We all know that double color mould have pressure in the process of injection molding processing technology. To put it bluntly, double color mould pressure maintaining phase function is continuous pressure, compaction melt, increase the density of the plastic, a kind of technology to compensate for plastic shrinkage behavior. What are the precautions for so double color mold pressure-keeping?

1. In the holding stage, due to high pressure, plastic part of compressible characteristics. In high pressure region, plastic is relatively compact, high density; In the low pressure area, the plastic is relatively loose, low density, thus causing density distribution with changing position and time.

2. In the process of double color mold pressure-keeping, due to the mold cavity is filled with plastic, high back pressure. In the process of compaction pressure, injection molding machine screw can only make tiny movement forward slowly, the plastic flow speed is relatively slow, then the current called the holding current. Because in the holding stage, plastic mold cooling solidification is accelerated, the melt viscosity increase quickly, so the resistance within the mold cavity is very large.

3. The pressure in the process of plastic flow rate is extremely low, the flow is no longer play a leading role; Pressure of the main factors affecting the holding process. Plastic has been full of cavity pressure maintaining process, gradually solidified melt at this time as the transfer medium of pressure. The pressure in the cavity with plastic to the surface of the wall, has a tendency to open mould, so need proper clamping force of clamping.