Size reduction offers recycling processors the ability to enhance efficiency, with low-speed, meter-fed granulators that tackle sprues, runners and small parts, to high-speed closed-loop systems to feed regrind back into the machine hopper and shredders to larger scrap.
Recycling programs typically focus on turning scrap and non-conforming parts back into size and form that is close to the virgin material used by the plastics processor.
A granulator is basically a rotary grinder used to grind trim, scrap, sprues and runners into feedstock-sized flakes for reprocessing, thus reducing waste and saving money.
On the shop floor, a granulator can be integrated into an extrusion system, grinding trim and scrap for recycling to the extruder. Using an air conveying system the trim and scrap is fed into a suction nozzle and conveyed to a chipper or small granulator that reduces the material to flake. The flake is then fed into a hopper to be reintroduced into the extruder.
For increased savings and environmental protection, the regrind that results will share the required material characteristics that will enable it to be mixed with the original material to make more parts.
Size-reduction services can include pulverizing, blending, grinding, metal and contamination removal, repackaging, classifying, fines removal, and certified destruction.
Granulating and shredding of plastic can be done in injection molding, blow molding and rotomolding shops, as well as film manufacturing and other extrusion. The process also can vary from the range of materials being used, including PE, PP, PVC, PS, PU and PET.
Shredders and granulators tend to come at the very front of a recycling line. So they represent an operator’s first chance to alter the state of material and play into the ways a facility reacts to shifts in the stream.
Today, size-reduction specialists are updating designs to ensure machinery capabilities remain aligned with the material showing up on recycling lines.