date：2019-12-31view：963
no runner feed injection mold
the so-called no runner condensate mold is in the injection molding, the molten material in the runner always maintains the hot flow state. when the mold is opened, only the solidified product needs to be taken out, and no flow channel condensate is generated. compared with the traditional injection mold, this is an advanced injection mold technology, which is a hot point in the development of plastic injection molding technology. its biggest characteristic is can improve the utilization rate of material, reduce production cost, ensure the forming quality of parts.
thermoplastic fluidless plastic injection mold, it is to point to the mold through the use of heat insulation or heating method, so that from the injection molding machine nozzle to the mold cavity gate this section of the flow channel of plastic melt always remain molten, and can be continuously injected into the mold cavity.
thermosetting plastics are thermosetting injection mold, that is, by controlling the temperature to keep the molten material in the flow channel within the set temperature. development of fluid-free solidification mold technology
no runner condensate mold also known as hot runner mold, hot runner is not a new technology, in thermoplastic injection mold applications have been more than 30 years of history. e.r.nowles patented the hot runner technology in the united states as early as 1940.
it is estimated that more than a quarter of injection moulds in europe now use hot runner technology, and more than a sixth in the united states. in foreign countries, components of hot runner system have been serialized and commercialized. it is predicted that the application proportion of hot runner technology will increase year by year. in recent years, hot runner technology is still developing and improving.
in china, hot runner technology has been gradually applied since the 1980s and is still in the development and application stage. in the injection mold, its application rate is only about 2% ~ 3%. but the development prospect is very good, the market potential demand is very big.
the development of hot runner mold technology has the following trends:
1) develop and study various new nozzles, hot runner plates and related technologies to meet the requirements of different plastics and products. such as leakage prevention, wear resistance, high temperature resistance and thermal balance.
2) micro hot nozzle, heating element and temperature control technology.
3) 3d cad and its simulation technology of hot runner system.
2. hot runner injection mold
a hot runner is a heater set inside or around the runner so that the plastic melt in the runner is always in a molten state.
adiabatic runner needs to be cleaned before each use, while hot runner only needs to heat the solidified plastic in the runner to the melting temperature, and then air out. can be produced again. its application scope is wider than the adiabatic runner, and also suitable for the forming of larger products with multiple point sprue.
the hot runner system consists of two basic units: the splitter plate and the nozzle. the diverter plate is installed in the fixed mold part to transfer the molten material from the injector nozzle to the mold plate, and then the molten material is directly transferred to the mold cavity by the hot nozzle, or indirectly feed to multiple mold cavities through a cold channel. the nozzle usually passes through the cavity plate at an angle of 90 with the shunt plate.
the hot runner mold is equipped with heating, temperature measurement, insulation and cooling devices. the hot runner plate is heated and insulated, and the nozzle is the same. the diverter plate and each nozzle have separate heating elements and temperature control systems. hot runner mold has high requirement on temperature control precision, so it is difficult to prevent thermal balance imbalance.
