6. Waste recycling

Thermoplastics that solidify after cooling can be replasticized for reuse in injection and extrusion processes. In this way, defective parts, waste material from :

• channels for feeding molds (sprues) and/or production start-ups;

• in-process material changes (purging);

• sheets from which thermoformed parts (skeletons) have been cut;

can be fragmented into calibrated grains, which are then mixed with virgin pellets when the plasticizing cylinders of extruders or injection molding machines are fed.

Similarly, thermoplastic packaging (bags, bottles, cans, containers) can be compacted in a baler after use. This waste is shredded to obtain small volumes, which are then fragmented in blade mills to...