POM YUNTIANHUA GF‑25
POM YUNTIANHUA GF‑25
POM YUNTIANHUA GF‑25 is 25 % glass‑fiber‑reinforced copolymer acetal. It delivers high stiffness, elevated heat‑deflection temperature, excellent dimensional stability and low molding shrinkage.
Main Applications
Automotive: engineering & industrial fittings, automotive components (under‑hood parts, valve parts, accelerator pedal etc.). Precision mechanical & industrial parts: high‑stiffness gears, bearings, cams, conveyor components requiring high‑precision, wear‑resistance and low‑friction. Consumer & others: furniture structural parts.
Physical Properties
| Property Category | Item | Test Standard | Typical Data | Unit |
|---|---|---|---|---|
| Physical Properties | Density | ISO 1183 | 1.60 | g/cm³ |
| Water absorption (23℃,24h) | ISO 62 | 0.60 | % | |
| MFR (190℃/2.16kg) | ISO 1133 | 6.0 | g/10min | |
| Mechanical Properties | Tensile yield strength (23℃) | ISO 527‑2 | 130 | MPa |
| Elongation at break (23℃) | ISO 527‑2 | 2.5 | % | |
| Tensile modulus (23℃) | ISO 527‑2 | 8000 | MPa | |
| Flexural strength (23℃) | ISO 178 | 180 | MPa | |
| Flexural modulus (23℃) | ISO 178 | 7500 | MPa | |
| Charpy notched impact (23℃) | ISO 179/1eA | 7.0 | kJ/m² | |
| Thermal Properties | HDT (1.8 MPa) | ISO 75‑2/A | 160 | ℃ |
| Others | UL94 rating | UL94 | HB | — |
Injection Molding Parameters
| Process Stage | Parameter | Recommended Range | Unit | Remarks |
|---|---|---|---|---|
| Pre‑treatment | Drying temperature | 100‑120 | ℃ | Drying recommended for better dimension & appearance, avoid bubbles/silver streaks |
| Drying time | 2‑4 | h | ||
| Injection | Rear zone | 160‑180 | ℃ | Narrow processing window; strictly avoid＞230℃, formaldehyde gas will be generated by decomposition |
| Middle zone | 170‑200 | ℃ | ||
| Front zone | 180‑210 | ℃ | ||
| Nozzle temperature | 180‑210 | ℃ | Slightly lower or close to front zone to prevent drooling | |
| Melt temperature | 190‑210 | ℃ | ||
| Mold temperature | 60‑90 | ℃ | Higher mold temp improves crystallization, dimensional stability, gloss & reduces sink marks | |
| Injection pressure | Adjust by part geometry & wall thickness | — | ||
| Hold‑up pressure | Proper hold‑pressure to reduce sink marks | — | ||
| Back pressure | Keep low | — | Excessive back‑pressure causes shear‑heating degradation | |
| Injection speed | Optimize according to product | — | Slow speed causes ripple; excessive speed brings jet mark & shear degradation | |
| Screw speed | Keep moderate | rpm | Avoid excessive shear heat leading to material decomposition | |
| Barrel residence time | ＜20‑30 | min | Short residence required to prevent decomposition | |
| Short‑term shutdown | Drop barrel temp to 150 | ℃ | Purge barrel thoroughly for long‑term shutdown | |
| Barrel purging material | PE / PP | — | Must purge with PE/PP after halogen‑containing polymers to prevent violent reaction | |
| Post‑treatment | Annealing (optional) | For high‑quality non‑ambient‑use parts | — | To release internal stress |
Note: All information above is for reference only!
