Plastic compounding

Compounding consists of preparing plastic formulations by mixing and/or blending polymers and additives in a molten state to achieve the desired characteristics.

[2] There are different critical criteria to achieve a homogeneous blend of the different raw material.

The hopper feeds the begin of the screw which will gradually transport the resins towards the die.

Co-kneaders and twin screws (co- and counter rotating) as well internal mixers are the most common used compounders in the plastic industry.

[3] The extrudate, which look like long plastic strands, are then cooled in a water bath, or by spraying as the conveyor belt moves it to the granulator.