Are you clear about the conditions of injection molding?

Recently there are a lot of partners injection molding conditions what, the following I will take a look at the conditions of injection molding what aspects!

1、Injection pressure

Injection pressure exists to overcome the resistance of the melt in the process of flow, or we say the other way around, the resistance that exists in the process of flow is the need for injection molding machine pressure to offset to ensure that the filling process is carried out smoothly.

2、Injection time

The injection time is very short and the impact on the molding cycle is relatively small, but the adjustment of injection time has a great effect on the gate and runner and cavity pressure control.

Reasonable injection time helps to fill the melt ideally, and it is very important to improve the surface quality of the products and reduce the dimensional tolerance.

3、Injection temperature

The injection temperature must be controlled within a certain range.

If the temperature is too low, the melt will be poorly plasticized, affecting the quality of the molded parts and increasing the difficulty of the process; if the temperature is too high, the raw material will be easily decomposed.

In the actual injection molding process, the injection temperature is often higher than the barrel temperature, and the higher value is related to the injection rate and material properties, up to 30 ℃.

4、Pressure and time

At the end of the injection molding process, the screw stops rotating and just pushes forward, at which time the injection enters the pressure-holding stage.

In the process of pressure-holding, the nozzle of the injection molding machine continuously replenishes the material to the cavity to fill the empty volume due to the shrinkage of the part.

5、Back pressure

The use of high back pressure is conducive to color dispersion and plastic melting, but also extend the time of screw retraction, reducing the length of plastic fibers, increasing the pressure of the injection molding machine, so the back pressure also needs to be low, generally not more than 20% of the injection pressure.