sink mark injection molding defects
(1) What is sink mark (appearance)? A sink mark refers to the surface depression caused by resin shrinkage. After the crystalline resin is cooled and solidified, its volume is greatly reduced, which results in the sink mark. Since the shrinkage (shrinkage ratio) is basically fixed, and the greater the thickness the higher the shrinkage, the sink...
(1) What is bubble (appearance)? Bubble refers to the phenomenon in which the surface of a molded product  bulges. Bubbles are prone to occur in the following two scenarios, i.e., the surface of the product gradually starts to bulge when it is taken out of the mold after...
PVC injection molding
Thanks to its low price, inherently anti-inflammatory features, great hardness and rigidity, as well as the outstanding resistance to chemicals and the shrinkage as low as 0.2-0.6%, PVC products are widely used in electrical appliances, machinery, construction, daily necessities, toys and packaging. Based on the characteristics of the PVC material, its injection...
PP plastic injection molding
1.      PP - Chemical Name: Polypropylene, Shrinkage Rate: 0.012-0.018%; Relative Density: 0.9-0.91 g/cm3 2.     The appearance of PP: White, translucent and waxy when uncolored; natural color, cylindrical and smooth pellets of 2-5mm in any direction; odorless, non-toxic, and no mechanical impurities 3.  The applications of PP: Suitable for the production of...
Nylon PA plastic injection molding
Nylon (polyamide, abbreviated as PA) refers to a plastic composed of polyamide resins, which can be obtained by polycondensation of diamines and dibasic acids, or by ring-opening polymerization of lactams formed by dehydration of amino acids. Different from PS, PE and PP, PA does not gradually soften with the rise of temperature, but softens within a narrow...