Sol Gel 101


Sol-gel coating is a process that converts an inorganic liquid substance into a gel that can be applied to virtually any metal substrate. Sol-Gel coatings are generally applied by spraying or dipping followed by a thermal or high heat firing process. Porcelain Industries is the only North American applicator of Thermolon coatings and can help you design your product to take advantage of Sol-Gel's benefits.

Thermolon offers:

  • Excellent non-stick capabilities
  • Extreme durability
  • Scratch, abrasion and corrosion resistance
  • Food-contact compliance (e.g. FDA CFR21 § 175.300; German LFGB §30 and §31)
  • Zero-PTFE and no PFOA
  • Low Carbon footprint

What is it made of?

Thermolon is developed from an inorganic, ceramic polymer based on silica that is coated using a sol-gel process. It is a mineral-based coating made primarily out of a combination of silicon and oxygen - the same basic elements found in sand. Thermolon's inorganic origins allow it to overcome environmental and engineering inefficiencies found in organic non-stick coatings such as PTFE.

How is it applied?

Unlike traditional PTFE coatings, which can require up to three product applications, Thermolon requires only a single layer for proper application. Thermolon’s 50% faster curing time and two oven curing requirement (PTFE can require up to four ovens) improves the overall efficiency of the application process.

Thermolon's efficiencies in curing temperature and speed also reduces manufacturing energy usage, making it one of the most environmentally-friendly coatings. In fact, Thermolon products emit 50% less CO2 during the coating process than PTFE coated products.

Sol-Gel Mechanical Properties

Thermolon is inorganic in its composition, giving it a much higher temperature resistance than traditional coatings that contain PTFE. Organic coatings (PTFE) are limited to a 260°C resistance due to food contact regulations; Thermolon can resist heat up to 450°C.

In temperatures up to 460°C:

  • Thermolon shows no change in color or any other coating defects.
  • Thermolon shows no measurable loss in weight.
  • Thermolon emits no toxic fumes.

Thermolon offers release properties superior to traditional coatings. In a study of brand name cookware, Thermolon ranked the highest of all competitors when comparing non-stick properties for a variety of food types.

Compared with popular organic coatings whose pencil hardness averages at 2H, Thermolon’s hardness measurement is 9H. A measurement of 9H is the highest possible level of hardness.

  • Thermolon retains its pencil hardness of 9H even up to 200°C.
  • Thermolon keeps hardness properties in high temperature conditions.

Thermolon coatings set the standard for high impact resistance by preventing cracking and delimination, even during extreme impact.

  • Thermolon offers impact resistance three times higher than normal criterion requirements.

In addition to coating effciency, Thermolon’s one-step application process improves abrasion, corrosion and maintenance properties over traditional coatings.

  • Thermolon’s abrasion/corrosion resistance is over nine times higher than traditional coatings.

From the composition and material properties to the application process, Thermolon offers more health and environmental benefits than traditional PTFE coatings.

  • Thermolon is food contact compliant (FDA CFR21 § 175.300).
  • Because Thermolon is PTFE-free, there are no harmful emissions on overheating beyond 450 °F.
  • Thermolon application contributes up to 60% less CO2 emissions than traditional coatings.

Thermolon offers a unique, environmentally-friendly coating process that is highly efficient produces consistent results.

Process steps:

  • Thermolon coat
    • Blending              
    • Mixing                 
    • Maturing 
  • Substrate
    • Degreasing                           
    • Sand Blasting
    • Cleaning 
    • Preheating
    • Coating                        
    • Oven curing
  • Packing - Membrane thickness = 35=/-5um


Erbium oxide gives a pink color and has been used as a colorant in glasses and porcelain enamel glazes.