Plywood is a composite material made of thin layers (plies) of wood veneer glued and pressed together, often with their grains at right angles, resulting in a strong, stable, and versatile sheet material.
In Canadian building projects, plywood is one of the most well-known multi-purpose engineered wood-based panel products. Resin and wood fibre sheets are joined by plywood to create a composite material supplied in panels.
The face veneers in a standard plywood panel are of more excellent quality than the core veneers. The purpose of the core layers is to improve resistance to bending forces by increasing the spacing between the outer layers where the bending stresses are most significant.
Well, in this reading, we’ll explore what plywood is, its applications, types, and how they are produced.
Let’s begin!
What is Plywood?
Plywood is a material created by adhering thin “plies” or layers of wood veneer together while rotating the wood grain of the neighbouring layers by up to 90 degrees.
It belongs to the family of produced boards, which also includes particle board, orientated strand board, and medium-density fibreboard (MDF) (chipboard).
Just as earlier mentioned, plywood is a composite material made of thin layers (plies) of wood veneer glued and pressed together, often with their grains at right angles, resulting in a strong, stable, and versatile sheet material.
Furthermore, in order to create plywood, which is an engineered wood sheet material, thin layers or frail strands of wood veneers were glued together at a 90-degree angle to the wood grains.
It is a special kind of produced board that can be compared to a blend of chipboard and medium-density fibreboard (MDF) (Particle Board). It is a complicated substance that fastens wood sheets with fibre and resin.
Due to its low moisture content and ease of usage for a variety of applications, plywood has gained popularity during the past 10 years. Plywood has grown to be used extensively, mostly outside.
The well-known British powerboat manufacturer builds its Motor Torpedo Boats and Motor gunboats out of plywood.
Related: What is Wood? its Properties and How it Produce
Uses of Plywood
Applications of plywood include:
- Construction: Used for roofing, walls, floors, and framing.
- Furniture: Used for making cabinets, shelves, and other furniture pieces.
- Interior Design: Used for panelling, flooring, and decorative elements.
- Boat Building: Used for boat hulls, decks, and other parts.
- Formwork: Used in concrete construction for holding concrete in place until it sets.
- Plywood is used for its resistance to warping, twisting, shrinkage, cracking, and breaking.
- Exterior bonded plywood is suitable for outdoor use, but moisture levels should be kept low for optimal performance.
- Plywood’s dimensions and strength remain unaffected by sub-zero temperatures, enabling unique applications.
- Plywood has been used in marine and aviation applications since World War II, with notable examples including the British de Havilland Mosquito bomber and the hard-chine Motor Torpedo Boats.
- Plywood is used to create curved surfaces, such as skateboard ramps, due to its easy bending along the grain.
- Common applications include floors, walls, roofs in home constructions, wind bracing panels, vehicle internal bodywork, packaging and boxes, fencing, concrete formwork systems, transport vehicles, container floors, and scaffolding materials.
- Birch plywood is suitable for specialised ends due to its smooth surface, accurate thickness, and durability.
Types of Plywood
The various types of plywood include:
Softwood Plywood:
Softwood Because it is made of spruce, pine, and fir, plywood is sometimes known as spruce-pine-fir, or SPF. Although cedar (Cedrus sp.) and douglas fir can both be used to make it (Pseudotsuga menziesii).
When constructed from spruce (Picea sp. ), the noticeable grains are covered by a technique to make the plywood more effective and as hard as concrete when used for building and shuttering strands.
Hardwood Plywood:
Hardwood Angiosperms are used to make plywood. This kind of plywood can be recognized by its stiffness, surface hardness, inflexibility, and resistant qualities. Heavy weight can be supported using this.
Tropical Plywood:
To create this sort of plywood, various tropical timber species are blended. Although it was formerly only gathered from the Asian region, it is now being collected from Africa and America.
Popular tropical plywood has some unique features like strength, density, evenness, inflexibility, resistance quality, thickness.
Due to its tropical climate, South Asia produces the most plywood. This style is utilised in nations including Japan, Thailand, Taiwan, Korea, Dubai, and even the United States and England.
The negative consequence of this type is that due to the extreme manufacturing of this type, deforestation is becoming a major issue for some nations, like Malaysia, the Philippines, and Indonesia, all of which export plywood internationally.
