teflon uniformly and economically. Company chemists had developed several ways to polymerize TFE, but the properties of the resulting product varied significantly from batch to batch. And nearly every step of the manufacturing process raised problems that no chemical manufacturer had faced before. Equipment had to withstand temperatures and pressures beyond previous limits. Even a minute quantity of oxygen would react with the gases used as raw materials, fouling the process lines and valves.
After the synthesis was completed, fabricating Teflon into useful articles raised another set of difficulties. Its melting point was so high that it could not be molded or extruded by conventional methods. A further problem was caused by the very properties that had made Teflon so valuable to begin with. Chemistry students like to joke about the inventor who isolates a substance that will dissolve anything, then cannot find a container to hold it. With Teflon, Du Pont’s chemists faced the opposite problem: How do you make the greatest nonstick substance ever invented bond to another surface?
Research led to the production of Teflon in three basic forms: granules, a fine powder, and an aqueous dispersion. Borrowing the technique of sintering from powder metallurgy, Teflon was compressed and baked into blocks that could be machined into the required shape. In this process the application of heat did not actually melt the Teflon, but it softened the microscopic granules and made them stick together when pressed. Powder could also be blended with hydrocarbons and cold-compressed to coat wires and make tubing. Aqueous dispersions were used to make enamels that could be sprayed or brushed onto a surface and then baked in place.
Another technique involved etching the surface of a piece of Teflon with specially formulated solvents that extracted some of the fluorine atoms. These solvents left behind a thin, carbon-rich surface layer to which conventional adhesives could bond. Yet another solution was to implant fine particles of silica in the Teflon, creating a rough “sandpaper surface” that would also accept adhesives. This method was not as effective as chemical etching, but it was adequate for some purposes. Du Pont chemists also developed fluorocarbon resins that would stick to both Teflon and metal surfaces. And of course, sheets of Teflon could be attached to other items with screws, bolts, clamps, and other mechanical fasteners.
Machine parts requiring a uniform coating could be immersed in a “fluidized bed”—a layer of Teflon powder that was agitated with a stream of air until it behaved like a liquid. The item to be coated was first heated to 650 degrees Fahrenheit and then dipped in the fluidized bed for a second or two. After the excess powder was blown off, a film of one to two thousandths of an inch was left behind. As with other methods, repeated applications were often required to get a thick enough film. This method was especially useful with irregularly shaped mechanical components, such as valves and rotors, as well as with small items like ball bearings.
By 1948 Du Pont had made enough progress to prepare for full-scale production. Two years later the company’s first commercial Teflon plant, designed to produce a million pounds a year, went on line at the Washington Works, on land once owned by George Washington near Parkersburg, West Virginia. Du Pont stepped up its efforts to market Teflon for industrial applications, promoting the use of tape and sheets for insulation in many kinds of electrical equipment. Teflon was also used for gaskets, packings, valve components, pump components, bearings, sealer plates, and hoppers. To help users understand the polymer’s unusual properties and tricky fabrication requirements, Du Pont sent out a team of scientists to advise customers on integrating Teflon into their production processes. Members of the research, manufacturing, and sales staff met regularly to compare notes.
Within a year Teflon was also being used in commercial food processing. Du Pont saw the potential for expansion in this field but decided to proceed slowly. In bread manufacturing, rollers were coated with Teflon to keep dough from sticking. Teflon-lined bread pans and muffin tins became standard equipment in many bakeries. Teflon coatings also stopped dough from sticking to cookie sheets and reduced the number of damaged cookies that had to be thrown away. In candy factories Teflon coated conveyor belts, hooks for pulling taffy, and the cutting edges of slicing machines. In all these applications, Teflon proved much more effective than the old method of coating the surface with oil or grease.
A 1953 Du Pont television commercial showed a Teflon-coated bread pan and boasted that it had “baked 1,258 loaves of bread and ... never had a drop of grease in it.” The first draft of the script for this ad also predicted that frying pans would be coated with Teflon in the future, but that line was deleted before the commercial was filmed. Du Pont was reluctant to market Teflon-coated cookware for home kitchens because of concerns that misuse might lead to injuries and lawsuits. Until the company could be sure that Teflon was absolutely safe in untrained hands, it preferred to stay with industrial users. Nylon, another Du Pont product, had become a great success in consumer products, but it was not subjected to the extreme conditions that Teflon cookware would encounter.
Du Pont’s tests showed that while Teflon could withstand brief exposure to temperatures as high as 1,000 degrees Fahrenheit, it began to soften at 620 degrees Fahrenheit. This was no problem for baking pans, which are rarely subjected to temperatures above 500 degrees, but it could potentially cause problems with pans used on stovetops. Researchers found that at high temperatures, small quantities of gaseous decomposition products were released. Because some of these gases were toxic and might cause temporary flu-like symptoms, adequate ventilation was required. Although the fumes given off by overheated Teflon pans were less toxic than those given off by heated cooking oil or butter, Du Pont decided to proceed with caution. Even as late as 1960 the company sold less than 10 million pounds of Teflon per year, with receipts of a piddling (by Du Pont standards) $28 million. Expanding consumer uses would be the key to boosting sales, but Du Pont had to convince itself that Teflon was harmless before selling it to the housewives of America.
While Du Pont hesitated, an enterprising French couple took matters into their own hands. Marc Grégoire, an engineer, had heard about Teflon from a colleague who had devised a way to affix a thin layer of it to aluminum for industrial applications. The process involved etching the aluminum with acid to create a microscopically pitted surface, covering the surface with Teflon powder, and heating it to just below its melting point, which caused it to interlock with the aluminum surface.[/FONT][FONT="][/FONT]
[FONT="]How Teflon is made from chloroform and hydrogen fluoride[/FONT][FONT="] [/FONT]
[FONT="]The Manhattan Project consumed about two-thirds of Arlington’s PTFE output, and the remainder was used for other military applications. It proved to be ideal for the nose cones of proximity bombs because it was both electrically resistive and transparent to radar. It was also used in airplane engines and in explosives manufacturing, where nitric acid would destroy gaskets made of other materials, and as a lining in liquid-fuel tanks, whose cold temperatures could make other linings brittle. When the Army needed tape two-thousandths of an inch thick to wrap copper wires in the radar systems of night bombers, it was painstakingly shaved off a solid block of PTFE at a cost of $100 per pound. The high cost was justified because PTFE did a job nothing else could do.
When peace returned, Du Pont decided to go ahead with commercializing PTFE, since its manifold military uses had shown its great industrial potential. With its unmatched knowledge of polymers, the company was in a good position to take advantage of the postwar manufacturing boom. In 1944 the company had registered the trademark Teflon, probably suggested by the abbreviation TFE. The new substance was an ideal fit for Du Pont’s traditional marketing strategy, which was to shun the manufacture of commodity plastics and specialize in sophisticated materials that could command premium prices. Other materials with some of Teflon’s properties were available, but none were as comprehensively resistant to corrosion, and none of the lubricants or low-friction materials then in use were anywhere near as durable or maintenance-free.[/FONT][FONT="][/FONT]
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[FONT="]Acid corrodes a rod of ordinary plastic but leaves Teflon unaffected.[/FONT][FONT="] [/FONT]
[FONT="]The company faced significant obstacles before it could produce large amounts of Teflon uniformly and economically. Company chemists had developed several ways to polymerize TFE, but the properties of the resulting product varied significantly from batch to batch. And nearly every step of the manufacturing process raised problems that no chemical manufacturer had faced before. Equipment had to withstand temperatures and pressures beyond previous limits. Even a minute quantity of oxygen would react with the gases used as raw materials, fouling the process lines and valves.
After the synthesis was completed, fabricating Teflon into useful articles raised another set of difficulties. Its melting point was so high that it could not be molded or extruded by conventional methods. A further problem was caused by the very properties that had made Teflon so valuable to begin with. Chemistry students like to joke about the inventor who isolates a substance that will dissolve anything, then cannot find a container to hold it. With Teflon, Du Pont’s chemists faced the opposite problem: How do you make the greatest nonstick substance ever invented bond to another surface?
Research led to the production of Teflon in three basic forms: granules, a fine powder, and an aqueous dispersion. Borrowing the technique of sintering from powder metallurgy, Teflon was compressed and baked into blocks that could be machined into the required shape. In this process the application of heat did not actually melt the Teflon, but it softened the microscopic granules and made them stick together when pressed. Powder could also be blended with hydrocarbons and cold-compressed to coat wires and make tubing. Aqueous dispersions were used to make enamels that could be sprayed or brushed onto a surface and then baked in place.
