Abstract: Traditional metal and glass packaging with oxygen and water vapor permeability of completely, the food and pharmaceutical packaging, the best material, but with the continuous development of packaging, plastic packaging materials has become a metal, glass packaging materials, strength strong competitors. However, the main structure of plastic flexible packaging materials are plastic polymers, has some permeability to gas, and therefore can not fully replace the metal and glass packaging. Therefore, water vapor permeability of flexible packaging material (or barrier) of the test of testing more and more important in the packaging. The test method has many different kinds, air permeability test sub-pressure method and equal pressure method, partial pressure of law problem is that the overall test pressure problem and packaging issues, such as press laws to solve these problems; moisture permeability testing points the weighing method and the sensor method, there is packaging weighing method as the overall test problem, sensors can solve this problem. Measured by different test data and the problems encountered in the experiment analysis and comparison, concluded that the permeability test medium pressure method is superior to partial pressure method, water vapor permeability test sensing method is better than weighing method. Therefore, the equal pressure method and the sensing method will be the future trend.
Keywords: flexible packaging materials; permeability; moisture permeability; Overall test
