Permeation means that gas or water vapor enters the surface from a high concentration area, diffuses to the material, and desorbs from another surface in a low concentration area. The speed of penetration is related to the structure, thickness, thickness uniformity, temperature, humidity of the packaging material. It is also related to the type of diffusing agent. There are two types of permeation for a package: one through the packaging material, and the other through the joints of the packaging materials in the package (eg, the heat seal of the sealing portion of the heat seal). The latter type of penetration is generally small and is often overlooked by people, but under some specific conditions, it may have a great impact on the overall sealing of the package. For high-barrier packaging, in order to have high sealing performance for the entire package and reduce the penetration of the heat seal, the seal should have a sufficient width, and the heat sealing material used must have a certain barrier performance.
- The difference between biodegradable bags and ordinary PLA stic bags January 30, 2023