Plywood is one of the most popular materials used for furniture making, interior designing, and commercial purposes, among other things. It is an extremely versatile material that is well known throughout the world.
There are different types of plywood and they are readily available in any plywood store near you. But what exactly is plywood and how is it made? In this blog post, let us learn more about plywood, the different types of plywood in India, and its numerous uses in both indoor and outdoor projects.
What is Plywood and How is it Made?
Plywood is a wood-based paneling material containing numerous thin layers of wood bonded crosswise along the grain. Waterproof phenol-formaldehyde adhesive is used to glue together the cross-laminated sheets of wood, and then they are cured under heat and pressure to form plywood. Each layer is called a veneer, and it is fused with other veneers to form plywood.
How plywood is Manufactured?
The manufacture of plywood involves 8 processes, namely:
- Debarking and bucking logs
- Heating logs
- Peeling logs into veneers
- Drying veneers
- Bonding veneers together
- Pressing veneers in a hot press
- Plywood cutting, and
- Other finishing procedures like sanding
The first stage of debarking involves feeding the logs through one of several different types of debarking equipment. The goal of this procedure is to remove the tree’s outer bark without causing significant damage to the wood. Following the removal of the bark, the logs are cut into the desired lengths. This process is known as bucking.
The logs (now known as blocks) are then heated. Hot water baths, steam heat, hot water spray, or a mix of the three are used to heat the blocks to roughly 93°C (200°F).
The blocks are then processed to make veneer. Next, they are taken to a veneer dryer where they are dried to moisture content that ranges between 1 to 15 percent.
After drying, resins like phenol-formaldehyde or urea-formaldehyde are used to glue together the different layers of veneers. After that, the veneer assembly is sent to a hot press where it is set under heat and pressure.
After that, the plywood goes through a finishing process in which the edges are cut and the face and back are sanded smooth. The type of finishing chosen depends on the intended end result.
Versatility of Plywood
Plywood is a material that is widely regarded as one of the best substitutes for wood. It’s because they have the same visual appeal as wood but cost a fraction of the price.
Working with plywood is less time-consuming and it is readily available as plywood sheets in various sizes, allowing woodworkers to quickly transform it into plywood furniture and plywood wardrobes.
Depending on their intended usage, plywood pieces are shaped differently. If the plywood is to be used for construction, then it is pressed into large flat sheets. For the purpose of manufacturing aircraft, boats, or furniture, the plywood is shaped into curves.
Here the grain of each layer of ply runs at right angles. This keeps the layer firm and durable while also reducing the possibility of it shrinking.
Types of Plywood
Depending on the amount of strength required, some projects will require thicker boards, while others would require smaller boards. Plywood’s are available in different thicknesses. Three-, five-, and multi-ply plywood are the most prevalent, with three-ply being the most popular.
Three-ply is stronger and long-lasting. Five-ply is more durable than three-ply, and multi-ply can be utilized for exterior tasks such as roofing. Additionally, there are different types of plywood available in India.
Understanding the various types of plywood helps you to choose the best plywood that is suited to your specific project. Here are some of the major types of plywood:
1. Hardwood plywood:
The phrases “softwood” and “hardwood” do not refer to the softness or hardness of the wood. There are some varieties of hardwood that might be lighter and softer than softwoods.
For instance, although Balsawood is very soft, it is considered hardwood. So then, how is it classified? The difference lies in the botanic structure of the wood.
Hardwood contains more pores and vessels than softwood. They are usually dark-colored, and the wood texture is of higher density and contains thicker cell walls.
Hardwoods are usually manufactured from deciduous trees. Oak, poplar, maple, cherry, and larch are some of the most common wood species used to make hardwood plywood.
Uses: Flooring, Roofing, furniture, sports equipment, musical instruments, painting boards
2. Softwood plywood:
Softwood is typically made from pine, fir, spruce, larch, or cedar. They are lighter in color and have lower densities, and are flexible. They are best for roof sheathing, exterior frame, and subflooring. Softwood trees grow at a faster pace and are cheaper and easily available when compared to hardwood.
Uses: Windows, construction framing, used in the construction industry
3. Aircraft plywood:
It is considered a durable type of plywood. Aircraft plywood is made of hardwood that helps in creating strong broads and repelling moisture and heat.
They consist of very thin veneers that keep it light and flexible while still offering a lot of strength. As a result, it’s ideal for manufacturing structures that can support a lot of weight.
Uses: Boats, aircrafts, architectural models, musical instruments, furniture
4. Gurjan plywood:
It is known as one of the best plywoods in India and it is very popular. So what is Gurjan plywood? It is made from the wood of Gurjan trees, which can be found in abundance across Southeast Asia.
