The effect of flow rate on product quality in the injection molding process
June 25, 2022
Flow rate: related to the speed of the injection molding machine, such as screw speed, injection speed, mold and neutron speed.
Screw speed: In addition to adjusting the pre-plastic flow rate, it is mainly affected by the pre-plastic back pressure. If the pre-plastic flow rate is adjusted to a large value, the pre-plastic back pressure is high. As the screw rotates, the plastic has a large shear force in the barrel, and the plastic molecular structure is easily cut. The product has black spots and black streaks, which affect the appearance quality and strength of the product. And the barrel heating temperature is not easy to control. The pre-plastic flow setting is too low, and the pre-plastic storage time is prolonged, which will affect the molding cycle.
Injection speed: It is reasonable to set the injection speed, otherwise it will affect the product quality, the injection speed is too fast, and the product has bubbles, charring, discoloration and so on. If the injection speed is too slow, the product is insufficiently formed, and there is a weld mark or the like.
Mode and neutron flow: should not be set too large, otherwise the ejection and core pulling action is too fast, resulting in unstable ejection and ferrule, the product is easy to white.
