Compounds with Fillers
- Barrel Temperature: Slightly higher than unfilled resin.
- Mold Temperature: Mineral slightly higher than unfilled resin; carbon black higher than mineral filled.
- Injection Pressure: Must be higher than unfilled resin because of higher viscosities.
- Back Pressure: 50-100 psi (0.34-0.69 MPa).
- Injection Speed: 1-2 in/sec (25-50 mm/sec).
- Screw Speed: 60-90 rpm.
Compounds with Fibers
- Barrel Temperature: Glass fiber slightly higher than particulate; carbon fiber slightly lower than unfilled resin.
- Mold Temperature: Glass fiber higher than particulate; carbon fiber higher than glass or particulate.
- Injection Pressure: Must be higher than unfilled resin because of higher viscosities.
- Back Pressure: 50-100 psi (0.34-0.69 MPa).
- Injection Speed: Slowest speed without sacrificing appearance.
- Screw Speed: Minimum speed without causing delays in molding cycles.