PVA water soluble bag is mainly composed of polyvinyl alcohol, which is a kind of polymer compound. Its molecular main chain contains a large number of hydroxyl groups and ester groups, and its molecular structure contains many hydroxyl groups. Because its molecular chain contains a large number of hydroxyl groups and ester groups, it has excellent physical properties such as solubility, hygroscopicity, and softness.

In terms of chemical properties, PVA is a polymer compound with good chemical resistance, solvent resistance and electrical insulation properties. Moreover, its mechanical properties can be enhanced through appropriate modification. Since the molecular structure of PVA contains a large number of hydroxyl groups and ester groups, it has a certain degree of hydrophilicity, and these hydrophilic groups present a "hydration layer" in aqueous solution. This hydration layer can hinder the rate of diffusion of water molecules across the surface of the film. As a result, the hydrophilic groups on the surface of the film migrate to the inside of the film and gather in the film. In order to prevent the hydration reaction between these hydrophilic groups and water molecules on the surface of the film, it is necessary to add a certain amount of antioxidant and dispersant to improve its oxidation resistance and dispersibility.

PVA water-soluble bags have good transparency and gloss, and are sensitive to light (easy to fade); but because PVA water-soluble bags change their molecular structure through dissolution and recrystallization to improve their physical properties (such as strength, hardness, etc.), So when it is used as a packaging bag, it has poor heat resistance (such as above 60 degrees). Therefore, when using PVA water-soluble bags as packaging, care should be taken to avoid using them in high-temperature environments, and not to expose them to sunlight for a long time, otherwise the PVA water-soluble bags will decompose and lose their physical properties.

PVA water soluble bags are made of PVA as the main raw material. PVA water-soluble packaging bags are available in a variety of specifications, and their thickness can reach 0.5 mm or thicker, mainly 1.0 mm and 1.4 mm.

According to different packaging products, PVA water-soluble packaging bags can also be divided into ordinary packaging types, waterproof and moisture-proof types, and high-temperature resistant types. Among them, ordinary packaging PVA water-soluble packaging bags can be used for moisture-proof and oil-proof, and have good waterproof performance; waterproof and moisture-proof PVA water-soluble packaging bags can be used for moisture-proof, but not moisture-proof; high-temperature resistant PVA water-soluble packaging bags It is better in high temperature resistance.

1. Temperature resistance: PVA water-soluble packaging bags have good heat resistance, and they will not decompose or soften when kept at 110°C for 5 minutes.

2. Flexibility: PVA water-soluble packaging bags have good toughness, and have good performance in terms of tensile strength and elongation at break.

3. Transparency: PVA water-soluble packaging bags have high transparency and gloss, and their clear and bright appearance can be observed from different angles.

5. Odor: PVA water-soluble bags have no irritating odor at room temperature.

7. Weather resistance: PVA water-soluble bags have good adaptability to the environment and climate. It can be used in different environments within the range of 0~70°C. When used at 40°C, its weather resistance and thermal shrinkage will not change; when the temperature rises above 65°C, its weather resistance and thermal shrinkage will change.

8. The water-soluble bag can be dissolved in water, ethanol, acetone and other organic solvents; when dissolving, heating method can be used, and it can also be dissolved into a colorless and transparent state by chemical reaction under certain conditions after mixing with water.

9. Packaging: PVA water soluble bags can be used for the packaging of medicines, food, cosmetics and other products, as well as chemical products, dangerous goods, electronic products and other items.