Causes and treatment methods of air bubbles in thermosetting injection molding machine products
Generally, the birth of bubbles is mainly in the thick-walled tube of the product or at the final interface. The reasons for the formation of bubbles are different, the phenomena that occur are different, and the treatment methods will also be different. The breakdown is as follows:
Phenomenon 1: Bubbles appear in thicker products, pet prefrom mould.the surface layer expands, plastic household mold.and there are bubbles in the cross-section after cutting.
Causes and solutions: 1. The high-efficiency thermosetting injection molding machine does not maintain the amount during the feeding process, resulting in too high injection pressure, and only needs to adjust the feeding amount; 2. The skill cooling time is not enough. Cold-pressed film can also be used outside the equipment to reduce the temperature and refrigeration; 3. If the temperature is too high, black bars will appear in the product. If the dissolution state is mild, only moderate cooling is required. household plastic mold.If all the barrels are dissolved, it can only be disassembled and cleaned; 4. Air bubbles will appear if the plastic inlet of the mold is too small or the exhaust pipe is not good. This is also the reason of the machine, and only the machine equipment can be improved.precision core parts.
Phenomenon 2: There are cracks in the solid core product, accompanied by blackening. Under high pressure conditions, when the thermosetting injection molding machine is processing, the gas burns the product through friction and wraps it in the product, and bubbles or cracks will occur in the internal structure of the solid product.
When forming a solid core product, pay attention to two operating points, one is to reduce the injection pressure, and the other is to slow down the injection speed, and the crack phenomenon will disappear. In addition, check whether the feeding is too much at any time, and reducing the feeding can also improve this phenomenon.
Phenomenon 3: Plastic products with different thicknesses, some of which are thicker have air bubbles.
In such a situation, it should be noted that the size of each plastic inlet of the plastic product formed at the same time is very different from the net weight of the product, otherwise thick products are likely to produce air bubbles; If the above phenomenon occurs, the mold must be exhausted frequently; when customizing products for thermosetting injection molding machines, extra thick and thick products should also be prevented.
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