Main classifications of rubber powder in the market
Release Time:
2016-08-12
Source:
Main classifications of rubber powder in the market
Currently, the main applications in the market are Redispersible Latex Powder These include vinyl acetate–ethylene copolymer latex powder (Vac/E), ethylene–vinyl chloride–vinyl laurate terpolymer latex powder (E/VC/VL), vinyl acetate–ethylene–higher fatty acid vinyl ester terpolymer latex powder (VAC/VeoVa), acrylate–styrene copolymer latex powder (A/S), vinyl acetate–acrylate–higher fatty acid vinyl ester terpolymer latex powder (Vac/A/VeoVa), polyvinyl acetate homopolymer latex powder (PVac), and styrene–butadiene rubber latex powder (SBR), among others. The first three account for 80% of the market, with the first one being the dominant type.
Vinyl acetate is a thermoplastic adhesive produced by the polymerization of vinyl acetate monomer in the presence of an initiator; it is commonly known as white latex or simply PVAC emulsion, with the chemical name polyvinyl acetate emulsion. It uses water as the dispersing medium, is safe to use, non-toxic, non-flammable, easy to clean, cures at room temperature, exhibits excellent adhesion to wood, paper, and textiles, delivers high bond strength, forms a colorless, transparent, and flexible cured film that does not contaminate the substrates, and boasts good emulsion stability with a shelf life of more than six months. Consequently, it is widely employed in printing and bookbinding as well as furniture manufacturing, serving as an adhesive for paper, wood, fabric, leather, ceramics, and other materials. It can also be used as a modifier for adhesives such as phenolic resins and urea-formaldehyde resins, and is further utilized in the production of polyvinyl acetate emulsion paints.
The drawbacks of polyvinyl acetate emulsion adhesives include poor water and moisture resistance: they readily absorb moisture in humid air and exhibit creep under high-temperature conditions, leading to a reduction in bond strength. Additionally, storage at temperatures below −5°C can cause freezing, which damages the emulsion. A new type of white latex adhesive uses a polymer derived from the polymerization of polyvinyl alcohol and formaldehyde as a modifier, thereby improving the emulsion’s water resistance and freeze–thaw durability and broadening its range of applications.
Redispersible polymer powder is a modified emulsion powder obtained by spray-drying polymer emulsions, with vinyl acetate, ethylene, or acrylate esters as the main components in binary or ternary copolymers. It exhibits excellent dispersibility, redisperses into an emulsion upon contact with water, forms a film, and possesses good flexibility.
Resin adhesive powder: Its main component is DBP, which has poor dispersibility, is harmful to human health, emits a pungent odor, and severely corrodes XPS boards. It is a new type of product consisting of rubber, polymer polymers, and finely ground adhesive powder.
