What should I do if there are bubbles when the injection mold is formed?

Author: MULAN - Plastic Molding Manufacturer

In our daily work, we often encounter air bubbles during the molding of injection molds, which is a very headache and very annoying, especially for junior machine technicians who are faced with air bubbles. First of all, when we face the bubbles, we must find the root of the problem. Is it a mold problem, or a machine problem? Next, mold injection molding manufacturers will analyze the causes and solutions of bubbles in injection mold molding. ① Defects in the mold design (too small glue, uneven layout of the glue design, too small flow channel, trapped air, etc.) The above problems in the injection mold molding should be rectified from the mold itself: the glue should be increased If it is enlarged, the vent hole should be added, and the inlay should be added.

② The setting parameters of the injection molding machine are unscientific, for example: the molding temperature of pp material is 180--220. As a result, if the result is set at 230--250, there are 100% bubbles, and the standard temperature of acrylic is 200--230. The result is not familiar Professional injection molding technicians set the material temperature at 230---250, which is too high for the material, which cannot bear it, and will be carbonized into air. ③ The speed setting of the storage motor of the injection molding machine is too fast, the ejection position is set too much, and the back pressure is too small, causing the screw of the injection molding machine to form air into the cavity and form bubbles. Experienced technicians in the mold injection molding process will operate in this way: the plastic motor speed is set at about 45%--55%, the ejection position is set at 3mm__5mm, and the back pressure is set at about 10--15bar ④Material problem (not dried , with moisture) operate according to the baking temperature and time of raw materials.

⑤The molding temperature of the injection mold is very important. The mold temperature of the front mold and the rear mold should not be matched with one high temperature and one low temperature (generally, the front mold is 20__30 degrees higher than the rear mold, which is more reasonable). In fact, the most important thing is that you must understand the mold when molding the injection mold. Knowing the ingredients will give you a quick fix.