Another technique involved etching the surface of a piece of Teflon with specially formulated solvents that extracted some of the fluorine atoms. These solvents left behind a thin, carbon-rich surface layer to which conventional adhesives could bond. Yet another solution was to implant fine particles of silica in the Teflon, creating a rough “sandpaper surface” that would also accept adhesives. This method was not as effective as chemical etching, but it was adequate for some purposes. Du Pont chemists also developed fluorocarbon resins that would stick to both Teflon and metal surfaces. And of course, sheets of Teflon could be attached to other items with screws, bolts, clamps, and other mechanical fasteners.
Machine parts requiring a uniform coating could be immersed in a “fluidized bed”—a layer of Teflon powder that was agitated with a stream of air until it behaved like a liquid. The item to be coated was first heated to 650 degrees Fahrenheit and then dipped in the fluidized bed for a second or two. After the excess powder was blown off, a film of one to two thousandths of an inch was left behind. As with other methods, repeated applications were often required to get a thick enough film. This method was especially useful with irregularly shaped mechanical components, such as valves and rotors, as well as with small items like ball bearings.
By 1948 Du Pont had made enough progress to prepare for full-scale production. Two years later the company’s first commercial Teflon plant, designed to produce a million pounds a year, went on line at the Washington Works, on land once owned by George Washington near Parkersburg, West Virginia. Du Pont stepped up its efforts to market Teflon for industrial applications, promoting the use of tape and sheets for insulation in many kinds of electrical equipment. Teflon was also used for gaskets, packings, valve components, pump components, bearings, sealer plates, and hoppers. To help users understand the polymer’s unusual properties and tricky fabrication requirements, Du Pont sent out a team of scientists to advise customers on integrating Teflon into their production processes. Members of the research, manufacturing, and sales staff met regularly to compare notes.
Within a year Teflon was also being used in commercial food processing. Du Pont saw the potential for expansion in this field but decided to proceed slowly. In bread manufacturing, rollers were coated with Teflon to keep dough from sticking. Teflon-lined bread pans and muffin tins became standard equipment in many bakeries. Teflon coatings also stopped dough from sticking to cookie sheets and reduced the number of damaged cookies that had to be thrown away. In candy factories Teflon coated conveyor belts, hooks for pulling taffy, and the cutting edges of slicing machines. In all these applications, Teflon proved much more effective than the old method of coating the surface with oil or grease.
A 1953 Du Pont television commercial showed a Teflon-coated bread pan and boasted that it had “baked 1,258 loaves of bread and ... never had a drop of grease in it.” The first draft of the script for this ad also predicted that frying pans would be coated with Teflon in the future, but that line was deleted before the commercial was filmed. Du Pont was reluctant to market Teflon-coated cookware for home kitchens because of concerns that misuse might lead to injuries and lawsuits. Until the company could be sure that Teflon was absolutely safe in untrained hands, it preferred to stay with industrial users. Nylon, another Du Pont product, had become a great success in consumer products, but it was not subjected to the extreme conditions that Teflon cookware would encounter.
Du Pont’s tests showed that while Teflon could withstand brief exposure to temperatures as high as 1,000 degrees Fahrenheit, it began to soften at 620 degrees Fahrenheit. This was no problem for baking pans, which are rarely subjected to temperatures above 500 degrees, but it could potentially cause problems with pans used on stovetops. Researchers found that at high temperatures, small quantities of gaseous decomposition products were released. Because some of these gases were toxic and might cause temporary flu-like symptoms, adequate ventilation was required. Although the fumes given off by overheated Teflon pans were less toxic than those given off by heated cooking oil or butter, Du Pont decided to proceed with caution. Even as late as 1960 the company sold less than 10 million pounds of Teflon per year, with receipts of a piddling (by Du Pont standards) $28 million. Expanding consumer uses would be the key to boosting sales, but Du Pont had to convince itself that Teflon was harmless before selling it to the housewives of America.
While Du Pont hesitated, an enterprising French couple took matters into their own hands. Marc Grégoire, an engineer, had heard about Teflon from a colleague who had devised a way to affix a thin layer of it to aluminum for industrial applications. The process involved etching the aluminum with acid to create a microscopically pitted surface, covering the surface with Teflon powder, and heating it to just below its melting point, which caused it to interlock with the aluminum surface.[/FONT][FONT="][/FONT]
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[FONT="]In France, the birthplace of nonstick cookware an advertisement proclaims: "Tefal never sticks."[/FONT][FONT="] [/FONT]
[FONT="]Grégoire, an avid fisherman, decided to coat his fishing gear with Teflon to prevent tangles. His wife, Colette, had another idea: Why not coat her cooking pans? Grégoire agreed to try it, and he was successful enough to be granted a patent in 1954.The Grégoires were so happy with the results that they set up a business in their home. Starting around 1955, Marc coated pans in their kitchen and Colette peddled them on the street. French cooks, despite their customary reverence for tradition, snapped them up. Encouraged by this reception, the Grégoires formed the Tefal Corporation in May 1956 and opened a factory.
Soon afterward France’s Conseil Supérieur de l’Hygiene Publique officially cleared Teflon for use on frying pans. The Laboratoire Municipale de Paris and the École Supérieur de Physique et Chimie also declared that Teflon-coated cookware presented no health hazard. In 1958 the French ministry of agriculture approved the use of Teflon in food processing. That same year the Grégoires sold one million items from their factory. Two years later sales approached the three million mark.
Du Pont executives, who were aware of these developments in France, decided to seek the approval of the U.S. Food and Drug Administration (FDA) for wider use of Teflon in cooking and food processing. The company tested frying pans and other cooking surfaces under conditions even more rigorous than those used in France. Du Pont’s researchers concluded that utensils coated with Teflon were “unquestionably safe” for both domestic and commercial cooking. In January 1960 the company gave the FDA four volumes of data, collected over nine years, on the effects of Teflon resins in food handling. Within a few months the FDA decided that the resins did not “present any problems under the Food Additives Amendment.” Despite the favorable FDA decision, Du Pont continued to move slowly, since marketing Teflon-coated cookware was not a high priority. Then one man’s enthusiasm nudged Du Pont into action.[/FONT][FONT="][/FONT]
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[FONT="]Workers in a Tefal factory[/FONT][FONT="] [/FONT]
[FONT="]Thomas G. Hardie was an American who admired French culture. After graduating from college, he served in the military, worked for the Marshall Plan in Paris, and became a foreign correspondent for an American newspaper chain. Then he entered his family’s business, Nobelt, a Maryland firm that makes textile machinery. During a business trip to France in 1957 or 1958, Hardie met Marc Grégoire at a party on the Left Bank. The Frenchman enthusiastically told Hardie about his business and the factory he was building in a Paris suburb. Hardie was intrigued by Grégoire’s tale of the fast-selling cookware.
After Hardie went home to Maryland, he decided that the popular French pans would sell in the United States too. He went back to Paris to meet with Grégoire, who was reluctant to do business with an American because he didn’t trust Yankees. But Hardie was very persuasive and eventually won Grégoire’s confidence. With visions of quick success, he returned to the States with the rights to manufacture nonstick cookware using Tefal’s process.
During the next two years Hardie called on many American cookware manufacturers, trying to persuade them to make Teflon-coated pans. He had no success because the idea of nonstick pans was simply too new. All these rejections turned Hardie’s business venture into a personal crusade. Although he had no experience in the import business, he cabled the French factory to ship him 3,000 Tefal pans, which he warehoused in a barn on his sheep farm in Maryland. He sent free sample pans, along with promotional literature, to housewares buyers at 200 department stores. Not one of them placed an order.[/FONT][FONT="][/FONT]
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[FONT="]Half-inch Teflon tubing being extruded, 1955.[/FONT][FONT="] [/FONT]
[FONT="]Next Hardie met with an executive at Du Pont in Wilmington, Delaware. By describing the success of nonstick pans in France, he was able to convince the executive that cookware could be a valuable new market. When the executive objected that the name Tefal was too close to Teflon, Hardie agreed to market his imported French pans under the name T-fal. Later a Du Pont salesman was assigned to accompany Hardie on a visit to Macy’s in New York City. There, in a tiny basement office, a buyer named George Edelstein placed a small order. Hardie was so excited that he sent a victory cable to the French factory. On December 15, 1960, during a severe snowstorm, the T-fal “Satisfry” skillets went on sale for $6.94 at Macy’s Herald Square store. To almost everyone’s amazement, the pans quickly sold out.
