Sol-Gel Coatings Compared to Other Nonstick Coatings
Sol-gel Coatings vs. Traditional Nonstick Coatings
Traditionally, non-reactive systems are preferred by nonstick coating producers. Formulators, usually try to avoid chemical reactions within their formulations due to the fact that it could affect the quality and functional properties of the eventual coating. So they purchase pre-polymerized materials from manufacturers and blend them for different use cases.
Quite to the opposite, with sol-gel technology, the formulators receive the ingredients of the process as monomers and create the polymer network on the surface of the substrate by means of chemical reactions after the coating is applied.
The Relationship Between PFOA and PTFE
Mainly due to inaccurate media coverage, there is a common belief that PFOA and PTFE industrial coatings are the same, but the truth is quite different. PFOA, or perfluorooctanoic acid, is a chemical that was, until recently, widely used to produce PTFE (better known by its trademark Teflon®). Based on EPAs recommendations, reputable manufacturers have gradually phased out and finally discontinued its use by the end of 2015. With a track record of over 70 years of safe use, nonstick, PFOA free, PTFE coatings are still one of the safest products ever put into the market.
Key Differences Between Sol-gel Coatings and PTFE Coatings
The performance and properties of sol-gel coatings can be compared to PTFE industrial coating services in different areas categorized as follows:
- Release: Sol-gel coatings have a better initial release than most conventional PTFE coatings. However, the nonstick property of sol-gel coatings can diminish faster than a conventional PTFE coating. Proper use and care can play a significant role in decreasing the rate of decline.
- Abrasion resistance: Sol-gel coatings are less ductile than PTFE materials.
- Temperature resistance: The release characteristics of sol-gel coatings begin to deteriorate by temperatures above 662°F while the coating itself will survive up to 842°F. On the other hand, a conventional PTFE coating will begin to lose quality at 500°F.
- Stain resistance: Sol-gel coatings have a better resistance to stain compared with traditional PTFE coatings, mainly because of their tighter network of molecules.
- Colors: Sol-gel generated coatings can maintain color at high temperatures and can be made in different colors like red, green, blue and even white. On the other hand, PTFE coatings can mainly be made in black, gray, bronze and other limited colors.
Unique Sol-gel Coating Types
Just as all conventional PTFE coating services are not the same, sol-gel coatings have different types too. Sol-gel coatings are in fact hybrid coatings and usually have 2 or more parts that are mixed to reach the ultimate coating. So, for instance, a one-layer sol-gel coating consists of 2 or more parts that are mixed to achieve the final result. For a two layer coat, each layer has multiple parts that must be mixed separately and applied as instructed by the manufacturer to achieve the desired results. The number of parts per coating layer varies between different brands and products. The necessary mixing hours can also vary greatly and while some require no more than 3 hours, others need as much as 24 hours of mixing before the product is ready.
Performance wise, some of the more recent sol-gels feature more than twice the release of other industrial coatings. A few create a tighter network of polymers and feature improved resistance against stain. For the same reason, these few enjoy more visually appealing gloss.
There is also a brand of sol-gel coatings that is fully compliant with the US and EU regulations for food contact.
Why are Sol-Gel Coatings Often Referred to as Green or Environmentally-Friendly Coatings?
Many brands of cooking utensils that use sol-gel coatings maintain that their products are environmentally friendly due to the fact that their coatings don't contain PFOA or PTFE.
To qualify for green credentials, the whole life span of a product has to be taken into account. Based on current sol-gel technology, most cookware with such a coating, enjoy a shorter nonstick life compared to their conventional PTFE match. As a result, consumers are bound to buy more sol-gel pans than a single pan with one of the better PTFE coatings which requires additional raw materials and energy to manufacture, produce and transport the subsequent pans.
In addition, most reputable coating suppliers are already meeting EPA recommendations by delivering PTFE coating services with formulations free of PFOA.
To qualify for green credentials, one must consider all these factors.