What is the foaming principle of pearl cotton material?

Pearl cotton packaging material adopts physical foaming instead of chemical foaming, and its production process requires relatively strict selection and temperature control of physical foaming agent, foaming assistant, anti-shrinkage agent and nucleating agent.

When selecting physical foaming agent, it is required that it should be in gas state under standard conditions and easy to liquefy under pressure. Because the foaming of EPE pearl cotton resin is the result of physical foaming agent changing from liquid to gas, it is also required that the foaming agent is colorless, odorless, non-toxic and non-corrosive, leaving no residue in the polymer after foaming, with low permeability in polyethylene melt, low vapor pressure at room temperature, high volatility, small molecular weight and high density. EPE foaming film equipment is carried out by physical foaming. The foaming agent is colorless, tasteless, non-toxic and non-corrosive. After foaming, no residue will be left in the polymer, and it has low permeability, low vapor pressure at room temperature, high volatility, low molecular weight and high density in polyethylene melt. Its gas cost per unit volume is low, and it can be dissolved in polyethylene in the extruded state. With the increase of temperature and pressure, the change of solubility will increase, which is easy to make plastic foam dense. Its foaming process is the result of physical foaming agent changing from liquid to gas. Therefore, physical foaming agent, foaming assistant, anti-shrinkage agent and nucleating agent are all important factors affecting the foaming effect of EPE foaming film equipment. Secondly, strictly control the temperature. When selecting physical foaming agent, it is required to be gaseous in standard state and easy to liquefy under pressure.