POM KEPITAL F20‑03
POM KEPITAL® F20‑03 (Korea Engineering Plastics)
POM KEPITAL® F20‑03 is a general‑purpose injection‑molding polyoxymethylene copolymer. It is widely adopted in multiple fields for good wear resistance, dimensional stability and balanced comprehensive mechanical properties.
Main Applications
Automotive industry: automotive components such as gears, bearings, transmission parts, fuel‑system parts, door‑lock assemblies and seat‑belt components.
Electrical‑electronic: electrical components, connectors, housings, switches.
Industrial components: wear‑resistant self‑lubricating engineering parts including gears, bearings, cams, sliders, pump housings and valves.
Home appliances: washing‑machine gears, coffee‑machine components, spray‑device parts.
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,60%RH) | ASTM D570 | 0.22 | % | |
| MFR (190 °C / 2.16 kg) | ASTM D1238 / ISO 1133 | 9.0 | g/10 min | |
| Molding shrinkage (flow direction) | ASTM D955 / ISO 294‑4 | 2.0 | % | |
| Mechanical Properties | Tensile strength at yield (23 °C) | ASTM D638 / ISO 527‑2 | 62.3 | MPa |
| Elongation at break (23 °C) | ASTM D638 / ISO 527‑2 | 50‑60 | % | |
| Flexural strength (23 °C) | ASTM D790 / ISO 178 | 91.2 | MPa | |
| Flexural modulus (23 °C) | ASTM D790 / ISO 178 | 2620 | MPa | |
| Charpy notched impact strength (23 °C) | ASTM D256 / ISO 179/1eA | 6.5 | kJ/m² | |
| Rockwell hardness (M‑scale) | ASTM D785 | 80 | — | |
| Tear strength | ASTM D732 | 54.9 | MPa | |
| Thermal Properties | HDT @1.8 MPa (unannealed) | ASTM D648 / ISO 75‑2/A | 100‑110 | °C |
| HDT @0.45 MPa (unannealed) | ASTM D648 / ISO 75‑2/B | 158 | °C | |
| Melting point (DSC,10 °C/min) | DSC | 165 | °C | |
| Vicat softening temperature | ASTM D1525 | To be confirmed | °C | |
| Coefficient of linear thermal expansion (20‑80 °C) | ASTM D696 | 1.3×10⁻⁴ | cm/cm/°C | |
| Electrical Properties | Volume resistivity | ASTM D257 / IEC 60093 | 1×10¹⁴ | Ω·cm |
| Surface resistivity | ASTM D257 / IEC 60093 | 1×10¹⁶ | Ω | |
| Dielectric strength | ASTM D149 / IEC 60243‑1 | 19 | kV/mm | |
| Relative permittivity (1 MHz) | ASTM D150 | 3.3 | — | |
| Dissipation factor (1 MHz) | ASTM D150 | 0.007 | — | |
| Flammability | UL94 rating (0.75 mm) | UL 94 | HB | — |
Injection‑Molding Parameters
| Parameter | Typical Value / Range | Remarks & Instructions |
|---|---|---|
| Drying Treatment | Drying is recommended. Although POM has low moisture absorption (0.22 %), moisture at high temperature will cause thermal degradation, bubbles and silver streaks. | |
| Drying temperature | 80‑100 °C | |
| Drying time | 2‑4 h | Keep moisture content ≤0.1‑0.2 %. Material bed thickness ≤30 mm for uniform drying. |
| Barrel Temperature | ||
| Rear zone (feed zone) | 150‑170 °C | Avoid over‑temperature to prevent bridging. |
| Middle zone (compression zone) | 170‑190 °C | Main plasticizing zone; keep uniform temperature. |
| Front zone (metering zone) | 180‑200 °C | Close to nozzle. Excess temperature triggers POM degradation. Alternative reference:180‑210 °C. |
| Nozzle temperature | 170‑190 °C | Usually slightly lower than front‑zone temperature to prevent drooling. |
| Melt temperature | ~180‑205 °C | Avoid high temperature and long residence time (≤20 min). Decomposition temperature approx.220‑240 °C. |
| Mold temperature | 40‑80 °C (60‑80 °C preferred) | Higher mold temperature (80‑120 °C): higher crystallinity, better dimensional stability & surface gloss, longer cooling cycle. Lower mold temperature (40‑60 °C): fast cycle, risk of incomplete crystallization, larger shrinkage and residual stress. |
| Injection pressure | 80‑120 MPa | Adjust by wall‑thickness;120‑150 MPa for thin‑wall parts,80‑120 MPa for thick‑wall parts. |
| Injection speed | Medium (30‑80 mm/s) | Medium‑to‑high speed. Too‑fast causes turbulence & burning; too‑slow causes short shots & obvious weld‑lines. Multi‑stage speed: low speed for runner filling, medium‑high speed for cavity filling. |
| Hold‑up pressure | 50‑70 % of injection pressure | Compensate POM shrinkage, reduce 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 & degassing; excessive back‑pressure leads to over‑heat degradation. |
| Screw speed | 30‑80 rpm | Avoid high rotational speed to prevent shear‑heat degradation. |
| Cooling time | 10‑30 s | Adjust by part thickness and mold temperature to guarantee full cooling and deformation‑free ejection. |
Note: All data above is for reference only.
