Current classification of moisture-proof packaging

Nowadays, due to the instability of the environment, some medicines may be affected by moisture and deterioration. Therefore, moisture-proof packaging is now very important. The moisture-proof packaging products are generally classified into the following three types:

First, Products whose quality will decrease after moisture absorption

When the water content of such products increases to a certain extent, the product will lose its use value. This type of product should be moisture-proof and packaged to prevent the product from absorbing external water vapor. For example, crisp foods, medicines, dried foods, chemical products, fertilizers, etc.

effervescent packaging

Second, Products with degraded quality after dehumidification

When such products lose water to a certain extent, they will lose their use value. Unlike 3.1 products, these products need to be dehumidified, but they are also called moisture-proof packaging. For example, bread, cake, Chinese medicine secret pills, cosmetics, water-milk products, water-dispersible liquid products, and the like. For the above two types of products, they absorb moisture in the air, or the rate of evaporation of water into the air gradually decreases with time, and finally reaches a state of equilibrium with the external environment. That is, if the external temperature and humidity are constant, the equilibrium moisture of the product does not change. At this time, the moisture contained in the product is called the equilibrium moisture of the product at that temperature. At a certain temperature, the higher the humidity of the air, the more balanced the product is, and vice versa.

desiccants

Third, Products that react chemically with water in a humid environment

These products are neither hygroscopic nor dehydrated, but chemical reactions with water can degrade product quality and even lose value. For example, in the wet environment, metal products, weapons, precision instruments, etc., if there is oxygen, rust the steel parts or tarnish other metal surfaces. The external humidity has a great influence on corrosion; when the relative humidity is low. As the humidity increases, the corrosion rate increases not too fast, but when the relative humidity reaches the critical humidity, the rate of metal corrosion increases sharply.

Therefore, when designing moisture-proof packaging, we need to select the appropriate packaging materials and reasonable moisture-proof packaging structure according to the humidity conditions of the circulation environment and the characteristics of the product itself, or take additional materials to achieve the purpose of moisture-proof packaging.