In general, the hot runner system is divided into single-head hot runner systems, hot runner systems, and long valve gate hot runner systems. Single-head system consists of a single hot runner nozzle, the nozzle head, nozzle connection plate, temperature control systems and other components.

Single-head plastic mold hot runner system structure is relatively simple. The molten plastic from the injection molding machine nozzle connection plate after the nozzle to the nozzle head, into the cavity. The need to control the size of d, D, L, and by adjusting the thickness of the nozzle connection plate, so that the fixed mold clamping plate fixed to the end face of the nozzle connection plate, controlling the axial displacement of the nozzle, or the direct use of the injection molding machine nozzle against the nozzle webs end surfaces, may also achieve the same purpose. Suitable location in the fixed mold fixed plate is provided a lead trough, let the cord exits from the mold is connected to terminal block mounted on the mold.

Long hot runner system plastic mold structure is more complex. Molten plastic from the injection molding machine nozzle connection plate after plate of hot runner nozzle flow to the nozzle head, and then injected into the cavity. Hot runner nozzle and the stationary platen system has a radial dimension D1 complex requirements and limit the axial dimension requirements. The nozzle head with the fixed mold insert has a radial dimension d with the requirements to ensure that the plastic does not overflow the molten state to a non-cavity parts, and hardness requirements given hardened mold inserts about 50HRC. The actual distance of the parting surface to heat the nozzle must be strictly controlled axial distance L between the positioning surface of the nozzle size should be at room temperature, according to state L ', plus the actual amount of the lower mold extend the normal operating temperature of the nozzle ΔL OK. In order to ensure that the nozzle and the manifold plate fit, reliable, not to the manifold plate deformed above the top of the nozzle is provided to adjust the pad, the pad and adjust the nozzle surface along its axial positioning limits the movement of the nozzle in the axial direction, and effectively control the deformation of the manifold plate that may arise. At room temperature, adjust the control pad and the manifold plate and the fixed mold fixed plate gap between 0.025mm to heat the mold, at operating temperature just pressing state adjustment pad. Hot runner systems and positioning seat positioning pin together control the manifold plate position in the mold. Spud and stationary platen with a radial dimension D2 with the requirements, and the depth h must be controlled accurately, the axial positioning seat plays a supporting role in the manifold plate, directly subjected to injection pressure injection machine. Positioning pin fixing plate and manifold plate having mating requirements. Must be left between the manifold plate and the template is sufficient clearance, so as to wrap insulation. The manifold plate and the mounting plate must be provided with adequate wiring groove, so that the cord exits from the mold is connected to terminal block mounted on the mold. Radial dimension D1 coordination requirements between the nozzle and the connecting plate fixed mold plate fixed to an injection molding machine with a nozzle head on with a good web mold. Near the manifold plate, the fixed template, manifold plate fixed plate fixed mold fixing plate screwed up, reinforcing the rigidity of the manifold plate.

Valve gate hot runner system plastic mold most complicated structure. It is the ordinary long plastic hot runner system has the same structure, in addition to more than a needle valve actuator control valve needle opening and closing movement. This corresponds to a hydraulic actuator, the use of injection molding machine with a hydraulic device connected to the mold to form a hydraulic circuit to achieve the needle valve opening and closing movement, control molten plastic is injected into the cavity.