Checkweighing and inspection system manufacturers & suppliers

Home / News / Product News /

Why are the nozzles and hot runners of the injection molding machine blocked?

Why are the nozzles and hot runners of the injection molding machine blocked?

Issue Time:2020-10-27

According to our experience, the clogging problem is mainly caused by metal impurities that cannot be absorbed by the magnetic frame such as copper, aluminum, and stainless steel. Especially nozzles and runners with a diameter of 1-2 mm are most likely to be blocked! To

Generally, manufacturers only use magnetic stands, but they cannot absorb metals such as copper. These metals are about 0.5-2 mm, which is invisible to the naked eye when mixed in plastic.


Since metal impurities cannot be completely avoided, what should we do? To

The user can install metal separation equipment at several key points in the plastic production process, usually a strong magnetic stand and a plastic metal separator. To

Take plastic granulation as an example: first, the powder can be detected at the inlet of the extruder, secondly, the plastic cut into pellets after extrusion, and the plastic pellets after bagging.


Take the reuse of crushed materials as an example. In view of the high price of raw materials, more and more users tend to reuse the nozzle materials produced in their own production process, and mix the nozzle materials with new materials in a certain proportion before using. . Of course, such mixed use is based on the premise that it does not affect product quality, and it can indeed save a lot of costs.

If the pulverized material is not tested and removed for metal impurities, such reuse will definitely pose a relatively large safety risk. That may save the cost of raw materials, but at the same time increase the cost of equipment repair and maintenance. Taking into account factors such as production shutdown, the actual loss often exceeds the cost of saving raw materials. To

Shredded materials or recycled materials usually contain a lot of metal impurities, especially metal particles such as copper, aluminum, solder, and stainless steel. Therefore, it is best to use a strong magnetic stand and a plastic metal separator at the same time when using these materials, so as to avoid the interference of metal impurities. Otherwise, the plastic reuse and cost saving plan will basically not be realized.

Even if metal impurities do not cause damage to the plastic machinery, the mixing of these metal impurities into molded products, such as plastic connectors, will definitely cause the product to be unqualified in terms of insulation; in addition, if it enters the plastic sheet production line such as press rollers, it may cause The pressure roller is damaged. To

In short, the risks caused by the presence of metal impurities always exist and should be prevented in advance.

Syndar has been focusing on innovations in food packaging, weighing, and quality inspection and control. Experienced and aggressive employees

News