Key Points Of Pressure Control During Injection Molding Of Folding Chair

Update:05 Nov 2021

  When folding chair manufacturers produce plastic chai […]

  When folding chair manufacturers produce plastic chair surfaces, the process used is injection molding. However, the control points that need to be paid attention to when using this process are as follows:

  1) Injection pressure: In the current production, the injection pressure of almost all injection machines is based on the pressure applied by the plunger or the top of the screw to the plastic (converted from the oil pressure) as the standard. The role of injection pressure in injection molding is to overcome the flow resistance of the plastic from the barrel to the cavity, to give the molten material the rate of filling the mold, and to compact the molten material.

  2) Plasticizing pressure: (back pressure) When using a screw injection machine, the pressure on the top of the screw when the screw rotates and retreats is called plasticizing pressure, also known as backpressure. The size of this pressure can be adjusted by the overflow valve in the hydraulic system. In the injection, the size of the plasticizing pressure needs to be changed with the design of the screw, the requirements of the product quality, and the type of plastic. If these conditions and the screw speed are the same, increasing the plasticizing pressure will strengthen the shear Function, that is, it will increase the temperature of the melt, but it will reduce the efficiency of plasticization, increase the reverse flow, and leakage, and increase the driving power.

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