What to do if there are quality defects in injection molded parts

Author: MULAN -Plastic Molding Manufacturer

After the plastic parts are formed, some bad problems will appear, which will affect the assembly efficiency or the performance of the whole machine. There is a certain difference from the predetermined quality standard (inspection standard), which cannot meet the company's quality requirements. Injection mold processing manufacturers suggest that in addition to strengthening the quality awareness training of employees, timely deal with defective parts (such as selection, processing, etc.); these defects may be caused by the following aspects: molds, raw materials, process parameters, equipment, environment and personnel.

Unsatisfactory injection molding (lack of glue): usually lack of glue means that the cavity is not full. Moreover, the injection molded parts are not full, with air bubbles, cavities, shrinkage cavities, etc., which do not conform to the standard model, and can also be called lack of glue. Weld marks (stripes): linear traces on the surface of plastic parts, formed by the fusion of plastics in the mold, the melts are not completely fused together at the junction, and cannot be fused together to produce weld lines.

The expression is a straight line, developing from deep to shallow. This phenomenon has a certain influence on the appearance and mechanical properties. Such as the welding marks on the bottom of the hook plate.

Warpage: After the plastic part is released from the mold or after a period of time, the shape of the plastic part will rotate and twist. If there is a straight edge facing inward or outward, or if there is undulation in the flat part, there is local and global deformation. Chromatic aberration: The color of the injection molded part is different from the single standard color sample when observed with the naked eye, and it is judged as chromatic aberration under the standard light source.

Chromatic aberration is a common defect in injection molding. There are many factors affecting color difference, including raw resin, color masterbatch, mixing of color masterbatch and raw materials, injection molding process, injection molding machine, etc. In the actual production process of injection mold processing manufacturers, we generally control color difference from the above aspects.