POM YUNTIANHUA M90
POM YUNTIANHUA M90
POM YUNTIANHUA M90 is medium‑viscosity, standard‑flow copolymer acetal with well‑balanced overall performance. It delivers good dimensional stability, excellent comprehensive mechanical properties, wide service temperature range, outstanding chemical resistance and wear resistance, suitable for a wide range of general‑purpose mechanical parts.
Main Applications
Automotive: hood components, wheel parts, valves, exterior parts, automotive electronics. Electrical & electronic: gears, bearings and structural components for home appliances such as washing‑machine & juicer parts, timer assemblies, keyboard & switch components. Precision mechanical & industrial parts: gears, bearings, cams, screws, levers, pulleys, sprockets, pipe valves and other high‑precision, wear‑resistant, low‑friction structural components. Consumer & others: toys, sports goods and thin‑wall articles.
Physical Properties
| Property Category | Item | Test Standard | Typical Data | Unit |
|---|---|---|---|---|
| Physical Properties | Density | ISO 1183 | 1.41 | g/cm³ |
| Water absorption (23℃,24h) | ISO 62 | 0.60‑0.70 | % | |
| MFR (190℃/2.16kg) | ISO 1133 | 9.0 | g/10min | |
| Mechanical Properties | Tensile yield strength (23℃) | ISO 527‑2 | 62 | MPa |
| Elongation at break (23℃) | ISO 527‑2 | 30‑50 | % | |
| Tensile modulus (23℃) | ISO 527‑2 | 2700 | MPa | |
| Flexural strength (23℃) | ISO 178 | 61 | MPa | |
| Flexural modulus (23℃) | ISO 178 | 2400‑2600 | MPa | |
| Charpy notched impact (23℃) | ISO 179/1eA | 6.0‑7.0 | kJ/m² | |
| Izod notched impact (23℃) | ISO 180/1A | 7.5 | kJ/m² | |
| Rockwell Hardness (M‑scale) | ISO 2039‑2 | M82(R114) | — | |
| Thermal Properties | HDT (1.8 MPa) | ISO 75‑2/A | 115 | ℃ |
| Vicat A50 (10 N) | ISO 306 A50 | 163 | ℃ | |
| Vicat B50 (50 N) | ISO 306 B50 | 150 | ℃ | |
| Melting point | ISO 3146 | 172 | ℃ | |
| Linear thermal expansion coefficient | ASTM D‑696 | 11×10⁻⁵ | K⁻¹ | |
| Max continuous service temperature | — | 100 | ℃ | |
| Electrical Properties | Volume resistivity | IEC 60093 | 10¹⁵ | Ω·cm |
| Surface resistivity | IEC 60093 | 10¹⁵ | Ω | |
| Dielectric strength (20℃) | IEC 60243 | 25 | kV/mm | |
| Dielectric constant (20℃,1kHz) | IEC 60250 | 3.9 | — | |
| Dissipation factor (20℃,1MHz) | IEC 60250 | 85×10⁻⁴ | — | |
| Others | UL94 rating(0.75 mm) | UL94 | HB | — |
| Molding shrinkage‑flow (24h,4mm) | — | 2.8‑2.9 | % | |
| Molding shrinkage‑cross (24h,4mm) | — | 2.1‑2.4 | % |
Injection Molding Parameters
| Process Stage | Parameter | Recommended Range | Unit | Remarks |
|---|---|---|---|---|
| Pre‑treatment | Drying temperature | 80‑90 | ℃ | Low‑hygroscopic; drying recommended for better dimension & appearance, avoid bubbles/silver streaks; drying optional for well‑stored material |
| Drying time | 2‑4 | h | ||
| Injection | Rear zone | 160‑180 | ℃ | Narrow processing window; strictly avoid＞210‑230℃, formaldehyde gas will be generated by decomposition |
| Middle zone | 170‑200 | ℃ | ||
| Front zone | 190‑210 | ℃ | ||
| Nozzle temperature | 180‑210 | ℃ | Slightly lower or close to front zone to prevent drooling | |
| Melt temperature (POM‑C) | 190‑210 | ℃ | Do not exceed 210℃ for copolymer POM | |
| Mold temperature | 80‑105 | ℃ | Higher mold temp improves crystallization, dimensional stability, gloss & reduces sink marks; up to 120℃ for thin‑wall / long‑flow complex parts | |
| Injection pressure | 70‑120 | MPa | 120‑140 MPa for small‑gate, thin‑wall long‑flow parts | |
| Hold‑up pressure | 50‑100 | MPa | Longer hold‑time for thicker wall to reduce shrinkage | |
| Back pressure | 0.5‑2.0 | MPa | Keep low; excessive back‑pressure causes shear‑heating degradation | |
| Injection speed | Medium‑high | — | Fast for thin‑wall; slow for thick‑wall to avoid jetting | |
| Screw speed | 60‑90 | rpm | Avoid excessive shear heat | |
| Barrel residence time | ＜20‑30 | min | Short residence required; max 1 h at 190℃ | |
| Short‑term shutdown | Drop barrel temp to 150 | ℃ | Clean barrel for long‑term shutdown | |
| Barrel purging material | PE / PP | — | Do NOT use PVC or halogen‑containing polymers | |
| Post‑treatment | Annealing (optional) | 120‑130, 2‑4 | ℃‑h | For high‑precision / non‑ambient‑use parts; add ~10 min per 1 mm wall thickness |
Note: All information above is for reference only!
