Natural adhesives are made from organic sources such as vegetable matter, starch (dextrin), natural resins or from animals e.g. casein or 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 is 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. Casein based glues are made by precipitating casein from milk protein using the acetic acid from vinegar. This forms curds, which are neutralized with a base, such as sodium bicarbonate (baking soda), to cause them to unclump and become a thicker plastic-like substance.
Last modified: Saturday, 26 November 2011, 5:27 AM
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