Blow molding product manufacturers talk about cooling of extrusion blow molding products

Author: MULAN - Plastic Molding Manufacturer

The cooling of blow molded products is a very important stage in the plastic extrusion blow molding process, which has a great influence on the performance, production efficiency and cost of extrusion blow molded products. Plastic blow molding, originated in the early 1930s, has developed rapidly after going through multiple stages. It is currently the third largest plastic molding method for injection molding and extrusion molding. Compared with other molding methods (such as injection molding), blow molding equipment has lower cost, strong adaptability, good molding performance and complex shapes. Blow molding products. Blow molding products have a high degree of integrity, good comprehensive performance, high added value, and low cost. They can replace plastic injection molding products, thermoforming products, structural foam products and metal products. In fact, plastic blow molding is a very fast-growing plastic molding method, and there is still great potential for development. According to the method of parison molding, plastic blow molding can be divided into two categories: extrusion blow molding and injection blow molding. Let's focus on extrusion blow molding. Its process generally includes three stages, namely, the molding of the parison, the blowing of the parison in the mold to form the product, and the cooling of the product. The cooling time of extrusion blow molding products accounts for more than 60% of the entire molding cycle, and thick-walled products account for 90%. Therefore, improving the cooling efficiency of blow molded products can shorten the molding cycle, reduce energy consumption and increase productivity. Cooling is the main factor affecting the performance of blow molded products. Uneven cooling will cause different shrinkage rates in various parts of the product, causing warping of the product, skewing of the bottleneck, etc., and may also cause premature mechanical damage to the product. In addition, cooling and shrinkage also affect the residual thermal stress in the product. The cooling of extrusion blow molded products generally includes external cooling (heat conduction between the outer surface of the product and the cavity), internal cooling (convective heat transfer between the inner surface of the product and cooling air or other media) and cooling after mold opening (the internal cooling of the product). , natural convection heat transfer between the outer surface and the workshop air or other media). Graphics and texts are for learning and communication. For more industry information, please pay attention to Proficient Mold Proficient in molds | Blow molding products factory | Started in 1998, trustworthy.