A powder or pellet is melted, injected into a mold, cooled under pressure, and ejected. It is fast and easy to automate, with little waste. Able to produce finished goods from raw material in one process. Colors are molded in and parts can be assembled by snap fits, fasteners, adhesives and welding.
A softened plastic tube is extruded into a mold and then inflated. This process is most commonly used to produce bottles.
A sheet of softened polymer material is drawn into a mold using vacuum. Sometimes pressure can also be applied to improve details.
Material is shaped by being forced through a tooling die. Think of it like squeezing toothpaste out of its tube. The two dimensional profiles are endless.
A heated mold is squeezed around a preformed blank or powder. It can be slower, but these themoset materials withstand higher temperatures and stresses.