The wire drawing problem of needle valve hot runner system generally appears relatively rare, a small number of oil pressure systems and is the sealing method of the valve needle hitting the water nozzle material occasionally, because when the valve needle seals the glue, a piece of plastic in the hot nozzle will be pushed forward to the water nozzle position, and when the needle is in place, a part of the material in the water nozzle cools and shrinks, and the oil pressure system is relatively large but slow, so the glue extruded in the hot nozzle is easy to stick to the surface of the valve needle to form a wire drawing. The solution is as follows:
1. The hot nozzle is heated in two stages.
2. Shorten the formation of valve pins and reduce the influence of valves on water nozzles.
3. The valve pin is opened to the return groove to reduce the plastic pushed out.
4. Reduce the gate size of the system when the amount of glue is allowed.
5. Add a cooling device to the hot nozzle gate area to reduce the temperature of the valve pin
