The extruder screw and alloy barrel are the soul parts […]
The extruder screw and alloy barrel are the soul parts of the extruder, and their combination is related to the working quality of the extruder, the plasticizing capacity of the material, and the production efficiency. Therefore, when the screw and barrel of the extruder are severely worn, it will affect the output of extrusion. It can be seen that the maintenance and repair of alloy barrels are important!
1. The screw of the extruder rotates in the barrel, and the friction between the material and the two causes the working surface of the screw and barrel of the extruder to gradually wear out: the diameter of the screw of the extruder is gradually reduced, and the diameter of the inner hole of the barrel is gradually increased. . In this way, the matching diameter gap between the screw and barrel of the extruder increases a little as the two gradually wear.
However, since the resistance of the die head and the splitter plate in front of the alloy barrel has not changed, this increases the leakage flow of the extruded material when it advances, that is, the amount of material flowing from the diameter gap to the feeding direction increases. As a result, the output of the extruder is reduced. This phenomenon increases the residence time of the material in the barrel and causes the material to decompose. In the case of polyethylene, the hydrogen chloride gas produced by decomposition strengthens the corrosion of the screw and barrel of the extruder.
2. Because the material is not plasticized uniformly or metal foreign matter is mixed into the material, the torque of the screw of the extruder increases suddenly. This torque exceeds the strength limit of the screw of the extruder, causing the screw of the extruder to twist and break. This is an unconventional accident damage.
3. If there are fillers such as calcium carbonate and glass fiber in the material, it can accelerate the abrasion of the screw and barrel of the extruder.
The wear resistance directly affects the production cost and product quality. At present, 6542 high-speed steel and C-type sleeves are usually used on the market. The service life of the two is generally only 3 months. When some hard materials are produced, they even need to be replaced within a few days.