Basic concept of mold cavity size for blow molding products

Author: MULAN - Plastic Molding Manufacturer

Basic concept of mold cavity size for blow molding products The cavity size of the blow molded product is mainly determined by the overall size of the blow molded product and the shrinkage rate of the material. Shrinkage generally refers to the ratio between the size of the mold cavity at room temperature (20-22 ) and the size of the blown product after molding for 24 hours. The shrinkage of most plastic products is in-process If it occurs within 24 hours, the shrinkage of some blow molded products with thicker walls can be delayed for several days. There are many factors that affect the shrinkage rate of blow molded products: such as different materials used; different product volumes; different wall thicknesses of products; molding cycles in molds; In addition, blow molded products The shrinkage rate of the three molding directions is also different, and the shrinkage rate in the longitudinal direction is generally slightly larger than that in the transverse direction. The shrinkage rate of commonly used plastic blow molding products can be looked up in the table. The shrinkage rate is not a constant number in each blow molding product. It is often related to the wall thickness, weight, blow molding process, cooling and setting time, and the shape of the product. The value of the shrinkage rate is in The length, width and thickness direction of blow molded products are different; therefore, in the design of some engineering blow molded parts, it is necessary to carefully measure the relevant shrinkage value in advance. For some blow molding products that require high installation accuracy, it is necessary to measure the actual shrinkage rate according to specific conditions such as blow molding equipment, materials, and molding processes, so as to obtain the correct shrinkage rate, and then determine whether blow molding is required according to the actual situation. Blow molding product stereotypes, Blow molded product calibrator sometimes plays a vital role in the dimensional stability of the product. Proficient in moulds|blow molding products| Started in 1998, trustworthy.