Plywood is a versatile wood product that is used for a number of different products. It is commonly used instead of regular wood because it is far cheaper and resistant to cracking, warping, shrinking and splitting. It is an important wood in the building and furniture industry, but can also be used for many other applications. You may have noticed that plywood is different from other types of wood, read on to find out how it is made.
How is plywood made?
Basically plywood is made by layering a number of thin slices of wood (called veneer) together. These layers of wood are created from a log by a machine that basically peels a thin layer of wood away. The wood is then cut to the correct dimensions and allowed to dry. Once the wood is suitably dry it is layered together so that the grain of each layer is at a 90 degree angle to the last (called cross-graining). This protects the wood from splitting and reduces expansion or shrinkage. After the wood is layered to a suitable thickness each sheet is glued together with a special glue, urea-formaldehyde for indoor use and phenol-formaldehyde for outdoor use. In the final process the newly glued plywood is baked at 140 °C (284 °F) at a specific pressure to form the finished panel. The plywood is then patched, cut, sanded and refinished for shipping.
Did you know?
Although plywood originated in ancient Egypt around 3500 B.C. the modern version was invented by Immanuel Nobel, who was the father of the famous inventor Alfred Nobel.
The glue used in the manufacture contains formaldehyde, which is carcinogenic (cancer causing). This has led to concerns about the use of plywood. Manufacturers are now able to produce plywood with virtually no emissions from the glue!
Plywood is used to cover windows during a hurricane to prevent damage to the glass.