Injection Molding Lifter Design in Plastic Injection Mold Tooling The lifter is mainly used to form the internal undercuts of an injection molded plastic part, and at the same time it also offers ejection function. Considerations in lifter design include selecting abrasion-resistant and durable materials to withstand pressures and ensure operational efficiency. Ejector pins are … Read more
The Pantone Color Matching System is largely a standardized color reproduction system, providing resources and tools for accurately identifying and matching colors in design and printing. The importance of colour in customizing products and ensuring brand representation cannot be overstated. By standardizing the colors, different manufacturers in different locations can all refer to the Pantone … Read more
Black specks/streaks and impurities are the most important factors that lead to rejects in the normal production process. Stubborn stains mainly affect the appearance of the product and lead to scrap. Most of the impurities and black specks are usually caused by foreign substances, i.e., they have nothing to do with the raw material itself. … Read more
April 6, 2018 The causes and countermeasures described below are aimed to solve the common injection molding defects that might occur in ordinary circumstances. The examples are just based on my own personal work experience, so if there is anything inappropriate, you are welcome to correct me! Short shots (incomplete filling) – injection molding defects … Read more
The setting of hold pressure is aimed to prevent resin backflow, while at the same time compensating for resin shrinkage caused during the cooling process, so as to achieve the optimal molding outcome. If the holding pressure is set too high, the product will be prone to flash, over filling or stress concentrating near the … Read more
Definition of silver Streaks: Silver streaks are also referred to as silver marks, which appear like burst blisters on the surface of injection molded parts, mostly in the shape arrows pointing to the gate. Causes of Silver Streaks: I. Equipment 1. The nozzle hole is too small, the material leaks or draws at the nozzle, … Read more
Cracks are a commonly seen defect in plastic injection molded products, of which the main causes are stress and deformation, mainly including residual stress, external stress and product deformation caused by external environment. (I) Cracking caused by residue stress The residual stress is mainly generated in the following three scenarios, i.e., overfilling, product ejection and … Read more
Bayer Plastics has some good Information about surfaces and injection molding available on their web- Site. According to a (German) Document the VDI 3400 texture surfaces correspond to the following Ra / Rz Values and require the following drafting angles: VDI 3400 defines surface texture standards for mold-making. It categorizes roughness classes using Ra values. … Read more
The defects in the injection molding of acrylic PMMA usually include: short shot, silver streaks, sink marks, voids, jetting, weld marks, gray / black specks, cracking, warpage, and material impurity, while the preventive measures against them are usually: Short Shot This is caused because the resin does not fill the cavity fully. To prevent its … Read more
Plastic annealing process The purpose of plastic annealing is to eliminate internal stress. For example, in the area where the thin and thick parts meet, the cooling of the thick part is slower than that of the thin part, causing the joint to shrink unevenly. As a result, there is stress concentration in the area. … Read more