Type, material and daily maintenance of screw barrel of injection molding machine

Type of screw barrel for injection molding machine:

1. Features of gradual gradual change screw: The compression section is longer, the energy conversion is gentle during plasticization, and it is mostly used for PVC and other plastics with poor thermal stability.

2. Features of mutant mutant screw: The compression section is short, and the energy conversion is more intense during plasticization. It is mostly used for polyolefin, PA and other crystalline plastics.

3. Features of general-purpose general-purpose screw: The general-purpose screw with strong adaptability can be adapted to the processing of a variety of plastics and avoid frequent screw replacement.

Material of manufacturing barrel:

At present, the commonly used materials in China are 45, 40Cr and 38CrMoAIA. The material for the barrel of the imported extruder is commonly used alloy steel 34CrAINi and CrMoV9. The yield strength of this material is about 900 MPa. After nitriding, the hardness is above 1000HV, which is abrasion-resistant and has good corrosion resistance. Tungsten carbide alloy barrel, tungsten carbide alloy + chromium alloy barrel, tungsten carbide alloy + chromium alloy + nickel alloy barrel, using Material alloy steel as the base material, and casting the above alloy in the inner hole to improve the wear resistance and resistance of the barrel Corrosion performance.

Daily maintenance of the barrel:

1. Do not start the machine when the barrel screw has not reached the preset temperature. Prevent metal fragments and debris from falling into the hopper. If processing recycled materials, a magnetic hopper should be added to prevent iron filings from entering the hopper.

2. Make sure that the plastic in the barrel is completely melted when using anti-salvation to avoid damage to the transmission system parts when the screw retreats. When using new plastic, the remaining material in the barrel should be cleaned. When the temperature of the molten plastic is normal but black spots or discoloration of the injection molded product are constantly found, check whether the screw head, rubber ring, and rubber meson are worn. When the product is injection molded, try to make the material evenly plasticized to reduce the transmission torque of the screw and increase its service life.

Through the above introduction, I believe that everyone has a certain understanding of the screw barrel of the injection molding machine. In addition, there are many classifications of the screw barrel of the injection molding machine. In daily use, we must also pay attention to maintenance. Only with good maintenance can we make better use of the screw and barrel of the injection molding machine.