PE breathable film is a kind of breathable and impermeable material, the main component is polyethylene. To be exact, it is a polymer material synthesized from polyethylene.
Micropores are formed after tape casting, micro embossing, and the drawing process, and the distribution density of micropores is large so that the breathable film has high moisture permeability and only air leaks without liquid leakage.
Because of its soft and skin-friendly, high tensile strength, good moisture permeability, and other characteristics, it is widely used in various fields of life, such as female sanitary napkins, baby and adult diapers, medical-surgical gowns, protective suits, etc.
At the same time, PE breathable film is also the most important material for medical packaging of masks.
At present, sanitary napkins, baby diapers, and adult diapers basically use PE breathable films, and the air permeability is around 2000-2500.
Characteristics of PE film
1. It has superior and uniform air permeability, effectively isolates moisture, discharges heat and moisture, and has moisture resistance.
2. More skin-friendly softness has an excellent hand feel, which makes your product more soft and comfortable, and is not easy to cause red buttocks such as eczema on a baby’s delicate skin.
3. Has excellent tensile and elongation properties
4. Has good chemical resistance, not easy to corrode.
Process flow of PE breathable film
From the point of view of processing technology, there are two main processing methods for breathable film, one is the flat film casting method, and the other is blowing film method. Most of China adopts the casting method.
The main process flow of the tape casting method is as follows: PE raw material + porogen – mixing and metering – extrusion granulation – extrusion casting – stretching setting – cooling – trimming – coiling.
Throughout the process, the effect of the stretching process on the film properties is very important. During the stretching process, 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 small cavities. The cavities can not make the liquid molecules pass through, but only the gas molecules. This makes the stretched film waterproof and breathable. The size of voids can be adjusted, which depends on the size, morphology, stretching mode, and stretching ratio of CaCO3 particles.
When the stretching temperature is at a certain value, with the increase of the stretching ratio, the pore size of the PE breathable film increases, the air permeability increases, and the stretching performance becomes worse; as the thickness increases, the air permeability decreases.