my Grandfather invented ply wood, he invented the machines to strip the wood of the tree's and the glue as the glue of that era was made from calfs hoofs and stained the wood so he had to invent a glue that wouldn't stain the wood, them he invented the way of gluing the sheets together in opporesite ways for strenght. them my uncle invented plastic while working for dunlop during the war as they couldn't get rubber and needed a substitute