Wood Composites

Engineered wood, man-made wood, or manufactured board; includes a range of derivative wood products which are manufactured by binding or fixing the strands, particles, fibres, or veneers or boards of wood, together with adhesives, or other methods of fixation to form composite materials.

With reconstituted wood materials, changes in properties are studied at the fibre, particle, flake, or veneer level. Properties of such materials can be changed by combining, reorganizing, or stratifying these elements.

The basic wood elements that can be used in the production of wood-based panels

Three general categories: plywood, particle and fiber composites, and wood–non wood composites.

The third category, wood–non-wood composites, includes products made from combining wood fibers with agricultural fibers, with thermoplastics, and with inorganic materials.

Conventional wood composite materials fall into five main categories based on the physical configuration of the wood used to make the products: plywood, oriented strand board, particleboard, hardboard, and cellulosic fiber board.

Can be tailored to the end-use application of the product. Varying the physical configuration of the wood. Adjusting the density of the composites. Other ways include varying the resin type and amount and incorporating

additives to increase water or fire resistance or to resist specific environmental conditions.

Classification of wood-based composites

Veneer-based material Plywood Laminated veneer lumber (LVL) Parallel-laminated veneer (PLV)

Laminates Laminated beams Over laid materials Wood– non-wood composites

Composite material Cellulosic fibreboard Hardboard Particleboard Wafer board Flake board

Oriented strand board (OSB) COM-PLYc

Edge-adhesive-bonded material Lumber panels

Components I-beams T-beam panels Stress-skin panels

Wood–non-wood composites Wood fibre–plastic composites Inorganic-bonded composites Wood fibre–agricultural fibre composites

Larger particles - higher strength properties Wood particle geometry is important – typically, the anatomical longitudinal

direction should parallel the long axis of the particle. Parallel alignment of particles gives strength properties more similar to

solid wood Higher in longitudinal direction. Asymmetric.

Smaller particles - smoother surface More adhesive - higher strength properties and water resistance Composites swell more than solid wood upon exposure to water (except

veneer-based products)

Plywood

PLYWOOD Plywood is a flat panel built up of sheets of veneer called plies, united under

pressure by a bonding agent to create a panel with an adhesive bond between plies.

The properties of plywood depend on the quality of the different layers of veneer, order of layer placement, adhesive used, and control of bonding conditions.

It is always constructed with an odd number of layers with the grain direction of adjacent layers oriented perpendicular to one another.

Since layers can consist of a single ply or of two or more plies laminated such that their grain is parallel, a panel can contain an odd or even number of plies but always an odd number of layers.

The outside plies are called faces or face and back plies; the inner plies are called cores or centres; and the plies with grain perpendicular to that of the face and back are called cross bands.

BrandPrice/per sq.

ft.(Rs.)

Duro Commercial 32.54

Greenply 34.52CenturyPly 35.84

SPECIFICATIONS The top selling and most commonly manufactured plywood

size in India is 8 feet by 4 feet. Other sizes such as 8x3, 7x4, 7x3, 6x4 and 6x3 sq.feet are also manufactured.

The core may be veneer, lumber, or particleboard, with the total panel thickness typically not less than 1.6 mm (1/16 in.) or more than 76 mm (3 in.).

Plywood can be glued, screwed, cut and sawed, and fasteners can be used too, much like solid wood.

USES SOFTWOOD: Floors, walls and roofs in houses; wind bracing panels, vehicle internal body

work packages and boxes, and fencing. HARDWOOD: Panels in concrete form work systems, floors, walls and roofs in transport

vehicles, container floors,scaffolding.

Advantages Improved utilization of wood. Greater resistance to splitting High strength-to-weight and strength-

to-thickness ratios, and its stiffness and strength are more equal in width and length than are stiffness and strength of solid wood

The form permits many applications where large sheets are desirable.

Excellent dimensional stability along its length and across its width.

Minimal edge-swelling makes plywood perhaps the best choice for adhesive-bonded tongue-and groove joints, even where some wetting is expected.

Disadvantages Size:Plywood is available "off the shelf" almost

exclusively in unwieldy 4-foot-by-8-foot sheets. Plywood cannot be made thinner by surfacing, as can be done with lumber. Attempting to do so will severely damage the plywood.

Can be custom-ordered in the same size and shape as other lumber if desired, but the expense is prohibitive.

More susceptible to moisture and weather damage than regular lumber.

Capillary action, draw the water deep into the wood. This compromises the integrity of both the wood and the adhesive used to hold the layers together.

Failure effects are catastrophic. Plywood, used for sheathing, in shingle roofing, when fails, comes to notice much later, when the failure is pronounced that there is no alternative but to remove and replace the entire sheet.

