How to control pressure in two-color injection molding

The two most important processes for two-color injection molding and two-color injection molding are filling and pressure holding. Next, Heng zhao will tell you how to control pressure in two-color injection molding.

1. Injection pressure
In the current two-color injection molding process and 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 by 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
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.

In addition, increasing the plasticizing pressure can often make the temperature of the melt uniform, the mixing of pigments uniform, and the gas in the melt can be discharged. In general operation, the decision of plasticizing pressure should be as low as possible under the premise of ensuring good product quality. The specific value varies with the types of plastic two-color molds used, but usually rarely exceeds 20 kg/cm².

The pressure control related to two-color injection molding and two-color injection molding processing is briefly introduced here, and I hope it will be helpful to everyone. Heng zhao specializes in the design and production of two-color molds, welcome to consult.