Technical principles and methods of moisture-proof packaging

The technical principle of moisture-proof packaging is: Use a low moisture-permeable or moisture-impermeable material to isolate the product from the moist atmosphere so as to avoid the influence of moisture on the product. For this purpose, the following methods can be used for moisture-proof packaging:

1 Use suitable moisture-proof materials. Moisture-proof materials are the key factors affecting the quality of moisture-proof packaging. Any material that can delay or prevent the penetration of external moisture can be used as a moisture barrier for moisture-proof packaging. Materials that meet this requirement include metals, plastics, ceramics, glass, and moisture-resistant paper, wood, and fiber products. The most commonly used materials are plastics, aluminum foil, and the like. The selection of moisture-proof materials is mainly considered by several factors such as environmental conditions, packaging levels, moisture permeability of the materials, and economy.

2 design a reasonable packaging modeling structure. Tests have shown that the packaging structure has a great influence on the moisture absorption of the articles. The greater the bottom area of ​​the packaging containers, the greater the hygroscopicity of the packaging and the contents. The closer to the bottom, the greater the moisture content. Therefore, when designing the moisture-proof packaging modeling structure, The bottom area should be reduced as much as possible. In addition, the protruding parts of the packaging container are also easy to absorb moisture, and these parts should be rounded as much as possible.

3 Moisture-proof materials that are easy to absorb moisture. Some packaging materials, such as paper products, have poor moisture resistance. If used for moisture-proof packaging, they must be protected against moisture. The methods are as follows:

a wax coating. Wax is a good moisture-proof material. The wax is melted and the paper is immersed in the wax liquid.

b Coating. The paints mainly include clear oil, varnish, etc. Before the operation, a starch paste is brushed on the surface of the paper and the paint is applied.

c plastic coating. The main raw material is polyvinyl butyral, a thermosetting plastic, which is dissolved in ethanol, then coated with a rubber roller, and then dried and dried.

4 Add a suitable moisture barrier. Add one or more layers of moisture-proof material, such as tar paper, kraft paper, wax paper, aluminum foil, plastic film, etc., to a moisture-sensitive package.

5 Sealed packaging with moisture-proof material. The use of materials with excellent moisture resistance, such as metal, ceramics, glass, composites, etc., as containers, packaging of dry products, and then the container's mouth is strictly sealed, moisture can not enter.

6 add desiccant. Add an appropriate amount of desiccant in the sealed package, so that the residual moisture inside and the moisture through the moisture barrier layer are absorbed by the desiccant, so that the contents are protected from moisture. It should be noted that this type of packaging is required. Moisture-proof material with low moisture content, otherwise it is counterproductive.