The functional design requires that the plastic part sh […]
The functional design requires that the plastic part should have the function that meets the purpose of use, and meet certain technical indicators. The plastic part is a mouse base, and the probability of bearing external forces is small, such as impact load, vibration, and friction. The temperature is room temperature, which reduces the requirements for thermal deformation temperature, embrittlement temperature, and decomposition temperature when selecting materials; as a daily product, the production batch should be medium to medium or large batch production, so the production cost must be considered And mold life, various factors must be integrated in the choice of materials.
There are many factors that affect the accuracy of the product. The first is the manufacturing accuracy of the mold and the amount of mold wear, and the second is the fluctuation of the shrinkage of the plastic caused by the changes in the molding process conditions. In addition, the change in efficiency after molding and the shape of the mold structure also have a certain effect on dimensional accuracy. Therefore, the accuracy requirements for plastic products should not be too high, and the low accuracy level should be selected as much as possible under the condition of ensuring the use function.
The surface roughness of plastic parts is mainly determined by the surface roughness of the mold, in addition to avoiding cold scars, ripples and other defects as far as possible from the process when molding. The apparent defects of plastic parts are their unique quality indicators, including lack of material, flash and flash, depression and shrinkage, air holes, warping, etc. The surface roughness of the cavity wall of the mold is the decisive factor of the surface roughness of the plastic part, which is usually a grade higher than that of the plastic part.