Application · Recycling & PET
Recycled Plastic Pelletizing: Film, Bottle Flakes & Regrind
Recycling output is decided at the feeder, not at the screw. Film needs forced feeding and pre-compaction; the same extruder may deliver only 40% of its pellet capacity on loose film. A reference recycled plastic pelletizing page from Kerke.
Quick answer
Waste plastic recycling covers PE/PP film, woven bags and rigid scrap on single-screw or two-stage SE/SE lines with forced feeding, two-stage venting and 100–2,000 kg/h output. The right configuration depends on bulk density and contamination, not on the resin alone.
Workshop photos and a running video — shot on our own lines, not stock images.
What sets the limit
Scrap is shredded, compacted and forced into the extruder, melted, filtered (40–80 µm depending on product), devolatilized and pelletized. Washing and drying upstream determine whether the pellets are saleable.
| Parameter | Value / range |
|---|---|
| Feed types | PE/PP film, woven bag, rigid scrap, lumps |
| Feeding | Forced feeder / compactor |
| Venting | 2-stage vacuum or atmospheric |
| Output | 100–2,000 kg/h |
| Pelletizing | Strand, water ring, or die-face hot cut |
| Model | SE-120/SE-150, SE/KTE two-stage |
Output figures are measured on the reference material stated above. Filler grade, bulk density and moisture move output by ±15% — that is why every quotation we issue is tied to a trial report.
Process flow, step by step
- FeedingLoss-in-weight dosing of polymer and filler; side feeder or liquid injection where the formulation needs it.
- Melting and dispersingScrew geometry with 45°/90° kneading blocks; barrel profile set by the polymer.
- DevolatilizationVacuum vent at −0.06 to −0.09 MPa removes moisture and volatiles before the die.
- Pressure build-upThrottle or discharge section stabilises die pressure; a melt pump where gauge control matters.
- Pelletizing and packingStrand, water ring, or die-face hot cut; then centrifugal dryer, vibrating screen and bagging.
Equipment configuration
| Stage | Equipment | Why this choice |
|---|---|---|
| Main machine | Two-Stage Single Screw Line SE/SE | Architecture follows the filling level and the mixing duty, not the required tonnage. |
| Screw geometry | Building-block elements, W6Mo5Cr4V2, bimetallic liner | Wear package for abrasive filler; mixing blocks only where dispersion demands them. |
| Feeding | Loss-in-weight feeder, side feeder where needed | Recipe accuracy: ±0.5% short term on the weighed component. |
| Pelletizing | Pelletizing system | Chosen by polymer and filler ceiling — water contact is the deciding column. |
| Downstream | Centrifugal dryer, vibrating screen, bagging | Fines below 2% and moisture below the specification of your downstream process. |
Output by model
| Configuration | Stage 1 | Stage 2 | Output (kg/h) | Feed |
|---|---|---|---|---|
| SE-120 / SE-120 | 120 mm | 120 mm | 200–400 | Film, bag, rigid regrind |
| SE-150 / SE-150 | 150 mm | 150 mm | 400–800 | Film, woven bag |
| SE-180 / SE-180 | 180 mm | 180 mm | 800–2,000 | Woven bag, heavy film |
Three mistakes that cost the most
1. Buying the pelletizing line before solving washing: moisture above 1% gives porous, smelly
Buying the pelletizing line before solving washing: moisture above 1% gives porous, smelly pellets.
2. Undersized filtration: screen changes every 20 minutes stop the line more than they improv
Undersized filtration: screen changes every 20 minutes stop the line more than they improve quality.
3. Single vent on printed film
Single vent on printed film — inks and moisture need two-stage degassing on a 44D line; one vent leaves smell and voids in every pellet.
FAQ
Single screw or two-stage for film?
Two-stage with a compactor for film and woven bag (bulk density below 150 kg/m³); single screw is enough for rigid regrind.
What filtration is realistic?
80–100 µm for construction film and bags; 40–60 µm for injection-grade regrind.
Can you include the washing line?
Yes — 500 kg/h and 1,000 kg/h crushing-and-washing lines are quoted as a package with the pelletizing line.
What output can you guarantee for this application?
The reference band is 100–2,000 kg/h, measured on the stated material. We quote a guaranteed figure only after a trial on your own material, because filler grade, bulk density and moisture move output by ±15%.
Can we run our material before ordering?
Yes — send 25–50 kg. We return pellets, a running video and a report with temperatures, screw speed, feeder settings and output per hour. The trial is free; you cover the freight.
What is the delivery time?
30–45 working days for standard configurations, 45–70 for custom screw geometry and ODM work. Voltage and frequency are built for the destination country.
Where these numbers come from
Parameters are taken from the Kerke product parameter table and the product master data sheet, and cross-checked against commissioning records for lines in the same application. Formulations and temperature windows are typical industry values, not a recommendation for your specific compound — every figure marked reference must be confirmed on a material trial before it becomes a contractual number.
Reviewed by the Kerke process team, Nanjing. Page updated 6 November 2026.
Send 25–50 kg and we run it on our lab extruder: pellets, running video and a capacity report back in 3–7 days.
Recycled plastic pelletizing — the short version
Note on recycled plastic pelletizing: the numbers above are reference ranges from Kerke's own trial runs, not catalogue promises. Screw geometry, wear package and pelletizing method are set on the trial bench first, so the output you compare is the output you get. If your grade is not in the tables, send it — the closest configuration is usually a change of screw set, not a different machine.
Related on this site: Machine range: KTE-50B to 135D · Pelletizing methods compared · quotation and free trial · Wikipedia: Masterbatch






