Learning the Basics
Posted on Thursday, July 7, 2022
Whether it’s your 10-year-old niece who can teach you a shortcut on your new smartphone or a chemist providing definitions for technical terminology in your favorite powder coating magazine, there are opportunities to learn all around us. Learning how stuff works is a large portion of how we grow, especially in our careers. If you’re a powder coater, learning the basics of the formulation process and terminology provides some background on how (and why) the mysterious powder that you apply every day works. Time to make some powder coating flash cards; there will be a test!
Acrylic resin: A polymer derived from acrylic acid, methacrylic acid, and acrylate monomers.
Additives/Agents: General term. Compounds that are added in low concentrations to the powder coating formula which affect performance properties such as gloss, surface, durability, or color stability.
Anti-gassing agent: Additive used to help reduce the effect on appearance caused by gases or moisture released from a cast substrate during cure.
Antioxidant: Additive used to reduce oxidation and discoloration within a powder coating formulation.
Binder: Components that provide the film formation of the powder coating, typically comprised of resins and curing agents.
Catalyst: A compound that accelerates a chemical reaction without being consumed by the reaction.
Crosslinker: Chemical that reacts with the resin to form a molecular bond that allows the binder to fully develop its durability and resistance properties.
Cure agent: Hardener or crosslinker.
De-gassing agent: Additive that chemically scavenges oxygen and/or promotes the dissolution of the gases into the resin to minimize bubble formation in the coating film.
Dry blend agent: AKA: Post additive. Material added to a powder coating after extrusion to improve electrostatic properties such as fluidization and flow.
Epoxy resin: Reactive types of prepolymers and polymers containing epoxide groups, also known as polyepoxides. Epoxy resins can react with themselves or a wide range of co-reactants.
Extender/Filler: Material, either naturally occurring or synthetic, that is added to reduce cost in a powder coating formula without substantial effect on performance.
Flow agent: Additive used in a powder coating formula to increase self-leveling and minimize defects to produce a uniform film during the cure process.
Isocyanate: Material that is comprised of double bonded nitrogen, carbon & oxygen (N=C=O) that will react readily with a hydroxyl group to form urethane (polyurethane) structures.
Masterbatch: Most often a mixture of a functional material and a carrier. There are generally two types; a pigment masterbatch which allows a small amount of pigment to be added, and an additive masterbatch which generally enables a liquid additive to be absorbed onto a dry carrier (such as a silica) to enable the formulator to incorporate a dry material instead of a liquid into the coating.
Plasticizer: A low molecular weight material added to the polymers to improve their elastic type properties, such as elongation and flexibility.
Polymer: A generic term referring to a class of compounds of very large molecules built up by the combination of smaller molecules.
Resin: A specific material based on a polymer. Resins are produced by the chemical companies and given tradenames and product codes.
Triglycidyl Isocyanurate: Commonly known at TGIC, it is a tri-functional epoxide structure that is used as a crosslinker for carboxyl polyester resins.
UV absorber: A material that can absorb UV energy and convert it to a low level of heat. They are used to reduce coating degradation when exposed to sunlight.
Vinyl resin: Synthetic plastic polymer made from vinyl compounds.
Wax: A material that is a solid at ambient conditions that then becomes a low viscosity fluid at higher temperatures, used to modify surface properties such as gloss or slip.
While you may not strive to be a chemist in your next career, understanding the basics of how powder coating works can help you do your job better. Not only does it provide context for how you do your job, but it can also help you ask more informed questions if something goes wrong. Keep studying!
Alison Kroviak is a research chemist at Stepan.