Shortly afterward Hardie made his second sale when he telephoned Roger Horchow, a buyer for the Dallas department store Neiman Marcus. Horchow agreed to test a sample skillet even though his store didn’t have a housewares department. He gave the skillet to Helen Corbitt, a cookbook editor who ran a popular cooking school in Dallas. Corbitt loved it, prompting Neiman Marcus to place a large order and run a half-page newspaper advertisement. The store sold 2,000 skillets in a week. Hot-chow later recalled, “Skillets were piled up, still in the shipping crates, as in a discount house, with the salesladies handing them out to customers like hotcakes at an Army breakfast.” The news spread to other department stores. Buyers jumped on the nonstick bandwagon, and Hardie was swamped with orders.
The inventory in Hardie’s barn was quickly exhausted. He phoned France daily to ask for more pans, but the French plant couldn’t work fast enough to supply both sides of the Atlantic. Hardie flew to France to press his case with Grégoire. He even lent Tefal $50,000 to expand its facilities, but it still could not meet the American demand. To cope with the avalanche of orders, which reached a million pans per month in mid-1961, Hardie built his own factory in Timonium, Maryland.[/FONT][FONT="][/FONT]
[FONT="]In France, the birthplace of nonstick cookware an advertisement proclaims: "Tefal never sticks."[/FONT][FONT="] [/FONT]
[FONT="]Grégoire, an avid fisherman, decided to coat his fishing gear with Teflon to prevent tangles. His wife, Colette, had another idea: Why not coat her cooking pans? Grégoire agreed to try it, and he was successful enough to be granted a patent in 1954.The Grégoires were so happy with the results that they set up a business in their home. Starting around 1955, Marc coated pans in their kitchen and Colette peddled them on the street. French cooks, despite their customary reverence for tradition, snapped them up. Encouraged by this reception, the Grégoires formed the Tefal Corporation in May 1956 and opened a factory.
Soon afterward France’s Conseil Supérieur de l’Hygiene Publique officially cleared Teflon for use on frying pans. The Laboratoire Municipale de Paris and the École Supérieur de Physique et Chimie also declared that Teflon-coated cookware presented no health hazard. In 1958 the French ministry of agriculture approved the use of Teflon in food processing. That same year the Grégoires sold one million items from their factory. Two years later sales approached the three million mark.
Du Pont executives, who were aware of these developments in France, decided to seek the approval of the U.S. Food and Drug Administration (FDA) for wider use of Teflon in cooking and food processing. The company tested frying pans and other cooking surfaces under conditions even more rigorous than those used in France. Du Pont’s researchers concluded that utensils coated with Teflon were “unquestionably safe” for both domestic and commercial cooking. In January 1960 the company gave the FDA four volumes of data, collected over nine years, on the effects of Teflon resins in food handling. Within a few months the FDA decided that the resins did not “present any problems under the Food Additives Amendment.” Despite the favorable FDA decision, Du Pont continued to move slowly, since marketing Teflon-coated cookware was not a high priority. Then one man’s enthusiasm nudged Du Pont into action.[/FONT][FONT="][/FONT]
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[FONT="]Workers in a Tefal factory[/FONT][FONT="] [/FONT]
[FONT="]Thomas G. Hardie was an American who admired French culture. After graduating from college, he served in the military, worked for the Marshall Plan in Paris, and became a foreign correspondent for an American newspaper chain. Then he entered his family’s business, Nobelt, a Maryland firm that makes textile machinery. During a business trip to France in 1957 or 1958, Hardie met Marc Grégoire at a party on the Left Bank. The Frenchman enthusiastically told Hardie about his business and the factory he was building in a Paris suburb. Hardie was intrigued by Grégoire’s tale of the fast-selling cookware.
After Hardie went home to Maryland, he decided that the popular French pans would sell in the United States too. He went back to Paris to meet with Grégoire, who was reluctant to do business with an American because he didn’t trust Yankees. But Hardie was very persuasive and eventually won Grégoire’s confidence. With visions of quick success, he returned to the States with the rights to manufacture nonstick cookware using Tefal’s process.
During the next two years Hardie called on many American cookware manufacturers, trying to persuade them to make Teflon-coated pans. He had no success because the idea of nonstick pans was simply too new. All these rejections turned Hardie’s business venture into a personal crusade. Although he had no experience in the import business, he cabled the French factory to ship him 3,000 Tefal pans, which he warehoused in a barn on his sheep farm in Maryland. He sent free sample pans, along with promotional literature, to housewares buyers at 200 department stores. Not one of them placed an order.[/FONT][FONT="][/FONT]
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[FONT="]Half-inch Teflon tubing being extruded, 1955.[/FONT][FONT="] [/FONT]
[FONT="]Next Hardie met with an executive at Du Pont in Wilmington, Delaware. By describing the success of nonstick pans in France, he was able to convince the executive that cookware could be a valuable new market. When the executive objected that the name Tefal was too close to Teflon, Hardie agreed to market his imported French pans under the name T-fal. Later a Du Pont salesman was assigned to accompany Hardie on a visit to Macy’s in New York City. There, in a tiny basement office, a buyer named George Edelstein placed a small order. Hardie was so excited that he sent a victory cable to the French factory. On December 15, 1960, during a severe snowstorm, the T-fal “Satisfry” skillets went on sale for $6.94 at Macy’s Herald Square store. To almost everyone’s amazement, the pans quickly sold out.
Shortly afterward Hardie made his second sale when he telephoned Roger Horchow, a buyer for the Dallas department store Neiman Marcus. Horchow agreed to test a sample skillet even though his store didn’t have a housewares department. He gave the skillet to Helen Corbitt, a cookbook editor who ran a popular cooking school in Dallas. Corbitt loved it, prompting Neiman Marcus to place a large order and run a half-page newspaper advertisement. The store sold 2,000 skillets in a week. Hot-chow later recalled, “Skillets were piled up, still in the shipping crates, as in a discount house, with the salesladies handing them out to customers like hotcakes at an Army breakfast.” The news spread to other department stores. Buyers jumped on the nonstick bandwagon, and Hardie was swamped with orders.
The inventory in Hardie’s barn was quickly exhausted. He phoned France daily to ask for more pans, but the French plant couldn’t work fast enough to supply both sides of the Atlantic. Hardie flew to France to press his case with Grégoire. He even lent Tefal $50,000 to expand its facilities, but it still could not meet the American demand. To cope with the avalanche of orders, which reached a million pans per month in mid-1961, Hardie built his own factory in Timonium, Maryland.[/FONT][FONT="][/FONT]
asus450000
عضو
[FONT="]Starting with Apollo, NASA used Teflon cloth and Teflon-coated fibers in its space suits.[/FONT][FONT="] [/FONT]
[FONT="]Unfortunately for him, around the same time, several major American cookware companies decided that the time was right to start making Teflon pans. Suddenly the market was saturated with nonstick cookware. Because the American companies had no experience with Teflon coatings, much of it was inferior to the French product, and nonstick pans soon acquired a bad name. Just as quickly as the U.S. demand for nonstick pans had soared, it plummeted, and warehouses were filled with unsold stock. Hardie sold his factory and focused on his family’s business. (T-fal cookware, the standard of quality in the, early 1960s, is still being manufactured and is sold in stores in the United States and abroad.)
Despite the problems with early Teflon cookware, Du Pont’s managers still believed that it had enormous potential. So the company commissioned some research. Six thousand consumers, along with a sampling of professionals in the cookware business, were asked what was wrong with Teflon products. The respondents overwhelmingly liked the idea of Teflon cookware; the problem lay with faulty production methods that turned out shoddy pans whose coatings scraped off much too easily.
Du Pont knew that cookware could be more than just a way to sell lots of Teflon. It could also be an invaluable marketing tool, a vehicle to familiarize vast numbers of consumers with Teflon and its properties. Conversely, low-quality merchandise could only harm the product’s reputation. As a result the company established coating standards for manufacturers and initiated a certification program, complete with an official seal of approval for Teflon kitchenware. To verify compliance with its standards, Du Pont performed more than 500 tests per month on cookware at its Marshall Laboratories in Philadelphia.
The Du Pont certification program was so successful that a marketing survey in the mid-1960s found that 81 percent of homemakers who had purchased nonstick pans were pleased with them. By 1968 Du Pont had developed Teflon II, which not only prevented food from sticking to the pans but was also (supposedly) scratch-resistant. Later generations of Teflon cookware, with thicker coatings and improved bonding, would be introduced under the trade names Silverstone in 1976 and Silverstone Supra in 1986.
