NANJING LESUN SCREW CO.,LTD

The Causes of Extruder Screw Abrasion and the Methods of Reducing Abrasion

The extruder screw is operated under high pressure, high temperature, high mechanical torque and high friction environment for a long time. Generally, the extruder screw has undergone surface nitriding treatment to improve the surface hardness, that is, to improve the wear resistance.


However, if the cause of wear is neglected and the wear is not minimized, it will inevitably greatly reduce the working life of the extruder screw for sale.


Ⅰ. Reasons for abrasion of extruder screw and methods to reduce abrasion


1. The screw speed of the extruder should be adjusted properly, because some plastics are added with strengthening agents, such as glass fiber, minerals or other fillers. The frictional force of these substances on metal materials is often much greater than that of molten plastics.


When injecting these plastics, if a high speed is used, while increasing the shearing force to the plastic, it will also make the reinforcement correspondingly produce more torn fibers. The shredded fibers contain sharp ends, which greatly increase the abrasion force. When inorganic minerals slide at high speed on the metal surface, their scraping effect is not small. Therefore, the speed should not be adjusted too high.


2. Each plastic raw material has an ideal plasticizing processing temperature range, so the processing temperature of the barrel should be controlled to make it close to this temperature range.


Granular plastic enters the barrel from the hopper and first reaches the feeding section. Dry friction is bound to occur in the feeding section. When these plastics are not heated and melted unevenly, it is easy to cause the inner wall of the barrel and the outer surface of the extruder screw to increase. Similarly, in the compression section and the homogenization section, if the melting of the plastic is disordered and uneven, it will also cause increased wear.


Ⅱ. If the screw assembly gap in the extruder barrel is too large, what will be influenced?


1. The output of the products produced by the extruder is unstable or the output decreases.


2. If the working surface gap between the screw and the extruder barrel is too large, the amount of reflux material generated when the screw is plasticized and the melt is pushed forward is large. The result of this is that part of the molten material stays in the barrel for a long time and becomes yellow, which causes discoloration or focal spots on the surface of the product.


3. If the gap is too large, the pressure of the extruded melt will be unstable, resulting in a large error in the geometric shape and size of the product's cross-section.


4. Because the gap is too large, the melt flow rate pushed out by the screw and barrel of the extruder is also unstable, which makes the surface of the product prone to horizontal wrinkles.


After ten years of vigorous development, our company now has a number of advanced CNC machine tools and special processing equipment for screw manufacturing. Now our machining operations have basically realized intelligence and automation.


Advanced processing methods, strong technical force, and sophisticated processing technology ensure that the quality and technical indicators of each production fully meet customer requirements. If you want to learn more, please feel free to contact us!

  • How to Prevent the Dual-alloy Screw from Slipping?

    How to Prevent the Dual-alloy Screw from Slipping?

    November 5, 2021When the bi-alloy extruder screw is difficult to press at the feeding port, or the adhesive force along the length of the extruder barrel cannot be formed to convey the material, the screw of the bi-a...view
  • The Reasons Why the Extruder Screw Suddenly Does Not Rotate

    The Reasons Why the Extruder Screw Suddenly Does Not Rotate

    June 8, 2021During the extrusion process, the extruder screw may suddenly get stuck. At this time, if the protection device of extruder does not work, the operator should immediately stop the operation. More comm...view
  • Three basic structural forms of extruder screw

    Three basic structural forms of extruder screw

    August 3, 2021According to the change of the screw lift and the depth of the screw groove, the screw of the conventional full-thread three-stage extruder can be divided into three types:Ⅰ. Isometric variable depth...view
  • Repair Welding Plan after Extruder Screw Wear

    Repair Welding Plan after Extruder Screw Wear

    November 24, 2021The components of the extruder screw frequently suffer from wear and tear, and the cost of direct replacement is relatively large, and the economy is poor. Today we perform repair welding on the worn ...view
top Inquiry