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STICK IT ON!
Adhesives touch our lives daily. Look around and you’ll find them everywhere…in the chair you sit on, your footwear, your bag, the wallpaper, our buildings, even in this magazine!
Making hide, skin or fish glue
Animal glue – made from the protein extracted from the bones, hide, hoofs and horns of animals by boiling. |
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1 Hides and other scraps are washed to remove dirt and soaked for softening. This is called stock, which is then passed through a series of water and lime baths to help break them down. The hides are rinsed with weak acids to remove the lime. |
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Cellulose adhesive – made from a natural polymer found in trees and woody plants. |
Fish glue – a similar protein-based glue made from the skins and bones of fish. |
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2 The stock is cooked at high temperatures or pressures – 160°F (70°C) to break down the collagen. Clean water treatments are done at increasing temperatures, resulting in ‘glue liquor’, which is extracted and reheated for thickening. |
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Rubber-based solvent cements – adhesives made by combining one or more rubbers or elastomers in a solvent. |
Casein glue – made from a protein isolated from milk. |
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3 Impurities are removed to make the glue clear by using chemicals, alum or acid followed by egg albumin. |
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Epoxies – adhesive systems made by a complex chemical reaction. |
Starch – a carbohydrate extracted from edible plants such as corn, rice, wheat and potatoes, better known as paste. |
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4 Additives like sulphurous acid, phosphoric acid and alum are mixed with the glue liquor to make brown, clear or white glue. |
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Hot melt adhesives – thermoplastic polymers that are tough and solid at room temperature but turn liquid at elevated temperatures. |
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5 Vacuum evaporators help concentrate runny glue, which is then dried. For example, the glue can be chilled into either sheets or blocks and suspended on nets, or dropped as beads or ‘pearls’ into non-water bearing liquor. These are then mixed to the right consistency and pumped into bottles or tubes for sale. |
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Other adhesives that are made using higher technology and complicated chemical processes include RTV silicone adhesive,
Anaerobic adhesive and Cyanoacrylate. |
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  Early hunters may have improved their aim by sticking feathers to arrows with beeswax, a primitive adhesive.
The world's largest glue manufacturer is a dairy called Borden Company.
The Tower of Babel was probably built with the aid of mortar and tar or pitch.
The Egyptians used glue to produce Papyrus.
Greek and Roman artists used glues extensively for their mosaic floors and tiled walls and baths that are still intact after centuries! |
Red Alert!!!
Solvents in most adhesives are hazardous to human health. They react in a variety of ways, ranging from dizziness to poor coordination, unsteady gait, short term memory loss, fits, reduced attention span, coma, dementia and peripheral neuropathy!
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