Cause analysis: Silver-white stripes appearing along the plastic flow direction near the surface or surface of the product. The production of silver wire is generally caused by vaporization of moisture or volatile matter in the plastic or moisture adhering to the surface of the mold, and the injection screw of the injection molding machine sometimes generates silver bars. The material has impurities.
Countermeasures: plastic moisture, volatiles, insufficient drying. The plastic melt is overheated or the cylinder is decomposed for too long, generating a large amount of gas, and the discharge is incomplete, and a silver wire is generated upon curing. The mold temperature is too low and the plastic melt cures rapidly, resulting in incomplete exhaust. The surface of the mold is attached with oil or moisture or a release agent, which evaporates into a gas form and liquefies as the plastic melt cools and solidifies. The screw is entangled in the air, and the cooling of the lower part of the hopper is sufficient, the temperature on the hopper side is low, and the temperature difference is different from the barrel, and the rubber granule often scratches the screw and is easily brought into the air. Poor exhaust at the beginning of the injection. The plastic melt that was initially injected quickly solidified, so that the gas was not completely discharged, and a silver wire occurred. The injection pressure is too high and the injection speed is too fast. When the thickness of the meat changes drastically, the compressed plastic melt in the flow rapidly decompresses and expands, and the volatile decomposition gas contacts the cavity to be liquefied.