No matter what kind of screw is used, its tip is usually equipped with a stop valve. In order to prevent plastic from flowing out of the nozzle, a pressure reducing device or a special shooting nozzle is also installed. If you use anti-abortion supply and marketing, you must check regularly, because it is an important part of the shooting tank. At present, the switch-type nozzle is not commonly used because the plastic inside the nozzle equipment is easy to leak and decompose. At present, each type of plastic has a suitable nozzle type.
In order to obtain a high-quality melt, the plastic must be heated or melted consistently and mixed thoroughly. Only use the correct screw to melt and mix properly, and there is enough pressure in the injection cylinder to achieve the consistency of mixing and heat.
Increasing the resistance of oil return can produce back pressure in the shooting cylinder. But the screw takes longer to reset, so there is more wear and consumption in the drive system of the injection molding machine. Keep back pressure as much as possible, isolate it from air, and also need the same melting temperature and mixing degree
Many injection molding machines are equipped with screw retreat or suction devices. When the screw stops, it is retracted by hydraulic pressure to suck back the plastic at the tip of the nozzle. This device allows the use of an open nozzle. The amount of sucking back may be reduced because the ingress of air can cause problems for some plastics.
In most injection molding cycles, it is necessary to adjust the amount of rotation of the screw, so that after the injection of the screw, a small amount of soft cushion plastic is left, which can ensure that the screw reaches an effective advancing time and maintains a fixed shooting pressure. The cushion material for small injection molding machines is about 3mm; for large injection molding machines, it is 9mm. No matter how large the screw gasket value is used, it must remain unchanged. Now the size of Medical Mould the screw pad can be controlled within 0.11mm.
