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What are the reasons for the easy damage of the flat double barrel

  Flat double barrelRotating in the cylinder, due to the friction between the material and the two, the working surface of the screw and the cylinder gradually wears. The diameter of the flat double barrel is reduced by friction, and the diameter of the inner hole of the cylinder is enlarged by friction. Therefore, the gap between the fitting diameter of the flat double barrel and the cylinder body is getting larger and larger, and the flat double barrel is subjected to surface nitriding treatment in order to improve the surface hardness during operation. Since the resistance of the cylinder head and the splitter plate in front of the cylinder remains unchanged, the leakage flow rate when the extruded material advances, that is, the flow amount from the diameter gap to the material supply direction increases. As a result, the extruder output decreases. As a result, the residence time of the material in the cylinder increases and the material is decomposed. When the material is polyethylene, the gas produced by decomposition strengthens the corrosion of the screw and the cylinder, forming a vicious circle. Then, let's understand the reasons why the lower flat double barrel is easily damaged!



  Flat double barrelPhysical properties of the material: When the material produced by the crusher contains filling materials such as calcium carbonate and glass fiber, the friction force of these substances on the metal material is often much larger than that of the molten plastic. When injection molding these plastics, the high speed will increase the shear force on the plastic, and correspondingly will produce more chopped fibers. The chopped fibers contain sharp ends, and the wear force increases greatly. So the speed of the extruder studio should not be too high.

Flat double barrel corrosion resistance, abrasion resistance, high temperature resistant resin may unknowingly damage the screw and cylinder. For example, some engineering materials, thermoplastic elastomers, and biopolymers can create a corrosive environment. In addition, a reinforcing material (for example, glass fiber, glass ball, etc.), a part of the filler, and an additive have abrasiveness.

In order not to affect production efficiency and product quality, processors must closely monitor the hazards of these materials to equipment. In order to maintain high processing standards, it is necessary to establish a preventive maintenance plan (hereinafter referred to as "PM" plan). If necessary, check and measure the screw and cylinder, pull out the screw, reinstall or replace it. Because very little wear will also affect the quality of the product.

To protect the equipment from corrosive and corrosive resins, the best way is to select the appropriate materials for the manufacture of screws and cylinders. In order to cope with corrosive, abrasive and high temperature melts, the processing cost of manufacturing wear-resistant cylinders and screws exceeds that of standard polyolefin screws by about 3 to 4 times. This is because the price of wear-resistant alloys is relatively high and difficult to process. However, they can provide longer life and extended maintenance intervals.

When the flat double barrel material is not plasticized or mixed with metal foreign matter: the torque force of the screw increases sharply, the torque exceeds the screw strength limit of the screw extruder, and the screw moves, which is not a conventional damage.

The plasticizing range of each plastic is different: each plastic has an ideal plasticizing processing temperature range. Granular plastic enters the barrel from the hopper and first reaches the feeding section. The feeding section will inevitably produce dry friction. If these plastics melt due to insufficient heat Uniformity, the plastic will melt unevenly. Similarly, in the compression section and the homogeneous section, the melting state of the plastic is not uniform, and the wear increases.

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