The hot runner is heated to ensure that the plastic of the runner and gate remains molten. Because there is a heating rod and a heating ring near or in the center of the runner, the whole runner from the nozzle outlet of the injection molding machine to the gate is in a state of high temperature, so that the plastic in the runner remains molten. Generally, it is not necessary to open the runner to take out the coagulant after stopping the machine, but only to heat the runner to the required temperature when starting the machine. For this reason, the hot runner process is sometimes referred to as a hot collector system, or as channelless molding. Advantages and Disadvantages of hot runner technology Hot runner technology has the following advantages over conventional cold runner:
1. Save raw materials and reduce costs.
2, shorten the molding cycle, improve the efficiency of the machine
3. Improve the surface quality and mechanical properties of products.
4, do not need to use three plate automatic blow molding machine can be used point gate.
5, can be economically to the side gate forming a single product.
6, improve the degree of automation.
7, the use of needle valve gate control gate freezing.
8. The quality of injection parts of the multi-mold cavity automatic blow molding machine is consistent.
9. Improve the surface aesthetics of injection products.
However, every technology has its own disadvantages, and the hot runner technology is no exception:
1. The automatic blowing machine has complex structure, high cost and high maintenance cost.
2. It takes a period of time for the injection molding process to be stable, resulting in more waste products at the opening price.
3. Melt leakage and heating element failure will have a great impact on product quality and production schedule.
The third disadvantage above can be reduced by purchasing quality heating elements, hot runner plates and nozzles and maintaining them carefully when in use.
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