The screw is the heart of the plastic recycling granulator machine, and its design directly determines the plasticizing effect, output, energy consumption, and melt quality.

Unlike processing virgin materials, recycled materials are characterized by complex composition, varying viscosities, and the presence of impurities and volatiles. Therefore, screws dedicated to recycling must be specially designed:

1. High Compression Ratio: Recycled materials are typically less dense and more fluffy, requiring a higher compression ratio (generally between 2.5:1 and 4:1) for effective compaction, degassing, and plasticization.

2. Efficient Mixing Section: Recycled materials often consist of mixed types or colors of plastics, requiring intensive mixing to ensure melt uniformity. Barrier screws, pin-type screws, or the inclusion of dedicated mixing elements are commonly used.

3. Reinforced Feeding Section:Recycled flakes have poor flowability and are prone to “bridging” at the feed throat. Therefore, the feed section typically features deeper flights and a larger pitch design to enhance material grabbing and conveying capabilities.

4. Venting and Devolatilization Design: Recycled materials release significant amounts of moisture and low-molecular volatiles (such as residual adhesive from labels or degradation by-products) during processing. Two-stage vented screws or barrels equipped with venting ports connected to vacuum pumps are common solutions, effectively removing these gases and preventing bubbles or voids in the pellets.

Why Choose Purui Machinery:

With over 25+ years of expertise and a footprint in over 100 countries, Purui Machinery continues to lead the way in plastic regeneration.

Purui Machinery is a high-tech enterprise specializing in the R&D and manufacturing of plastic recycling machinery. Its product portfolio includes plastic pelletizing lines, washing lines, and crushing equipment. Purui is dedicated to providing global customers with the most efficient, reliable, and intelligent plastic regeneration systems.

Contact Us to Get Your Customized Recycling Solution:

E-mail: [email protected]

Tel / Whatsapp: +8617701563079

Partner with Purui Machinery - Turn your plastic waste into premium-grade sustainable profits.