A car bumper is one of the most important exterior parts of a car. Not only has sufficient strength and rigidity, but also plays a buffer role in collision accidents, protects the body, and pursues harmony with the body shape. In order to achieve these goals, current automobile bumpers are all made of plastic, commonly known as plastic bumpers.
The shape of a car's front bumper resembles a saddle. The material is PP+EPDM-T20, and the shrinkage rate is 0.95%. Among them, PP is the main material of the bumper. EPDM can add flexibility to insurance coverage. T20 means adding 20% talcum powder to increase the hardness of the bottle cap.
The characteristics of the shape of the car bumper are:
1. The shape is complex, the size is large, and the wall thickness is relatively small, which belongs to large thin-walled plastic parts.
2. K/Os, S/Os, large ribs, resistant to melt flow.
3. There are 3 undercuts on the inner side of the car bumper, and it is difficult to pull the core horizontally at each position.
The conclusion is:
1. Adopt internal grading technology to ensure the appearance of plastic parts.
2. The automobile bumper adopts the "composite inclined top" secondary core-pulling structure, which solves the problem of horizontal core-pulling of complex parts.
3. The eight-point needle valve sequence valve hot runner pouring system is adopted to solve the melt-filling problem of large thin-walled plastic parts.
4. Hydraulic pressure is used as the driving force of the demoulding system, which solves the problem of the large demoulding force of plastic parts and difficulty in tablet reset.