Odour characterisation of recycled HDPE in different washing and processing processes

Area of Science:

• Polymer Science
• Environmental Science
• Materials Engineering

Background:

• Increasing polymeric waste poses a significant environmental pollution challenge.
• Recycling and reusing plastic materials minimize environmental impact and energy consumption.
• Unpleasant odors in recycled plastics, particularly high-density polyethylene (HDPE), hinder their acceptance in production.

Purpose of the Study:

• To eliminate malodor from waste high-density polyethylene (HDPE) for enhanced reuse in the packaging industry.
• To investigate the effectiveness of washing and processing techniques in odor reduction.
• To enable the incorporation of greater recycled content in new products.

Main Methods:

• HDPE waste was sourced from a recycling company.
• Materials underwent washing, characterization, and processing (extrusion and injection).
• Odor analysis was performed using gas chromatography and olfactory panels at each stage.

Main Results:

• Washing processes significantly reduced the odor of HDPE.
• Extrusion and injection processing further diminished odor.
• Acetone treatment followed by extrusion/injection eliminated specific odor-causing components.

Conclusions:

• Washing and advanced processing techniques are effective in mitigating odor issues in recycled HDPE.
• These methods facilitate the broader application of recycled HDPE in the packaging sector.
• The findings support increased utilization of recycled materials, contributing to a circular economy.