As Teflon became better known to consumers, rumors began to circulate that it was unsafe. Tales sprang up about how Teflon had caused the mysterious deaths of unidentified workers. In other versions users of nonstick cookware had suffered the flu or seizures after breathing Teflon fumes. Industrial safety bulletins and at least one medical journal warned readers of Teflon’s supposed dangers.[/FONT][FONT="][/FONT]
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[FONT="]An assortment of industrial parts made from granular PTFE shows the material's versatility and the wide range of applications in which it can be used.[/FONT][FONT="] [/FONT]
[FONT="]Whenever one of these false reports came to Du Pont’s attention, the company demanded a published retraction. It also published a booklet called The Anatomy of a Rumor that summarized the results of research carried out at Du Pont and elsewhere. In addition, Du Pont tried to set the record straight by acknowledging whatever minor problems could be documented. The company admitted that there had been isolated incidents of “polymer fume fever,” which produced symptoms similar to those of influenza for a brief period but had no lasting effects. It also acknowledged at least one case of a worker suffering “the shakes” after smoking cigarettes that might have been contaminated with Teflon dust. In fact, as early as 1954 Du Pont had instructed its employees not to smoke or carry cigarettes with them while working with Teflon. However, no serious illnesses or injuries had ever been linked to Teflon.
When Teflon cookware was introduced, many national magazines printed articles about the new products. Most discussed the safety issue, and several mentioned the rumors, but none gave any credence to the gossip. Nevertheless, Consumer Reports got so much mail about the rumors after a 1961 article that the editors had to print a second article refuting them again. As late as 1973 Consumer Reports was still receiving mail on the “old bugaboo about nonsticks,” prompting the editors to publish yet another article emphasizing that they knew of “no consumer illnesses resulting from... nonstick cookware in ordinary home use.”
As nonstick cookware became accepted, Teflon made the transition from a low-volume specialty material used chiefly in industry to a mass-market consumer item. Today Teflon is used to insulate fabrics in tablecloths and carpets and to coat the surfaces of steam irons. Teflon plumbing pipes and valves can be found in many new homes; Teflon flakes add toughness to nail polish. In fiber form, as part of the fabric known as Gore-Tex, it is beloved by campers and skiers for its ability to insulate while wicking moisture from the skin. It can also be found in pacemakers, dentures, medical sutures, artificial body parts, printed circuits, cables, space suits, and thousands of other manufactured products. The surest sign of the slippery material’s success is its adoption as a slang term in political discourse, where Teflon is used to describe an officeholder who unaccountably remains popular despite having opinions with which one disagrees.
While the discovery of Teflon was unplanned, the rest of its story is anything but accidental. Plunkett’s training in fluorine chemistry allowed him to recognize what he had found and to analyze its properties, a byway he might not have been able to explore in a smaller firm. When the project grew beyond laboratory scale, he knew he could hand it off to other departments with confidence. Du Pont had the knowledge base to find ways of producing the monomer cheaply enough, controlling the polymerization, applying the useful but hard-to-handle polymer to industrial use, and making sure that consumer products were durable, safe, and reliable. Large research groups can have their disadvantages, but in the case of Teflon, Du Pont’s size was a critical ingredient in its success.
Anne Cooper Funderburg is a freelance writer in Mandeyule, Louisiana, who writes about all facets of American history.
[/FONT][FONT="][/FONT][FONT="]visits since October 26, 2000[/FONT][FONT="]
[/FONT]
[FONT="]Unfortunately for him, around the same time, several major American cookware companies decided that the time was right to start making Teflon pans. Suddenly the market was saturated with nonstick cookware. Because the American companies had no experience with Teflon coatings, much of it was inferior to the French product, and nonstick pans soon acquired a bad name. Just as quickly as the U.S. demand for nonstick pans had soared, it plummeted, and warehouses were filled with unsold stock. Hardie sold his factory and focused on his family’s business. (T-fal cookware, the standard of quality in the, early 1960s, is still being manufactured and is sold in stores in the United States and abroad.)
Despite the problems with early Teflon cookware, Du Pont’s managers still believed that it had enormous potential. So the company commissioned some research. Six thousand consumers, along with a sampling of professionals in the cookware business, were asked what was wrong with Teflon products. The respondents overwhelmingly liked the idea of Teflon cookware; the problem lay with faulty production methods that turned out shoddy pans whose coatings scraped off much too easily.
Du Pont knew that cookware could be more than just a way to sell lots of Teflon. It could also be an invaluable marketing tool, a vehicle to familiarize vast numbers of consumers with Teflon and its properties. Conversely, low-quality merchandise could only harm the product’s reputation. As a result the company established coating standards for manufacturers and initiated a certification program, complete with an official seal of approval for Teflon kitchenware. To verify compliance with its standards, Du Pont performed more than 500 tests per month on cookware at its Marshall Laboratories in Philadelphia.
The Du Pont certification program was so successful that a marketing survey in the mid-1960s found that 81 percent of homemakers who had purchased nonstick pans were pleased with them. By 1968 Du Pont had developed Teflon II, which not only prevented food from sticking to the pans but was also (supposedly) scratch-resistant. Later generations of Teflon cookware, with thicker coatings and improved bonding, would be introduced under the trade names Silverstone in 1976 and Silverstone Supra in 1986.
As Teflon became better known to consumers, rumors began to circulate that it was unsafe. Tales sprang up about how Teflon had caused the mysterious deaths of unidentified workers. In other versions users of nonstick cookware had suffered the flu or seizures after breathing Teflon fumes. Industrial safety bulletins and at least one medical journal warned readers of Teflon’s supposed dangers.[/FONT][FONT="][/FONT]
[FONT="] [/FONT]
[FONT="] [/FONT]
[FONT="] [/FONT]
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[FONT="]An assortment of industrial parts made from granular PTFE shows the material's versatility and the wide range of applications in which it can be used.[/FONT][FONT="] [/FONT]
[FONT="]Whenever one of these false reports came to Du Pont’s attention, the company demanded a published retraction. It also published a booklet called The Anatomy of a Rumor that summarized the results of research carried out at Du Pont and elsewhere. In addition, Du Pont tried to set the record straight by acknowledging whatever minor problems could be documented. The company admitted that there had been isolated incidents of “polymer fume fever,” which produced symptoms similar to those of influenza for a brief period but had no lasting effects. It also acknowledged at least one case of a worker suffering “the shakes” after smoking cigarettes that might have been contaminated with Teflon dust. In fact, as early as 1954 Du Pont had instructed its employees not to smoke or carry cigarettes with them while working with Teflon. However, no serious illnesses or injuries had ever been linked to Teflon.
When Teflon cookware was introduced, many national magazines printed articles about the new products. Most discussed the safety issue, and several mentioned the rumors, but none gave any credence to the gossip. Nevertheless, Consumer Reports got so much mail about the rumors after a 1961 article that the editors had to print a second article refuting them again. As late as 1973 Consumer Reports was still receiving mail on the “old bugaboo about nonsticks,” prompting the editors to publish yet another article emphasizing that they knew of “no consumer illnesses resulting from... nonstick cookware in ordinary home use.”
As nonstick cookware became accepted, Teflon made the transition from a low-volume specialty material used chiefly in industry to a mass-market consumer item. Today Teflon is used to insulate fabrics in tablecloths and carpets and to coat the surfaces of steam irons. Teflon plumbing pipes and valves can be found in many new homes; Teflon flakes add toughness to nail polish. In fiber form, as part of the fabric known as Gore-Tex, it is beloved by campers and skiers for its ability to insulate while wicking moisture from the skin. It can also be found in pacemakers, dentures, medical sutures, artificial body parts, printed circuits, cables, space suits, and thousands of other manufactured products. The surest sign of the slippery material’s success is its adoption as a slang term in political discourse, where Teflon is used to describe an officeholder who unaccountably remains popular despite having opinions with which one disagrees.
While the discovery of Teflon was unplanned, the rest of its story is anything but accidental. Plunkett’s training in fluorine chemistry allowed him to recognize what he had found and to analyze its properties, a byway he might not have been able to explore in a smaller firm. When the project grew beyond laboratory scale, he knew he could hand it off to other departments with confidence. Du Pont had the knowledge base to find ways of producing the monomer cheaply enough, controlling the polymerization, applying the useful but hard-to-handle polymer to industrial use, and making sure that consumer products were durable, safe, and reliable. Large research groups can have their disadvantages, but in the case of Teflon, Du Pont’s size was a critical ingredient in its success.
