Water based adhesive glue that is categorized in one of the following 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 filmy finish. In general, these adhesives are solvent free, making them safe to use in close quarters and areas that may not be well ventilated, such as classrooms. The most popular water based adhesive is white glue or wood glue.
Vegetable glue is a common type of water based adhesive. These glues have a starch base and a brittle finish. Commonly used to bind books, this adhesive has a brown color and a reputation as a durable, long-term bond for paper. The vegetable based adhesive is more likely to break down when exposed to water.
Another water based adhesive is resin cement. Resin cements are emulsions, mixes of liquids that cannot be blended. With resin cements, polymers such as ethelyne vinyl acetate (EVA) or polyvinyl acetate (PVA) are emulsified and placed in water, which acts as a carrier. While resin cements are white when wet, they dry clear 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 utilize either animal parts processed especially for making 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 quick-set application is necessary. Casein glue is used to label wine and beer bottles because of its moisture resistance.
Latex cements are composed of emulsified elastomers. These water based adhesives are generally white in color, and they are usually put on one part and allowed to dry. Depending on the formulation, the adhesive can remain tacky or dry into a solid bond. Often used for self-stick envelopes and stamps, latex cements are also used to bond fabric and leather goods.
The primary advantage of using a water based adhesive completely devoid of solvents 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 eliminating the solvents in the adhesive, the toxicity of the adhesive is also reduced; however, manufacturing water based adhesives generates more wastewater and uses more energy than its solvent based counterpart. Deciding the most useful adhesive for a particular use requires careful consideration of the advantages and limitations of all available adhesives.