When to use the crusher and when to use the shredder

For plastic processing, the choice between a shredder and a crusher mainly depends on the material form​ and output requirements. In simple terms: use a shredder for large, tough, or hard-to-handle​ plastics, and a crusher for small, uniform​ plastics.

1. When to Use a Shredder?

A shredder specializes in coarse processing​ and is suitable for handling large, tough, or difficult-to-process plastics.

Applicable Scenarios:

• Large Hard Materials: Such as large plastic barrels, plastic pallets, sprues, and large pipes.

• Tangling Materials: Such as bundled plastic films, FIBCs (bulk bags), and woven bags.

• Mixed Materials: Such as plastic waste containing metal or impurities (shredder blades are more wear-resistant and less prone to damage).

Working Principle: Uses low-speed, high-torque​ shearing force, like scissors, to "tear" or "cut" the material.

Output Result: Larger output size (usually above 20mm), in the form of irregular chunks or strips, mainly used for volume reduction​ (to reduce size for transportation) or as pre-processing for a crusher.

2. When to Use a Crusher?

A crusher specializes in fine processing​ and is suitable for handling medium-sized, brittle plastics, with the goal of pelletizing.

Applicable Scenarios:

• Injection Sprue Waste: Edge trimmings or defective parts from injection molding machines.

• Bottle Flakes/Thin Sheets: Such as plastic bottles, plastic shells, and thin-walled pipes.

• Recycling and Pelletizing: Requires crushing plastics into fine particles for cleaning, melting, and extrusion.

Working Principle: Uses high-speed rotating blades​ to "break" the material through impact, collision, and shearing.

Output Result: Smaller output size (usually below 10mm), in the form of uniform granules, which can be directly used for injection molding or pelletizing.

One-Sentence Summary: If your plastics are large and bulky​ (e.g., large barrels, pipes) or soft and flexible​ (e.g., films, bags), use a shredder​ first; if your plastics are small fragments​ (e.g., sprues, bottle flakes), use a crusher​ directly.