Anne Cooper Funderburg is a freelance writer in Mandeyule, Louisiana, who writes about all facets of American history.
[/FONT][FONT="][/FONT][FONT="]visits since October 26, 2000[/FONT][FONT="]
[/FONT]
asus450000
عضو
[FONT="]Teflon is the registered trade name of the highly useful plastic material polytetrafluoroethylene (PTFE). PTFE is one of a class of plastics known as fluoropolymers. A polymer is a compound formed by a chemical reaction which combines particles into groups of repeating large molecules. Many common synthetic fibers are polymers, such as polyester and nylon. PTFE is the polymerized form of tetrafluoroethylene. PTFE has many unique properties, which make it valuable in scores of applications. It has a very high melting point, and is also stable at very low temperatures. It can be dissolved by nothing but hot fluorine gas or certain molten metals, so it is extremely resistant to corrosion. It is also very slick and slippery. This makes it an excellent material for coating machine parts which are subjected to heat, wear, and friction, for laboratory equipment which must resist corrosive chemicals, and as a coating for cookware and utensils. PTFE is used to impart stain-resistance to fabrics, carpets, and wall coverings, and as weatherproofing on outdoor signs. PTIZE has low electrical conductivity, so it makes a good electrical insulator. It is used to insulate much data communication cable, and it is essential to the manufacture of semi-conductors. PTFE is also found in a variety of medical applications, such as in vascular grafts. A fiberglass fabric with PTFE coating serves to protect the roofs of airports and stadiums. PTFE can even be incorporated into fiber for weaving socks. The low friction of the PTFE makes the socks exceptionally smooth, protecting feet from blisters.
History
PTFE was discovered accidentally in 1938 by a young scientist looking for something else. Roy Plunkett was a chemist for E.I. du Pont de Nemours and Company (Du Pont). He had earned a PhD from Ohio State University in 1936, and in 1938 when he stumbled upon Teflon, he was still only 27 years old. Plunkett's area was refrigerants. Many chemicals that were used as refrigerants before the 1930s were dangerously explosive. Du Pont and General Motors had developed a new type of non-flammable refrigerant, a form of Freon called refrigerant 114. Refrigerant 114 was tied up in an exclusive arrangement with General Motor's Frigidaire division, and at the time could not be marketed to other manufacturers. Plunkett endeavored to come up with a different form of refrigerant 114 that would get around Frigidaire's patent control. The technical name for refrigerant 114 was tetrafluorodichloroethane. Plunkett hoped to make a similar refrigerant by reacting hydrochloric acid with a compound called tetrafluoroethylene, or TFE. TFE itself was a little known substance, and Plunkett decided his first task was to make a large amount of this gas. The chemist thought he might as well make a hundred pounds of the gas, to be sure to have enough for all his chemical tests, and for toxicological tests as well. He stored the gas in metal cans with a valve release, much like the cans used commercially today for pressurized sprays like hair spray. Plunkett kept the cans on dry ice, to cool and liquefy the TFE gas. His refrigerant experiment required Plunkett and his assistant to release the TFE gas from the cans into a heated chamber. On the morning of April 6, 1938, Plunkett found he could not get the gas out of the can. To Plunkett and his assistant's mystification, the gas had transformed overnight into a white, flaky powder. The TFE had polymerized.
Polymerization is a chemical process in which molecules combine into long strings. One of the best known polymers is nylon, which was also discovered by researchers at Du Pont. Polymer science was still in its infancy in the 1930s. Plunkett believed that TFE could not polymerize, and yet it had somehow done so. He sent the strange white flakes to Du Pont's Central Research Department, where teams of chemists analyzed the stuff. The polymerized TFE was curiously inert. It did not react with any other chemicals, it resisted electric currents, and it was extremely smooth and slick. Plunkett was able to figure out how the TFE gas had accidentally polymerized, and he took out a patent for the polymerized substance, polytetrafluoroethylene, or PTFE.
PTFE was initially expensive to produce, and its value was not clear to Plunkett or the other scientists at Du Pont. But it came into use in World War II, during the development of the atomic bomb. Making the bomb required scientists to handle large amounts of the caustic and toxic substance uranium hexafluoride. Du Pont provided PTFE-coated gaskets and liners that resisted the extreme corrosive action of uranium hexafluoride. Du Pont also used PTFE during the war for making nose cones of certain other bombs. Du Pont registered the trademark name Teflon for its patented substance in 1944, and continued to work after the war on cheaper and more effective manufacturing techniques. Du Pont built its first plant for the production of Teflon in Parkersburg, West Virginia in 1950. The company marketed Teflon after the war's end as a coating for machined metal parts. In the 1960s, Du Pont began marketing cookware coated with Teflon. The slick Teflon coating resisted the stickiness of even scorched food, so cleaning the pans was easy. The company marketed Teflon for a variety of other uses as well. Other related fluoropolymers were developed and marketed in ensuing decades, some of which were easier to process than PTFE. Du Pont registered another variant of Teflon in 1985, Teflon AF, which is soluble in special solvents.
Raw Materials
PTFE is polymerized from the chemical compound tetrafluoroethylene, or TFE. TFE is synthesized from fluorspar, hydrofluoric acid, and chloroform. These ingredients are combined under high heat, an action known as pyrolosis. TFE is a colorless, odorless, nontoxic gas which is, however, extremely flammable. It is stored as a liquid, at low temperature and pressure. Because of the difficulty of transporting the flammable TFE, PTFE manufacturers also manufacture their own TFE on site. The polymerization process uses a very small amount of other chemicals as initiators. Various initiators can be used, including ammonium persulfate or disuccinic acid peroxide. The other essential ingredient of the polymerization process is water. The Manufacturing Process
PTFE can be produced in a number of ways, depending on the particular traits desired for the end product. Many specifics of the process are proprietary secrets of the manufacturers. There are two main methods of producing PTFE. One is suspension polymerization. In this method, the TFE is polymerized in water, resulting in grains of PTFE. The grains can be further processed into pellets which can be molded. In the dispersion method, the resulting PTFE is a milky paste which can be processed into a fine powder. Both the paste and powder are used in coating applications.
Making the TFE[/FONT]
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History
PTFE was discovered accidentally in 1938 by a young scientist looking for something else. Roy Plunkett was a chemist for E.I. du Pont de Nemours and Company (Du Pont). He had earned a PhD from Ohio State University in 1936, and in 1938 when he stumbled upon Teflon, he was still only 27 years old. Plunkett's area was refrigerants. Many chemicals that were used as refrigerants before the 1930s were dangerously explosive. Du Pont and General Motors had developed a new type of non-flammable refrigerant, a form of Freon called refrigerant 114. Refrigerant 114 was tied up in an exclusive arrangement with General Motor's Frigidaire division, and at the time could not be marketed to other manufacturers. Plunkett endeavored to come up with a different form of refrigerant 114 that would get around Frigidaire's patent control. The technical name for refrigerant 114 was tetrafluorodichloroethane. Plunkett hoped to make a similar refrigerant by reacting hydrochloric acid with a compound called tetrafluoroethylene, or TFE. TFE itself was a little known substance, and Plunkett decided his first task was to make a large amount of this gas. The chemist thought he might as well make a hundred pounds of the gas, to be sure to have enough for all his chemical tests, and for toxicological tests as well. He stored the gas in metal cans with a valve release, much like the cans used commercially today for pressurized sprays like hair spray. Plunkett kept the cans on dry ice, to cool and liquefy the TFE gas. His refrigerant experiment required Plunkett and his assistant to release the TFE gas from the cans into a heated chamber. On the morning of April 6, 1938, Plunkett found he could not get the gas out of the can. To Plunkett and his assistant's mystification, the gas had transformed overnight into a white, flaky powder. The TFE had polymerized.
Polymerization is a chemical process in which molecules combine into long strings. One of the best known polymers is nylon, which was also discovered by researchers at Du Pont. Polymer science was still in its infancy in the 1930s. Plunkett believed that TFE could not polymerize, and yet it had somehow done so. He sent the strange white flakes to Du Pont's Central Research Department, where teams of chemists analyzed the stuff. The polymerized TFE was curiously inert. It did not react with any other chemicals, it resisted electric currents, and it was extremely smooth and slick. Plunkett was able to figure out how the TFE gas had accidentally polymerized, and he took out a patent for the polymerized substance, polytetrafluoroethylene, or PTFE.
