Plywood is a building product that is common all over the world. It’s used in everything from furniture to house construction. The big advantages of plywood include: Standard size (4 feet x 8 feet), Low cost, Strength and Stability (warping and shrinkage is much less of a problem)
If plywood did not exist, you would end up making the same size piece of wood from a collection of flat boards. That approach would be a lot more expensive and not nearly as strong or stable.
To make plywood:
- A log is softened with steam and then mounted on a lathe.
- A long knife peels off a thin layer of wood in a continuous veneer sheet. Once dried, a thin veneer sheet like this is very strong in one direction (along the grain) and very weak in the other (across the grain).
- Several layers of veneer (generally five or seven) are layered together with the grain direction alternating between the different layers. Glue is used between the layers.
- The stack is heated and pressed to form a rigid panel.
Because the grain direction of the layers of veneer alternate, the panel is extremely strong in all directions.