Cyclic Olefin Copolymer

Thermal Behavior

Glass transition threshold determines the upper service limit and mould temperature requirement during injection processing. Increasing the cyclic olefin copolymer norbornene ratio elevates heat deflection values while demanding higher cavity wall temperatures to prevent premature skin freezing. High melt viscosity requires elevated injection pressure compared to standard polyolefins.

Shrinkage remains isotropic and low, typically between zero point one percent and zero point six percent.

Moulding Parameter

Melt temperature settings between two hundred and forty degrees Celsius and three hundred degrees Celsius ensure full cavity fill without thermal degradation. High injection speeds prevent flow marks in thin-wall optical lenses. Regrind additions above fifteen percent increase yellow index values.

Mold surface finishes require mirror polishing to prevent surface haze on final parts.

Dimensional Stability

Low water absorption under zero point zero one percent over twenty-four hours prevents dimensional distortion under humid operating conditions. Parts moulded from cyclic olefin copolymer maintain tight mechanical tolerances across variable climate environments. Hydrophobic polymer backbones resist aggressive polar solvents during sterilization protocols.

Internal stress levels must be monitored using cross-polarizers to prevent environmental stress cracking. Tensile modulus remains stable across a wide temperature band, preventing optical distortion in sensor housing assemblies.