Posted by Ryan Pilling on Mar 2, 2011 in Interesting Facts | 1 comment
In the exciting world of adhesives, glue is the organic side of things. Technically, for something to be a true “glue” it will get its sticky quality from an animal or vegetable ingredient.
The classic example is sending an old horse to the great glue factory in the sky. In fact horse hooves, along with bone, hide, and connective tissues, provide collagen as the main ingredient for glue. (in all mammals, including you dear reader, over 25% of the protein content is collagen)
The process of turning pony toes into glue is, to boil it down, essentially… boiling it down. The collagen leaks out in a jelly-like form, is collected, and ground into powder. When you’re ready to make antique furniture, you mix it with a bit of water, heat it up, and you’re ready to brush it on your joins.
Collagen glue like that has been used for at least 8000 years, and has only been replaced by chemical adhesives for common use in the past century.
Vegetable glue, commonly called paste, is an even simpler recipe: starch and water. The starch most commonly used is corn starch, but white flour works as well.
When sticking things together, the best adhesive is one that shares chemical properties of the items you want to make stick. That’s why paste works so well with paper. The starch, which is a carbohydrate, is similar to the carbohydrate cellulose that forms the paper.
So animal glue is basically Jell-O without the strawberry flavouring, and white paste is gravy without the beef flavouring. So don’t get too upset if you find your child eating glue… it’s almost healthy.
