Cellulose Acetate Propionate
| Symbol: | CAP |
| Crystallinity: | Crystalline* |
| Trade Names: | Tenite |
Description:
Cellulosics are developed by combining cellulose with esters, which produces a hard, scratch resistant part that is capable of intense color. CAB and CAP are tougher than CA but all are chemically resistant, electrically insulating and sound absorbing. NOTE: Although crystalline materials, all process like amorphous materials. All are heat sensitive.
Processing Considerations:
- Residence Time: Residence time ranges between 2 to 4 minutes.
- Back Pressure: Back pressure is typically 150 PSI (1500 plastic pressure) or less.
- Drying: All material must be dried, typically between 150°F and 185°F for 2 – 3 hours..
- RPM: Typically ranges from 30 to 100 RPM.
Screw Design Based on:
- Low Compression Ratio
- Medium Transition Length
- Medium Meter Channel Depth
Other Information:
- Mixer: A low shear, mixing screw can be used to run CAP. Reiloy Westland Corporation’s Eagle mixer has been proven to successfully process this resin.
- Barrier: Barrier designed screws are not recommended.
- Custom Design: A screw custom designed to process CAP is recommended over a general purpose design.
- Recommended Valve: The recommended valve is a 3-piece free flow.
- Screw & Barrel Material Recommendation: CAP materials develop gasses which produce acetic, butyric and propionic acids. Corrosion is a problem and special alloys should be used in manufacturing screws and barrels to process CAP.
- Similar to Resin: CAP processes similar to CA (Cellulose Acetate), CAB (Cellulose Acetate Butyrate) & COC (Cyclic Olefin Copolymers).
*Materials are very viscous which means they are highly resistant to flow.
Various additives and/or fillers can have an effect on a resin’s process behavior. For more detailed information, please contact Reiloy Westland Corporation.