The ziplock bag is very convenient and efficient in our lives, but its airtightness is also very important. In order to obtain sufficient barrier properties, the performance and thickness of each layer of the ziplock bag should be fully considered when designing the ziplock bag. There are three commonly used methods to test the sealing performance of ziplock bags?
These three points can't be less
1. Waterless soaking method
Ziplock bags are generally suitable for packaging where the performance of external materials will be significantly reduced under the action of water, such as packaging with paper materials for the outer layer.
The sample is filled with a test solution (such as a colored aqueous solution with obvious color difference from the filter paper). After sealing, place the sample on the filter paper and observe the leakage of the test solution from the inside to the outside. To measure both positive and negative conditions, it can also be placed in a vacuum chamber and tested under negative pressure.
2. Vacuum observation method
The materials suitable for ziplock bags are the same as above. Through vacuum suction, the internal and external pressure difference of the sample is generated, and the recovery of the sample shape after expansion and vacuum release is observed, so that the sealing performance of the sample can be determined.
3. Water pressure
Ziplock bags are generally suitable for packaging where the performance of external materials does not significantly decrease under the action of water, for example: packaging with plastic film on the outer layer. The vacuum chamber is evacuated to generate the internal and external pressure difference of the sample immersed in the water, and the gas escape or water infiltration test is observed to determine the sealing performance of the sample.