Lab-scale and full-scale industrial composting of biodegradable plastic blends for packaging.

Area of Science:

• Materials Science
• Environmental Science
• Polymer Science

Background:

• Compostable plastic packaging acceptance in industrial facilities is inconsistent.
• Plastic residue persistence after composting hinders universal acceptance despite certifications.
• This study investigates the disintegration discrepancy of compostable plastics.

Purpose of the Study:

• To compare the disintegration rates of rigid (polylactic acid-based) and soft (polybutylene succinate-based) compostable packaging.
• To evaluate performance in both lab-scale and industrial composting environments.
• To identify factors influencing compostable plastic degradation in real-world conditions.

Main Methods:

• Lab-scale disintegration tests conducted in triplicates following ISO 20200 for up to 12 weeks.
• Industrial composting plant exposure for 3 weeks with duplicate samples.
• Supplementary lab-scale test mirroring industrial conditions for 3 weeks.

Main Results:

• Rigid packaging retained significantly more mass (98.3%) in the industrial plant than in lab tests (55.7% at 12 weeks).
• Soft packaging also showed high mass retention (93.9%) in the plant versus lab tests (0.3% at 12 weeks).
• Lab disintegration was high, but industrial composting showed minimal degradation for both packaging types.

Conclusions:

• Compostable plastics disintegrated effectively in lab settings but poorly in industrial composting.
• Substrate composition and heterogeneity in industrial plants significantly impact degradation rates.
• Optimizing substrate and thermophilic duration is key for successful industrial treatment of compostable plastics.