With ordinary mould match, although the needle valve type hot runner system is the price of money is higher, to determine the thickness of the die and mould processing capacity and higher (except the spring nozzle needle valve type), the system is more complex, easily left gate mark on products of faults, but after using this system, the output quality not high quality products. The hot channel flow plate is connected with the nozzle and the injection molding machine, and the plastic melt in the molten state of the injection mold is separated to each nozzle through the heating channel plate. Therefore, it not only has the advantages of high precision, high reliability, but also simple and convenient loading and unloading on the mold. In addition, the height of the nozzle is large (as shown in figure 1), thus increasing the mold的制造本钱。 
  Nozzles have a variety of specifications and models to choose from, which are generally determined according to customers' different requirements or according to different plastic characteristics. In a hot runner system, there are two types of gate: open type and needle valve type. As a result, the products into the water just seem to contact directly to the injection molding machine nozzle, make the finished product in the stripper, because the role of the needle valve and closed the nozzle mouth, avoid one or a few on the nozzle, thus have no fee. For the cylinder usually use needle valve type nozzle, in with the mold assembly process, in order to guarantee and the cavity plate, runner plate, mold with high accuracy (alignment) on the bottom, is needed to progress mould machining precision of the corresponding supporting departments, at the same time, it also brings much inconvenience to installation and maintenance work.