EPE pearl cotton Packaging materials are made of physical foaming instead of chemical foaming, and their production process is relatively strict for selection of physical foaming agents, foaming agents, shrinkage reducing agents, nucleating agents and temperature control.
When choosing a physical foaming agent, first of all, it is best to be gaseous under standard conditions and easily liquefied under pressurized conditions. Because the foaming of EPE pearl cotton resin is the result of liquid blowing into gaseous state, the second requirement is that the foaming agent is colorless, odorless, non-toxic, no rot, and does not leave residue in the polymer after foaming, and has low permeability in polyethylene melt. At room temperature steam pressure is low, volatile high, low molecular weight and high density. Its unit volume has low gas cost and can be dissolved in polyethylene in extrusion state. The temperature and pressure will increase, and the change of solubility will increase.