Injection molding is a complex manufacturing process that can produce high-quality plastic parts. However, there are several defects that can occur during the injection molding process. Here are some common injection molding process defects:
This occurs when the plastic part cools and contracts unevenly, causing it to warp or twist. Warping can be caused by uneven cooling, improper mold design, or incorrect material selection.
These are depressions or indentations that appear on the surface of a plastic part. Sink marks are caused by uneven cooling, thick areas of the part, or insufficient packing pressure.
Flash is excess plastic material that protrudes from the parting line of the mold. It is caused by excessive injection pressure, poor mold alignment, or worn or damaged molds.
Short shots occur when the plastic material does not completely fill the mold cavity, leaving the part incomplete or with missing sections. Short shots can be caused by insufficient injection pressure, improper material selection, or inadequate venting.
The burn marks are dark or discolored areas on the surface of the part caused by overheating of the plastic material. Burn marks can be caused by excessive injection speed or pressure, inadequate cooling, or poor venting.
Voids are empty spaces or air pockets within the plastic part. Voids can be caused by inadequate injection pressure, poor mold design, or insufficient cooling.
Overall, injection molding process defects can be caused by a variety of factors and can be challenging to prevent. Careful attention to mold design, material selection, and process parameters can help to minimize these defects and produce high-quality plastic parts.