Plastic molds can be divided into three categories according to the different types of gating system
(1) Hot runner mold: the structure of this kind of mold is roughly the same as that of the fine nozzle. The considerable difference is that the flow channel is located in one or more hot runner plates and hot pump mouths with constant temperature. There is no cold material demoulding, and the flow channel and gate are directly on the product. Therefore, the flow channel does not need demoulding. This system is also called no nozzle system, which can save raw materials and is suitable for expensive raw materials In case of high product requirements, it is difficult to design and process, and the mold cost is high.
(2) Large gate mold: the runner and gate are on the parting line and demoulded together with the product during mold opening. The design is quite simple, easy to process and low cost, so many people use the large gate system.
(3) Fine nozzle mold: the runner and gate are not on the parting line, but generally directly on the product. Therefore, more groups of nozzle parting lines should be designed. The design is complex and the processing is difficult. Generally, the fine nozzle system should be selected according to the product requirements.
Hot runner system, also known as hot runner system, is mainly composed of hot runner sleeve, hot runner plate and temperature control electric box. Our common hot runner system has two forms: single point hot gate and multi-point hot gate. Single point hot gate is to directly inject molten plastic into the mold cavity with a single hot gate sleeve. It is suitable for plastic molds with single cavity and single gate; The multi-point hot gate branches the molten material into each sub hot gate sleeve through the hot sprue plate, and then enters the mold cavity. It is suitable for single cavity multi-point feeding or multi cavity mold