As the name implies, the difference between the cold runner and the hot runner surface lies in the cold and heat. The cold runner is the basic form of the injection molding automatic blow molding machine. The so-called cold runner is a conventional injection molding automatic blow molding machine. After the injection is finished, there is a conglomerate in the flow channel that needs to be taken out!

With the reduction of resources, competition in the market, and the rise in raw material prices, it is very necessary to make a fuss about the issue of saving materials. This is also an important reason for the emergence of hot runners, which can be said to be an inevitable outcome of the development of social industrialization.

The emergence of hot runners solves the problem of resource waste and cost saving, and at the same time, it has achieved relatively large results in the injection molding process. The hot runner has gradually developed into the general direction of the development of injection molding automatic blow molding machines, and will surely become popular! Due to cost accounting problems, many small and medium-sized automatic blow molding machines have not applied hot runners, and a small amount of materials must be injection molded by cold runner automatic blow molding machines.

There are cold runners and hot runners in the fully automatic blow molding machine industry. In addition to the different injection molding processes, there are the following differences.

What is a hot runner?
The hot runner is heated to ensure that the plastics of the runners and gates remain molten. Since the heating rod and the heating ring are arranged near or in the center of the flow path, the entire flow path from the nozzle exit of the injection molding machine to the gate is in a high temperature state, so that the plastic in the flow path is kept molten, and it is generally unnecessary to open the flow path to take out the condensation after the shutdown. Material, just turn on the flow channel to the required temperature. Therefore, hot runner processes are sometimes referred to as hot manifold systems, or as no runner molding. Advantages and Disadvantages of Hot Runner Technology Hot runner technology has the following advantages over conventional cold runners:

1. Save raw materials and reduce production.
2, shorten the molding cycle and improve machine efficiency
3. Improve the surface quality and mechanical properties of the product.
4. It is not necessary to use a three-plate automatic blow molding machine to use a point gate.
5. It is economical to form a single product with a side gate.
6. Improve the degree of automation.
7. The gate can be controlled by a needle valve gate.
8. The quality of the injection molded parts of the multi-cavity automatic blow molding machine is the same.
9. Improve the surface appearance of injection molded products.


However, each technology has its own shortcomings, and hot runner technology is no exception:
1. The automatic blow molding machine has complex structure, high cost and high maintenance cost.
2. It takes a period of time for the injection process to be stable after the start-up, resulting in more scraps.
3. When there is melt leakage and heating element failure, it has a great influence on product quality and production schedule.

The third disadvantage mentioned above can be reduced by purchasing quality heating elements, hot runner plates and nozzles and carefully maintained during use.