Plastic Science: How to solve the silver streaks produced during plastic injection?

Silver streaks are also called (mica marks), bubbles. The surface finish of the injection molded parts is inconsistent in some places, and a silver surface appears.Possible causes and recommended remedies:

Injection molding machine

A. The surface temperature of the melt is too high, reduce the temperature of the injection cylinder

B. Plastic stays in the injection cylinder for too long, reduce the total cycle time, the injection volume is too small for the injection molding requirements

C. The melt temperature is too low to make the mold filling time unstable. Increase the injection cylinder temperature. Increase the nozzle temperature. Increase the mold filling speed.

D. Insufficient injection pressure Increase injection pressure

E. The temperature controller is inaccurate, which makes the control different. Check whether the temperature controller is accurate and controllable

Mould

A. The surface temperature of the mold is too low. Increase the mold temperature and limit the speed of the coolant flowing through the mold.

B. There is some unplasticized plastic cold material on the injection molded part. Increase the size of the cold material cavity. Expand the end of the runner to form an additional plastic cold material cavity. The nozzle and nozzle sleeve heated by electricity are used.

C. The runner and gate are too small or the length is too long, causing the plastic to condense during transportation. If necessary, increase the runner diameter and gate depth

D. Excessive mold release agent on the mold surface Clean the mold surface thoroughly with white alcohol