The warping deformation of ABS engineering plastic parts is mainly characterized in that the shape of ABS engineering plastic parts rotates or twists after the plastic parts are demoulded, and the plane part of the plastic parts fluctuates, and the straight edges bend or twist inward and outward.

When the injection pressure is too high, the molecular orientation along the melt flow direction is quite different from that along the vertical flow direction. After filling the mold, the oriented molecular morphology always tries to restore the original curled state, which leads to the shortening of the length of plastic parts in this direction. Therefore, the shrinkage of plastic parts along the melt flow direction is greater than that along the vertical flow direction. The higher the injection pressure, the faster the flow rate, the greater the difference between the two flow directions, so the greater the warping deformation. In this respect, the injection pressure can be appropriately reduced.