The causes and solutions of plastic degradation in injection molded parts?

1. Injection molding machine
A. Excessive heating of plastic in the injection cylinder.
Reduce the melt temperature.
B. The temperature controller is not functioning properly.
Check if the temperature controller is in the correct area to control the injection cylinder.
Recalibrate the temperature controller and check for any adhesive connections, contacts, etc.
C. Incorrect thermocouple type used.
Check if the type of thermocouple used is consistent with the one provided on the temperature controller, such as FECON.
Check if all thermocouples are operating satisfactorily.
D. The retention time of plastic in the injection cylinder is too long.
Check the injection weight. If it is less than 25% of the injection pressure of the injection molding machine, transfer the mold to a smaller injection molding machine.
If there is no injection molding machine with a smaller size available, reduce the temperature of the injection cylinder to the lowest value, which will produce injection molded parts that meet quality requirements.
E. Plastic is stuck in the injection cylinder when production is stopped.
When stopping production, clean the injection cylinder and keep the screw in the forward most position.
F. Plastic is "stranded" and degraded at a certain point in the injection cylinder.
Check the injection cylinder to remove any residue on the clamping surface.
2. Mold
A. The injection quantity of the mold is too small.
Move the mold to a smaller capacity injection molding machine.
3. Plastic
A. The moisture content in plastic is too high.
Use the correct drying sequence.
B. Quality differences or impurities in recycled materials.
Separate and strictly inspect impurities in recycled materials.