Hot runner system classification

In general, the hot runner system is divided into Thermal system (COOL ONE) External thermal hot runner system, Including HOT SPRUE BUSHINGS, HOT ONE/GATE-MATE And needle valve hot runner system (POLYVALVE).

The single nozzle hot runner system consists of a single hot nozzle, a hot nozzle head, a hot nozzle connecting plate, and a temperature control system. Single mouth hot runner system plastic mold structure is relatively simple. The molten state plastic is injected into the hot nozzle connecting plate from the injection molding machine, and after the hot nozzle reaches the hot nozzle tip, the cavity is injected. It is necessary to control the dimensions d, D, L, and by adjusting the thickness dimension of the hot nozzle connecting plate so that the fixed mold fixing plate presses the end surface of the hot nozzle connecting plate to control the axial displacement of the hot nozzle or directly use the hot nozzle of the injection molding machine to withstand The end face of the hot mouth connecting plate can also achieve the same purpose. A lead wire slot is provided at a suitable position of the fixed mold fixing plate to allow the power cord to be led out of the mold and connected to the wiring block installed on the mold.

The plastic mold structure of the multi nozzle hot runner system is rather complicated. The molten plastic is injected into the heat nozzle connecting plate by the injection molding machine, and then reaches the hot nozzle through the runner plate to the hot nozzle, and then injections into the cavity. The hot nozzle and the fixed template of the hot runner system have radial dimension D matching requirements and axial size limit requirements. The hot mouth and the fixed insert block have radial size d matching requirements, ensuring that the melting state of the plastic does not overflow to the non - cavity, and requires the hardness of the die insert to harden about 50HRC.The distance between the parting surface and the axial orientation surface of the hot nozzle must be strictly controlled. This size should be determined by the actual distance L 'of the hot nozzle at normal temperature and the actual extension of the hot nozzle under the normal working temperature of the mold at the L. In order to ensure that the hot nozzle and the hot runner plate are reliable, not to cause the deformation of the hot runner plate, the adjustment cushion above the top of the hot nozzle is set up. The adjustment pad and the axial orientation surface of the hot nozzle restrict the axial movement of the hot nozzle, and effectively control the possible deformation of the hot runner plate.

Under the condition of normal temperature, the adjustment pad is controlled by the 0.025mm gap between the heat flow plate and the fixed plate for the mold to be heated so that the adjusting pad is properly pressed in the working temperature state. The locating seat and the locating pin of the hot runner system together control the position of the hot runner plate in the mold. The positioning seat and the fixed template have radial size D2 requirements, and the depth of H must be controlled accurately. The axial position of the positioning seat supports the function of the hot runner plate and directly bears the injection pressure of the injection machine.The locating pin and the hot runner plate have matching requirements. There must be enough space between the hot runner plate and the template to wrap the insulation material. The hot runner plate and the fixed plate must be provided with enough wiring grooves so that the power cord can be drawn from the mold and connected to the wiring base installed on the mould. A radial dimension D1 matching requirement is arranged between the hot nozzle connecting plate and the fixed mould fixing plate, so that the injection head of the injection molding machine matches well with the hot nozzle connecting plate on the mould. Near the hot runner plate, the fixed formwork, the hot runner plate fixing plate and the fixed mould plate are connected with screws to enhance the rigidity of the hot runner plate.The needle valve type hot runner system is the most complicated structure of the plastic mold. It has the same structure as the common multi nozzle hot runner plastic mould, and there is a set of valve needle transmission device to control the opening and closing motion of the valve needle. The transmission device is equivalent to a hydraulic cylinder, which uses the hydraulic device of the injection machine to connect with the mold to form a hydraulic circuit to realize the opening and closing of the needle and controlling the injection cavity of the molten state of the plastic.