Adhesives

An adhesive may be defined as material which applied to surfaces of materials can joint and resist separation. Adhesive is the general term and includes cement, glue, paste, etc. The term adhesion is used when referring to the attraction between the substances.

A Brief History of Adhesives

We can appreciate the adhesive function on nature, marine organism are attach to hard substrates due to secreted adhesive; this adhesive are able to displace water, spread and form adhesive bonds with the substrate; many insects secrete a fluid-base adhesive that allows climb and walk upside down on diverse substrates and some birds use their saliva to hold their nests together. The uses of adhesives by the human being remote to ancient times, when some natural materials were melted on a rock by the action of the sun, and this materials shown sticky properties; some of the other materials used by early human beings as adhesives are now called beeswax, rosin, rubber, shellac, sulfur, tar, and vegetable gums. The mainly use for this materials were: developed tools and as sealants for warrens. The Egyptians utilized gum Arabic from the acacia tree, egg, glue, semiliquid balsams, and resins from trees. Wooden coffins were decorated with pigments bonded with “gesso”, a mixture of chalk and glue. Glues from fish, stag horns, and cheese (Glutine casei) were known in the days of Theophilus for fixing together wooden objects. The first commercial glue plant was founded in Holland in 1690, that casein glues appear to have been manufactured in Germany and Switzerland in the early nineteenth century, and that the first U.S. patent (number 183,024) on a casein glue was issued in 1876.

Wax in adhesives

Adhesives due to its transition from fluid to solid, are involved in many industries: electronic, wood, textiles, rubber and plastics, sealants, etc. There is a growth of adhesives in industry, and so the use of waxes in adhesives. The various functions of wax in the adhesives may be summed as follows: a) As a laminating adhesive, with or without the aid of other material, such as rubber, resin, etc.

b) As a protective coating for wrapping which will by the aid of heat act as a “self-sealing” agent.

c) As an ingredient of “hot melt” cement – useful in sticking dissimilar material together.

d) As an ingredient of the sticky surfacing agent for paper material, such as flypaper.

e) As a lubricator in glues; and as flexing agent in adhesives.

f) As a combining agent with rubber-wax adhesive which can be applied by heat to the end of a shot cartridge.