Spring needle nozzle does not require an external hydraulic or pneumatic drives, but the use of injection pressure and the spring will come to realize the nozzle port automatic switch, the reliability of its action is based on high-precision needle valve and the shunt with the base shuttle above. Therefore, it not only has high a ccuracy, high reliability, the advantages of working together and the mold is simple and convenient. Hot runner feed system that is non-flow casting system is the only product after product ejection system itself, without casting solidification of material, the mold with this casting system called hot runner systems. In the hot runner system, there are two forms of casting ports: open and needle type. Needle-type hot runner system works is: the nozzle and hot runner plate installed in the injection mold, using the principle of heat, so that the plastic came out from the injection molding machine barrel remain molten. As a result, products can directly into the water if exposed to the same injection molding machine nozzle, so that finished in the ejection, due to the role of needle nozzle mouth closed to avoid one or several outlet, which no fee material generated. Compared with the normal mold, although the needle-type hot runner system has high cost, scheduled to die thickness and volume of processing large fixed mold (except outside the nozzle needle spring), the system is complex, easy to stay on the product so under the gate marks the shortcomings, but using this system, can produce high quality and stable quality products. The advantages of needle-type hot runner mold is: Can shorten the processing cycle, improve production efficiency; Since replacing the cold runner, does not produce material to (intake material), no longer crushed, can save a lot of raw materials; Improve product consistency, no signs of raised gate, complete elimination of the gate salivation, without drawing the phenomenon; Significantly improve the appearance of the product; Help reduce the stress products, reduce product caused by brittle deformation and structure, thereby enhancing the production capacity of complex structured products and service life; Programmed to provide more processing in order to accurately adjust the injection molding process; Replacement of injection materials without restriction. Typically, needle-type hot runner system consists of three parts - hot runner plates, nozzles and thermostat. Hot runners plate connected with the nozzle and injection molding machines, injection molding out of the molten plastic melt segregation by adding to each hot runner nozzle plate. Diversion of plastic melt injected into each nozzle by heating cavity, through the full lower injection pressure, the product can reduce stress, improve product quality. Thermostat to control the use of thermocouples in the nozzle and manifold heater temperature, the molten plastic to keep the best to play in the hot runner temperature control system role. Nozzle with a wide choice of specifications and models, generally based on different needs of customers or for different plastic properties determined. Cylinder is usually used for the nozzle needle, the die assembly in its process, in order to ensure that with the cavity plate, flow plate, the mold on the floor of the high-precision (coaxial) complexes to be improved the corresponding part of the mold with precision, the same time, it also gives the installation and maintenance work to bring a lot of inconvenience. In addition, the height of the nozzle a larger size, thus increasing the manufacturing cost of the mold. In recent years, Fraser Ltd. in Japan based on the nozzle needle, developed a patented spring-valve nozzle. The nozzle is characterized by: injection pressure and the spring can stretch as the driving force to the nozzle of the automatic switch to achieve, without additional pressure or hydraulic device such as an external drive. Spring needle nozzle because of the unique structure, with the mold assembly, only with the cavity plate (single blocks) occurs between the assembly, thereby greatly reducing the installation and maintenance of the difficulty of the process, reduce manufacturing costs of the mold, while also eliminates the need for pneumatic cylinder nozzle needle control device. Particularly in the casting mold in a single point, they bring convenience and use of the simplified structure is die nozzle needle cylinder or other forms of nozzles that can not be compared. Nozzle needle spring works are: Pressure did not result in the case of injection, the spring will remain off the needle. Injection molding machine to work, the injection pressure rising. When a certain pressure, the injection needle to overcome the spring pressure to back pressure, nozzle port is opened. In the set pressure state, the largest open mouth of the nozzle and make plastic filled cavity. When the mold cavity is filled with plastic and after a certain time after the holding pressure, injection pressure drops, the spring action of the spring needle automatically and reliably under the top, back to the original state, when the nozzle mouth is closed. Nozzle needle spring the main advantages are: Nozzle mouth off very reliable. Needle under the action of the spring force can be completely shut down the nozzle mouth, no ladder or gate prominent phenomenon in the Ministry. Plastic nozzle runner stranded in the phenomenon does not occur. The use of streamlined flow path nozzle type, prevents the plastic stays in the nozzle sprue affect the quality of injection molded parts. Needle and oriented with high precision parts, spring does not produce plastic reflux into the interior problem. Since spring is the use of materials, superalloys are made through special processing technology, so long life. The selected nozzle has high strength alloy materials, through the use of advanced equipment and ultra-precision processing means, it has a high precision and high quality. Good balance of the gate. In each nozzle, due to the same pressure, so that valve can be opened simultaneously, and thus will not have caused the imbalance in the gate forming undesirable phenomenon.

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