Sometimes the stretch film feels of good quality when looking at it, but the sealing effect is not good when used. So in this situation, how can we test whether the sealing performance of the film is good or not? Below S2 will teach you a few ways to check its sealing, come and take a look.
During manufacturing, it can be divided into manual stretch film and machine stretch film. Mechanical films are generally used with film machines, while manual stretch films require purely manual operation to package items. Let’s talk about the issues you need to pay attention to when using manual stretch film. When using manual stretch film, you must wrap it one full circle, and then wrap it several more times. The film should be wrapped to the entire top.
The film has a certain degree of toughness, so it must be tightened when packaging to ensure that the items will not fall apart during transportation or handling. Manual stretch film can be divided into many specifications according to its width and thickness. Different specifications of film have different pulling forces. The pulling force of packaging machines is generally relatively large and the film used is thicker. If the manual stretch film is used on a winding machine, it will be forcibly torn.
Therefore, manual stretch film cannot be used on the winding machine. Assuming that the ziplock bag loses its sealing property, it will be no different from an ordinary plastic bag. So, how to detect the sealing property of the film?
For vacuum investigation method, the applicable materials for ziplock bags are the same as above. By evacuating the vacuum, the internal and external pressure differences of the sample are generated, and the sealing performance of the sample is determined by observing the expansion of the sample and the recovery of the sample shape after the vacuum is released.
Water pressure method (vacuum method), by evacuating the vacuum chamber, causing a sample immersed in water to generate an internal and external pressure difference, and observing the escape of gas or the ingress of water in the sample, thereby measuring the sealing performance of the sample . In the anhydrous penetration method, the sample is filled with test liquid, and after sealing, the sample is placed on filter paper to observe the leakage of the test liquid from the inside to the outside of the sample. Both sides should be tested.
Therefore, when you want to test the sealing of the stretch film, you can use the above methods to test whether the winding effect of the film is excellent, whether the sealing effect is up to standard, etc.
Post time: 4月-01-2024
