Plywood: what this material is, types, application

Skateboard boards, railway cars, packaging of goods, hockey courts, furniture - such dissimilar objects are united by the fact that plywood is used in their construction. It is a versatile material that is stronger and cheaper than wood. Let's look at what plywood is, what it is and where it is used.

What is plywood

Plywood consists of several sheets of veneer glued under pressure. The layers are arranged perpendicularly and so are the fibers. The material is made rigid and strong due to this folding and pressing. Unlike wood, the sheet does not delaminate on the fiber and does not crack. The outer surfaces look like a slice of wood.

As a binder, several types of glue are used:

• albumin-casein and urea glue - safe for health, does not emit toxic fumes.
• Melamine glue - few hazardous substances are present.
• Urea-formaldehyde and phenol-formaldehyde glue - contain a lot of toxic substances.
• Bakelite glue - gives the material resistance to aggressive environments, low and high temperatures.

Types of plywood

The main types of plywood material:

• Water-resistant plywood.
• Hardwood plywood is made from dense wood and phenol-formaldehyde resin, which creates an adhesive bond.
• Seiba - plywood made of Seiba wood. The feature is a low weight. It is often used to make table tops, the seats of stools and chairs.
• Laminated plywood F/F - the basis on both sides is covered with a phenolic film. It is used for making flooring and furniture. Laminated F/W plywood has a smooth coating on one side and a mesh coating on the other. Such plywood is used for truck body and floor cladding.
• Hardwood plywood types are best if they are B/BB grade. It can be a mixed species of light hardwood, but beech, maple and walnut have the best color and wood grain. This is why these wood species are widely used in joinery and furniture production.
• Flexible plywood is a flexible material, it is used to make original interior objects. The surface can be polished, painted, veneered, covered with plastic or paper.

Plywood is classified according to quality:

• Elite (class A) - a perfect surface without flaws.
• Grade 1 (class B) - smooth even surface, beautiful wood grain, no knots.
• 2nd class (class C) - small knots are present - up to 1.5 inches.
• Grade 3 (class D) - there are defects and knots up to 2.5 inches.

Application of plywood

Plywood is used for such tasks:

• In the manufacture of furniture, stronger cheaper plywood serves as the basis of the body, more expensive sheets go to the facades.
• In construction industry plywood is used for formwork, facing, sound and temperature insulation, floor insulation etc.
• BS1088 plywood is used for decks and boards of small vessels.
• When erecting inner walls, plywood serves as partition wall cladding and is hidden behind the trim. High quality grade 1 sheets can serve as exterior cladding.
• Roof or floor cladding is made of plywood.
• Special heavy-duty and lightweight plywood is used in aircraft construction.
• Billboards and road signs are made of plywood.

Plywood is chosen in accordance with the purpose and whether it requires increased water resistance and resistance to corrosive environments. Indoors, it is better to use sheets bonded with an adhesive that is safe for health.