Polyethylene is a white powder with a glass transition temperature of 77~90 ℃. Glass transition is for amorphous polymers, where the polymer changes from a highly elastic state to a glassy state by cooling. For PVC powder, glass transition refers to the temperature range during which PVC transforms from a white powder to a glassy state. Glass PVC will start to decompose again at around 170 ℃. Light and heat have a significant impact on it, making it easy to produce hydrogen chloride. Pay attention to temperature control during transportation, and it is best not to exceed 40 ℃.

  In order to carry out molding, a grinding machine is used to transform phenolic resin from dry formed particles or blocks into powder. During the transportation between the grinding machine and the processing equipment or storage bin, the powder engineering adopts negative pressure conveying of PVC raw materials. The main purpose of this design is to maximize the performance of the equipment, avoid overheating of the grinding machine, and prevent all suction airflow from being sucked in from the grinding machine, which plays a role in blowing and cooling the grinding machine. Due to the fact that the air volume required for blowing is much greater than that required for suction, special attention should be paid in the design. The air volume of the suction device is determined based on the needs of blowing the grinding machine rather than the saturation air volume coefficient of suction.

  In addition, attention should also be paid to the application of two types of pneumatic conveying equipment, bag filter and rotary feeder, in the system: negative pressure thermosetting plastic bag filter should have a low ratio of processing air volume to filtration area, and should be equipped with explosion venting vents, bag filters, and all parts of the entire dust collector should be grounded to eliminate static electricity; The clearance between the impeller and the housing of the rotary feeder should be tight to reduce plastic thermal deformation.