What are the methods to improve the performance of the barrel and screw of the injection molding machine?

Update:13-11-2020
Summary:

What are the methods to improve the performance of the […]

What are the methods to improve the performance of the barrel and screw of the injection molding machine?

Each plastic has an ideal plasticizing temperature range, and the barrel processing temperature should be controlled to be close to this temperature range. When granular plastic enters the barrel from the hopper, injection screw barrel will first reach the feeding section, where dry friction inevitably occurs. When these plastics are not fully heated and melted unevenly, the inner wall of the cylinder and the surface of the screw of the injection molding machine barrel will wear more easily. Similarly, in the compression section and the homogenization section, if the molten state of the plastic is disordered, wear will increase. So what are the methods to improve the performance of the barrel and screw of the injection molding machine?

How to improve the performance of the barrel and screw of the injection molding machine:

1. The speed should be adjusted appropriately. Some plastics are supplemented with reinforcing agents, such as glass fibers, minerals or other fillers. Compared with molten plastics, these materials tend to have greater friction on the barrel and screw of an injection molding machine. When molding these plastics, if they are manufactured at high rotational speeds, the shearing force on the plastics will increase, and the reinforcing materials will correspondingly generate more fibers. The chopped fiber contains sharp ends and fraying. The force is increasing. When the inorganic mineral slides on the surface of the barrel screw of the injection molding machine at high speed, the scraping effect is not small. Therefore, the screw speed of the barrel of the injection molding machine should not be adjusted too high.

2. Remove the debris in the plastic. Generally speaking, the newly purchased plastic has no debris, but it may be mixed with impurities during transportation, weighing, drying, and color mixing, especially after adding recycled materials. Small as metal scrap, the heating ring nut paper clip is as big as it has been mixed into the barrel. The damage to the barrel and screw of the injection molding machine is self-evident (the cylinder will also be damaged at the same time). Therefore, a magnet bracket must be installed to strictly manage and Monitor materials.

3. Remove moisture. The moisture contained in the plastic has a certain effect on the surface wear of the barrel and screw of the injection molding machine. If the plastic is not completely removed of moisture before injection, the residual moisture enters the compression part of the barrel screw of the injection molding machine, and forms high-pressure pressure "steam particles" melted in the molten plastic, and advances with the barrel screw of the injection molding machine. From the cross section of the screw of the injection molding machine barrel to the thread head, these "steam particles" are released and expanded during the injection process, just like the fine impurities of hard particles, which will cause frictional damage to the wall surface