Recycle or Not? An Exploration of Microplastic Generation During Plastic Processing via a Local Case Study

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Microplastic (MP) pollution is a growing global concern.
• Research has focused on MP sources, but plastic processing remains understudied.
• Plastic processing contributes significantly to environmental MP release.

Purpose of the Study:

• To investigate microplastic generation during virgin and waste plastic extrusion.
• To identify factors influencing MP formation in plastic processing.
• To evaluate potential MP removal strategies in industrial settings.

Main Methods:

• Quantified microplastic generation (10 μm-5 mm) during extrusion of virgin and recycled plastics.
• Analyzed the impact of feedstock, polymer type, and pelletizing methods on MP yield.
• Simulated microplastic removal efficiency using available technologies.

Main Results:

• Processing 1 ton of plastic generated 2.13 × 10^5–9.79 × 10^7 MPs (0.01–10.85 g).
• Feedstock, polymer type, and pelletizing significantly influenced MP generation.
• Global MP generation from plastic processing in 2022 was estimated at 1.34 × 10^16–2.63 × 10^16 particles.
• Simulations showed up to 84.35% MP removal is possible, with higher efficiency for larger particles.

Conclusions:

• Plastic processing is a critical, underestimated source of microplastic pollution.
• Virgin plastic processing and water ring pelletizing require targeted MP inspection and removal.
• Plastic recycling generates fewer and larger MPs, facilitating removal and should be promoted.