POM Loyocon MC90
POM Loyocon® MC90 (Kailong Longyu Chemical)
POM Loyocon® MC90 is an injection‑molding copolymer polyoxymethylene with well‑balanced comprehensive properties. It is widely applied in multiple fields for favorable mechanical strength, excellent wear resistance and dimensional stability.
Main Applications
Automotive industry: thrust‑rod ball seats, speedometer parts, driven gears, valves, fuel‑system components (fuel filters, fuel tank caps, fuel‑pump grooves, fuel‑filling assemblies, fuel‑tank flanges, connectors), oil‑delivery‑system parts, radiator water‑valve assemblies, radiator housing covers, coolant expansion tanks, water‑valve bodies, water‑pump impellers, carburetor housings, door handles, window‑crank arms, seat‑belt buckles, fasteners and other automotive fittings.
Industrial components: wear‑resistant, self‑lubricating engineering parts such as gears, bearings, cams, sliders, pump housings and valves; also suitable for springs, snap‑fits and knobs.
Electrical‑electronic: various switches, switch buttons, electrical components, speaker grilles, regulator handles.
Home appliances: household‑appliance parts including washing‑machine gears and coffee‑machine components.
Physical‑Mechanical‑Thermal Properties
| Property Category | Test Item | Test Standard | Test Data | Unit |
|---|---|---|---|---|
| Physical Properties | Density | ISO 1183 | 1.41 | g/cm³ |
| Water absorption (24 h) | ISO 62 | 0.22‑0.25 | % | |
| MFR (190 °C / 2.16 kg) | ISO 1133 | 7.8‑9.0 (9±1) | g/10 min | |
| Molding shrinkage (flow direction) | — | 1.8‑2.2 | % | |
| Mechanical Properties | Tensile strength at yield | ISO 527‑2 | 62.0‑62.6 | MPa |
| Elongation at break | ISO 527‑2 | 35‑45 (40‑45) | % | |
| Flexural strength | ISO 178 | 85.0‑88.0 (87‑88) | MPa | |
| Flexural modulus | ISO 178 | 2350‑2700 | MPa | |
| Charpy notched impact strength (23 °C) | ISO 179/1eA | 5.6‑6.4 (6.5) | kJ/m² | |
| Rockwell hardness (M‑scale) | ASTM D785 | 75‑80 | — | |
| Thermal Properties | HDT @1.8 MPa | ISO 75‑2 | To be confirmed (typical POM:90‑110) | °C |
| Melting point (DSC) | DSC | To be confirmed (copolymer POM:162‑173) | °C | |
| Other Properties | Color b‑value | — | ≤1.5‑≤2.0 | — |
| Thermal stability | — | ≤0.03 | %/min |
Injection‑Molding Parameters
| Parameter | Typical Value / Range | Remarks & Instructions |
|---|---|---|
| Drying Treatment | Although POM has low moisture absorption (0.22‑0.25 %), drying is recommended. Moisture under high‑temperature conditions will cause degradation, bubbles and silver streaks, and improves dimensional stability. | |
| Drying temperature | 80‑100 °C | Dehumidifying dryer is preferred. |
| Drying time | 2‑4 h | Ensure moisture content ＜0.2 %. Material bed thickness ≤30 mm for uniform drying. |
| Barrel Temperature | POM has a narrow processing window (0‑215 °C). Temperature shall never exceed 220 °C; otherwise pungent formaldehyde gas will be generated. Material residence time inside barrel shall not exceed 20 minutes. | |
| Rear zone (feed zone) | 150‑170 °C or 165‑175 °C | Near feed throat. Avoid over‑temperature to prevent bridging. |
| Middle zone (compression zone) | 170‑190 °C or 190‑200 °C | Main plasticizing zone; keep uniform temperature. |
| Front zone (metering zone) | 180‑200 °C or 190‑200 °C | Close to nozzle. Excess temperature causes 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 60‑80 °C | Higher mold temperature (80‑100 °C): higher crystallinity, better dimensional stability and surface gloss, longer cooling cycle. Lower mold temperature (40‑60 °C): fast cycle, incomplete crystallization, larger shrinkage risk and residual‑stress risk. |
| Injection pressure | 80‑150 MPa | Adjust by wall thickness and fluidity; 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 and burning; too‑slow causes short shots and prominent weld lines. Multi‑stage speed recommended: low speed for runner filling, medium‑high speed for cavity filling. |
| 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.
