POM Celanese KP20
POM Celanese KP20
POM Celanese KP20 is a copolymer resin featuring high flowability, excellent thermal stability, good chemical resistance, high rigidity and strength.
Main Applications
Automotive parts: fuel‑pump assemblies, seat‑belt mechanical components. Industrial parts: wear‑resistant and self‑lubricating components such as bearings, gears, pump and valve parts. Consumer goods: luggage handles & locking systems, furniture fittings (supports, drawer sliders), zippers.
Physical‑Mechanical‑Thermal Properties
| Property Category | Test Item | Data | Test Standard |
|---|---|---|---|
| Physical Properties | Density | 1.41 g/cm³ | ISO 1183 |
| Melt volume‑flow rate (MVR) | 8.0 cm³/10min | ISO 1133 | |
| MVR test temperature | 190 °C | ISO 1133 | |
| Mechanical Properties | Tensile modulus | 2600 MPa | ISO 527‑2/1A |
| Tensile strength at yield | 64 MPa | ISO 527‑2/1A | |
| Flexural modulus (23 °C) | 2450 MPa | ISO 178 | |
| Charpy notched impact strength (23 °C) | 5.8 kJ/m² | ISO 179/1eA | |
| Thermal Properties | HDT @1.8 MPa | 100 °C | ISO 75‑1/-2 |
Injection‑Molding Parameters
| Parameter | Typical Value / Range | Remarks & Instructions |
|---|---|---|
| Drying Treatment | Drying is recommended; moisture will cause degradation under high‑temperature conditions. | |
| Drying temperature | 80‑100 °C | Dehumidifying dryer is recommended. |
| Drying time | 2‑4 h | Material bed thickness ≤30 mm to guarantee uniform drying. |
| Barrel Temperature | POM has a narrow processing temperature window. Temperature shall never exceed 220 °C; otherwise irritating formaldehyde gas will be generated. Material residence time inside barrel shall not exceed 20 minutes. | |
| Rear zone (feed zone) | 150‑170 °C | Near feed throat. Avoid excessive temperature to prevent bridging. |
| Middle zone (compression zone) | 170‑190 °C | Main plasticizing zone; keep temperature uniform. |
| Front zone (metering zone) | 180‑200 °C | Close to nozzle. Over‑temperature will trigger POM degradation. |
| Nozzle temperature | 170‑190 °C | Usually slightly lower than front‑zone temperature to prevent drooling. |
| Melt temperature | ~180‑205 °C | Must not exceed 220 °C. Avoid high temperature and long residence time to prevent POM degradation (decomposition temperature approx. 220‑240 °C). |
| Mold temperature | 40‑80 °C (or 80‑90 °C) | High mold temperature delivers uniform crystallization and good toughness with longer cooling cycle; low mold temperature leads to poor surface gloss and high residual stress. |
| Injection pressure | 80‑150 MPa | Adjust according to wall thickness and fluidity; 120‑150 MPa for thin‑wall parts, 80‑120 MPa for thick‑wall parts. |
| Injection speed | Medium‑to‑high (30‑80 mm/s) | Excessively fast speed brings turbulence and burning; too‑slow speed causes short shots and prominent weld lines. Multi‑stage speed control is suggested. |
| Hold‑up pressure | 50‑70 % of injection pressure | Compensates POM shrinkage, reduces sink marks and dimensional deviation. |
| Hold‑up time | 5‑15 s | Adjust according to part wall thickness. |
| Back pressure | 0.5‑2.0 MPa | Low back‑pressure improves melt homogeneity and degassing; excessive back‑pressure results in overheating and degradation. |
| Screw speed | 30‑80 rpm | Avoid excessive rotational speed to prevent shear‑heat‑induced degradation. |
| Cooling time | 10‑30 s | Adjust according to part thickness and mold temperature to ensure full cooling and anti‑deformation upon ejection. |
Note: All data above is for reference only.
