Thermal Spray Non Stick Coatings: Out of the Skillet and into Your Design
Thermal spray non stick coatings can offer a big advantage over traditional Teflon or other release coatings. So, dust off your kitchen metal spatula. And when you get back to the office, here's to re-thinking your design.
This will be most evident in applications where mechanical stresses or abrasion are higher.
Wire or plasma spray, many thermal spray coatings, are well documented for protecting, isolating, anchoring the softest of non stick polymers, including silicone.
Disadvantages of thermal spray non stick coatings are their inability to coat uniformly over complex surfaces. They are also ‘line of sight’, which makes coating complex surfaces difficult, or internal surfaces without high accessibility, impossible.
Thickness of thermal spray non stick coatings can be as low as 0.003 to 0.005 inch or as high as 0.010 to 0.015 inch, per surface. Surface textures comparable to fine or coarse grit sand paper, 300 micro inch or more, are not uncommon. So be sure you understand these factors and your sticking mechanism before specifying in your product design. Other than re-machining, grinding, thermal spray coatings will not be easily removed. Expect too, some loss in parent metal since your service provider will most likely have aggressively grit blasted those surfaces prior to coating, to promote adhesion.
Today, thermal spray non stick coatings can integrate ceramic, Teflon (PTFE) and most any other non stick product available. Based on their low likelihood of migration into food product in any continuous, measurable amount, many are also non-objectionable with the Food & Drug Administration (FDA).
Depending on the mechanics of the environment, HVOF (high velocity oxygen flame) forms of thermal spraying may be ideal, based on increased density, stronger bonds and lower residual tensile stress. Compared with other combustion powder thermal spray process (LVOF), plasma spray or vacuum arc spray, which are also popular.
Remember: Besides material selection from your thermal spray non stick coatings, the key to sustainable release performance may be in surface finish or service temperature. Be sure your coating service provider fully understands your requirements.