What is plywood?
Plywood is a multi-layered building material,which is made by gluing a specially processed veneer. From plywood can make a lot of things, this material is widely used in construction, furniture manufacturing, insulation products - it is available, easy to manufacture and inexpensive.
Technique of manufacture, or what is made of plywood
Plywood is made from birch, as well as coniferous wood. The log, which is called Churak, is cleaned of bark and dirt and subjected to moisture-heat treatment for several hours.
When the wood softens a little, churakfixed in a special machine, on which it rotates around its axis. With the help of a grinding knife, a wide shaving is removed from the log, which is called veneer.
Strips of veneer are painted on sheets thatpass sorting by quality, it is necessary to weed veneer with cracks and other defects. Then it must be dried and placed in special bags, as a rule, an odd number of veneer sheets is placed in the package. Laying is done in a special way - the fibers of adjacent sheets should be perpendicular to each other.
When the bag is formed, the veneer surfaceIt is covered with glue and the bag is immersed under pressure at elevated temperature. The increased pressure combines the individual sheets of veneer into one whole. Now the plywood has to be cooled, dried and subjected to additional processing
Depending on the purpose for which the plywood is made, it can be additionally subjected to one- or two-sided grinding, laminating, facing, and the like.
Types of plywood
Plywood is classified according to a number of features:
- material - coniferous and birch;
- purpose - construction, industrial, furniture, etc .;
- number of layers - three-, five-, multi-layer;
- impregnation - treated with albumin, casein, phenol formaldehyde, bakelite glue, etc .;
- surface treatment - unpolished, polished with one and two sides;
- grades - E (elite), sort I, II, III, IV.
Great influence on the quality of plywood hasimpregnation. So, impregnated with albumin or casein glue plywood is environmentally friendly material; phenol-formaldehyde glue - is characterized by high strength and reliability; bakelite glue - the maximum resistance to the effects of an aggressive environment.
Plywood is used in many areas, and here are the main ones:
- Furniture manufacturing. Plywood is best suited for the manufacture of furniture components due to its lightness, stability, and the simplicity of the final finish.
- Manufacturing of packing. The main advantages of plywood in comparison with other packaging materials are moisture resistance, low price, light weight, safety and hygiene, durability.
- Building. Plywood is used for formwork works, as it can withstand multiple pouring, and also it has high strength for wear. Also, plywood is used to create a variety of wooden structures for decoration and cladding, as its further processing does not cause complications.
- Children's toys and furniture. We mentioned above that plywood treated with albumino-casein glue is environmentally friendly material, and this property is of great importance when creating children's furniture and toys.
Read also: How to lay plywood on the floor.
For more information on building materials and repairs, go to the Building Materials section.