Research Module: Extruding Recycled Multilayer Plastic Film - Research

Research Module: Extruding Recycled Multilayer Plastic Film

precious-plastic-philippines

Started 7mo. Edited 7moStarted 7 months ago. Last edit 7 months ago

Products

In Progress

Research Question Can we extrude multilayer plastic film into beams strong enough for construction or furniture applications? This question guides our exploration of transforming waste plastic films—often challenging to recycle due to their thin, contaminated nature—into durable, load-bearing beams. By testing extrusion parameters and mechanical properties, we'll determine if this process can yield viable alternatives to traditional materials like wood or metal. Context and Motivation Plastic waste, particularly thin multilayer films from packaging (e.g., LDPE, HDPE, and EVOH layers), poses a significant recycling hurdle. These films are lightweight, mixed-material composites that clog standard sorting systems and degrade during conventional reprocessing, contributing to over 300 million tons of annual plastic pollution globally. Our project addresses this by repurposing these films through extrusion into solid beams, potentially enabling structural reuse in low-load applications like furniture frames or modular construction panels. The motivation stems from the circular economy imperative: if successful, this could divert landfill-bound films into value-added products, reducing virgin plastic demand by up to 20-30% in niche markets. We're inspired by emerging "upcycling" techniques in plastic processing, aiming to achieve beams with compressive strengths comparable to softwoods (e.g., >10 MPa) while minimizing energy use in extrusion. This not only tackles environmental challenges but also opens doors for affordable, customizable building materials in developing regions or disaster-relief scenarios.

extrusion

More Information

606

1 Research Module: Extruding Recycled Multilayer Plastic Film

precious-plastic-philippines

Published 7mo. Edited 7moPublished 7 months ago. Last edit 7 months ago

In our baseline experiment conducted on October 13, 2025 (10 days ago), we produced a plastic board prototype weighing 3-3.4 kg using varying ratios of rigid and flexible recycled plastics. The focus was on optimizing feed composition for smooth extrusion, minimal foaming, and efficient motor performance. We logged key metrics including extrusion time and kW draw from the 7.5 kW motor (with 6 kW heating capacity). Key Parameters and Setup: Materials: Rigid: Post-consumer black PP pellets (3 mm size, used as control). Flexible: Shredded multilayer films (down to <6 mm flakes). Ratios Tested: 0-100% rigid PP blended with the remainder flexible films. Equipment: Lab-scale single-screw extruder with a vibrating feed hopper for assisted material flow. An operator monitored and gently pushed material into the screw using a wooden stick to prevent bridging. Process: Extrusion at standard melt temperatures (~180-200°C, based on PP compatibility); output formed into a flat board profile via a simple die. Results Summary: Optimal Ratio: 25% rigid PP to 75% flexible films yielded the best performance—smooth flow, least foaming, and stable motor draw (~4-5 kW peak). Challenges Observed: Higher rigid content (>50%) improved push-through of flexibles but increased energy draw and poor finish in the molded boards. Higher flexible content (>75%) caused "slippage" (material slipping on the screw without advancing), leading to inconsistent feeding and higher motor strain (up to 6.5 kW). The rigid PP acted as a "carrier" for the flexibles, enhancing shear and melt homogeneity. The resulting board showed promising rigidity for a prototype but exhibited surface irregularities from uneven flexible distribution—ideal for initial mechanical testing in upcoming runs. Initial Plasticizer Trial Observations: We've begun incorporating bio-based plasticizers to further reduce viscosity and power draw. Starting with palm oil 1.5% weight, and used motor oil 1.5% by weight. Reduced motor draw by ~15-20% (down to 4 kW in preliminary mixes). Improved melt flow, resulting in smoother extrudate with fewer defects. Next: Testing other organics like steric acid, glycol, and rice husk for compatibility and long-term stability. Used motor oil performed worse than the palm oil. mainly because the motor oil was thicker, did not mix as wll with the flake. Today we are trying this procedure: Mixing PP reccyled red pellet, 30 kilos with 500 grams of palm oil in the cement mixer. when the pellets are uniform coated we add in 250 grams of red oxide cement pigment powder and mix. this makes the pigment stick to the pellet as a sort of masterbatch coloring and the oil lubricates/compatilizes the mix. We then add the pellet at 1 part pellet to 3 parts shred fluff plastic 6mm flake size, along with additional 250 ml of oil and a additional small amount of color powder. Then we mix in the cement mixer for 5 min. The oil has virtually emiminated airborne microplastic dust.

Download files

0 downloads

Precious Plastic Community is a project by One Army.Please sponsor the work or help us build the software.