PMMA Sumitomo Chemical MH
PMMA Sumitomo Chemical MH
PMMA Sumitomo Chemical MH is general‑purpose polymethyl methacrylate with good heat‑resistance and outstanding optical performance. It also features favorable mechanical properties, excellent electrical insulation and dimensional stability.
Main Applications
Automotive industry: indicator lamp & taillight housings, instrument housings, rear decorative panels, instrument display screens.
Optics & lighting: sunglass lenses, optical lenses, lamp covers, diffusion panels.
Electrical & electronics: transparent insulating components.
Sheets & profiles: extruded sheets, tubes and rods for construction and decoration.
Industrial applications: components requiring high transparency and moderate heat‑resistance.
Properties
| Property Category | Item | Test Standard | Value | Unit |
|---|---|---|---|---|
| Physical | Density | JIS K7112 | 1.19 | g/cm³ |
| Water absorption (24 h) | JIS K7209 | 0.3 | % | |
| MFR(230℃/3.8 kg) | JIS K7210 | 2.0 | g/10min | |
| Molding shrinkage (flow direction) | ASTM D955 | 0.20‑0.60 | % | |
| Refractive index | JIS K7105 | 1.49 | — | |
| Light transmittance (3.2 mm) | JIS K7105 | 93.0 | % | |
| Haze | JIS K7105 | ＜0.5 | % | |
| Mechanical | Tensile strength (yield) | JIS K7113 | 76.0 | MPa |
| Flexural strength | JIS K7203 | 120 | MPa | |
| Flexural modulus | JIS K7203 | 3200 | MPa | |
| Elongation at break | JIS K7113 | 13 | % | |
| Rockwell hardness‑M | JIS K7202 | M100 | — | |
| Charpy notched impact | JIS K7110 | 1.4 | kJ/m² | |
| Thermal | HDT (1.8 MPa, annealed) | JIS K7207 | 101 | ℃ |
| Vicat softening temperature | JIS K7206 | 109 | ℃ | |
| Linear thermal expansion coefficient | ASTM D696 | 7.0×10⁻⁵ | cm/cm/℃ | |
| Electrical | Volume resistivity | JIS K6911 | ＞1.0×10¹⁵ | Ω·cm |
| Surface resistivity | JIS K6911 | ＞1.0×10¹⁶ | Ω | |
| Dielectric constant (60 Hz) | JIS K6911 | 3.10 | — | |
| Dissipation factor (60 Hz) | JIS K6911 | 0.04 | — | |
| Flammability | UL94 (1.5 mm) | UL94 | HB | class |
Injection‑Molding Parameters
| Process | Item | Recommendation | Notes |
|---|---|---|---|
| Predrying | Drying temperature | 80‑85 ℃ / 91 ℃ | Desiccant dryer required |
| Drying time | 4‑5 h / 2‑4 h | Target moisture＜0.1%, eliminate bubbles & silver‑streaks | |
| Barrel setting | Rear zone | 185‑205 ℃ | Melt onset ~160 ℃, decomposition＞270 ℃ |
| Middle zone | 220‑240 ℃ | ||
| Front zone | 210‑230 ℃ | ||
| Nozzle | 210‑230 ℃ | ||
| Melt temperature | 238‑272 ℃ | Strictly control residence time to avoid degradation | |
| Mold temperature | 34‑71 ℃ | Higher temp improves gloss yet lengthens cycle time | |
| Injection pressure | 80‑140 MPa | High‑viscosity material; easy to generate internal stress with fast cooling | |
| Injection speed | Medium | Excessive speed causes surface defects & internal stress |
Note: All data for reference only, please refer to official TDS for mass‑production.