PTFE was initially expensive to produce, and its value was not clear to Plunkett or the other scientists at Du Pont. But it came into use in World War II, during the development of the atomic bomb. Making the bomb required scientists to handle large amounts of the caustic and toxic substance uranium hexafluoride. Du Pont provided PTFE-coated gaskets and liners that resisted the extreme corrosive action of uranium hexafluoride. Du Pont also used PTFE during the war for making nose cones of certain other bombs. Du Pont registered the trademark name Teflon for its patented substance in 1944, and continued to work after the war on cheaper and more effective manufacturing techniques. Du Pont built its first plant for the production of Teflon in Parkersburg, West Virginia in 1950. The company marketed Teflon after the war's end as a coating for machined metal parts. In the 1960s, Du Pont began marketing cookware coated with Teflon. The slick Teflon coating resisted the stickiness of even scorched food, so cleaning the pans was easy. The company marketed Teflon for a variety of other uses as well. Other related fluoropolymers were developed and marketed in ensuing decades, some of which were easier to process than PTFE. Du Pont registered another variant of Teflon in 1985, Teflon AF, which is soluble in special solvents.
Raw Materials
PTFE is polymerized from the chemical compound tetrafluoroethylene, or TFE. TFE is synthesized from fluorspar, hydrofluoric acid, and chloroform. These ingredients are combined under high heat, an action known as pyrolosis. TFE is a colorless, odorless, nontoxic gas which is, however, extremely flammable. It is stored as a liquid, at low temperature and pressure. Because of the difficulty of transporting the flammable TFE, PTFE manufacturers also manufacture their own TFE on site. The polymerization process uses a very small amount of other chemicals as initiators. Various initiators can be used, including ammonium persulfate or disuccinic acid peroxide. The other essential ingredient of the polymerization process is water. The Manufacturing Process
PTFE can be produced in a number of ways, depending on the particular traits desired for the end product. Many specifics of the process are proprietary secrets of the manufacturers. There are two main methods of producing PTFE. One is suspension polymerization. In this method, the TFE is polymerized in water, resulting in grains of PTFE. The grains can be further processed into pellets which can be molded. In the dispersion method, the resulting PTFE is a milky paste which can be processed into a fine powder. Both the paste and powder are used in coating applications.
Making the TFE[/FONT]
- [FONT="]1 Manufacturers of PTFE begin by synthesizing TFE. The three ingredients of TFE, fluorspar, hydrofluoric acid, and chloroform are combined in a chemical reaction chamber heated to between 1094-1652°F (590-900°C). The resultant gas is then cooled, and distilled to remove any impurities.[/FONT]
- [FONT="]2 The reaction chamber is filled with purified water and a reaction agent or initiator, a chemical that will set off the formation of the polymer. The liquid TFE is piped into the reaction chamber. As the TFE meets the initiator, it begins to polymerize. The resulting PTFE forms solid grains that float to the surface of the water. As this is happening, the reaction chamber is mechanically shaken. The chemical reaction inside the chamber gives off heat, so the chamber is cooled by the circulation of cold water or another coolant in a jacket around its outsides. Controls automatically shut off the supply of TFE after a certain weight inside the chamber is reached. The water is drained out of the chamber, leaving a mess of stringy PTFE which looks somewhat like grated coconut.[/FONT]
- [FONT="]3 Next, the PTFE is dried and fed into a mill. The mill pulverizes the PTFE with rotating blades, producing a material with the consistency of wheat flour. This fine powder is difficult to mold. It has "poor flow," meaning it cannot be processed easily in automatic equipment. Like unsifted wheat flour, it might have both lumps and air pockets. So manufacturers convert this fine powder into larger granules by a process called agglomeration. This can be done in several ways. One method is to mix the PTFE powder with a solvent such as acetone and tumble it in a rotating drum. The PTFE grains stick together, forming small pellets. The pellets are then dried in an oven.[/FONT]
- [FONT="]4 The PTFE pellets can be molded into parts using a variety of techniques. However, PTFE may be sold in bulk already pre-molded into so-called billets, which are solid cylinders of PTFE. The billets may be 5 ft (1.5 m) tall. These can be cut into sheets or smaller blocks, for further molding. To form the billet, PTFE pellets are poured into a cylindrical stainless steel mold. The mold is loaded onto a hydraulic press, which is something like a large cabinet equipped with weighted ram. The ram drops down into the mold and exerts force on the PTFE. After a certain time period, the mold is removed from the press and the PTFE is unmolded. It is allowed to rest, then placed in an oven for a final step called sintering.[/FONT]
- [FONT="]5 The molded PTFE is heated in the sintering oven for several hours, until it gradually reaches a temperature of around 680°F (360°C). This is above the melting point of PTFE. The PTFE particles coalesce and the material becomes gel-like. Then the PTFE is gradually cooled. The finished billet can be shipped to customers, who will slice or shave it into smaller pieces, for further processing.[/FONT]
- [FONT="]6 Polymerization of PTFE by the dispersion method leads to either fine powder or a paste-like substance, which is more useful for coatings and finishes. TFE is introduced into a water-filled reactor along with the initiating chemical. Instead of being vigorously shaken, as in the suspension process, the reaction chamber is only agitated gently. The PTFE forms into tiny beads. Some of the water is removed, by filtering or by adding chemicals which cause the PTFE beads to settle. The result is a milky substance called PTFE dispersion. It can be used as a liquid, especially in applications like fabric finishes. Or it may be dried into a fine powder used to coat metal.[/FONT]
- [FONT="]7 One of the most common and visible uses of PTFE is coating for nonstick pots and pans. The pan must be made of aluminum or an aluminum alloy. The pan surface has to be specially prepared to receive the PTFE. First, the pan is washed with detergent and rinsed with water, to remove all grease. Then the pan is dipped in a warm bath of hydrochloric acid in a process called etching. Etching roughens the surface of the metal. Then the pan is rinsed with water and dipped again in nitric acid. Finally it is washed again with deionized water and thoroughly dried.[/FONT]
- [FONT="]8 Now the pan is ready for coating with PTFE dispersion. The liquid coating may be sprayed or rolled on. The coating is usually applied in several layers, and may begin with a primer. The exact makeup of the primer is a proprietary secret held by the manufacturers. After the primer is applied, the pan is dried for a few minutes, usually in a convection oven. Then the next two layers are applied, without a drying period in between. After all the coating is applied, the pan is dried in an oven and then sintered. Sintering is the slow heating that is also used to finish the billet. So typically, the oven has two zones. In the first zone, the pan is heated slowly to a temperature that will evaporate the water in the coating. After the water has evaporated, the pan moves into a hotter zone, which sinters the pan at around 800°F (425°C) for about five minutes. This gels the PTFE. Then the pan is allowed to cool. After cooling, it is ready for any final assembly steps, and packaging and shipping.[/FONT]
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asus450000
عضو
[FONT="]Quality Control[/FONT][FONT="]
Quality control measures take place both at the primary PTFE manufacturing facility and at plants where further processing steps, such as coatings, are done. In the primary manufacturing facility, standard industrial procedures are followed to determine purity of ingredients, accuracy of temperatures, etc. End products are tested for conformance to standards. For dispersion PTFE, this means the viscosity and specific gravity of the dispersion is tested. Other tests may be performed as well. Because Teflon is a trademarked product, manufacturers who wish to use the brand name for parts or products made with Teflon PTFE must follow quality control guidelines laid down by Du Pont. In the case of nonstick cookware manufacturers, for example, the cookware makers adhere to Du Pont's Quality Certification Program, which requires that they monitor the thickness of the PTFE coating and the baking temperature, and carry out adhesion tests several times during each shift.
Byproducts/Waste
Though PTFE itself is non-toxic, its manufacture produces toxic byproducts. These include hydrofluoric acid and carbon dioxide. Work areas must be adequately ventilated to prevent exposure to gases while PTFE is being heated, or when it cools after sintering. Doctors have documented a particular illness called polymer fume fever suffered by workers who have inhaled the gaseous byproducts of PTFE manufacturing. Workers must also be protected from breathing in PTFE dust when PTFE parts are tooled.
Some waste created during the manufacturing process can be reused. Because PTFE was at first very expensive to produce, manufacturers had high incentive to find ways to use scrap material. Waste or debris generated in the manufacturing process can be cleaned and made into fine powder. This powder can be used for molding, or as an additive to certain lubricants, oils, and inks.
