POM Kolon Kocetal K300
POM Kolon Kocetal® K300
POM Kolon Kocetal® K300 is a general‑purpose, medium‑viscosity injection‑molding polyoxymethylene copolymer. It features balanced mechanical properties, good heat resistance, excellent wear resistance and dimensional stability for wide‑range applications。
Main Applications
Automotive industry: automotive pumps, carburetor components, fuel hoses, power valves, universal‑joint bearings, motor gears, crankshafts, handles, instrument panels, window‑lifter assemblies, electrical switches, seat‑belt buckles.
Industrial components: wear‑resistant, self‑lubricating engineering parts including gears, bearings, cams, sliders, pump housings and valves.
Electrical‑electronic: electrical components, connectors, housings, switches.
Home appliances: washing‑machine gears, coffee‑machine components.
Others: precision‑mechanical parts, toys, zippers.
Physical‑Mechanical‑Thermal‑Electrical Properties
| Property Category | Test Item | Test Standard | Test Data | Unit |
|---|---|---|---|---|
| Physical Properties | Density | ASTM D792 / ISO 1183 | 1.41 | g/cm³ |
| Water absorption (24 h, 23 °C) | ASTM D570 / ISO 62 | 0.22 | % | |
| MFR (190 °C / 2.16 kg) | ASTM D1238 / ISO 1133 | 9.0‑10.0 | g/10 min | |
| Molding shrinkage (flow direction) | ASTM D955 / ISO 294‑4 | 2.0‑2.2 | % | |
| Mechanical Properties | Tensile strength at yield (23 °C) | ASTM D638 / ISO 527‑2 | 62.0‑65.0 | MPa |
| Elongation at break (23 °C) | ASTM D638 / ISO 527‑2 | 50‑70 | % | |
| Flexural strength (23 °C) | ASTM D790 / ISO 178 | 85.0‑92.0 | MPa | |
| Flexural modulus (23 °C) | ASTM D790 / ISO 178 | 2400‑2650 | MPa | |
| Charpy notched impact strength (23 °C) | ASTM D256 / ISO 179/1eA | 7.0‑9.5 | kJ/m² | |
| Rockwell hardness (M‑scale) | ASTM D785 / ISO 2039‑2 | 78‑80 | — | |
| Thermal Properties | HDT @1.8 MPa (unannealed) | ASTM D648 / ISO 75‑2/A | 95‑110 | °C |
| HDT @0.45 MPa (unannealed) | ASTM D648 / ISO 75‑2/B | 158‑160 | °C | |
| Melting point (DSC) | DSC | 166‑167 | °C | |
| Vicat softening temperature | ASTM D1525 | To be confirmed | °C | |
| Coefficient of linear thermal expansion | ASTM D696 / ISO 11359‑2 | 11‑13×10⁻⁵ | cm/cm/°C | |
| Electrical Properties | Volume resistivity | ASTM D257 / IEC 60093 | 10¹⁴‑10¹⁶ | Ω·cm |
| Surface resistivity | ASTM D257 / IEC 60093 | 10¹³‑10¹⁶ | Ω | |
| Dielectric strength | ASTM D149 / IEC 60243‑1 | 19 | kV/mm | |
| Relative permittivity (1 MHz) | ASTM D150 | 3.7 | — | |
| Dissipation factor (1 MHz) | ASTM D150 | 0.006 | — | |
| Flammability | UL94 rating (1.5 mm) | UL 94 | HB | — |
Injection‑Molding Parameters
| Parameter | Typical Value / Range | Remarks & Instructions |
|---|---|---|
| Drying Treatment | Drying recommended. Though POM has low moisture absorption (0.22 %), moisture at high temperature causes degradation, bubbles and silver streaks. Drying improves dimensional stability. | |
| Drying temperature | 80‑90 °C | Dehumidifying dryer preferred. |
| Drying time | 3‑5 h | Keep moisture content ≤0.1 %. |
| Barrel Temperature | POM has narrow processing window. Exceeding 220 °C triggers decomposition and pungent formaldehyde gas. Avoid long residence time inside barrel. | |
| Rear zone (feed zone) | 160‑180 °C / 165‑175 °C / 180‑190 °C | Avoid excessive temperature to prevent bridging. |
| Middle zone (compression zone) | 180‑190 °C / 170‑190 °C / 190‑200 °C | Main plasticizing zone. |
| Front zone (metering zone) | 190‑200 °C / 170‑190 °C / 190‑200 °C | Close to nozzle. |
| Nozzle temperature | 190‑200 °C | Usually slightly lower than front‑zone temperature. |
| Melt temperature | ＜230 °C (target 200 °C) | Strictly below 220 °C; residence time ≤20 min to prevent thermal degradation (decomposition approx.220‑240 °C). |
| Mold temperature | 60‑80 °C | Higher mold temperature (80‑100 °C): higher crystallinity, better dimensional stability & surface gloss, longer cooling cycle. |
| Injection pressure | 49.0‑78.5 MPa (medium pressure) | High melt viscosity requires sufficient injection pressure. |
| Hold‑up pressure | 29.4‑49.0 MPa | Relatively high hold‑up pressure is required to compensate shrinkage and reduce dimensional deviation. |
| Injection speed | Medium | Too‑fast causes turbulence and burning; too‑slow causes short shots and prominent weld lines. |
| Back pressure | 0.981‑2.94 MPa | Low back‑pressure improves melt homogeneity and degassing; excessive back‑pressure induces over‑heating degradation. |
| Screw speed | Do not use high speed | Prevent shear‑heat‑caused degradation. |
| Cushion | Keep small | Avoid long melt residence time inside barrel. |
Note: All data above is for reference only.
