Definition and classification of blow molding machine industry
Views: 6 Author: Site Editor Publish Time: 2022-06-29 Origin: Site
How is the blow molding machine industry defined? Blow molding machine, also known as hollow extrusion blow molding machine, is a rapidly developing plastic processing method. The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is placed in a split mold while it is hot (or heated to a softened state), and compressed air is introduced into the parison immediately after closing the mold to blow the plastic parison. It expands and sticks closely to the inner wall of the mold, and after cooling and demoulding, various hollow products are obtained. The definition and classification of the blow molding machine industry are as follows. The manufacturing process of blown film is very similar in principle to blow molding of hollow products, but it does not use a mold. From the perspective of plastic processing technology classification, the molding process of blown film is usually included in extrusion. The blow molding process began to be used to produce low density polyethylene vials during World War II. In the late 1950s, with the birth of high-density polyethylene and the development of blow molding machines, blow molding technology was widely used. The volume of hollow containers can reach thousands of liters, and some production has adopted computer control. Plastics suitable for blow molding include polyethylene, polyvinyl chloride, polypropylene, polyester, etc., and the obtained hollow containers are widely used as industrial packaging containers.
Definition of hollow blow molding machine industry
The market research report of blow molding machine shows that after the liquid plastic is sprayed out, the plastic body is blown to a certain shape of the mold cavity by the wind blowing from the machine to make a product. This kind of machine is called a blow molding machine. The plastic is melted and quantitatively extruded in the screw extruder, and then formed through the oral film, and then cooled by the air ring, and then pulled by the tractor at a certain speed, and the winder winds it into a roll.
Blow molding machines can be divided into three categories: extrusion blow molding machines, injection blow molding machines and special structure blow molding machines. Stretch blow molding machines can fall into each of the above categories. Extrusion blow molding machine is a combination of extruder, blow molding machine and mold clamping mechanism. It consists of extruder and parison die, inflation device, mold clamping mechanism, parison thickness control system and transmission mechanism. The parison die is one of the important parts that determines the quality of blow molding products, and there are usually side feed die and central feed die. When large-scale products are blow-molded, the accumulator-type parison die is often used. The smallest volume of the storage tank is 1kg, and the largest can reach 240kg. The parison thickness control device is used to control the parison wall thickness, and the control point Z is up to 128 points, generally 20 to 30 points. The extrusion blow molding machine can produce hollow products with a volume ranging from 2.5ml to 1000 liter.
Injection blow molding machine is a combination of injection molding machine and blow molding mechanism, including plasticizing mechanism, hydraulic system, control electrical appliances and other mechanical parts. Common types are three-station injection blow molding machines and four-station injection blow molding machines. The three-station machine has three stations for preform, inflation and demoulding, and each station is separated by 120°. The four-station machine has one more preforming station, and each station is separated by 90°. In addition, there are double-station injection blow molding machines with 180° separation between the stations. The plastic containers produced by the injection blow molding machine are accurate in size and do not require secondary processing, but the mold cost is high.
The special structure blow molding machine is a blow molding machine that blows hollow bodies with special shapes and uses from sheets, molten materials and cold blanks for parisons. Due to the different shapes and requirements of the products produced, the structure of the blow molding machine is also different.
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