Injection blow molding product defects - surface layer peeling and delamination solution

Author: MULAN - Plastic Molding Manufacturer

Defects of injection blow molding products - surface layer peeling and delamination solutions The peeling and delamination of the surface layer of injection blow molding products means that the surface of the product near the gate has a flaky rough surface (delamination, shelling). This phenomenon easily occurs in plastics containing inorganic fillers. The appearance defects of peeling and delamination of the surface layer not only affect the appearance of the product to a certain extent, but also affect the strength or function of the product. Although it is a slight appearance defect, it is difficult for customers to accept. Unless it is an unsolvable situation on the mold, at this time the customer may give in and negotiate to determine the acceptance criteria and acceptance limit template. Reason analysis of injection blow molding products: Use the method of man, machine, material, method and environment to analyze the surface layer peeling of the product, and analyze all the factors that affect the product. Material factors: 1. Whether the material compatibility is too poor 2. Whether the material has too much moisture or mixed with miscellaneous materials Mold factor: whether the gate is correct Injection molding process factors: 1. Whether the injection speed and injection pressure are correct 2. Whether the temperature setting is appropriate Analysis process: When there is an abnormality in the product, do not rush to adjust the injection molding parameters, but first check whether there are other influencing factors, and finally adjust the injection molding parameters. If the gate design of the mold is not correct, the temperature of the plastic raw material entering the mold cavity will exceed the set temperature, causing chemical reactions between the plastic raw material and its additives, thereby changing the properties of the material. Reason classification of injection blow molding products Material 1 The two materials themselves are not compatible, and the fusion of the materials is only promoted by adding a compatibilizer. 2 Inorganic additives are incompatible with raw materials. 3 Mixed with miscellaneous materials. 4 The material has too much moisture. mold If the gate size is too small, it will cause high shear force when the melt passes through the gate, which will cause the plastic material to heat up and decompose, which in turn will cause the surface of the product to peel. Injection molding process 1 The material temperature and mold temperature are set too low. 2 Injection pressure and injection speed are too high. Injection Blow Molding Product Solutions Material 1 Change material. 2 Reduce additives or replace additives, and readjust the formula. 3 Add less return materials or confirm whether there are miscellaneous materials mixed in the raw materials. 4 Pay attention to the time control of the baking material. mold Redesign gate shape or size. Injection molding process 1 Increase material temperature and mold temperature.2 Multi-stage injection, reduce injection speed and injection pressure.