Advantages of internal heating of hot runner nozzle
The use of internally heated nozzles is very economical.
Anyone who is in charge of the planning, production, operation or repair of injection molds knows that the best way to control the heat distribution has a very important meaning, it can reduce the waste of data and the decline due to nozzle leakage or poor molding quality of parts. The downtime for repairs.
Therefore, eliminating the dangers caused by overheating and leakage is a policy sought by many people. In the mold planning or production process, it is very important to summarize the internally heated [hot runner] nozzles or injection molding machine nozzles. Economic implications, because they help save money.
The primary reason for choosing internally heated nozzles to save money is that they are 100% sealed. The molten plastic will not leak to the outside, nor will it damage the wiring in the channel or near the nozzle. However, the use of externally heated conventional nozzles may cause leakage and system damage, and this has indeed occurred.
For example, if an externally heated nozzle leaks in a warm runner system, the leaked molten plastic will flow into the circuit channel and engulf them, forming all nozzles and channels that are blocked by a lot of plastic. If the entire heating system is affected, it may become a very expensive repair operation.
Because a warm runner system usually occupies most of the overall cost of a mold, some people always pay special attention to the warranty period of the system, but they do not think about the frequent burning of the mold or other doubts that will add downtime and cause high cost of. The use of internally heated warm runner nozzles can reduce pressure because they have the function of avoiding malfunctions compared with externally heated traditional systems. They are like setting up a safe item, so that downtime and parts replacement costs are guaranteed.
In most cases, the internally heated warm runner nozzle can be retrofitted on the basis of the existing warm runner system. In addition, it should be pointed out that the two-half combined warm runner nozzles currently on the market have the same characteristics, and their operating effects are excellent.
internal differences
Use externally heated nozzles, and the sensitive components of the heating system (such as thermocouples, heating coils and sleeves, etc.) are installed on the outside of the nozzle body. When the coil is heated, it begins to expand, forming a gap between itself and the nozzle body, making it unable to evenly contact the nozzle body. Because of this, the coil needs to be heated at a higher temperature so that it can properly heat the plastic. There is not only the danger of uneven heating, but the higher temperature also means that there is a danger of overheating and the coil being burned (forming a heater failure).
