Application · Cable Compound
Cable Compound Pelletizing: PVC, XLPE & HFFR
Three cable compounds, three pelletizing answers: PVC needs air, XLPE tolerates water, HFFR needs both low shear and no water. Choosing one pelletizer for all three is how lines get rebuilt in year two. A reference cable compound pelletizing page from Kerke.
Cable Compound Pelletizing — workshop photo 1, Kerke workshop, Nanjing
Cable Compound Pelletizing — workshop photo 2, Kerke workshop, Nanjing
Cable Compound Pelletizing — workshop photo 3, Kerke workshop, Nanjing
Cable Compound Pelletizing — workshop photo 4, Kerke workshop, Nanjing
Cable Compound Pelletizing — workshop photo 5, Kerke workshop, Nanjing
Cable Compound Pelletizing — workshop photo 6, Kerke workshop, NanjingQuick answer
Cable compound pelletizing adds precision filtration (≤ 100 µm screen packs) and gentle conveying to a compounding line, so pellets are free of gels and contamination at 200–2,000 kg/h. The pelletizer and screen changer are chosen together, not separately.
Workshop photos and a running video — shot on our own lines, not stock images.
What sets the limit
Melt from the compounding stage passes a continuous screen changer, then a die and cutter with closed-loop water or air cooling; pellets are de-dusted, screened and packed.
| Parameter | Value / range |
|---|---|
| Filtration | 60–100 µm screen packs, continuous changer |
| Pelletizing | Air-cooled hot die-face / strand / underwater |
| Output | 200–2,000 kg/h |
| Pellet quality | Low dust, uniform cut, no tails |
| Model | KTE/SE series + LQ pelletizer |
| Downstream | Vibrating screen, metal detector, packing |
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 packingAir-cooled hot die-face / strand / underwater; then centrifugal dryer, vibrating screen and bagging.
Equipment configuration
| Stage | Equipment | Why this choice |
|---|---|---|
| Main machine | Pelletizing Systems: 7 Methods Compared | 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
| Method | Best for | Output range | Watch out |
|---|---|---|---|
| Water-cooled strand | Filler/colour masterbatch, engineering plastics | 100–2,000 kg/h | Floor space, strand breakage at high filler |
| Air-cooled strand | PLA, starch blends, moisture-sensitive polymers | 100–800 kg/h | Slow cooling, longer line |
| Water ring strand | PET, PA, high-temperature polymers | 300–2,000 kg/h | Water temperature control |
| Water ring hot die-face | Filler/black masterbatch, PE/PP | 200–2,000 kg/h | Die hole blockage at high filler |
| Air-cooled hot die-face | PVC, HFFR/LSZH, XLPE, WPC | 100–1,500 kg/h | Air flow uniformity, dust |
| Underwater hot die-face | TPE/TPU, hot melt, EPP, compounds needing round pellets | 200–2,000 kg/h | Water temperature and flow; die freeze-off on start-up |
| Spray drying | PET with high water carry-over, sticky products | 300–1,500 kg/h | Energy cost |
Three mistakes that cost the most
1. Screen packs that are too coarse let gels through; too fine and output collapses.
Screen packs that are too coarse let gels through; too fine and output collapses.
2. No metal detector before packing: a broken cutter blade reaches the customer.
No metal detector before packing: a broken cutter blade reaches the customer.
3. Pellet surface moisture above spec
Pellet surface moisture above spec — insulation grades absorb it into micro-voids; the fluid-bed dryer down to <0.05% is part of the line, not an option.
FAQ
What screen size for MV cable compound?
80–100 µm for medium-voltage insulation; 60 µm for jacketing is usually enough.
How often do screens need changing?
Every 2–6 hours depending on contamination; a continuous changer avoids stopping the line.
What output can you guarantee for this application?
The reference band is 200–2,000 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.
Cable compound pelletizing — the short version
Note on cable compound 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