What Is a Scrap Plastic Grinder?

A scrap plastic grinder is a high-speed size-reduction machine that processes pre-shredded material into uniform, small fragments. It serves as secondary reduction equipment in recycling lines, positioned after a primary shredder to achieve the precise particle size required for washing, pelletizing, or direct reuse. While grinders handle plastics primarily, the same technology applies to paper, cardboard, biomass, wood, tires, and textiles.

How It Fits Into a Recycling Line

A scrap grinder operates as a standalone unit or integrates into a complete line with conveyors, shredders, and balers. In most recycling operations, it sits downstream of the primary shredder. The shredder handles bulk reduction from large items to 50–100 mm fragments; the grinder then refines these to 5–20 mm chips with consistent dimensions. This two-stage approach protects the grinder from overload and extends blade life.

Rubber crusher granulator:

Plastic Pipe crusher granulator:

Film crusher granulator:

Key Design Features

High-speed rotor — Up to 650 RPM for efficient shearing of ductile plastics

Replaceable blades — Mounted with nuts and screws; cutting chamber opens for quick blade change without full disassembly

Heat-treated blades — High resistance to wear and thermal fatigue, extending service intervals

Interchangeable screens — Outlet screen controls output particle size; mesh size customized to downstream requirements

Wanrooe Grinder Range

Mini grinders — Laboratory or small-batch processing, 10–50 kg/h

Medium grinders — Standard recycling operations, 100–500 kg/h

Large grinders — High-volume industrial lines, 500–2,000 kg/h

Selection depends on material type, input size, target output dimension, and hourly capacity. Contact us with these parameters for model recommendation.

FAQ: Scrap Plastic Grinders

Can a grinder replace a shredder?

No. Grinders lack the torque and feed opening to handle large, bulky items. Running unshredded material through a grinder causes jamming, motor overload, and rapid blade damage. Use a shredder first, grinder second.

How do I prevent heat buildup in the grinding chamber?

Heat softens plastic, causing it to stick to blades and screens. Solutions: reduce rotor speed for heat-sensitive materials, use water-cooled chambers, or increase blade-to-screen clearance. Monitor motor current — rising current often indicates overheating.

What screen size should I use?

Match screen size to downstream requirements. Pelletizing typically needs 6–12 mm. Washing lines accept 12–20 mm. Direct reuse in molding may require 4–8 mm. Finer screens reduce throughput and increase heat — balance quality with productivity.