Plywood is made up of fine layers of wood veneers attached together placing wood grains 90 degrees to one another and is an engineered wood sheet and plywood mostly uses for outdoors.
Plywood is a type of manufactured board with a mixture of medium density fibreboard and chipboard and attaches fiber sheets and resin of wood.
Because of its relatively low moisture content property which makes various tasks easy to perform with this, the plywood has become popular with this property. For the construction of motor torpedo boats and motor gunboats, the renowned powerboat company uses plywood.
Manufacturing Process of Plywood:
There are following steps in the manufacturing of plywood as given below:
Selection of Log.
Exposure to Heat.
Gluing & Baking.
Selection of Log:
According to the demand for the type of plywood to be manufactured, the selection of a good log from selected tree wood is the first step and this log is called a peeler, and the peeler has a good diameter and straight.
For the processing of thin layers inside sawmill and made sheets of veneers, the large blade is used, and to get a better result, a horizontal placement of log under the blade is maintained and several layers are cut into pieces by continuously pressing the blade.
Exposure to Heat:
For removing water content, then the sheets exposed to heat and before the next step, good dehydration of sheets is confirmed.
Gluing & Baking:
To maintain the system of a different type of plywood, the sheets are glued together after drying, and to get the best result caution is maintained in this step.
For gluing, urea formaldehyde and phenol formaldehyde are used and for fungal resistance quality, Furmecyclox is used.
By pressing at required temperature and pressure, the glued plywood primary sheets are sent for baking and the minimum pressure is 1.9 Mega Pascal and minimum temperature is 140 degrees Celsius.
After the above process defects of manufactured plywood sheets are solved and reshaping and resizing takes place and finishing the unfinished edges.
Types of Plywood:
There are the following types of plywood such as;
Softwood plywood is made from spruce, fir, and pine and also be made from cedar, and as from the name, this type is not stronger than others.
For exterior frame sheathing, roof sheathing, and sub-flooring construction workers typically use softwoods. For the creation of things like sheds, temporary flooring, doghouses, shelving, etc this type is also used.
This type is made by using hardwoods like birch, maple, oak, and walnut and typically has between three and seven layers. To create an incredibly strong finish, the manufacturers glue the layers of wood at right angles to one another.
For things like furniture, packing cases, sporting equipment, musical instruments, and other projects that require strong frames, these woods are the best.
This type is among the highest-grade and most durable and to create an incredibly strong finished piece that can also resist moisture and heat, it uses hardwoods like mahogany or birch.
In the projects that need industrial-strength woods, like airplanes, boats, and furniture to hold a lot of weight, this type is commonly used.
The tropical plywood is made from the different types of timbers of the tropical area which are mixed and this type is popular for several reasons such as;
Evenness and Inflexibility
Thickness and Resistance quality.
This type is used as both industrial and construction-based and, also used in flooring, paneling, and the creation of laminated veneer lumber, etc.
For making flexible furniture or structures, this type is mostly used and it can give shape to new concepts in the manufacturing of modern furniture.
This type can give the combined effect of strength and durability and from specially treated veneers usually with a thinner central core veneer and two thicker outer veneers, this type is manufactured.
This type is made from woods of ash, oak, Red oak, birch, maple, and mahogany and to satisfy everyone’s taste these often come in many colors.
For indoor climbing walls, decorative furniture this type is used and is a high-quality product and cost-efficient.
These are stronger than any other wood products and are environmentally friendly.
In the moisture, humid, and wet environment this type is used and it is made with waterproof glue and also tends to be lightweight, virtually free of defects, and strong.
For building boats and boat parts, it is also used and also a smart option for durable outdoor furniture projects in coastal areas.
This type is made of Douglas fir or Western Larch and these woods are available in many grades like A-A, A-B, and, B-B.
Benefits of Plywood:
There are the following benefits such as;
In its laminated structure, it offers all the inherent advantages of the parent wood and enhanced properties.
High impact resistance:
Up to twice the design load, it has the ability to accommodate the occasional short-term overload and in the area where the seismic activity or cyclonic winds can occur, this is useful.
Surface dimensional stability:
It ensures that under changes of temperature and moisture plywood sheets remain relatively stable and in flooring and formwork construction where moisture exposure is very likely this is very important.
High Strength to Weight Ratio:
To use in structural applications like flooring, shear walls, formwork, and webbed beams, it is very cost-effective and to weight ratio, it has high strength and stiffness.
Due to its cross-laminated structure, the panel shear of plywood is nearly double that of solid timber and to use in gussets for portal frames, webs of fabricated beams and as bracing panels, this makes it a highly effective material.
When preservative treated, it can be used in chemical works and cooling towers as a cost-effective and durable material.
Disadvantages of Plywood:
For gluing urea and phenol formaldehyde are used and it causes cancer.
It is weaker than wood in many aspects.
Like wood, it is not durable.
It is lighter than normal wood.
For a long period of time, it cannot be exposed to wet or moisture weather.