Where did it all begin?

Nonstick coatings hit the selling floors in the early 1960s.

The first nonsticks were made primarily of polytetrafluoroethylene (PTFE). PTFE has the lowest coefficient of friction (CoF) of any known solid. In other words, the majority of materials (in this case foodstuffs) do not stick to it.

PTFE's low CoF "releases" the materials, making it easy to separate them from the coating. Therefore, on nonstick pans, most substances are easily removed from the surface.

Unfortunately, PTFE is also very soft and, if unprotected, wears quickly. While early nonsticks had good release, they were soft and wore out after little use. The result: nonstick-coated cookware earned the reputation of being "disposable".
 
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The 3  Keys to Proper Coating Application

What are the ABC's of Applying Nonstick Coatings

So if you're like many, and leave decisions regarding coating application up to the manufacturer, it may be time to start asking some key questions. Having the right product knowledge is all about preventing problems and saving valuable time and money. This issue of PKN was created to help you understand what can happen to your finished product when a mistake is made during the application process.

A. Proper Surface Preparation

Proper substrate preparation plays a crucial role in optimum coating adhesion and durability. This includes both cleaning and roughening the substrate surface to be coated. First, the surface must be thoroughly cleaned to remove all surface contamination. (Surface contaminants may result in decreased adhesion properties and defects in the dry film such as fisheyes, peeling or flaking.)

Then the substrate is roughened by chemical etching, or grit-blasting with abrasive media, which allows the coating to "bite" into the surface. This results in a strengthened coating-substrate bond.

B. Dry Film Thickness (DFT)

It is important that the coating be applied according to the recommended Dry Film Thickness measurement specified on the coating's Product Data Sheet (PDS). If a coating is applied too thickly, problems such as mud-cracking, sagging or blisters can occur. If too thinly, hazing or low gloss will be apparent.

C. Proper Cure

Curing bonds the coating to the substrate by heating at approximately 750F - 800F/400C - 425C for about 10 minutes for PTFE coatings and 550F - 600F/285C - 315C for sol-gel "ceramic" coatings. The bake schedule varies according to the type of coating being applied, but if the temperature is incorrect, or the timing is off, a host of defects can appear in the finished product. Some of these are reduced or no release, peeling of the coating, hazing, low gloss, orange peel appearance and mud-cracking.


 

 

 
 
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