Why injection molding machine nozzle,hot runner nozzle always been blocked?

Why injection molding machine nozzle,hot runner nozzle always been blocked? Especially for the small nozzle with 1-2 mm diameter.
According to our experience,the main problem is caused by copper,aluminum,stainless steel and other metal impurities which magnetic frame can not be absorbed. Many manufacturers use only the magnetic frame,but were unable to absorption of copper and other metals.These metals also about 0.5-2 mm,mixed in plastic inside ,the naked eye can not see.Since the metal impurities can not be completely avoided,how can we do it?

Users can install metal separation equipment in the plastics production process several key points, Usually a strong magnetic frame and metal separators. Plastic granulator example: first you can detect the powder inlet of the extruder,Secondly, after the cut detecting particles of plastic extrusion,then detect the particles after bagging.To crush material reuse,for example,in view of the reasons for the higher raw material prices, more and more users tend to reuse in their production process of outlet material,The outlet material in accordance with a certain proportion mixed with new material before use.This mixed-use does not affect the quality of products is based on the premise conditions, we can really save a lot of costs.

Crushed material or recycled material typically contains a relatively large metallic impurities,especially copper,aluminum,solder stainless steel and other metal particles.Therefore,the use of these materials would be best to use strong magnetic frame and metal separators.This can be good to avoid interference of metal impurities.Otherwise,plastic recycling and cost savings can not be achieved.

Even if the metal impurities not damage plastics machinery,However,these metal impurity molded product,For example,plastic connectors,etc., and will definitely cause product failure in terms of insulation.In addition,if the pressure roll into the plastic sheet material production line,it may cause damage to the pressure roller.

In short,due to the presence of metal impurities risk is always there,should advance prevention.