Molding problems manifest themselves in many ways, from visual defects like burn marks, to physical problems such as delamination. This category of defects covers that broad group not caused primarily by cooling or flow problems.
Troubleshooting delamination problems
Delamination, sometimes referred to as lamination or layering, is a defect in which the surface of a molded part can be peeled off layer by layer.
Troubleshooting dimensional variation problems
Dimensional variation is characterized by the molded part dimension varying from batch to batch, or from shot to shot while the machine settings remain the same.
Troubleshooting discoloration problems
Discoloration is a color defect characterized by a molded part's color having changed from the original material color.
Troubleshooting fish eyes problems
Fish eyes are a surface defect that results from unmelted material being pushed with the melt stream into the cavity and appearing on the surface of a molded part.
Troubleshooting flashing problems
Flashing occurs when a thin layer of material is forced out of the mold cavity at the parting line or ejector pins location.
Troubleshooting jetting problems
Jetting occurs when polymer melt is pushed at a high velocity through restrictive areas, such as the nozzle, runners, or gates; or into open, thicker areas, without forming contact with the mold wall.
Troubleshooting short shot problems
A short shot is the incomplete filling of a mold cavity which results in the production of an incomplete part.
Troubleshooting sink marks and voids
Sink marks and voids both result from localized shrinkage of the material at thick sections without sufficient compensation.