Peeling phenomenon of PC / ABS Alloy during injection molding

PC / ABS alloy material, as the main material used in automobile interior decoration and electrical appliance shell, has very important advantages. However, in the process of injection molding, the improper material itself, mold design and injection molding process lead to the phenomenon of product surface peeling. Let's first look at a description of melt fracture: in plastic extrusion or injection molding, when the fluid shear rate is low, the extrudate through the die or gate has a smooth surface and uniform shape. When the shear rate or shear stress increases to a certain value, the surface of the extrudate loses luster and becomes rough; When the extrusion rate increases again, many irregular nodules, twists or slubs will appear on the surface of the extrudate, and even break into fragments or columns, which we call "melt fracture".

In terms of materials, the fracture of fluid under high shear leads to the peeling phenomenon of products. Compared with other materials, the two-phase structure of PC and ABS is more prone to the fracture of fluid and the separation of two phases under high shear, which leads to the delamination and peeling phenomenon. For PC / ABS material, PC and ABS are partially compatible, so it is necessary to add appropriate compatibilizer in the modification process to improve its compatibility. Of course, because of the bad peeling caused by mixing is the first step we need to eliminate.