1. The first-level shooting speed is too fast. This is the main reason for the formation of air ripples at the water inlet, which causes the melt glue to produce a severe vortex at the moment it enters the cavity, causing vortex air ripples. Therefore, this is the first thing that the tuner should consider, and it is necessary to reduce the speed to try.
2. The glue inlet is too thin or too thin, which is also an important factor that causes air marks and spray marks on the water inlet. Because the glue inlet is too small or too thin, it will inevitably cause the melt glue to enter the cavity too quickly, which will cause ejection and air lines, which is also the reason for the serpentine lines. Therefore, when the speed cannot be lowered to the point that the problem cannot be eliminated, it is necessary to consider whether the water inlet is too thin or too thin, such as less than 0.5 mm or less.
3. The thicker the wall thickness of the injection molded part at the position of the rubber inlet and water inlet, the easier it is to produce air marks, such as more than 4 mm. Because the thicker the wall, the easier it is to generate vortices at the moment when the melt enters the nozzle, resulting in the formation of air ripples. When this happens, it is sometimes difficult to eliminate air marks when the water inlet is enlarged and the speed is reduced. At this time, it is better to change the rubber inlet to a place with a thinner wall, such as less than 3 mm.
4. The lighter the surface of the mold cavity, that is, the brighter the surface of the injection molded part, the easier it is to produce air marks. The injection molded parts are too bright, and even slight air marks will be revealed.
5. The temperature of the melt glue or the mold is too low, and injection molding will also produce shot marks caused by jelly glue, accompanied by matte air marks.
6. For raw materials that are easy to burn, if the temperature of the melt is too high, there will be air lines caused by excessive decomposition gas, such as the decomposition air lines of PC materials.