Used PTFE parts should be buried in landfills, not incinerated, because burning at high temperatures will release hydrogen chloride and other toxic substances. One study released in 2001 claimed that PTFE also degrades in the environment into one substance that is toxic to plants. This is trifluoroacetate, or TFA. While current levels of TFA in the environment are low, the substance persists for a long time. So TFA pollution is possibly a concern for the future.[/FONT]
[FONT="][/FONT]
[FONT="]انشاالله خدا وند نگه دار خودت و عزیزات باشه و هر چی از قادر متعال می خایی دعا می کنم بهت بده
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[FONT="]مهندس میدونم از یک صفحه اینا بیشترن ولی منتظر ترجمه دون به دونش هستم
[/FONT]
[FONT="]یاعلی و همینا که از من تایپ شده منظورم قبلیاشه بیزحمت[/FONT]
[FONT="]علی یار و یاورت
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Quality control measures take place both at the primary PTFE manufacturing facility and at plants where further processing steps, such as coatings, are done. In the primary manufacturing facility, standard industrial procedures are followed to determine purity of ingredients, accuracy of temperatures, etc. End products are tested for conformance to standards. For dispersion PTFE, this means the viscosity and specific gravity of the dispersion is tested. Other tests may be performed as well. Because Teflon is a trademarked product, manufacturers who wish to use the brand name for parts or products made with Teflon PTFE must follow quality control guidelines laid down by Du Pont. In the case of nonstick cookware manufacturers, for example, the cookware makers adhere to Du Pont's Quality Certification Program, which requires that they monitor the thickness of the PTFE coating and the baking temperature, and carry out adhesion tests several times during each shift.
Byproducts/Waste
Though PTFE itself is non-toxic, its manufacture produces toxic byproducts. These include hydrofluoric acid and carbon dioxide. Work areas must be adequately ventilated to prevent exposure to gases while PTFE is being heated, or when it cools after sintering. Doctors have documented a particular illness called polymer fume fever suffered by workers who have inhaled the gaseous byproducts of PTFE manufacturing. Workers must also be protected from breathing in PTFE dust when PTFE parts are tooled.
Some waste created during the manufacturing process can be reused. Because PTFE was at first very expensive to produce, manufacturers had high incentive to find ways to use scrap material. Waste or debris generated in the manufacturing process can be cleaned and made into fine powder. This powder can be used for molding, or as an additive to certain lubricants, oils, and inks.
Used PTFE parts should be buried in landfills, not incinerated, because burning at high temperatures will release hydrogen chloride and other toxic substances. One study released in 2001 claimed that PTFE also degrades in the environment into one substance that is toxic to plants. This is trifluoroacetate, or TFA. While current levels of TFA in the environment are low, the substance persists for a long time. So TFA pollution is possibly a concern for the future.[/FONT]
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[FONT="]انشاالله خدا وند نگه دار خودت و عزیزات باشه و هر چی از قادر متعال می خایی دعا می کنم بهت بده
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[FONT="]مهندس میدونم از یک صفحه اینا بیشترن ولی منتظر ترجمه دون به دونش هستم
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[FONT="]یاعلی و همینا که از من تایپ شده منظورم قبلیاشه بیزحمت[/FONT]
[FONT="]علی یار و یاورت
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asus450000
عضو
آقا مجتبی کجایی بابا خبر ازت نیست دیگه ترجمه نمی کنی
asus450000
عضو
آقا مجتبی ورشادی کجایی!!!!!!!!!!!!!!!!!!@@@@@@@@@@@@@@@@@@@@####################$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$4
zrobla
عضو جدید
به طور کلی پوشش های تفلون ، بقیه ی فلوروکربن ها و نچسب از طریق روشهای سنتی رنگ پاشی و یا رنگ پودری (الکترواستاتیک) روی موادباسلام و عرض خسته نباشید فراوان
بی زحمت ترجمه ای:
Teflon and other fluorocarbon and "non-stick" type coatings are mainly applied by traditional painting or powder coating techniques, then hot cured in ovens. These products are not easily applied by thermal spray, although they can benefit from a thermal spray metallic or ceramic coating as a base coat
Conventional PTFE coating is consisted of spraying the solved liquid teflon on the surface and heat the coated surface in an oven for several ours like what we do in IRAN in " Leab dadne ceramic va pokhtan dar koore" however you could you spray molten teflon on to the surface which is known as thermal spray or hot spray.
To find more info you could search "teflon spray coating", "non-stick coating", "thermal spray coating", etc.
http://www.syntheticcoatings.ie/Page.asp?PageID=8
here you may find some practical info
I am so sorry for writing in english as I cannot type in persian and need to follow the forum's rules
Thermal Spray
Thermal spray coating involves the use of a torch to heat a material, in powder or wire form, to a molten or near-molten state, and the use of a gas to propel the material to the target substrate, creating a completely new surface. The coating material may be a single element, alloy or compound with unique physical properties that are, in most cases, achievable only through the thermal spray process.
Thermal spray coatings are a highly cost-effective and straight-forward method for adding superior properties and performance qualities to a given engineering surface. The variety of products and coatings that can be enhanced by thermal spray are virtually limitless. The coatings are usually metallic, ceramic, carbides, or a combination of these materials to meet a range of physical criteria.
Thermal Spray Wire
MaterialHardness and Bond StrengthTypical Characteristics and ApplicationsCopper37 Rb
7324 PSIElectric conductivity;
Copper reclamation;
Used as alternate to copper platingMolybdenum14-36 Rb
5496 PSIAbrasion resistance;
Excellent adhesion to steel;
Excellent in molten metal environment in inert atmospheresCarbon Steel97-100 Rb
5700 PSIDimensional restoration of mismachined and worn partsTungsten Carbide52 Rc
6700 PSIExcellent bond strength;
Abrasion resistance;
Dredge cutter blades
FUNCTIONAPPLICATIONCOATINGWear ResistanceAdhesive WearBearings, piston rings, hydraulic press sleevesChrome Oxide, Babbit, Carbon SteelAbrasive WearGuide bars, pump seals, concrete mixer screwsTungsten Carbide, Alumina/Titania, SteelSurface Fatigue
WearDead centers, cam followers, fan blades (jet engines), wear rings (land based turbines)Tungsten Carbide, Copper/Nickel/Indium Alloy, Chrome CarbideErosionSlurry pumps, exhaust fans, dust collectorsTungsten Carbide, StelliteHeat ResistanceBurner cans/baskets (gas turbines), exhaust ductsPartially Stabilized ZirconiaOxidation ResistanceExhaust mufflers, heat treating fixtures, exhaust valve stemsAluminum, Nickel/Chrome Alloy, HastelloyCorrosion ResistancePump parts, storage tanks, food handling equipmentStainless Steel (316), Aluminum, Inconel, HastelloyElectrical ConductivityElectrical contacts, ground connectorsCopperElectrical ResistanceInsulation for heater tubes, soldering tipsAluminaRestoration of Dim.Printing rolls, undersize bearingsCarbon Steel, Stainless Steel
Click here for more information on the properties of Teflon© coatings. Online enquiry form
Synthetic Coatings Ireland's engineers will assist you in determining a suitable coating for your application. Take five minutes to complete our online form and we will respond the next business day - click HERE to go to the enquiry form.
ویدونم پخش پیلیه ولی دمتون گرم سریع تر
به طور کلی برای پوشش دادن مواد با تفلون، بقیه ی فلوروکربن ها و یا دیگر پوشش های نچسب از روش سنتی رنگ پاشی و یا رنگ پودری (الکترو استاتیک) استفاده میشود. سطج پوشش داده شده سپس در کوره پخته میشود تا به لایه ی زیرین بچسبد.
استفاده از اسپری گرم معمولا برای این گونه پوشش ها توصیه نمیشود گرچه استفاده از پوشش های فلزی و یا سرامیکی که به روش اسپری گرم انجام شده اند به عنوان پوشش پایه می تواند مفید باشد
در روش سنتی پوشش دهی با تفلون، تفلون به صورت محلول روی سطح اسپری میشود، سپس سطح پوشش داده شده در کوری برای چند ساعت پخته میشود. در روش اسپری داغ، تفلون مذاب روی سطح مورد نظر پاشیده میشود که معمولا به علت تفاوت دما بین سطح و تفلون مذاب کیفیت پوشش مطلوب نیست.
