Sealability and sealing are the most critical parameters of packaging work. However, the indices corresponding to the sealing property are not the same in each packaging method. If liquids and gases penetrate into and out of the packages, the materials in the package are affected and eventually deteriorate. The most critical factor regarding the tightness of the packaging material is its sealing strength.

In this regard, packaging materials are subjected to different tests such as burst pressure, heat sealing strength, heat sealing quality and sealing leakage property of the edges. Indices such as the rigid airtight index of the closure, the tightness of the closure, the tensile strength and the cap joint are the most important parameters for the water-resistant closure.

Generally, packaging materials are tested in different ways using special test equipment. For example, in the creep test, the pressure in the package is kept constant for a period of time and it is observed whether it is leaking. In the explosion test, the internal pressure is increased until the package breaks.

This method is used to determine the highest burst pressure of the packaging material. The sealing test results can be influenced by factors such as the material and dimensions of the package, the test method applied, the sensitivity of the sensor, and the speed of pressure in the package.

Different test methods can be applied depending on the situation. For example, in the examples described above, compressed air is introduced into the package. However, in some tests, vacuum air can also be used by reducing the pressure on the outside of the package. However, positive pressure tests are generally performed. In this way, various leak test technologies are combined. Such tests are carried out from flexible packaging bags to flexible tubes, closures and containers.

Tightness tests are also integrated with other test methods to assess the consistency of the package adhesion and the integrity of the package. Devices used in sealing tests, It determines the sealing quality, sealing performance, compressive strength, bursting pressure, torsional force and joint separation force of flexible packagings, sterilized packagings, plastic caps with opening protection, flexible tubes and the like.