Shredding and Recycling Rigid Plastics

WEIMA shredders can process nearly all common rigid plastics found in bins, crates, pipes, profiles, technical parts, and housings. Typical materials include PE, HDPE, PP, PS, PET, PA, PC, ABS, and PVC, each of which responds well to a correctly configured single-shaft shredder. On this page you’ll see PVC and vinyl shredded on a WLK 4, as well as HDPE bins processed on a PowerLine 2500. Knife style, rotor geometry, and screen size should always match your polymer mix and required flake size.

For high volumes of HDPE, a robust single-shaft shredder like the PowerLine 2500 or a WLK model with the right screen is a strong choice. These machines deliver stable torque and consistent flake quality, even with bulky or tough material. Hydraulic drives can be beneficial when load conditions vary significantly. The page highlights PowerLine 2500 running post-consumer HDPE bins and the WLK 1500 improving storage and transport efficiency for mixed rigid plastics. Match your screen size, infeed conveyor, and metal separation to your washing and extrusion requirements for a stable line.

It is not necessary for the material to be perfectly clean. WEIMA shredders are engineered to process moderately contaminated plastics and can reliably handle the typical dirt, dust, and surface residues found in both post-consumer and post-industrial streams. Nevertheless, removing stones, large metal parts, and other heavy contaminants is recommended to protect critical components such as knives, screens, and bearings. After shredding, established washing and separation processes remove remaining dirt, labels, and fines to prepare the flakes for further processing. Proper pre-sorting not only extends the service life of wear parts but also ensures stable throughput and consistent output quality.

Maintenance frequency depends on material type and contamination levels, but regular checks are essential. Perform quick visual inspections every shift and schedule weekly knife and screen reviews. Abrasive materials or dirtier input streams may require more frequent knife rotations. WEIMA shredders use heavy frames and wear protection to extend component life, but a simple maintenance plan and readily available spare parts ensure consistently high uptime.

Shredded material is typically washed, separated, and then pelletized into regranulate for reuse. A standard process sends flakes from the shredder to a wash plant, then uses density separation (e.g., sink-float) and metal separation to clean and sort the polymers. Once contaminants are removed, clean flakes move to an extruder where they are melted and pelletized. These pellets can then be reused for new products, including rigid packaging, bins, and technical parts. Properly configured sink-float systems achieve high polymer recovery rates.

The screen determines how coarse or fine your flakes will be. Smaller holes create finer flakes but reduce throughput, while larger holes increase capacity but produce coarser output. Choose a screen that supports your washing efficiency, extrusion stability, and end-product specifications. Finer flakes often wash and melt more uniformly, while coarser flakes may be perfectly adequate for many rigid plastic applications. Test runs with your actual material mix help identify the optimal size.

Shredding significantly reduces volume and produces uniform flakes that are easier to store, bale, silo, or load into big bags. A consistent flake size also stabilizes downstream processes like washing and extrusion. The WLK 1500 shown on this page demonstrates how size reduction can improve handling efficiency across the value chain. Uniform material flow helps minimize bottlenecks and reduces logistical effort.