It is used for packaging with insufficient strength and easy to leak powder. The filter paper can be used for small-size silica gel desiccant packaging. Good air permeability, poor breathability of composite paper, resulting in slow moisture absorption, generally not suitable for moisture-proof packaging of electronic products; non-woven fabric has a certain strength, but also has good air permeability, but is used to package montmorillonite, easy to leak powder Mesh paper has good air permeability, high strength, good dust resistance, and wide applicability.
Freeze-dried foods easily absorb moisture and become moist, and the main purpose of freeze-dried food packaging is to solve problems such as moisture absorption, moisture absorption and oxidative deterioration. Moisture-proof packaging techniques. In other words, it is easy to absorb the moisture in the air inside the package during packaging or storage.
Freeze-dried processed foods, research shows. In general, the maximum water absorption is 80 hours, and the hygroscopicity is also related to the processing freezing rate and different items.
Oxidized, oxidation-proof packaging technology for freeze-dried foods during storage. Mainly refers to the oxidation of fat in its components and the oxidation of carotene in oil-soluble components, oxidation of chlorophyll, oxidation of ascorbic acid, and the like. Due to the presence of oxidation it is difficult to avoid changes in product color and loss of vitamins. The degree of oxidation of fat is rather serious when the moisture content is low. This is because the water molecules adsorbed on the oil are partially broken during drying, and it is easy to make the surface of the fat contact with oxygen in the air to be oxidized, so only by reducing the moisture content Packaging techniques are difficult to resist.
The measures considered in the oxidation-proof packaging are the use of packaging materials with oxygen-absorbing functions, which are summarized above. Add antioxidants, so that the inner layer of the package has a water balance function (the inner layer of the package coated with water retaining agent) to maintain a certain amount of water in the package, low temperature storage, and can choose a good light-blocking packaging materials.