In its simplest form, compression moulding involves taking an accurately weighed pellet (charge) of a preheated resin or prepolymer, placing it in a die and, through heat and high hydraulic compression of a punch into the die cavity, forming a finished moulded part when the plastic has cooled.
The more accurately the plastic is measured means the less wastage (or flash) that is produced. This wastage cannot usually be recycled once (thermo)set.
This process lends itself to parts with a wide array of lengths, thicknesses, and complexities and is used across many different industries usually in quite high volumes.
Equipment and tooling costs are generally lower than other moulding processes.