White glue is among the most common water-based adhesives.
Water-based adhesive glue that falls into one of four categories: vegetable glues, resin cements, animal or protein glues, and latex cements. Each of the different types has its own characteristics. Depending on the formulation, the adhesive can result in a hard resin finish or a tacky, clear finish. In general, these adhesives are solvent-free, making them safe to use indoors and in areas that may not be well ventilated, such as classrooms. The most popular water-based adhesive is white glue or wood glue.
Bottle labels attached with water-based glue peel off easily when wet.
Vegetable glue is a common type of water-based adhesive. These glues have a starch base and a crumbly finish. Commonly used for book binding, this adhesive has a brown color and is reputed to be a long-term durable binder for paper. Vegetable-based adhesive is more likely to break down when exposed to water.
Another water-based adhesive is resin cement. Resin cements are emulsions, liquid mixtures that cannot be mixed. With resin cements, polymers such as ethylene vinyl acetate (EVA) or polyvinyl acetate (PVA) are emulsified and placed in water, which acts as a vehicle. Although resin cements are white when wet, they clean up dry and are relatively flexible. Resin cements are useful for bonding some plastics, paper, and wood.
Animal and protein substances are also used to make water-based adhesives. These glues use specially processed animal parts to make hot animal glue or animal milk, which is used to make casein glue. Hot animal glue is used at 140°F (about 60°C) and is brown in color. This water-based adhesive is used when a fast-drying application is required. Casein glue is used to label wine and beer bottles due to its resistance to moisture.
Latex cements are composed of emulsified elastomers. These water-based adhesives are usually white in color and are usually placed on one side and allowed to dry. Depending on the formulation, the adhesive can remain tacky or dry to a solid bond. Often used for self-adhesive envelopes and seals, latex cements are also used to bond fabrics and leather goods.
The main advantage of using a completely solvent-free water-based adhesive is the elimination of volatile and combustible materials. This reduces the risk of fire and explosion, especially during the manufacturing process and for industrial use adhesives. By removing solvents from the adhesive, the toxicity of the adhesive is also reduced; however, water-based adhesive manufacturing generates more effluent and uses more energy than its solvent-based counterpart. Deciding on the most useful adhesive for a specific use requires careful consideration of the advantages and limitations of all available adhesives.