Even the best-trained workers operating the best-maintained plastic injection molding equipment occasionally run into problems.

Below are some of the most common injection molding issues, along with some basic ideas of what may cause them. It's always smart to contact your machinery manufacturer for more assistance.

Burn marks: Likely cause - Trapped gas chars or burns the plastic in the finished piece. Possible solutions - Lower booster time, check for heater malfunction, change gate position.

Dark spots or streaks: Likely cause - Thermal damage to the melt. Possible solutions - Check for material contamination or too high of a percentage of regrind, clean the barrel and screw, decrease the overall cycle time.

Incomplete parts: Likely cause - The resin doesnâ??t completely fill the mold cavity. Possible solutions - Increase shot size, raise chiller temperature, raise melt temperature.

Jetting: Likely cause - An uninterrupted frontal flow of melt snakes into the cavity and cools off so that it does not fuse with the following material. Possible solutions - Increase gate diameter, lower injection speed, use higher compression screw.

Oversized part: Likely cause - Part too large compared to original drawings, usually due to inaccurate timing, pressure or temperatures. Possible solutions - Decrease booster time, cylinder temperature or holding pressure, increase gate size, raise mold temperature.

JSW is always available to help its clients with their toughest processing hurdles. Contact us now to take advantage of our expertise in plastic injection molding equipment.