Oriented Strand Board

Oriented Strand board Oriented strand board is an engineered structural-use panel

manufactured from thin wood strands bonded together with waterproof resin under heat and pressure.

Orientation of wood strands with a typical aspect ratio (that is, strand length divided by width) of at least 3 can produce a panel product with greater bending strength and stiffness in the oriented or aligned direction. OSB with aligned face

and random core

OSB with aligned faceand aligned core Brand Price/per

piece(8’ x 4’) Thick

7/16”LP Cumberland Rs. 470.25Tech Shield Rs. 660.80

USES: It is used extensively for roof, wall, and floor sheathing in

residential and commercial construction. Performance OSB panels are specifically engineered for

floor, roof, and wall sheathing purposes in wood frame construction.

SIZES: Panels are available in nominal 4'x8' sheets (1220x2440

mm) or cut to size dimensions. For industrial applications sizes up to 8'x24' (2440x7320

mm) and larger are available by special order. Some new mills manufacture master panels up to 12' (3660 mm) wide or other custom sizes from continuous presses.

The most common thicknesses are 1/4 ", 3/8", 7/16", 15/32", 19/32", 23/32". Other panel thicknesses including 7/8", 1-1/8" and 1-1/4" are available on special order. Panels 19/32" and thicker are manufactured either square-edged or tongue and grooved on the long edge.

WORKABILITY OSB is easy to saw, drill, nail, plane, file or sand. It contains wood, fully cured waterproof

and boil proof resin adhesive and a small amount of wax. Normal carpentry tools can be used, but carbide tipped blades are recommended for

prolonged use.NAILABILITY The many interleaved layers create panels with good nail holding properties. Nails can be

driven as close as 1/4" from the panel edges without risk of splitting or breaking out. However, an edge distance of 3/8" for structural applications is recommended.

Often power driven nails are used to fasten sheathing. GLUABILITY OSB may be glued with any adhesive recommended for wood. For

strong bonds, lightly sand the surfaces in the areas to be glued.PAINT ABILITY OSB may be finished with any good quality paint system

recommended for wood. For best results, the surface must be primed or sealed before painting.

Advantages Available in large sizes. OSB can be

manufactured into larger panels than plywood and offer more cost saving options for today’s builders

Consistent. Panels are dense and solid throughout the product. OSB panels do not have core voides like plywood panels do

Good shear strength.  Resource-efficient.OSB panels are

considered greener by some as they are manufactured from smaller, sustainably-grown trees rather than old-growth forests

Affordable. 

Disadvanages Heavy. OSB’s relative density could be

seen as a bad thing.  a 23/32 plywood panel weighs 2.2 pounds per square foot compared to 2.4 pounds for an OSB panel of the same thickness.

Lower moisture tolerance. When plywood is exposed to moisture it swells evenly throughout the panel and returns to its nominal thickness as the wood dries.

Prone to swelling edges and telegraphing.

Lower perceived value. Despite the fact that plywood and OSB meet the same performance requirements, the average consumer assumes OSB is an inferior product based on its look.

Particle Board

Particle Board Need to dispose of large quantities of sawdust, planer shavings, and to a

lesser extent, the use of mill residues and other relatively homogeneous waste materials produced by other wood industries.

Simply put, particleboard is produced by mechanically reducing the material into small particles, applying adhesive to the particles, and consolidating a loose mat of the particles with heat and pressure into a panel product.

Particleboard is typically made in three layers. The faces of the board consists of fine wood particles, and the core is made of the coarser material.

However, particleboard is generally not as strong as fibreboard because the fibrous nature of lignocelluloses is not exploited as well.

USES Packaging materials, furniture and non-structural building components. Particleboard is used for furniture cores, where it is typically overlaid with

other materials for decorative purposes. Particleboard can be used in flooring systems, in manufactured houses, for stair treads, and as underlayment.

Thin panels can be used as a panelling substrate.

ADVANTAGES Particleboard is cheaper, denser and more

uniform than conventional wood & plywood and is substituted for them when appearance and strength are less important than cost.

For constructing, cabinet box and shelves, it is well suited for attaching cabinet door hinges to the sides of frameless cabinets. Plywood has can feather off in sheaves when extreme weight is placed on the hinges. In contrast, particle board holds the screws in place under similar weight.

DISADVANTAGES Though it is denser than conventional

wood, it is the lightest and weakest type of fibreboard, except for insulation board.

A major disadvantage of particleboard is that it is very prone to expansion and discoloration due to moisture, particularly when it is not covered with paint or another sealer.

Therefore, it is rarely used outdoors or in places where there are high levels of moisture, with the exception of some bathrooms, kitchens and laundries, where it is commonly used as an underlayment - in its 'moisture resistant variant - beneath a continuous sheet of vinyl flooring.

