Product Peeling Problem

The peeling problem of plastic products is closely related to the fluid fracture caused by high shear stress. Under low shear stress or rate, small disturbance caused by various factors is suppressed by the melt; However, at high shear stress or rate, the disturbance in the fluid is difficult to restrain and develops into unstable flow; When a critical shear force is reached, the fluid will break.
resolvent:
(1) Materials: The PC and ABS components are partially compatible, so it is necessary to add appropriate compatibilizer during the modification process to improve their compatibility. Of course, bad peeling caused by mixing is the first step we need to eliminate;
(2) Mold: The principle of mold design should follow the direction of reducing shearing as much as possible. Generally speaking, products with dense dermatoglyphic surface are more prone to peeling (caused by the friction and shear between the melt in the cavity and the inner wall of the cavity during high-speed filling); At the same time, in the gate design, if the gate size is too small, it will lead to excessive shearing when the melt passes through the gate, and then lead to peeling on the product surface;
(3) Injection molding process: the main direction is to avoid excessive shearing. When it is difficult to fill the product, the method of high speed and high pressure can be used to improve it. Therefore, in the actual injection process, the method of increasing the injection temperature/mold temperature and improving the material fluidity can also be considered to reduce the flow resistance in the actual filling process, so as to avoid excessive shear caused by high speed and high pressure.