date：2020-06-18view：333
a hot runner is a heating method that ensures that the plastic flows and the gate remains molten. a hot runner system usually consists of a hot nozzle, a split plate, a temperature control box and accessories. hot nozzles usually include two types: open hot nozzles and needle valve type hot nozzles. because the form of hot nozzle directly determines the choice of hot runner system and mold manufacturing.
the advantages of hot runner system are as follows:
saving raw material and reducing product cost are the remarkable characteristics of hot runner system mold. ordinary gate system will produce a large amount of material, in the production of small products, pouring system runner weight may exceed the product weight. because plastic in hot runner mold has been in a molten state, the product does not need to repair gate, mainly is no waste treatment, so can save a lot of raw materials. work, time, energy and consumption are saved by eliminating waste recycling, selection, grinding, dyeing and other processes. since the injection molding material is no longer mixed with the gate material after recycling treatment, the product quality can be significantly improved, and because the pouring system plastic remains molten and the flow pressure loss is small, it is easy to achieve multi-gate, multi-cavity molds and low-pressure injection bulk products. hot gate is conducive to pressure transfer, to a certain extent can overcome the plastic parts due to the lack of filling materials caused by depression, shrinkage, deformation and other defects.
suitable for a variety of resins, convenient for setting molding conditions. due to the continuous improvement and development of hot runner temperature control system technology, the current hot runner can not only be used in the melting temperature range of wider polyethylene, polypropylene, but also can be used in the processing temperature range of narrower thermosensitive plastics, such as polyvinyl chloride, polyformaldehyde. for polyamide (pa), which tends to salivate, a hot runner system can be formed by selecting a valvular hot nozzle.
in addition, the operation is simplified, shorten the molding cycle is also the important characteristics of hot runner mold. compared with ordinary runner, it shortens opening and closing stroke, not only shortens demodulation and forming cycle of parts, but also helps to realize automatic production.
