TPE Thermoplastic Elastomer Welding Mark Problem

TPE thermoplastic elastomer as a soft plastic material applied in the injection moulding process will appear the problem of fusion mark, here I bring you to understand the TPE injection moulding process of fusion mark problem causes and how to solve.

TPE thermoplastic elastomer injection moulding is produced by the way the front part of the molten resin in different directions is cooled down and fails to be completely fused at the bonding place. Fusion marks are unavoidable and can only be improved by the rheological state of the melt flow front and the degree of molecular aggregation and entanglement.

How can TPE thermoplastic elastomer weld marks be solved?

A technical guide engaged in injection moulding processing suggests several improvements：

1.Effective cavity pressure is too low, increase the injection pressure, extend the injection time.

2.Increase the injection speed, high speed injection can make the TPE soft gel quickly reach the confluence, low-speed injection can let the air in the mould cavity have enough time to discharge.

3.Increase the back pressure and adjust the screw speed to obtain a higher uniform temperature of the melt: increase the screw speed, so that the viscosity of TPE plastic decreased, increase the back pressure, so that the plastic density increased.

4.Increase the temperature of the melt and nozzle temperature, high temperature plastic viscosity is small, smooth flow, fusion marks become thin, low temperature, reduce the decomposition of gaseous substances.

5.The release agent should be lower dose use, especially focus on silicone-containing demoulding reagent, otherwise it will make the material flow can be fused.

6.Lower the closing force of the mould, in order to facilitate the exhaust.