Due to the distinctive particularity of plastic parts of complex automobile parts, the following factors need to be fully considered in the design of injection molding, such as drying treatment of materials, new requirements of glass fiber reinforced materials for screws, driving form and clamping structure.
Firstly, when the commonly used resin materials such as automobile bumper and instrument panel are modified resins such as modified PP and modified ABS, the resin materials have different hygroscopicity. In order to meet the water content requirements during molding (General requirements ≤ 0.2%), the resin raw materials must be subject to hot air drying or dehumidification drying before entering the screw pre molding measurement of the injection molding machine.
Second, at present, domestic automotive plastic parts are basically non glass fiber reinforced plastic products. Compared with the use of short cut glass fiber reinforced resin, the material and structure of the screw of the injection molding machine used to form non glass fiber reinforced plastic parts are quite different. When designing the injection molding machine, we should pay attention to the alloy material and special heat treatment processing technology of the screw barrel to ensure its corrosion resistance and strength.
Third, due to the difference between auto parts and conventional products, its cavity surface is very complex, with unequal stress and uneven stress distribution. In the design, we should focus on the processing capacity it needs. The processing capacity of injection molding machine is reflected in two aspects: clamping force and injection molding capacity (expressed by the maximum theoretical injection volume).
Fourth, according to the characteristics of complex plastic parts of the automobile, the driving form of the injection molding machine and the design of the clamping mechanism are mostly used in China. At present, the hydraulic elbow of the hydraulic mechanical type or the full hydraulic type, or the injection molding machine of the central direct pressing clamping mechanism.
Fifthly, because the cavity surface of auto parts is very complex, the particularity of the injection molding machine should be considered in the design, and some special function programs should be configured: such as multi group core pulling function, timing control function, supporting mold changing device function of the injection molding machine, supporting part taking manipulator device function, etc. These special functions have obvious advantages in the production of automotive plastic parts.
Post time: Apr-22-2022