Enoch ferngren and William kopitke first verified the blow molding process. The principle of this process is derived from blowing glass products. In 1938, ferngren and kopitke built a bottle blower and sold it to Hartford empire. This is the beginning of the commercial blow molding process. In the 1940s, the variety and quantity of plastic products were very limited, so the blowing process was not developed rapidly until very late. With the increase of product types and productivity, more and more plastic products are produced by blow molding technology. In the soft drink industry in the United States, the number of plastic containers has grown from zero in 1977 to 10 billion in 1999.
Blow molding process was used to produce low density polyethylene vials during World War II. In the late 1950s, with the birth of HDPE and the development of blow molding machine, blow molding technology has been widely used. The volume of hollow containers can reach thousands of liters, some of which have been controlled by computer. The hollow containers are widely used as industrial packaging containers.
According to the method of blank making, blow molding can be divided into extrusion blow molding and injection blow molding. The newly developed ones are multi-layer blow molding and tensile blow molding.
Extrusion process is to squeeze the plastic into the extrusion die head through screw, and then cooperate with the mold and compressed gas to realize the product forming.
Extrusion blow molding process consists of 5 steps: 1. Plastic embryo is made from the raw material after plasticization; 2. the partial embryo was cut off by the closing of the mold; 3. fill the mold cavity with gas to make the mold shape and cool; 4. Open the mold and take out the formed container; 5. finish the flying edge to get the finished product
Post time: Jun-08-2021