Precautions for extrusion molding operation of plastic strapping

Packing steel belt manufacturers will introduce to you the precautions for plastic packing belt extrusion molding operations
　　(1) The filling ratio of the machine belt should be strictly controlled to ensure the tensile strength of the machine belt.
　　 (2) The temperature control of the barrel should be gradually increased from the feeding section to the homogenizing section. The mold temperature should be equal to or slightly lower than the maximum temperature of the barrel.
　　(3) When extruding and plasticizing the raw materials of the packing belt, a perforated plate and a filter screen should be added in front of the barrel. The number of meshes and layers of the mesh should be determined according to the requirements of the raw materials and the working conditions of the belt; the number of meshes should be greater than 80 meshes .
　　(4) The structure of the forming mold is a right-angle type, and the end surface of the discharge port is 150-250mm from the cooling water surface. During production, the distance between the two should be adjusted appropriately according to the width and narrow size requirements of the product.
　　(5) The extruded strip should be perpendicular to the water surface and enter the sink. If the strip is too wide, the distance from the mold to the liquid surface should be appropriately increased or the speed of the drawing roller should be increased; if the width of the strip is insufficient, the distance from the mold to the liquid surface should be reduced or the speed of the drawing roller should be reduced appropriately . If necessary, the amount of melt extrusion can also be changed by adjusting the rotation speed of the screw, so that the width of the belt can be adjusted.
　　(6) The temperature of the cooling water is controlled within the range of 25-40℃.
　　(7) The gap adjustment of the die in the forming mold should be slightly smaller than the thickness of the strip blank. This gap should be adjusted before the production start-up. During production, it can be adjusted appropriately according to the strip thickness requirements.
　　 (8) If the belt stretching heating adopts the oven method, the temperature in the oven should be divided into three temperature sections, the temperature of the inlet section of the belt should be higher, and the temperature of the outlet section should be lower. Pay attention to the stretching position of the belt. If it is stretched at the inlet section, it means that the temperature of the belt material and the oven temperature is too high; if the belt starts to stretch at the outlet section, it means that the temperature in the oven and the temperature of the belt material are too low; if the temperature of the belt material is lower than the oven temperature Appropriately, the stretching point of the belt should be in the middle section of the oven.
　　(9) Note that the belt stretching, shaping and winding speed should be synchronized. There must be a relatively constant tension during belt operation.
　　(10) The barrel temperature control in Table 13-1 does not have a relatively fixed temperature point. The production operation should be determined according to the ratio of each raw material component in the formula. For example: the temperature control with more fillers in the formula is slightly lower than the temperature control with less fillers in the formula; the extrusion speed and stretching speed are appropriately slowed down accordingly; the tensile strength of its products is also less than Tape products with less filler.