Recycled plastic offers significant cost advantages and is currently the primary method for extrusion plants to reduce costs. However, recycled materials often suffer from inconsistent composition, high impurity levels, and poor flow characteristics, differing vastly from virgin resins. Directly applying processing parameters designed for virgin material often leads to issues such as poor plasticization, unstable output, surface black specks, and product brittleness. Drawing on extensive experience in production and commissioning with recycled materials, Benk Machinery has compiled a set of practical guidelines for recycled material production line to help factories achieve stable mass production and reduce scrap rates.

Pre-processing and Sorting of Recycled Materials

1. Sorting and Contaminant Removal

Recycled materials of different types or varying degrees of degradation must never be mixed during production. Mixing in dissimilar plastics, rubber, or off-colored waste directly leads to extrusion failure and degraded product performance. Strict sorting is required prior to production to ensure that each type of recycled material is processed separately.

2. Shredding, Washing, and Impurity Removal

Recycled materials often have surface dust, oil, and residual moisture; they require shredding, friction washing, and dehydration/drying. Processing untreated, contaminated material frequently results in pinholes, black specks, and rough surfaces—the primary causes of high defect rates in recycled products.

Adjustment of Extrusion Process Parameters

Recycled materials have undergone multiple high-temperature processing cycles, resulting in degraded molecular properties and unstable flow characteristics. Extrusion temperatures should be lowered appropriately to prevent excessive material decomposition, yellowing, and brittleness. Simultaneously, screw shear speeds should be reduced; employing a low-speed, gentle plasticization mode prevents accelerated material aging and ensures a uniform, stable melt.

Filtration System Upgrades

Recycled materials contain far more impurities than virgin resins, making standard filter screens inadequate for production needs. Production requires more frequent screen changes and the use of multi-stage filtration structures to effectively capture fine impurities and charred particles. This effectively eliminates surface defects and significantly improves the surface finish of the recycled product.

Equipment and Production Line Optimization

Standard equipment designed for virgin resin often experiences unstable output and rapid screw wear when used for long-term recycled material production. To address the specific characteristics of recycled materials, Benk Machinery optimizes the screw and barrel structures of its extrusion equipment. These enhancements improve feed stability and wear resistance, enabling the continuous processing of highly filled and impurity-laden recycled materials.

Conclusion

The key to stable production in recycled material extrusion lies in thorough initial impurity removal, the use of low-temperature processing parameters, and precise filtration. By avoiding the blind application of parameters used for virgin materials and instead tailoring production strategies to the specific material, manufacturers can effectively enhance the quality of recycled products. Benk Machinery offers specialized extrusion lines for recycled materials, process optimization and commissioning, and equipment upgrade services.

FAQ

Q1: Why do recycled materials tend to yellow and become brittle during extrusion?

A: Recycled materials are inherently prone to degradation; excessive extrusion temperatures or shear forces accelerate material breakdown.

Q2: Is drying necessary when processing recycled materials?

A: Yes, drying is essential to remove moisture and prevent defects such as bubbles or pinholes in pipes and profiles.

Q3: What issues arise from mixed-material production?

A: Uneven plasticization and unstable molding can occur, making products highly susceptible to deformation, cracking, and quality degradation.

Q4: How can black spots on the surface of recycled products be minimized?

A: This can be improved by enhancing initial cleaning and impurity removal, as well as increasing filtration stages and screen-changing frequency.

Q5: Does Benk Machinery offer specialized extrusion equipment for recycled materials?

A: Yes, we provide complete, specialized extrusion line solutions tailored to various types of plastic recyclates.

Why Choose Benk Machinery?

From individual machines to complete production lines, Benk Machinery provides reliable and customized plastic processing solutions. Since 2012, we have focused on plastic extrusion, nergy-saving plastic recycling machine, and automated compounding centralized feeding systems, helping customers build efficient and cost-effective production facilities.

• Complete Extrusion Solutions: Professional expertise in plastic pipe, profile, sheet, plate and board extrusion lines.
• Customized Project Solutions: Equipment and production lines can be configured according to your materials, products, capacity and factory requirements.
• Stable & Cost-Effective Equipment: Reliable machine performance, efficient production and optimized energy consumption help reduce operating costs.
• Professional Service: From technical consultation and production to installation, commissioning and after-sales support, our team provides complete project assistance.

Contact Benk Machinery:

PPlanning to upgrade your factory? Contact Benk Machinery for a customized project solution.

• Email: [email protected]
• Tel / WhatsApp: +8615950962426