One of the most important functions of specialty compounding is the ability to create safer plastic. Even professionals have accidents, so when that happens, people need to have fail-safes to protect the user and the company making products. Flame retardant thermoplastics can make the difference between a life and death situation.
Flame retardants function in one of three ways. It would help if you chose the type that most closely meets the environment and application of your plastic parts. The three functions include:
Solid Phase Char-Formation - When this additive reacts, it forms a carbonaceous layer on the material's surface. This creates a layer of insulation that slows pyrolysis. In essence, the layer acts as a barrier that hinders the release of gases that fuel combustion. This type of additive is ideal in non-halogen systems that use nitrogen and phosphorous.
Vapor Phase Inhibition – This additive reacts during combustion; the reaction burns polymers in the vapor phase, disrupting the excessive release of free radicals (molecular level). In short, vapor phase inhibition shuts down the combustion process, and it is often used with halogenated flame retardant systems.
Cool and Quench – This additive is mostly used in halogen-free flame retardant systems. More specifically, they are used in extruded applications (cables & wires). An endothermic reaction is responsible for releasing water molecules that dilute and cool materials (slowing the combustion process).Related Reading