WebFlow lines – A common plastic injection molding defect in which discolored ring-shaped streaks, patterns, or wavy lines appear around gates or narrow sections of the finished product. Burn marks – Often appears as black or … Flow lines are off-color lines, streaks, and other patterns that appear on the surface of a part. These are caused by the shot of molten plastic moving at different speeds throughout the injection mold, which ultimately causes the resin to solidify at different rates. This is often a sign that injection speed and/or … See more Sink marks appear as depressions, dents, or craters in thick sections of a part. Thicker sections take longer to cool, which can have the often unanticipated side effect of the inner … See more What is delamination? Delamination is a condition that causes a part’s surface to separate into thin layers. These layers, which appear like coatings that can be peeled off, are caused by the presence of contaminants in the … See more “Short shots” refer to instances in which the resin doesn’t entirely fill the mold cavity, resulting in incomplete and unusable parts. What causes short shots in injection molding? Typically, they are the result of … See more Also called knit lines, these defects mark where two flows of molten resin came together as they moved through the mold geometry. This … See more

Common Defects in Plastic Part Engineering

WebFlow marks, also known as flow lines, are molding defects that can occur in the manufacturing process of injection molding. They are best described as "off tone" … WebNov 16, 2024 · Most Common Injection Molding Defects: 1. Burn Marks: One of the most common injection molding defects is “burn marks.” On molded plastic pieces, burn marks are black or rust-colored … shar jackson house

HOW TO IMPROVE FLOW MARK IN INJECTION MOLDING - Plastic …

WebApr 11, 2024 · Defects in Plastic Molding. Share: Injection moulding is an effective manufacturing process for making plastic products. A high pressure injector squeezes molten thermoset or thermoplastic resin into … WebJul 1, 2024 · There is also a secondary reason that if the product is too thick while the gate is small, the actual filling speed will be slowed down, which tends to cause flow marks. … WebAs discussed above, one of the things that contribute to plastic injection molding defects like sink marks and flow lines is the type of injection molding machine used. It is … shariz netherlands