Injection moulding is an indispensable part before molding and injection molding, or when the machine is replaced with other moulds for production. The quality of the test results directly affects whether the subsequent production of the factory is smooth. Therefore, during the test process of the injection mold, it is necessary to follow reasonable operation steps and record the technical parameters useful during the test mode to facilitate the mass production of the product . So, what kind of inspection work should be done before the injection mold trial?
- 1. Appearance. Is the surface texture correct? Is the material free of impurities? Are there scratches or scratches on the surface of the product?
- 2. Parting line. Is there a pincer at the parting position? Does it draw? (Note that the die at the hole position is also prone to deform the hole)
- 3. Gate. Infer the location of the weld line according to the gate distribution, and check the weld line. How to repair the excess material at the gate? Can the local position away from the gate be full? If glass fiber is added to the raw material, punching is likely to occur at the gate. In addition, floating fiber is easily generated on the product surface.
- 4. Deformation. Plastic products usually produce internal shrinkage deformation, which cannot be avoided at all. Therefore, the design should consider adding necessary ribs or reasonable structure to avoid deformation.
- 5. Miniature. Microcosm usually occurs on the back of thick glue and tendons.
- 6. Stress marks. Stress marks usually occur at the location of the thin glue and the back of the thimble or cylinder.
- 7. Thimble. Is the distribution of thimble uniform and reasonable? In order to avoid assembly interference, the thimble usually recesses the product by 0.05 ~ 0.1mm. When the product is ejected, is the back of the ejector pin white? Does the thread burr of the thimble exceed the design requirements? In order to avoid sticking the front mold, the top of the thimble will increase the undercut structure, which will be reflected on the product after demolding, and it needs to be repaired by subsequent processes.
- 8. Slanted top of slider insert. There will be traces around the slider, the insert and the sloping top. Is it within the design allowable range? When demoulding, the shoveling position is prone to shoveling.
- 9. Inserts. Insert injection molding (such as sheet metal parts, nuts, etc.), and hot-melt nuts after injection molding, at this time, it is necessary to determine the torque, pullout force, and whether the glue overflows.
- 10. Logo. Material / Date / Mould Cave Number / Product Number / Version Number / Recycling Mark.
- 11. Printing. Silk screen / pad printing / spraying / laser carving, etc. (Usually need to make corresponding tooling / fixture)
- 12. Measurement of key dimensions. Measure and verify key dimensions. Three treatment methods for unqualified size: (1) improvement by the mold manufacturer; (2) acceptance (given the allowable range value); (3) modification of drawing tolerances.