در روش اسپری داغ معمولا از یک مشعل جهت حرارت دادن متریال (در این مثال تفلون) استفاده میشود تا متریال به حالت مذاب یا نزدیک مذاب در آید. متریال مذاب سپس توسط فشار گاز به سمت هدف اسپری میشود تا یک لایه جدید روی سطح مورد نظر پدید آورد. متریالی که جهت پاشش استفاده میشود میتواند یک عنصر، آلیاژ یا مخلوط با ویژگی های مورد نظر باشد که معمولا اینگونه پوشش ها تنها از طریق پاشش حرارتی (اسپری داغ یا هرچیز دیگه ای که توی فارسی بهش میگند) قابل دسترس میباشند.
پاشش حرارتی یک رو ش آسان و ارزان برای پدید آوردن خواص (استثنایی) مورد نظر روی سطوح مهندسی می باشد. تنوع متریال ها و پوشش هایی که با این روش قابل تولید میباشند تقریبا نامحدود است و شامل فلزات، آلیاژها، سرامیک ها، مواد آلی و یا ترکیبی از اینها برای کاربردهای مختلف میشود
اون پایین هم نمونه ی متریال هایی که به این روش میشه برای پوشش دادن استفاده کرد رو نوشته
اگه میدونستم که خودم باید اینا رو ترجمه کنم از اول فارسی مینوشتم، ببخشید که ادبیات و جمله بندی خوب نیست ولی فکر میکنم که ایده ی مطلب رو میرسونه
zrobla
عضو جدید
zrobla
عضو جدید
تفلون، یکی از پر کاربردترین و معروفترین دستاوردهای مهندسی شیمی در امریکا، به صورت اتفاقی کشف شد. از این دسته نمونه ها در تاریخ مهندسی شیمی بسیار میباشند از لاستیک vulcanized گرفته تا ساخارین و Post-Its (خداوکیلی نمیدونم تو فارسی به این چی میگن تو اینترنت سرچ کن میفهمی چیه). تمام این دستاوردها در حالی کشف (یا اختراع) شدند که محققین به دنبال تولید ماده ی دیگری بودند. آنها (محققین) مواد مختلفی را به صورت تصادفی با یکدیگر مخلوط می کرده اند تا اینکه ناگهان به چنین مواد با ارزشی رسیده اند (یعنی اینکه همینطوری مواد رو با هم قاطی میکردند بدون هیچ برنامه ای تا اینکه یهو یه چیز بدرد بخور از توش در بیاد).
اما، ماجرای تفلون نشان میدهد که چگونه مهرت ها و استعداد هایی پرورش داده شده بودند تا بتوانند تفلون را از سطح آزمایشگاهی به بازار برسانند. تفلون در شرکت Du Pont تولید شد، جایی که بسیاری از دیگر مواد شیمیایی قرن بیستم در آن پدید آمد. تفلون در واقع یکی از محصولات جانبی تحقیق پیرامون سرد کننده ها (فریون) بود.
در ابتدای دهه ی ۱۹۳۰ دو شیمیدان از شرکت جنرال موتورز A. L. Henne و Thomas Midgley نمونه هایی رو از یک مخلوط به آزمایشگاه جکسون شرکت دوپونت در دیپ واتر نیوجرزی آوردند. این دو ماده فریون ۱۱ و فریون ۱۲ (سی اف سی) از هیدروکربون ها بودند که تعدادی یا همه ی اتمهای هیدروژن اونها با کلر و فلوئر عوض شده بود. محققین جنرال موتورز موفق به تولید خانواده ای از سردکننده ها برای بخش Frigidaire (سردخانه) شرکت شده بودند (این قسمت از شرکت در کار تولید یخچال و این جور چیزها بود). هدف این تحقیق تولید ماده ای برای استفاده در یخچال بود تا جایگزین موادی چون آمونیاک، اکسید گوگرد و پروپان بشود که نسبت به فریون هم کم بازده تر بودند و هم سمی و قابل انفجار لذا مناسب مصارف خانگی نبودند.
نتایج اولیه ی تحقیقات باعث شد تا جنرال موتورز با دوپونت شراکت کند تا از تخصص دوپونت در تولید و تحقیق استفاده کند. این دو شرکت یک شرکت سومی تشکیل دادند به نام Kinetic Chemicals که تا اواسط ۱۹۳۰ محدوده ی وسیعی از سی اف سی ها رو تولید و آزمایش کرده بود و بهترین نمونه ها را به تولید انبوه رسانده بود.
بهترین محصول این شرکت مبرد ۱۱۴ بود که بعدها به نام فریون ۱۱۴ یا retrafluorodichloroethane (CF2ClCF2Cl) شناخته شد. شرکت کینتیک طبق قراردادی تمام تولید فریون ۱۱۴ را به Frigidaire واگذار کرد لذا در سالهای پایانی ۱۹۳۰ دوپونت تصمیم گرفت تا تحقیقاتی انجام دهد تا بتواند سردکننده ای با خواص مشابه فریون ۱۱۴ تولید کند که قابل فروش به دیگر تولید کنندگان یخچال باشد.
یکی از شیمیدانانی که مسئول این پروژه شده بود فردی ۲۷ ساله به نام old Roy J. Plunkett بود که در سال ۱۹۳۶ و بعد از فارق التحصیلی در مقطع دکتری از دانشگاه اوهایو به استخدام دوپونت در آمده بود.
zrobla
عضو جدید
Plunkett روی یک نمونه سی اف سی تحقیق میکرد که انتظار میرفت خواص سرد کنندگی خوبی داشته باشد. او این ماده را از ترکیب گاز tetrafluoroethylene (TFE با اسید هیدروکلریک بدست آورده بود. برای ادامه ی تحقیقات Plunkett و دستیارش Jack Rebok مقدار ۱۰۰ پوند TFE را تحت فشار در یک سیلندر ذخیره کرده بودند تا در موقع نیاز از آن استفاده کنند. آنها سیلندر را در یخ خشک (دی اکسید کربن جامد) قرار داده بودند تا مانع انفجار یا شکستگی سیلندر بشوند.
صبح روز ششم آپریل ۱۹۳۸ Rebok سیلندر TFE را به دستگاهی وصل کرد که او و Plunkett برای آزمایشاتشون از اون استفاده میکردند. روش استاندارد اونها شامل گرم کردن گاز TFE و سپس اسپری کردن اون داخل اسید هیدروکلریک بود. با این حالِ این بار موقعیکه او شیر سیلندر TFE رو باز کرد هیچ چیزی از آن خارج نشد. آزمایش شیر نشان داد که شیر هیچ اشکالی ندارد. آیا احتمال داشت که گاز از سیلندر به خارج درز کرده باشد؟
آنها سیلندر را وزن کردند و مشخص شد که مقدار زیادی از گاز همچنان داخل سیلندر باید باشد. آنها باز هم با شیر خروجی سیلندر بازی کردند، حتی سیمی را داخل آن کردند تا شاید سوراخ آن باز شود. اما هیچ اتفاقی نیافتاد
صبح روز ششم آپریل ۱۹۳۸ Rebok سیلندر TFE را به دستگاهی وصل کرد که او و Plunkett برای آزمایشاتشون از اون استفاده میکردند. روش استاندارد اونها شامل گرم کردن گاز TFE و سپس اسپری کردن اون داخل اسید هیدروکلریک بود. با این حالِ این بار موقعیکه او شیر سیلندر TFE رو باز کرد هیچ چیزی از آن خارج نشد. آزمایش شیر نشان داد که شیر هیچ اشکالی ندارد. آیا احتمال داشت که گاز از سیلندر به خارج درز کرده باشد؟
آنها سیلندر را وزن کردند و مشخص شد که مقدار زیادی از گاز همچنان داخل سیلندر باید باشد. آنها باز هم با شیر خروجی سیلندر بازی کردند، حتی سیمی را داخل آن کردند تا شاید سوراخ آن باز شود. اما هیچ اتفاقی نیافتاد
asus450000
عضو
آقای مهندس ورشادی کجایی بابا ترجممون باد کرده اگه میشه خودت دوباره این قبلیالو رو دوستت ترجمه کارد کمل کامل مثل همیشه ترجمه کن توروخدا تو این شبایه عزیز دعات کنیم هیمن کار از ممون برمیاد
لطفاً تایپیک قبلیایه منوکه زدم بی زحمت که پشته هممن
لطفاً تایپیک قبلیایه منوکه زدم بی زحمت که پشته هممن
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