Why are there bubbles in the injection mold?

I believe that many friends have encountered the problem of bubbles in the injection mold during the manufacturing process of the injection mold. Especially as some friends who have just entered the industry, they will be helpless if they encounter this problem for a while. Dongguan PTJ has more than 10 years of experience. Professional injection mold experienceInjection Mold FactoryHome, let’s analyze the causes and solutions of bubbles in the injection mold today.

First of all, defects in the mold design cause bubbles in the injection mold

For example: Poor gate position of injection mold, too small gate, asymmetric gate arrangement of multi-gate parts, small runners, unreasonable mold cooling system, so that the mold temperature difference is too large, etc., causing the melt to be in the mold cavity The flow is discontinuous, blocking the air passage.

Secondly, the mold parting surface lacks necessary vents or insufficient vents, blockages, poor positions, and no processing such as inserts, thimble, etc.The gap is exhausted, causing the air in the cavity to not leave at the same time when the plastic enters.These reasons can also cause bubbles to appear in the injection mold.

Finally, if the surface roughness of the injection mold is poor, the frictional resistance is large, causing local hot spots, and the decomposition of the passing plastic will also cause the appearance of bubbles.

Of course, in addition to mold reasons, there will also be equipment, technology, raw materials and other reasons; therefore, every process in the injection mold manufacturing process needs to be very careful, try to avoid the phenomenon of bubbles in the injection mold, and reduce product production. The defect rate in the process can increase the competitiveness of injection mold manufacturers in the increasingly competitive mold industry.

We will be happy to hear your thoughts

Leave a reply


Need Help?

I’m Here To Assist You

How to make a perfect plastic injection mold and injection molding is always our goal.