Cleaning of Regrind Plastic Material in the Automotive Industry – USA

The Challenge: Dusty Plastic Regrind Limiting Production and PIR Use

The manufacturer produces a wide range of automotive components—door panels, bumpers, HVAC ducts, and fluid systems. Their goal was to increase the amount of Post-Industrial Recycled (PIR) resin in finished products, but dust-heavy regrind plastic created recurring issues:

• Dust contamination restricted regrind plastic blending to only 30% PIR.
• Vacuum loader screens and filters clogged frequently, causing downtime.
• The existing granulator evacuation system released fugitive dust, creating housekeeping and safety challenges.
• Regrind injection moulding quality suffered, increasing part rejects and maintenance.

Any new system needed to support safe dedusting, improve dust collection around injection molding machines, and deliver a fast payback period.

The Facts: Material Characteristics and Process Requirements

Regrind Material Profile

• Material: HDPE regrind
• Bulk density: 35 lbs/ft³
• Particle size: ~3/8”
• Throughput: ~650 lbs/hr
• Application: Regrind material blended with virgin resin

Production Environment

• 30+ machine-side grinders, each requiring reliable dedusting
• High-volume regrind material plastic streams feeding molding operations
• Clear need for a system that prevents dust recirculation and improves material cleanliness

The Solution: Kongskilde AirWash Dedusting & Conveying System

The manufacturer installed the Kongskilde AirWash 50 paired with the K-200 dust collector, creating a fully sealed and efficient dedusting separator screen system for plastic regrinds.

How the System Works

• Material moves from each granulator through a Kongskilde OK pipe system into the AirWash.
• The AirWash uses negative pressure conveying, pulling dust inward rather than blowing it into the workspace.
• Plastic regrind does not go through the fan, preventing rotor wear and preserving particle integrity.
• A two-stage cleaning process removes dust and fines, producing clean regrind ready for blending.
• Conveying air is filtered through the K-200 baghouse, where dust is safely captured in steel cans with sight glasses.

Equipment Specifications

• AirWash 50 with 5 HP fan motor
• 0.75 HP rotary airlock for controlled discharge
• K-200 filtration system for dust collection
• Modular piping for easy installation across 30+ grinder stations

This closed-loop setup enabled safe dedusting, improved dust collection for injection molding operations, and ensured consistent regrind material quality.

The Advantages and Benefits: Higher PIR Use, Cleaner Production, and Safer Operations

Increased Recycled Material Incorporation

After installation, the manufacturer increased PIR content from 30% up to 80% in select products. Cleaner regrind plastic improved part quality and allowed more reprocessed material to be blended into the molding process.

Reduced Downtime and Maintenance

• Screens and vacuum loader filters clogged far less frequently
• Stable, clean plastic regrind improved machine uptime
• Less wear on conveying components

Improved Worker Safety & Housekeeping

• Fugitive dust was eliminated at the source
• Cleaner floors, overhead structures, and equipment
• Improved respiratory health conditions for operators
• Lower insurance premiums due to reduced dust fire risks

Faster ROI and Lower Per-Piece Costs

• Rapid 6-month payback period
• Significant material cost savings from higher PIR usage
• Reduced labor associated with cleaning and dust management
• Lower overall cost per finished part