What are the causes of the bubble problem in plastic profiles

I.Thicker products, the surface is fat and bulging, there are bubbles at the sawing section, the reason may be:

1. Injection speed is too fast, enclosing the air, can not be excluded, forming bubbles.

2. Too much or too little feeding, too high injection pressure, will also produce this phenomenon, if properly adjusted feeding will improve this phenomenon.

3. Cooling time is too short (especially for thick-walled products). The solution can be cooled by cold water and cold pressing die outside the machine.

4. There is decomposition black line in the products, which is caused by the high temperature. If the situation is not serious, the temperature can be reduced appropriately. If the whole barrel is decomposed, the car must be dismantled and cleaned up.

5. Too small gate and bad exhaust of the mould will also produce this phenomenon.

II. There are holes and blackening in solid products. When solid products are moulded, the injection pressure should be low and the injection speed should be slow. Otherwise, air will be enclosed in the products by friction and scorching under high pressure, which will make the products black and empty. Therefore, if the injection pressure and injection speed are properly reduced, the void phenomenon will disappear. It can also be checked whether the amount of feeding is too much. It is also beneficial to reduce the amount of feeding properly.

III. When the thickness of plastic profile products is different, there are small bubbles in the thicker part of the products or large black bubbles in the extra-thick part of the products. At the same time, when forming several products with different shapes, it must be noted that the size of each gate should be equal to the weight of the product, otherwise, thick products are prone to bubble.

At the same time, attention should be paid to the exhaust of the die. The products often left on the front die make it difficult to exhaust, which is easy to produce the above phenomena. This phenomenon can be improved by modifying the die or increasing the holding time and cooling time to insufficient pressure on the thick section of the pregnant women. More importantly, when designing products, we should try to avoid extra-thick parts of products.