Plastic products will sometimes appear silver streaks in injection molding machine production in the process of forming the phenomenon, so how do we deal with it. Next, we first look at the causes of silver streaks: plastic mold materials and water vaporization of volatile liquid materials; decomposition; shearing.
The material contains a small amount of water, in addition to causing silver streaks, whitening, bubble wave flow, forming bad phenomenon also occurs. It also has a bad effect on the fluidity and thermal degradation of the material. From the barrel to the mouth of the nozzle flow side, the gate of the material, if the temperature gradient is too large, easy to shear the material. When the gas out of the mold variation, silver streaks occur.
The solution method of the plastic silver streaks:
1 complete drying of the material. With a short period of time to do the effect of drying is not good, generally 85. C temperature drying for 4 hours to raise the mold temperature, reduce the temperature of the heating cylinder, the cylinder nozzle for thermal insulation.
2 make the edge of the flow become thick
3 avoid differences in the design of the product thickness, the thickness of the local WIP additional gate.
Because most of the material must be dry. Usually attached to the cylinder dryer. As the special needs of polycarbonate like dry materials, dry preheating in bags or cans and then poured into the dryer. If it is PVC material, easy to decompose often occurs in silver streaks.
Note: the above information is organized by Jie Zheng mold on the Internet, welcome to reprint, indicate the source!