Technical > Design Guide > Nonstick (release) properties

Friction results from two surfaces sliding across each other and is measured by a number that describes the drag (force) between sliding parts. Release is the property of a surface which results in the inability of substances to adhere to it. It is a function of surface energy that can be measured by the angle of contact between the surface and a drop of liquid. The larger the contact angle, the greater release property a coating has.

Release is associated with cookware, coated to release food materials. But release is equally vital to industrial processes: thermoforming, rubber molding, automotive and adhesive assemblies, copying machines. In many applications, buildup of foreign particles is a far greater problem than high bearing loads or corrosion. Examples: carburetor shafts, choke plungers, butterfly spindles, conveyor parts, instrument probes, fluid injectors, fuser rollers for copiers.

Buildup of dirt, ice, soot, scale, food and other foreign material can jam valve butterflies, throttle shafts, float elements, orifices, plungers, solenoids and other mechanisms.

If contamination of a surface is anticipated, it can be minimized with a thin coating, enabling the part to shed the contaminants. If contamination is severe, buffing the coated surface will smear the fluoropolymer on the surface of the coating and increase its release property.

A thin coating of Xylan (17.5 microns/0.0007 in.) is usually sufficient to eliminate the problem. Most foreign matter is unable to cling to the waxy surface of the coating and falls off. What does not fall off is easily scraped off when the component brushes against a mating surface.