Processing Guidelines for Zeonex^®/Zeonor^®

Machine Selection

COP materials should be molded on a machine adequately sized for the size of the part. When selecting the machine, care should be taken to ensure that an adequate tonnage machine is selected (for injection molding – ideally within 60-70% of the official injection capacity).
 

The screw should be selected such that there is a large compression ratio for stability and degassing. Typically a compression ratio of 2.0 to 2.5 is suggested.
 

The screw and cylinder should be made from materials that have good releasing properties with COP materials. This includes H503 (H-alloy steel) for the cylinder and TiN, TiCN, and W2C coatings for the screw.

Machine Clean-Out

To maintain the best optical properties and to avoid cross-contamination/part defects, it is recommended to thoroughly clean the machine prior to molding COP materials.

Mold Design

Selection of proper mold design is important to obtain parts free from carbides/discoloring and to produce highly precise part surface quality.

Pre-Drying Prior to Processing

Air dissolved in COP pellets can cause discoloration, carbide formation, and voids. COP materials should be dried to remove air in the pellets for 4 to 24 hours at the noted temperature before molding. Drying for too long of a period may cause heat deterioration and possible discoloration.
 

Refer to the molding guidelines for the specific grade of COP you are running for the suggested drying time and temperature.