The production line uses PE breathable rubber particles as raw materials, and adopts the extrusion casting method to melt and extrude the PE modified breathable particles containing inorganic fillers, form the mold, and make the breathable film with sub nano pores after high-power stretching by the roller.

Process flow of PE breathable membrane

From the perspective of processing technology, there are two main processing methods of breathable membrane, one is flat film casting method, and the other is blowing film method. Casting method is mostly used in China, even in Asia, Europe and the United States.

The main technological process of tape casting method is as follows: PE raw material + porogen - mixing and metering - extrusion granulation - extrusion tape casting - drawing and setting - cooling - trimming - coiling.

In the whole process, the influence of stretching process on film properties is very important. In the process of stretching, when the binding force between the porogen CaCO3 particles and the surrounding PE polymer is less than the deformation force of PE polymer caused by stretching, the polymer separates along the edge of CaCO3 particles, resulting in some tiny cavities. The cavities can not make the liquid molecules pass through, but only the gaseous molecules pass through, so that the stretched film has the function of waterproof and breathable. The size of the cavity can be adjusted, which depends on the size, morphology and stretching mode of CaCO3 particles. When the stretching temperature is at a certain value, with the increase of the stretching ratio, the void diameter of PE breathable film increases, the permeability increases, and the tensile performance becomes worse at the same time; With the increase of thickness, the permeability decreases.

Main technical parameters