In many cases, the cold runner system is a more viable option. In some applications, it may provide a mold and a process that is capable of producing higher-quality parts. […]
During the injection and filling process, the plastic melt enters into the clearance of parting line,clearance of sliding surface of the slide, gap between inserts and holes of ejector pin which are related with mold cavity structure, and overflow thereby occurs […]
There may be a variety of solutions, especially for some specific situations, but the general solutions include: […]
During the process of injection molding, due to the poor exhausting condition of molds, the water vapor in the melt, the air in cavity, the volatile gas from volatile substance in raw materials as well as the material decomposition gas either remain inside the products to form air bubble […]
As for molding technics. Air bubble or air cavitation may occur in the plastic parts due to improperly-controlled material temperature and mold temperature, overfast injection speed, overlow injection pressure, too large or too small quantity of injection, insufficient dwell, unbalanced or insufficient cooling etc. […]
Crazing is silvery white filamentous speckle occurring on the surface or near-surface of injection products along the direction of melt flow. It is resulted from the moving of gas in the resin which is then stored in between the melt and surface wall of cavity and subsequently crushed. […]
1 Use plastics with low viscosity and sound fluidity or adjust prescription of plastics and reduce viscosity of melt; […]
The plastic melt condenses and solidifies before it can smoothly fill in the cavity part far away from the gate or that with thin section, the cavity therefore is insufficiently filled and the shape and structure of the molded products are incomplete, which is intrinsically due to the low fluidity and poor filling capacity of [...]
For large injection-molded parts, a servo-driven valve gate system can improve surface finish and part performance. The art of sequential molding has proven to be a beneficial process in many markets. Automotive suppliers are one of the largest users of this technology, especially for the production of plastic parts with Class A surface finishes. Sequential [...]
Properly improve injection and dwell pressure as well as the injection rate to increase melt’s compression tightness; prolong time of injection and dwell( the freezing of gate should not occur too early) to realize sufficient shrinkage compensation; […]