Different uses of PVA

Polyvinyl alcohol (PVA) is non-toxic, tasteless, harmless to human body, has good affinity with the natural environment, no accumulation and no pollution. PVA is a water-soluble polymer, which is characterized by good compactness, high crystallinity, strong adhesion, good film flexibility, oil resistance, solvent resistance, wear resistance, good air permeability and special water resistance treatment. And its different models generally have different applications!

1. Polyvinyl alcohol film the film made of this product has good transparency, tensile strength, crack resistance, moisture permeability, good gas insulation, oil resistance, organic drug resistance and no static electricity. Therefore, it is suitable for textile packaging.

2. Papermaking processing:

A. Polyvinyl alcohol can be used as paper surface sizing agent in paper industry. It has the characteristics of good film-forming property and high film-forming strength. It can improve the printing adaptability, smoothness, friction resistance, folding resistance, oil resistance and chemical resistance of paper. The average degree of polymerization as paper surface sizing agent is 1750 ± 50 PVA.

B. Pigment treatment agent: it can improve the whiteness and gloss of coated paper, good printing gloss, bright color and improve the quality of paper. It is best to choose polyvinyl alcohol with high average degree of polymerization.

C. Papermaking sizing agent: when papermaking, the powdered PVA and pulp are added together to beat and make paper, so the paper has high strength. It is best to choose polyvinyl alcohol with high average degree of polymerization.

3. Adhesive:

A. PVA aqueous solution has strong adhesion to materials containing cellulose (such as paper, cloth, wood, etc.), and has the advantages of safety and non toxicity. It can be used for laminating cardboard, bonding corrugated cardboard and office glue.

B. Urea formaldehyde resin and phenolic resin modified with polyvinyl alcohol can be used as adhesives for laminates and wood-based panels.

C. Polyvinyl alcohol aqueous solution (by adding appropriate fillers and additives) is also widely used to prepare adhesives for the connection of paper products such as printing and binding, paper tubes, cartons and so on.

D. Under the action of acid catalysis, polyvinyl alcohol can condense with formaldehyde, butyraldehyde, glyoxal or other aldehydes to produce polyvinyl acetal compounds with stronger water resistance, adhesion and mechanical strength (such as PVAF and PVB).

E.PVA is an excellent protective colloid and dispersant. It is used to produce emulsion (Bai Jiao) through homopolymerization of vinyl acetate or copolymerization with other monomers, which is very important in the production of Bai Jiao. Generally, the viscosity of emulsion increases with the polymerization degree of PVA. Partially alcoholic PVA (17-88) and fully alcoholic PVA (such as 17-99, 19-99, etc.) are usually used in combination. Some of the PVA can improve the stability of the emulsion, while fully purified PVA can improve the water resistance of the emulsion.

4. Warp size:

A: The sizing material mainly composed of polyvinyl alcohol has good adhesion to cotton, flax, polyester and vinylon viscose fibers. After the film is formed, it is smooth, smooth, strong and wear-resistant, which improves the weavability of warp yarn and reduces the friction and bending of warp yarn in the weaving process.

b. PVA is a water-soluble polymer compound, which is very convenient for sizing, sizing and desizing.

C. Polyvinyl alcohol with low average degree of polymerization (e.g. pva15-99, 16-99, 17-99) is usually selected as the slurry.

5. Vinylon raw materials: polyvinyl alcohol can be dissolved, spun, and then acetalized to produce vinylon fiber, which can be blended with cotton, wool, viscose fiber and other vinylon textiles. It is widely used in clothing, tarpaulin, rope, fishing net, rope, etc.