Contact adhesives

Contact adhesives must be applied to both surfaces and allowed some time to dry before the two surfaces are pushed together. Some contact adhesives require as long as 24 hours to dry before the surfaces are to be held together.Once the surfaces are pushed together, the bond forms very quickly.It is usually not necessary to apply pressure for a long time, so there is no need to use clamps.

Natural rubber and polychloroprene (Neoprene) are commonly used contact adhesives. Both of these elastomers undergo strain crystallization. Contact adhesives are used in strong bonds with high sheer-resistance like laminates, such as bonding Formica to a wooden counter, and in footwear, such as attaching an outsole to an upper.

Synthetic adhesives

Elastomers, thermoplastics, Emulsion, and thermosetting adhesives based on polyvinyl acetate, epoxy, polyyurethane, cynoacrylate polymers are examples of synthetic adhesives.

Natural Adhesives

Animal glue in granules

Natural adhesives are made from inorganic mineral sources, or biological sources such as vegetable matter, strach (dextrin), natural resins or from animals e.g.animal glue. They are often referred to as bioadhesives. One example is a simple paste made by cooking flour in water. Animal glues are traditionally used in bookbinding, wood joining, and many other areas but now are largely replaced by synthetic glues. Casein are mainly used in glass bottle labelling. Starch based adhesives are used in corrugated board production and paper sack production, paper tube winding, wall paper adhesives. Another form of natural adhesive is blood albumen (made from protein component of blood), which is used in the plywood industry. Animal glue remains the preferred glue of the luthier.