Jiezheng mould today editorial is to introduce the black bars in plastic mold products. In the production process of plastic mold products in black bars are usually caused by the following reasons: material thermal decomposition; Injection molding machine screw damage; Due to the friction and air compression carbide materials.
Material decomposition of waste residue and injection molding machine inside the cylinder and the black is the most common. The plunger in the injection molding machine, easy to remain in the residue of each part. Valve control nozzle injection molding machine, also easy to residual residue in the valve control part. Air is compressed into a high temperature in the cylinder, the high temperature gas plus in the gate of the shear heat, is likely to become black.
Elimination of plastic mold products black bars:
1. When material replacement, reduce the injection pressure, reduce the temperature of the heating cylinder.
2. Heating cylinder cleaning (use copper wire brush).
3. Cylinder repair.
In the mixed resin paint, paint, lubricants, uv absorber, charged to prevent overheating inside the cylinder, agent, etc for a long time the retention of the material thermal decomposition is black of the cause. Especially the heat resistance of some kinds of additives, the tendency is more significant.
With polycarbonate (PC), molding with valve control nozzle article also prone to black. With countercurrent prevent washer screw also easy with charred residue. Material replacement if no special cleaning materials, then use ordinary soft polystyrene.
Note: the above information by dongguan Plastic mold factory to sort out on the Internet, welcome to reprint, indicate the source!