Gas permeability test of clear protective film tape
Mar 27, 2019
Plastic is an important part of polymer materials, because polymer materials are composed of many molecular chains with a certain condensed structure. Therefore, regardless of how regular these polymer chains are placed, there must be empty space in the microscopic structure of the polymer, so that gas can be transmitted through these open spaces. Regarding the clear protective film tape, it is often used for packaging materials. Regarding the maintenance of the packaging material, it is particularly important that the clear protective film tape has a gas permeable function.
For example, food packaging, according to different packaging foods, it is necessary to select different requirements of the packaging film or packaging composite film, clear protective film tape ventilation function test generally uses fabric ventilation meter. The gas permeation amount is the amount of gas permeated through the permeated area per square meter at a steady temperature and an atmospheric pressure difference (in the normal state), the unit is cm3/m2·Pa. The gas permeability coefficient is The air permeability of the film per unit area and unit thickness is stabilized by a stable temperature and an atmospheric pressure difference, and the unit is cm3·cm/cm2·Pa. The principle is that the gas molecules are first dissolved in the solid film and then in the film to a low concentration. Disperse, after all, transpire on the other side of the film.
Put the sample taken into the test chamber, arrange it in sequence, completely cover the outside of the test chamber, then cover the upper chamber of the test chamber, and tighten the handle to compress the sample. In the experiment, the instrument should not be separated from the instrument, and the test curve displayed on the computer screen should be carefully observed. When the straight line portion of the curve exceeds the large-scale horizontal coordinate scale set by the software, it is clarified that the experimental data has stabilized and the experiment can be completed.
