The extrusion production of pipes, profiles, and sheets generates significant amounts of scrap, purge material (from the die head), and defective products. Simply discarding these materials not only wastes raw resources but also increases environmental disposal costs. Recycling through professional re-granulation processes significantly lowers material costs and represents a mainstream cost-reduction strategy for plastic factories today. Drawing on extensive on-site operational experience, Benk Machinery has developed a mature and stable production process for plastic extrusion production line.

Raw Material Pre-treatment

1. Sorting and Screening

The first step involves careful sorting to distinguish between different material types—such as PVC, PE, and PP—and to remove contaminants like metal, sand, and debris. Mixing different materials is strictly prohibited, as it degrades the properties of the recycled material and causes surface defects, rendering it unsuitable for reuse.

2. Shredding and Size Reduction

Sorted scrap is fed into a shredder to be reduced to uniform fragments. The size of the flakes must be consistent to ensure smooth downstream feeding—avoiding irregular flow rates—and to lay the groundwork for stable plasticization and granulation.

Washing and Impurity Removal

Workshop scrap is often contaminated with dust and oil, requiring a comprehensive process of water washing, friction cleaning, and dewatering. Thoroughly removing impurities and oil effectively prevents issues such as black specks, yellowing, and excessive contamination in the granules, thereby significantly enhancing the purity of the recycled material.

Melt Extrusion and Granulation

1. Uniform Feeding and Plasticization

Dried flakes are fed uniformly via an automatic feeding system. The equipment plasticizes the material at low, steady speeds to prevent thermal degradation caused by excessive heat. For aged material that has undergone multiple recycling cycles, temperatures can be adjusted to ensure thorough plasticization without scorching.

2. Filtration and Screen Changing

Precision filtration is performed multiple times during granulation to capture fine impurities. Frequent screen changes and multi-stage filtration are crucial for improving granule quality; they effectively resolve issues like blackening and high impurity content, making the recycled material suitable for secondary extrusion production.

Cooling, Pelletizing, and Storage

After extrusion, the melt is cooled via water quenching and air drying. Combined with uniform-speed pelletizing equipment, the process produces granules that are consistent and well-formed, free from agglomeration (sticking together) or fines (dust/powder). Finally, seal and store the product to prevent moisture absorption, ensuring it is ready for subsequent blending with virgin material.

Conclusion

The keys to successful scrap regranulation are: clean sorting, uniform shredding, thorough impurity removal, and low-temperature plasticization. With a standardized process, recycled material can be fully utilized in extrusion production, leading to significant savings in raw material costs. Benk Machinery offers customized recycling and granulation production lines tailored to specific scrap materials and output requirements.

FAQ

Q1: Can scrap materials of different types be granulated together?

A: No. Mixing materials leads to abnormal plasticization and degraded material properties, rendering the product unusable.

Q2: What causes black specks in the recycled granules?

A: This is usually caused by residual impurities, insufficient filtration precision, or excessively high plasticization temperatures.

Q3: Does scrap material require drying during the recycling and granulation process?

A: Yes. After washing, the material must be dewatered and dried to prevent moisture retention, which could cause bubbles or voids in the granules.

Q4: Can recycled granules be used directly on the production line?

A: High-quality recycled granules can be blended with virgin material without compromising the quality of the finished product.

Q5: Does Benk Machinery offer customized recycling and granulation lines?

A: Yes. We can customize complete recycling and granulation systems based on material type and production capacity requirements.

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