1.What is plywood?
Plywood is an engineered wood product, and has many varied applications. It is most commonly used for making the furniture that we use in our homes and offices, and also for other applications such as in building construction, and for doing the woodwork in boats and ships.
2.How plywood is made?
The veneers, which are thin slices of wood are obtained from logs of trees. The logs are mounted on a lathe machine, and are rotated about their longitudinal axis, while a cutter peels off thin layers from the log (Somewhat similar to the way we peel layers from vegetables). Glue is applied to all these peeled slices of wood veneers (plies) using glue spreader machines, and the plies are placed one upon the other. The stack then goes into a hot press machine, which firmly presses the veneers together and forms a strong bond between the individual plies so that they do not come apart. Thus a plywood sheet or board is made.
3.What is composition of plywood?
Plywood is made from several thin layers of wooden veneers stacked over one another. These veneers, called plies, are firmly glued to each other so that they don't come apart easily.
The number of plies in every plywood sheet is usually an odd number, such as 3-ply, 5-ply, 7-ply etc.
While stacking the veneers over one another, it is ensured that the grain direction of the plies in adjacent layers is perpendicular to each other. Because of this the plywood board becomes strong in both directions.
4.What are the types of plywood?
The three most well-known types are:
- It is Interior grade and meant for indoor use.
- Made using UF resins.
- Used in home and office furniture.
- It is Moisture resistant (MR grade) but it is not waterproof.
- Exterior grade for outdoor use.
- Made using phenolic resins.
- Used in kitchen and garden furniture.
- It is adequately waterproof, and known as BWR (Boiling water resistant) plywood.
- Used for marine applications, such as for boats and ships.
- Made using undiluted phenolic resins.
- Very strong and very waterproof.
- Apart from these 3 well-known types of plywood listed above, there are other kinds such as flexible plywood that can be bent, fire-retardant plywood that delays catching fire, structural plywood that is used for structural building work, and film-faced concrete shuttering plywood that is used for making the wooden moulds into which concrete is cast.
5.What are the Advantages of Plywood?
High uniform strength - wood is 25-45 times stronger along the grain than across the grain. Crossing the adjacent sheets tends to equalize the strength in all directions.
The balanced construction of a plywood panel with the grain direction of adjacent veneers at right angles tends to equalize stress, thus reducing shrinkage, swelling and warping.
Non-splitting qualities solid wood splits fairly readily along the grain. Plywood by virtue of the crossed laminations can be nailed or screwed near the edges without damage from splitting.
Availability of relatively large sizes - Sawn timber can be obtained in fairly long lengths but only in relatively narrow widths.
Plywood can be sold in sizes up to 6 ft * 25 ft and by the scarf jointing of small sheets up to 6 ft *40 ft, however 6 ft*3 ft is the most common size.
6.What is MR Grade Plywood?
MR grade plywood means Moisture Resistant plywood. In India, it is also known as Commercial grade plywood.
The important features of MR grade plywood are listed below.
- It is an Interior grade plywood, suitable for indoor use.
- The term MR (moisture resistant) can be a bit confusing in this regard. But customers should note that 'moisture resistant' does not mean 'waterproof'. It only means that the the plywood is capable of resisting humidity and moisture.
- The most common use of MR plywood is for making home and office furniture. Customers who want waterproof plywood for their furniture should opt for the better quality BWR grade plywood, which is waterproof and made using phenolic resins. BWR grade ply costs more than Commercial MR grade ply, but it is better for making furniture that is likely to get wet e.g. Kitchen cabinets.
7.What is BWR grade plywood?
BWR grade plywood means Boiling Water Resistant plywood. It is a waterproof plywood, and is widely used for making home and office furniture. Alongwith Commercial MR grade plywood, it is the best selling type of plywood in India.
There is another term BWP (Boiling Water proof) which is very similar sounding and almost means the same. BWP means Boiling Water Proof, and this term is generally used in the case of exterior grade waterproof blockboards. For plywood using the term 'BWR grade' is much more common.
The important features of BWR plywood are listed below.
- It is an exterior grade plywood, that can be used for indoor, semi-outdoor and outdoor use.
- BWR is a waterproof plywood. It can resist water better than the Interior grade MR (Moisture resistant) plywood.
- Phenolic resins are used for in its making. Phenolic resins means using 'phenol formaldehyde' adhesive, which is a synthetic plastic resin. This is what gives the plywood its waterproofing qualities.
- BWR grade plywood is commonly used for meeting those furniture requirements in the home, where the plywood is likely to get exposure to water. For Kitchen cabinets and other kitchen furniture, BWR grade is the preferred choice of plywood.
- The Indian Standards specification number for BWR grade plywood is IS:303
8.How to find duplicates in Crownply?
- All crownply products will have Scratchproof hologram stickers over a 8"X8" Sticker.
- All crownply products will have a Oval sticker in the middle.