Thickness Length x Width (mm) Applications12mm 1800 x 450/600/900/1200

2400 x 450/600/900/12003600 x 450/600/1200/1800

•Shelving•Furniture•Table lamination substrate•Storage containers16mm 1800 x 450/600/900/1200

2400 x 450/600/900/12003600 x 450/600/1200

18mm 1800 x 450/600/900/12002400 x 600/900/12002700 x 450/1200

SIZE AVAILABILITY

PRODUCT BRANDS

Fiber Boards

MDF – HDF-Insulation Board

Fiberboard The term fibreboard includes hardboard, medium-density fibreboard

(MDF), and insulation board. Because wood is fibrous by nature, fibreboard exploits the inherent

strength of wood to a greater extent than does particleboard. To make fibres for composites, bonds between the wood fibers must

be broken. In its simplest form, this is accomplished by attrition milling. Attrition milling is an age-old concept whereby material is fed between two disks, one rotating and the other stationary.

Fibreboard is normally classified by density and can be made by either dry or wet processes. Dry processes are applicable to boards with high density (hardboard) and medium density (MDF). Wet processes are applicable to both high-density hardboard and low-density insulation board

They are derived from renewable resources and are biodegradable.

Medium Density Fiber BoardDecorative Wall cladding in routed wave form or JalisWooden Handicraft items/ Toys and puzzlesEducational Tools/ Aids & casing for scientific instruments/ Model makingExhibition Stalls & Display/ POPAutomotive interior cladding & panelingPhoto lamination substrateRouting & carving of trophies/ Gift itemsRouted Shutters for Kitchens & wardrobes with membrane or polished surface

Medium- density fibreboard is frequently used in place of solid wood, plywood, and particleboard in many furniture applications. It is also used for interior door skins, mouldings, and interior trim components

Workability

STAPLING Staples can be used effectively for joint fitting. For best results it is

helpful to add adhesive to the joint prior to assembly.SCREWS The position of screws inserted into the faces and edges of MDF

should be decided in relation to board thickness and screw size. Screws inserted into the edges should be not less than 25mm from the corners. The screw must not be over tightened as further turning will reduce the holding strength

NAILINGMDF Panels can be fixed by nailing with good holding power and no split out when the following conditions are met: Using either annular grooved or helical nails Nails must be at least 25mm from the corner of the MDF panel. Nailing is not recommended to edges of 9mm and 12mm, screwing is recommended. Edge nailing is not recommended for MDF of 12mm thick or less.

SANDING AND FINISHING Special attention to sanding edges gives excellent resultsPAINTING For best results application of three coats is recommended.

First coat primer/undercoat is critical to the final finish.

SIZE AVAILABILITYPRODUCT BRANDSMDF with veneer overlay. Edges can be shaped and finished as required by end product.

ADVANTAGES It is inexpensive. It can be painted or stained to

look just like wood. No Grain or Knots- it easy to saw

MDF in any direction Strong and Stiff. Stable dimensions (won't expand

or contract like wood) Shape well.

DISADVANTAGES If one does not place nails at

close intervals, the board can droop in the middle.

 Urea-formaldehyde Resin and Dust - Working with MDF is hazardous to your health.

 Not very durable  The wood may split and the

fasteners do not hold well. Holes have to be pre-drilled for nails and screws.

Dulls blades more quickly than many woods

May warp or expand if not sealed.

High Density FibreShoe Heel & lastsLaminate flooring SubstratesEmbossed Panels for wall claddingKitchen shuttersFlat & molded door skinsDecorative display panelsRailway cushion baseAutomotive internal panels

The uses for hardboard can generally be grouped as construction, furniture and furnishings, cabinet and store work, appliances, and automotive and rolling stock. Typical hardboard products are prefinished panelling, house siding floor underlayment, and concrete form board.

Perforated Hardboard

ADVANTAGES HDF comes with a smooth surface. HDF is High density board has more

strength compared to MDF and Particle board

Great solution for indoor and outdoor furniture, wall panelling,  furniture, room partitions, and doors. 

Has more durability and warp-resistant characteristics as compared to wood laminate flooring.

DISADVANTAGES

Pine Panels2460mm x 2076mm x 6.4mm2620mm x 1455mm x 7.3mm2460mm x 2076mm x 7.6mm2460mm x 2076mm x 9.4mm2440mm x 2133mm x 11.4mm2440mm x 2133mm x 11.6mm

SIZE AVAILABILITY

PRODUCT BRANDS

Shouguang Hongyu Board Industry Co., Ltd.

A lot of carpenters prefer wood block board compared to HDF as they are more confident about the nail holding capabilities of natural wood whose blocks are used to build the block board