Well, this is my second post on this subject, and as promised, I’m going to chat a little bit about the history of composites.
All composites have an analog in mother nature, and man has been trying to copy her since we all swung down out of the trees and started walking on two feet. Why? Because mother nature is such a good engineer and has made some fascinating and wondrous things. A tree is an example of an extraordinarily well design and made composite material structure. And it has the ability to heal itself when damaged. We can’t do that yet even though we’ve been trying to do it for a few decades.
Anyway, back to the history. There is evidence in the archeologic records of ancient humans mixing straw (strings) and mud (glue) together to form bricks. They would let these bricks dry in the sun long enough make them solid, and then they used them to build their longhouses. The houses in Jericho were made of these mud and straw bricks (adobe). And around 3000-2500 years ago, man leaned that if he used the right clay and the right straw he could fire these mud bricks and they would resist even monsoon flooding.
Concrete came about in about 6500 BC when early Middle Eastern builders discovered that if they crushed and burned limestone, it would make a powder (cement) that they could mix with sand and gravel to make a stone the shape and size that they wanted it. And, the Egyptians modified this and used just the fired limestone, sand, and water to make a mortar that they could use to stick their fired mud and straw bricks together. And the pyramids are still standing to this day.
Plywood was invented in Mesopotamia in ~ 3500 BC where they put together strips of wood glued together with a pitch that they made from the bark of local trees. Plywood today uses the same idea where thin sheets of wood are glued and pressed together to make a board.
And in about 2200 BC the Egyptians used linen cloth or papyrus soaked in plaster and placed in a mold to make masks that they put over the faces of corpses before they buried them. This is very nearly the same technique used to make modern composites today, albeit the string and the glue are different today.
In today’s world, the first actual modern composite material that was ever made was invented by a brilliant Belgian chemist by the name of Leo Baekeland. He had invented a photographic paper that could be developed using a water process and had sold it to George Eastman. And of course, the story of that paper is Eastman Kodak which became the largest photographic film company in the world.
But Leo’s passion was polymers and plastics. So, when he was now independently wealthy he went back to trying to make a coating that was like shellac, and was playing around with phenols to see what he could make. Bakelite, which everyone has some of in their kitchen, is a composite that is made using Leo Baekeland’s resin impregnated into wood chips and molded and cured into something hard and durable. He filed his first patent in 1907.
String and glue had arrived.
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