POM 500AF American DuPont friction-resistant gear POM Teflon wear resistance rate

Bubbles (vacuum bubbles) are vacuum bubbles in which the gas is very thin. Generally speaking, if bubbles are found at the moment of mold opening, it is a gas interference problem. Vacuum bubbles are formed due to insufficient filling of the plastic or low pressure. Under the rapid cooling of the mold, the fuel in contact with the cavity is pulled, resulting in volume loss.
Solution:

Increase the injection energy: pressure speed, time and material volume, and increase the back pressure to make the mold full.

Increase material temperature and smooth flow. Lower the material temperature to reduce shrinkage, and increase the mold temperature appropriately, especially the local mold temperature where the vacuum bubble is formed.

Set the gate in the thick part of the part to improve the flow conditions of the nozzle runner and gate and reduce the consumption of pressure.

Improve mold exhaust conditions.