Application · Plastic Modification
MAH Grafted PP/PE: Continuous Melt Grafting
Maleic anhydride grafting is a reaction with a narrow window: below 190 °C the initiator never breaks down, above 230 °C the graft level falls as fast as it rose. A reference mah grafted pp page from Kerke.
Quick answer
MAH grafting (MAH-g-PP, MAH-g-PE, compatibilizers) runs as continuous reactive extrusion at 190–220 °C with L/D 48–52, multi-stage vacuum devolatilization and a strand or underwater pelletizer. Output 100–800 kg/h. Residual maleic anhydride and peroxide dosing accuracy decide product quality.
Workshop photos and a running video — shot on our own lines, not stock images.
What sets the limit
Resin, MAH and initiator are metered separately, melted and reacted in dedicated kneading blocks, then devolatilized twice to strip unreacted monomer before pelletizing.
| Parameter | Value / range |
|---|---|
| Reaction temperature | 190–220 °C |
| L/D | 48–52 |
| Devolatilization | 2-stage vacuum, < -0.09 MPa |
| Output (reference) | 100–800 kg/h |
| Pelletizing | Strand (preferred) or underwater |
| 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 (preferred) 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. Insufficient devolatilization
Insufficient devolatilization — residual MAH smells and fails the customer's VOC spec.
2. Peroxide fed by a volumetric pump: dosing drift changes grafting degree batch to batch.
Peroxide fed by a volumetric pump: dosing drift changes grafting degree batch to batch.
3. Residence time left uncontrolled
Residence time left uncontrolled — grafting peaks in a narrow window, and over-long mixing drops the graft degree while gelling the melt; reactive duty wants 52–60D with two vents.
FAQ
What grafting degree is achievable?
0.8–1.2% for MAH-g-PP is routine. Above 1.5% the melt viscosity and yellowing become hard to control.
Do I need explosion-proof design?
For MAH powder handling, yes — the feeding area requires dust-rated electrical equipment depending on local regulation.
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.
MAH grafted pp — the short version
Note on mah grafted pp: 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






