1、 The reason of producing silver bar in plastic products of injection machine
1. Vaporization of water and volatile liquid in materials
2. Decomposition of materials
3. Shear of material
2、 Associated knowledge
1. The material contains a small amount of water, in addition to causing sliver marks, wavy flow lines, albinism, bubbles, etc
Good things happen. It also has a bad effect on the fluidity and thermal degradation of materials.
2. If the gradient of temperature change is too large, it is easy to
Cutting of materials.
3. When the mould gas escapes and becomes poor, there will also be sliver marks.
1. Instant: completely dry the material. (it's not good to use high temperature and short time drying, generally 85. C
Temperature drying for 4 hours) increase the mold temperature, reduce the heating barrel temperature, and keep the barrel injection nozzle warm.
2. Short time: make the flow edge thicker
3. Long term: avoid the difference of thickness of the designed products, and add gates at the places where the thickness of the products is thick.
4、 Due to material differences:
1. Because most materials have to be dry. Usually a dryer is attached to the barrel.
2. Special materials such as polycarbonate, which need to be dried, should be preheated and dried before pouring into the bag or can
3. Materials such as PVC are easy to decompose and often have sliver marks