The Gurjan tree is a type of hardwood that is known for its exceptional strength and is considered high quality. The hardwood from these trees is used to make Gurjan plywood sheets, which are used for interior and commercial plywood projects.
Uses: Popularly used for making home and office furniture
5. Lumber core:
It is typically composed of three plies, each with two thin veneers on one side and a thick core. The exterior veneers are usually hardwood, while the inner core is made up of strips of wood fused together to form a single solid slab. This core can easily hold screws, making it an excellent choice of plywood for projects that require a strong screw hold.
Uses: Making shelves in cupboards or closets that are long or wide
6. Marine plywood:
Even though the name of the plywood contains the term ‘marine’, it is not completely waterproof. Water-resistant exterior glue is used to varnish marine plywood, which enables it to repel water.
This plywood can withstand mild wetness, but it is not completely waterproof. It is one of the highest quality varieties of plywood available, manufactured using western larch or Douglas fir wood.
For a plywood to be classified as marine plywood, the wood must have no knotholes in any of its plies, and additionally, water-resistant glue must be used. This ensures that the glue will hold the veneers together even when the wood becomes wet due to weather or other factors.
Uses: For building gazebos, planter boxes, and benches, as well as other outdoor furniture.
7. Overlaid plywood:
Overlaid boards have the same amount of plies as other varieties of plywood, but a thin veneer of decorative wood is applied on top. This makes for a more decorative looking plywood, and also offers resistance to water and scratches.
It also prevents small particles from sticking to it, making it quite a durable type of plywood.
Uses: Garden and outdoor furniture, industrial containers
8. Structural plywood:
It is also known as sheathing plywood. It is a type of plywood that can be used to reinforce frames and building components. It has a strong adhesive and may be used both on the inside and outside of buildings, although it is not as weather resistant as other varieties.
Structural woods often have a C or D grade, but not a higher grade than that. This makes them a less expensive option than some other plywoods. However, they may not be a durable option for outdoor construction.
Uses: For building beams and hoardings, used in crates, bins, boxes, outdoor furniture
9. Moisture Resistant (MR) grade plywood:
MR grade plywood is commonly known as commercial plywood. It is utilized in all types of furniture and is popularly used in the commercial industry. The chemical treatment of MR Grade plywood makes it resistant to termites and borers.
Commercial plywood is comprised of high-quality hardwood lumber that gives it maximum strength and durability, making it ideal for commercial and residential projects.
Uses: Interiors of office and home, doors, chairs, tables, wall-mounted cabinets, rooftops, partitions, wall panels
10. Exterior plywood or Boiling Water Resistant (BWR) grade plywood:
In this type of waterproof plywood, the layers are held together by using phenol formaldehyde, a kind of adhesive that is weather and water resistant. This makes the wood durable enough to handle outdoor conditions such as wind, and rain. It may be utilized indoors, semi-outside, or outdoors.
It’s commonly used to make furniture that might get wet. Exterior plywood is multi-ply as it consists of several layers. It is a good choice of plywood for doors and windows due to its sturdy and strong wood texture.
Exterior plywood comes in different types of wood. If you live in harsh seasons it is better to go for oaks as they can offer resistance against mold, moisture, and mildew.
Uses: Outdoor structures and furniture, decks, walkways, shed, outdoor shelving
11. Boiling Water Proof (BWP) grade plywood:
It is the most preferred plywood because of its excellent waterproof and weather protection qualities. It has good bonding strength derived from the use of strong adhesives, such as phenolic glue. It is mostly used in places where there is regular exposure to water such as the kitchen, dining table, bathrooms, offices, and so on.
BWP grade plywood costs a little more than BWR plywood since it lasts longer and can be used in different places. It offers excellent value for money because it is entirely borer and termite proof, and lasts a long time.
Uses: Interiors such as kitchens and bathrooms, boiling water units, storage units
Lamination of Plywood
Laminated plywood is plywood that has been improved aesthetically by the addition of decorative laminate sheets. These sheets are also known as laminates, and they are used to create protective and decorative surfaces on plywood.
Strong adhesives such as urea-formaldehyde and phenol formaldehyde are used for bonding, and the stacks are run through hot-pressing machines and laminated. The end product is sanded and finishing touches are added before being transported to various distributors and dealers.
Laminated plywood has many qualities:
- Water and moisture resistant
- Aesthetically appealing
- Repels chemicals, and
- Durable and long lasting
Choosing the Right Plywood
Before you choose a type of plywood, the first question you need to ask is: Are you searching for plywood that would look great as a piece of furniture, or are you primarily concerned with utility? Hardwood plywood, such as cherry or oak, is popularly used for making furniture.
Hardwood plywood is known for its visual appeal, whereas softwood plywood is considered a structural material. Choosing the wrong kind of plywood can be detrimental to your project. So before you decide, explore different plywood options and go for the plywood that meets your project needs.