Three items to help you select hot runner

Three items to select a hot runner

With the accumulation of our high-quality customers, we have developed new projects that use hot runner systems for plastic injection molds or injection molding accessories. We should analyze the pressure of injection parts before using a hot runner system. Use a heating method that can process the size of the plastic melt channel. Realize multi-area temperature control. We determine whether the hot runner system is correct for you through five items.

 Item 1

Hot runner system mold users have a misunderstanding. the plastic melt in the hot runner system is always hot, so hot runner injection pressure loss is much smaller than the cold runner. In fact, to meet the hot runner structure design needs, the melt flow distance in the hot runner system will greatly increase. Injection pressure loss in the hot runner system is not a small glimpse.

In practical applications, due to the hot runner injection pressure loss is too large. Resulting in injection molded part difficulties are many, so the processing flow of plastic (such As PC, POM, etc.). The melts flow from the hot runner system large parts weight, etc., It should be adopted can software flow analysis calculation. The heating method is to install the heater directly from the molten raw material through the internal heating system. A heating system realizes external heating raw material, which flows through the flow channel without hindrance. The external heating system solves the dead point problem in the melt channel. The melt in the shear curve is also more reasonable.

Item 2

Gate type: There are several types to choose from. Factors to consider include the allowed traces of the gate,

gate location, and type of injection molding materials. Whether non-crystalline, crystalline or thermoplastic elastomer, different gate types of specific raw materials restrictions. Understanding of the gate to use the most appropriate materials to help choose the best gate.

Can the types of processing plastic be considered when choosing a hot runner system, the type of plastic to be processed? For example, if the processing of glass-reinforced plastic (such as glass-reinforced nylon material, etc.) It should be used in the wear resistance of a good gate inserts. So easily processed, the thermal decomposition of plastic (PVC) should be used in the runner smooth. There is no flow of dead ends hot runner system. The processing flow of plastic (pc) should be considered to use a larger nozzle series runner cross-section dimensions and in the hot runner plate. The size of the melt Road Plastic injection molded parts and processing conditions in order to ensure optimal system performance analysis.

Therefore, not only to consider the weight of the product, but also to calculate the appropriate size of melt road. Including a melt flow index, injection time, injection molding cycle and the melt temperature and so on. Suitable melt channel size is critical to the performance of the hot runner. In appropriate melt channel size will lead to plastic degradation, resulting in injection molded parts uneven or filling is not complete,and slowly change color.

Item 3

In order to determine the optimal beam size, we need to consider such factors as pressure drop, residence time, temperature, shear rate, color change frequency and so on. Process parameters of complex hot runner system for plastics with sensitive processing temperature and narrow processing range. The multi-zone temperature control of hot runner design should be selected. The user can adjust and control the temperature distribution according to the local.

The ideal system should have a uniform temperature distribution, but there are actually many reasons for the difference in hot runner temperature. such as the mass of hot runner heating parts, heat loss and mold in hot runner. The larger the size and complexity system, the more multi-zone temperature control system should be selected.