Non-Stick Coatings

Non-stick coatings are used in many applications in order to prevent leakage and wear, limit friction and, in its most visible use, coat cookware to assist in preparing food. Many chemicals are used to create non-stick coatings, including polytetrafluorethylene (PTFE), the chemical name for DuPont’s Teflon. Chemical coatings often vary depending on the application, because certain non-stick coatings can react poorly under high heat. Non-stick coatings are applied to applications in either spray or layering techniques and high end coatings have long shelf lives regardless of adhesion technique.

Non-Stick Chemicals

PTFE is one of the most commonly used non-stick chemicals, either on its own or in combination with other chemicals. Generally, the higher the amount of PTFE in a non-stick coating, the better quality the coating will be. PTFE has a very low coefficient of friction, measured at 0.1 or less, one of the lowest known. It is hydrophobic, meaning that it repels water molecules, and can be heated to a very high temperature. However, if heated to 260 degrees Celsius or above (500 degrees Fahrenheit), PTFE undergoes pyrolysis, or chemical breakdown. At this temperature, it can release toxic fumes during deterioration. PTFE is also dielectric, meaning it acts as an insulator for electricity.

Other non-stick chemicals include perfluoroalkoxy, which is very similar to PTFE’s chemical properties of friction resistance and dielectricity, but is more formable than PTFE. This means it can be shaped into more complex shapes than PTFE, making it more suitable to applications with complex physical geometries. Fluorinated ethylene propylene is another non-stick coating. It is more flexible than PTFE and can undergo injection molding and screw extrusion techniques, making it suitable for applications that require complex geometries.

Non-Stick Coating Applications

Non-stick coatings can be used for a variety of applications because of their extensive beneficial properties. As stated, their low friction coefficient and hydrophobia makes them ideal for cooking surfaces, because they prevent food from sticking to the pan after use. This low friction coefficient makes cleaning and cooking easier.

Low friction properties are also useful in fasteners that perform sliding movements, such as bearings, gears, and slide plates. In these applications, non-stick coatings can function as reliable lubricants, especially when mixed with molybdenum disulfide or mineral oil. Non-stick coatings are also biocompatible, meaning they are not harmful to biological tissue, so they can be used for a number of applications that require low friction and biocompatibility, such as metallic implants and body piercings. Additionally, certain chemically-produced materials used in weather-proofing are combined with PTFE and other non-stick coatings.

Because of the dielectric properties of non-stick coatings, they are often used as insulators in certain cables and connector assemblies to prevent errant electric activity. Printed circuit boards (PCBs) utilize this insularity for this very reason. Additionally, the high melting point of most non-stick coatings is beneficial because they will not melt when the PCB is in use, even when operating on microwave frequencies.