MACHINE SELECTION

Processing Guidelines

Product Grade	Injection Molding	Blow Molding
ZEONEX 330R
ZEONEX 350R
ZEONEX 480
ZEONEX 480R
ZEONEX 690R
ZEONEX 790R
ZEONEX 5000
ZEONEX E48R
ZEONEX F52R
ZEONEX K22R
ZEONEX K26R
ZEONEX RS420-LDS
ZEONEX RS420
ZEONEX T62R
ZEONOR 1020R
ZEONOR 1060R
ZEONOR 1420R
ZEONOR 1430R

Cyclo Olefin Polymer (COP) materials should be molded on a machine adequately sized for the volume of the part being produced. When selecting the machine, care should be taken to ensure that a machine with adequate clamping pressure and appropriate barrel capacity is selected (for injection molding – the ideal part shot size is within 60 percent to 70 percent of the official injection capacity).

The screw should be selected so 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 Cyclo Olefin Polymer (COP) materials. Examples include 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 avoid cross-contamination/part defects, it is recommended that the machine be thoroughly cleaned prior to molding of Cyclo Olefin Polymer (COP) materials. Although olefin-based purge compounds are compatible with Cyclo Olefin Polymer (COP), implementing a full mechanical cleaning of the machine barrel and screw components is the preferred method of cleaning to reduce the risk of contamination.

MOLD DESIGN

Conventional mold tooling design and metal selection can be used for molding Cyclo Olefin Polymer (COP). High chrome or nitriding steel coatings should be avoided on mold surfaces or inserts due to increased chance of part sticking. Cyclo Olefin Polymer (COP) also exhibits very high transcription to mold surfaces; undercuts and burs should be eliminated for ease of part ejection.

Cyclo Olefin Polymer (COP) is compatible with hot runners, hot manifolds, and valve gating systems. Runners should possess full-round profile and be designed in a manner to avoid sharp corners or dead spaces in material flow. Care should be taken when using valve gates as to avoid high shear during the injection process, as this may cause silver streaking in the molded part. Hot runners and valve gating are typically not suggested for use when molding precision lens type parts.

PRE-DRYING PRIOR TO PROCESSING

Oxygen dissolved in Cyclo Olefin Polymer (COP) pellets can cause discoloration, carbide formation and bubbles. Cyclo Olefin Polymer (COP) materials are inherently hydrophobic, but should be preheated to reduce the amount of air in the pellets. The recommended time for preheating is 4 to 24 hours at the noted temperature prior to and during molding. Preheating the material for excessive lengths of time may cause material degradation or discoloration. For the suggested preheat time and temperature, refer to the molding guidelines for the specific grade of Cyclo Olefin Polymer (COP) being processed.

Contact ZEON for more detailed information regarding processing and design considerations for your specific injection molded or blow molded application.