Polyurethane
| Symbol: | PUR |
| Crystallinity: | Amorphous |
| Trade Names: | Isoplast, Royal Cast, SEP |
Learn more about Polyurethane.
Description:
Rigid thermoplastic polyurethane is available in injection and extrusion grades. It has excellent chemical resistance, high impact strength, good transparency and low shrinkage. Often used in housewares and electrical appliances.
Processing Considerations:
- Residence Time: Residence time is 1.5 to 4 minutes.
- Back Pressure: Keep back pressure at 125 PSI (or 1250 plastic pressure) or less.
- Drying: PUR resin must be dried or significant loss of physical properties can occur.
- RPM: Slow RPM is recommended.
Screw Design Based on:
- Low Compression Ratio
- Long Transition Length
- Deep Meter Channel Depth
Other Information:
- Mixer: A low shear mixing screw can be used to run PUR. Reiloy Westland Corporation’s Eagle mixer has been proven to successfully process this resin.
- Barrier: Barrier screws are not recommended.
- Custom Design: A custom screw designed to process PUR is recommended over a general purpose design screw.
- Recommended Valve: A three piece free-flow valve is recommended.
- Screw & Barrel Material Recommendation: Chrome or stainless steel screws and carbide barrels are recommended.
Use regrind only to 25%. Desired melt temperature results in a melt with the viscosity of honey. Various additives and/or fillers can have an effect on a resin’s process behavior. For more detailed information, please contact Reiloy Westland Corporation.