Regrind

material

Recycled plastic material created by grinding and reprocessing plastic scrap, runners, sprues, or rejected parts back into usable pellets or flakes for manufacturing.

In Simple Terms

Regrind is essentially recycled plastic made from your own manufacturing waste. When injection molding creates runners, sprues, or defective parts, these can be ground up and mixed back into virgin resin to reduce material costs and waste.

Why It Matters

Regrind significantly reduces raw material costs, minimizes manufacturing waste, and supports sustainability initiatives. However, it requires careful quality control as excessive regrind ratios can degrade mechanical properties and processing characteristics.

Technical Details

Regrind typically maintains 80-90% of virgin resin properties when used at 10-25% blend ratios. Multiple reprocessing cycles can reduce molecular weight and impact strength. Critical factors include contamination control, particle size consistency, moisture content, and thermal history to prevent degradation during remelting.

Real-World Examples

Injection molding automotive parts

A manufacturer grinds runners and sprues from HDPE automotive components, blending 15% regrind with virgin resin to maintain part quality while reducing material costs by 12%.

Blown film production waste

Edge trim and startup waste from LLDPE film production is ground and reprocessed, with up to 20% regrind ratio maintaining acceptable film properties for non-critical applications.

Quality control rejected parts

PET bottles failing pressure tests are ground into flakes and sold as post-industrial recycled material to manufacturers producing non-food contact applications.