Application · Plastic Masterbatch
Functional Masterbatch Line: Antistatic, Antibacterial & Flame Retardant
Functional masterbatch is a temperature-control problem, not a shear problem. Every active ingredient has a ceiling — brominated flame retardants below 220 °C, silver antibacterial below 230 °C — and the line must hold it. A reference functional masterbatch line page from Kerke.
Quick answer
Functional masterbatch (antistatic, antibacterial, flame retardant, UV, anti-block) runs at 10–60% active content on a twin screw with L/D 40–48 and tight temperature control (±2 °C). Output 100–800 kg/h. Additive heat sensitivity sets the temperature ceiling, not the polymer.
Workshop photos and a running video — shot on our own lines, not stock images.
What sets the limit
Multiple additives are metered by separate gravimetric feeders, mixed under low shear, and pelletized without exceeding the additive decomposition temperature. Barrel zoning is set from the additive TGA curve, not from the carrier resin.
| Parameter | Value / range |
|---|---|
| Active content | 10–60% depending on additive |
| L/D | 40–48 |
| Temperature control | ±2 °C, low-shear mixing for heat-sensitive additives |
| Pelletizing | Strand or underwater |
| Output (reference) | 100–800 kg/h |
| Model | KTE-50B, KTE-65B |
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 or underwater; then centrifugal dryer, vibrating screen and bagging.
Equipment configuration
| Stage | Equipment | Why this choice |
|---|---|---|
| Main machine | Co-Rotating Twin Screw Extruder | 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
| Model | Dia. (mm) | Speed (rpm) | Motor (kW) | Torque (N·m) | Output (kg/h) |
|---|---|---|---|---|---|
| KTE-50B | 50.5 | 500–600 | 55–75 | 2×525 | 80–200 |
| KTE-50D | 50.5 | 300–800 | 75–90 | 2×860 | 100–300 |
| KTE-52B | 51.4 | 500–600 | 55–75 | 2×720 | 80–200 |
| KTE-52D | 51.4 | 500–600 | 75–110 | 2×1050 | 100–400 |
| KTE-65B | 62.4 | 500–600 | 90–110 | 2×860 | 200–450 |
| KTE-65D | 62.4 | 300–800 | 132–160 | 2×1530 | 350–600 |
| KTE-75B | 71 | 500–600 | 132–160 | 2×1530 | 300–800 |
| KTE-75D | 71 | 300–800 | 200–315 | 2×2100 | 500–1000 |
| KTE-85B | 85 | 500–600 | 220–315 | 2×2100 | 550–1000 |
| KTE-95B | 93 | 500–600 | 250–315 | 2×3000 | 800–1500 |
| KTE-95D | 93 | 500–800 | 315–500 | 2×4800 | 1000–2000 |
| KTE-135B | 135 | 500–600 | 315–500 | 2×4800 | 1500–3000 |
| KTE-135D | 135 | 500–800 | 500–1000 | 2×7800 | 1500–4000 |
Three mistakes that cost the most
1. Quoting a line before the additive TGA is known
Quoting a line before the additive TGA is known — flame retardants decompose within a 15 °C window.
2. Single feeder for four additives: ratio drift shows up as batch-to-batch flame test failur
Single feeder for four additives: ratio drift shows up as batch-to-batch flame test failures.
3. Liquid additives injected at the wrong barrel position
Liquid additives injected at the wrong barrel position — inject after the filler is wetted and before the vent, or the vacuum pulls your most expensive ingredient straight out of the melt.
FAQ
Can you run 5 additives on one line?
Yes, with 5 gravimetric feeders and a recipe-controlled control system. That is the normal configuration for FR masterbatch.
What temperature accuracy is realistic?
±2 °C on barrel zones with PID control and a properly sized heater band; ±5 °C is what most budget machines deliver.
What output can you guarantee for this application?
The reference band is 100–800 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.
Functional masterbatch line — the short version
Note on functional masterbatch line: 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






