PVC Six Cross Pipe Fitting Mould

Mould name: six cross pipe fitting mould

Cavity: 1 cavities

Mould size:110x48x48x48x48mm

Mould steel:Germany2316 china2316 or4cr13 for the cavity and core

mould structure:Oil cylinder

Hardness of core/cavity: HRC 40-45°degree after vaccum heat treatment

Injection moulding machine:  530T

      Taizhou Huangyan Hong Jin mould Co., Ltd was established in 2002.We are professional in design and manufacture the pipe fitting mould for more than 23  years.

      Its gate is a little bigger than submarine gate. The product cycle time is short. But the gate cannot be separated from the product, so it need worker to cut. And product surface looks not so well.

1. Increase the holding pressure and time

Maintaining pressure: This is the most essential means. Increasing the holding pressure can continuously replenish the mold cavity. Usually set at 50% -80% of the injection pressure, for areas with severe shrinkage, it can be attempted to increase it to near the injection pressure.

Pressure holding time: It is necessary to ensure that the pressure holding time lasts until the gate solidifies and seals. If the holding time is shorter than the gate freezing time, the internal melt will inevitably flow back after the pressure is removed, resulting in shrinkage.

2. Reduce the temperature of the melt and mold

Melt temperature: Reduce the material temperature appropriately while ensuring fluidity. The temperature is too high, the material has a large coefficient of thermal expansion, and the cooling shrinkage rate is also high; And cooling can increase the viscosity of the melt, making the transmission of holding pressure more effective.

      Mold temperature: Although high mold temperature is beneficial for glossiness, excessively high mold temperature can prolong the cooling time, leading to excessive crystallization of crystalline materials (such as PP, PE, POM) and intensified shrinkage. For shrinkage marks, usually lowering the mold temperature appropriately (within the allowable deformation range) can help to quickly shape and reduce dents.

3. Adjust the injection speed

For thick walled parts, high-speed injection is usually used to ensure that the mold cavity is quickly filled before the melt cools and solidifies, reducing viscosity loss during the flow process.

      However, near the gate, excessive shear heat may cause local overheating, which needs to be fine tuned according to the actual situation.