Because of its greater thickness, Malaysian plywood is particularly well-known as Malaysian board in Bangladesh and extremely popular among Bangladeshis.
Aircraft Plywood:
Aircraft plywood is made from mahogany (Swietenia Macrophylla), spruce (Picea sp.), and birch (Betula sp.). African mahogany produces structural plywood for aircraft. European birch is the best variety of birch tree. This kind is renowned for its strength.
This type is also composed of mahogany, spruce, and birch, but it has the advantage of being heat resistant.
Decorative Plywood:
Overlaid plywood is another name for decorative plywood. typical materials include ash (Fraxinus species), oak (Quercus species), red oak (Quercus rubra), birch, maple (Acer species), and mahogany. Philippine mahogany is also known as rosewood and seraya (Dalbergia sisso).
Flexible Plywood:
Flexible Plywood is used to create flexible furniture and constructions, as the name implies. The majority of the furniture from the eighteenth century had curved construction. These are constructed of Baltic birch (Betula sp).
Marine Plywood:
Marine plywood is a form of plywood that can be utilised in environments that are moist, humid, or wet. It can be utilised in wetness for extended periods of time.
The marine plywood layers have too tiny of a core gap, which prevents the board from holding water inside the gaps. It is also resistant to fungi.
Structural Composition and Characteristics
The face veneers in a standard plywood panel are of greater quality than the core veneers. The core layer’s main purpose is to enhance the spacing between the outer layers, which experience the largest bending loads, and so raise the panel’s resistance to bending.
As a result, thicker panels can support the same loads over longer distances. The outermost layers of bending experience the highest stress, one in tension and the other in compression.
From its peak at the face layers to almost zero at the middle layer, bending stress decreases. Shear stress, on the other hand, is greater at the panel’s centre and the outer fibres.
Birch plywood (density about 680 kg/m3), mixed plywood (density approximately 620 kg/m3), and conifer plywoods (density 460–520 kg/m3) are the three primary categories into which basic plywood can be broken down in Europe.
How is plywood Made?
A plywood panel is made up of several layers, or plys, of softwood veneer that have been glued together with the grain directions of the veneer running parallel to one another.
These cross-laminated wood veneer sheets are joined by a waterproof phenol-formaldehyde resin glue, which is then heated and compressed to cure.
Plywood is typically created in BC from softwood species like Douglas fir, spruce, pine, and fir; this material is referred to as Canadian softwood plywood, or CSP. The most typical measurement is 4 feet by 8 feet. The most typical thickness of plywood is 1/2 inch.
Plywood comes in a wide range of options, from smooth, natural surfaces ideal for finish work to more affordable unsanded grades used for sheathing. This contains nearly twenty various grades and a dozen common thicknesses.
Graded Douglas-fir Plywood (DFP) and CSP are manufactured in Canada in accordance with CSA O121 and CSA O151 standards, respectively. Here are the quick steps and stages of plywood manufacturing:
- Thin Veneers: Plywood is constructed from multiple thin layers of wood veneer, typically 1/16 to 1/8 inch thick.
- Glueing and Pressing: These veneers are glued together, often with the grain direction of adjacent layers alternating at 90 degrees, and then pressed under high pressure and temperature to form a solid sheet.
- Engineered Wood: Plywood is an engineered wood product, meaning it’s manufactured from wood rather than a single piece of wood.
Related: 33 Types of wood and their uses
FAQs
What is the definition of plywood?
Plywood is a construction material made of thin layers of wood glued and pressed together, usually with their grains at right angles to one another.
What is the purpose of plywood?
Plywood can be used for furniture production and cabinetry to construction, flooring, and even boat building and other marine applications. There are many advantages to working with this lightweight wood material, but it’s important to keep in mind that plywood doesn’t have a lot of the same qualities as solid wood.
Is plywood waterproof?
Exterior plywood is weather (and water) resistant, so it’s strong enough to be used outside and also in areas that are exposed to water and humidity, like a garage. This type of plywood, often made from Douglas fir, is made stronger by adhering its layers with a waterproof glue in joinery production and furniture making.
Where is plywood used?
Birch plywood is known for its durability and resistance to warping, making it suitable for heavy-duty applications such as wall structures and flooring. It’s also used for household furniture due to its blemish-free finish and ability to withstand heavy weight.