How can the tightness of the stretch film be detected

Sometimes looking at the stretch film feels that the quality is very good, but the sealing effect is not good when used, so how can you detect whether the sealing of the film is good in the face of this situation? The following Xiaobian will teach you a few ways to check its tightness, come and see.
In the time of manufacturing, it can be divided into manual stretch film and mechanical stretch film. Machine films are generally used with film machines, while manual stretch films require pure manual operation of packaging items. Talk about the need to use manual stretch film to pay attention to what problems must be wrapped in a full circle when using manual stretch film, and then wrap a few more turns, and the film should be wrapped to the entire top.
The film has a certain toughness, so the packaging must be tightened, so that the talent will not be scattered during transportation or handling. Manual stretch film can be divided into many specifications according to its width and thickness, and the tensile force of different specifications of the film is different. The pulling force of the packaging machine is generally large, and the film used is thicker. If the manual stretch film is used on the winding machine, it will be forcibly pulled.
Therefore, the manual stretch film cannot be used on the winding machine. Assuming that the ziplock bag loses its tightness, it is no different from ordinary plastic bags, so how to detect the tightness of the film? Vacuum investigation method, ziplock bag applicable materials are the same as above. After vacuuming the vacuum, the pressure difference between the inside and outside of the specimen occurs, and the recovery of the specimen shape after the expansion of the test specimen and the release of vacuum is observed, so as to determine the sealing performance of the specimen.