Due to the volume shrinkage of Dalian injection molding, the surface raw materials at the wall thickness are pulled in, and there are concave marks on the surface of the finished product. Shrinkage is one of the most undesirable phenomena on the surface of finished products, mostly at the wall thickness. Generally, if the pressure decreases, the shrinkage probability will be greater.

When designing the mold, it is necessary to consider removing unnecessary thickness. Generally, the wall thickness of the molded product must be as uniform as possible; If the molding temperature of injection molded parts is too high, shrinkage is easy to occur on the back of wall thickness, ribs or protrusions. This is because the places easy to cool are solidified first, and the raw materials of the parts difficult to cool will move there. Try to control the shrinkage in a place that does not affect the quality of finished products.

Generally, reduce the molding temperature and mold temperature to reduce the shrinkage of raw materials, but it is bound to increase the pressure. The invention relates to a molding method of injection and molding. The advantages of injection molding method are fast production speed, high efficiency, automatic operation, many colors and varieties, simple to complex shapes, large to small sizes, accurate product sizes, easy renewal of products, and can form parts with complex shapes. Injection molding is suitable for mass production and molding processing fields such as products with complex shapes.