The terms “composite wood products” or “replicated wood grain” refer to a family of engineered wood panels that include particleboard, medium density fiberboard (MDF) and hardboard. Particleboard is made from small wood particles pressed together with glue under extreme heat and pressure to make a solid panel. MDF and Hardboard are made the same except the wood particles are further refined into individual fibers to provide a smooth edge to the panel.
In general, composite wood products turn wood waste and residuals into useful products and protect the environment. A USDA Forest Service study shows that, on average, only about 63% of a harvested tree can be used to make solid lumber. When Engineered Wood and other products are made from the remaining wood, over 95% of the tree can be saved.
Engineered Wood is the result of decades of research and development aimed at designing a structurally superior wood product for use in the construction of today’s furniture, cabinets and other home furnishings. It provides consistent, uniform strength and is free of defects. It is highly resistant to warping, cracking and splitting, and has no knots, voids or other surface imperfections.
High-end, furniture-grade medium density fiberboard (MDF) and particleboard are designed with qualities and capabilities not found in ordinary, construction-grade materials. Engineered wood is found in kitchen cabinets, furniture, mouldings and in many more applications.
How is it made?
Engineered Wood panels are made from the wood that remains after a tree is milled into lumber. This wood is cleaned and refined then combined with an ultra-strong adhesive under heat and pressure. The resulting panels are laboratory-tested to meet the stringent American National Standards Institute’s (ANSI) standards for furniture-grade wood panel products.
Is it Solid and Durable?
Yes. Engineered wood is real wood in an advanced form that makes it solid and durable.
Conserving Our Forests
In years past, most of this formerly wasted wood was burned or disposed of in landfills, contributing to air pollution and reducing available landfill space. Engineered wood helps conserve our forests by reducing the total amount of trees that are harvested to meet the consumer demand for wood products.
MDF: Medium-Density Fiberboard
Medium-density fiberboard (or fibreboard) (MDF) is an engineered wood product formed by breaking down hardwood or softwood residuals into wood fibers, often in a defibrator, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure. MDF is denser than plywood. It is made up of separated fibers, but can be used as a building material similar in application to plywood. It is stronger and much more dense than normal particle board.
Comparison to natural woods:
MDF does not contain knots or rings, making it more uniform than natural woods during cutting and in service. However, MDF is not entirely isotropic, since the fibres are pressed tight together through the sheet. Like natural wood, MDF may split when woodscrews are installed without pilot holes, and MDF may be glued, doweled or laminated, but smooth-shank nails do not hold well. Typical MDF has a hard, flat, smooth surface that makes it ideal for veneering, as there is no underlying grain to telegraph through the thin veneer as with plywood. A so-called “Premium” MDF is available that features more uniform density throughout the thickness of the panel.
Particle board, or particleboard (or chipboard in the UK and Commonwealth Nations such as Australia, New Zealand and others), is an engineered wood product manufactured from wood particles, such as wood chips, sawmill shavings, or even saw dust, and a synthetic resin or other suitable binder, which is pressed and extruded. Particleboard is a composite material.
Particleboard is cheaper, denser and more uniform than conventional wood and plywood and is substituted for them when appearance and strength are less important than cost. However, particleboard can be made more attractive by painting or the use of wood veneers that are glued onto surfaces that will be visible. Though it is denser than conventional wood, it is the lightest and weakest type of fiberboard, except for insulation board. Medium-density fiberboard and hardboard, also called high-density fiberboard, are stronger and denser than particleboard. Different grades of particleboard have different densities, with higher density connoting greater strength and greater resistance to failure of screw fasteners.
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 places that have high levels of moisture, with the exception of some bathrooms, kitchens and laundries, where it is commonly used as an underlayment beneath a continuous sheet of vinyl flooring. It does, however, have some advantages when it comes to constructing the cabinet box and shelves. For example, it is well suited for attaching cabinet door hinges to the sides of frameless cabinets. Plywood has the potential to feather off in sheaves when extreme weight is placed on the hinges. In contrast, particle board holds the screws in place under similar weight. Additionally, particleboard is favored for cabinet shelves that need to span a long width (30″ or more) since it will not bow under the weight like plywood.
History and Development
Modern plywood, as an alternative to natural wood, was invented in the 19th century, but by the end of the 1940s a shortage of lumber made it difficult to manufacture plywood affordably. Particleboard was intended to be a replacement. Its inventor was Max Himmelheber of Germany. The first commercial piece was produced during World War II at a factory in Bremen, Germany. It used waste material such as planer shavings, offcuts or sawdust, hammer-milled into chips, and bound together with a phenolic resin. Hammer-milling involves smashing material into smaller and smaller pieces until they pass out through a screen. Most other early particleboard manufacturers used similar processes, though often with slightly different resins. It was found that better strength, appearance and resin economy could be achieved by using more uniform, manufactured chips. Manufacturers began processing solid birch, beech, alder, pine and spruce into consistent chips and flakes. These finer layers were then placed on the outsides of the board, with the central section composed of coarser, cheaper chips. This type of board is known as three-layer particleboard.
More recently, graded-density particleboard has also evolved. It contains particles that gradually become smaller as they get closer to the surface.
Particle board has had an enormous influence on furniture design. In the early 1950s, particle board kitchens started to come into use in furniture construction but, in many cases, it remained more expensive than solid wood. A particle board kitchen was only available to the very wealthy. Once the technology was more developed, particle board became cheaper.
In general the much lower cost of sheet goods (particle board, medium density fiberboard, and other engineered wood products) has helped to displace solid wood from many cabinetry applications.
OSB: Oriented Strand Board
Oriented Strand Board is manufactured in wide mats from cross-oriented layers of thin, rectangular wooden strips compressed and bonded together with wax and resin adhesives (95% wood, 5% wax and resin).
The layers are created by shredding the wood into strips, which are sifted and then oriented on a belt or wire cauls. The mat is made in a forming line, the layers are built up with the external layers aligned in the panel’s strength axis with internal layers cross-oriented.
The number of layers placed is determined partly by the thickness of the panel but is limited by the equipment installed at the manufacturing site. However individual layers can also vary in thickness to give different finished panel thicknesses (typically, a 15 cm layer will produce a 15 mm panel thickness).
The mat is placed in a thermal press to compress the flakes and bond them by heat activation and curing of the resin that has been coated on the flakes. Individual panels are then cut from the mats into finished sizes.
Most of the world’s OSB is made in the United States and Canada in large production facilities. The largest production facilities can make over a billion square feet of OSB per day.
Different qualities in terms of thickness, panel size, strength, and rigidity can be imparted to the OSB by changes in the manufacturing process. OSB panels have no internal gaps or voids, and are water-resistant, although they do require additional membranes to achieve impermeability to water and are not recommended for exterior use. The finished product has similar properties to plywood, but is uniform and cheaper. When tested to failure, OSB has a greater load bearing capacity than milled wood panels. It has replaced plywood in many environments, especially the North American structural panel market. The most common uses are as Sheathing in walls, floors, and roofs.
So, how are composite wood products good for environment?
- Composite wood products are among the most environmentally responsible building materials available today
- They are typically made from recycled and recovered wood waste that that wood otherwise be burned or thrown into a landfill, so they allow to to make better use of our valuable natural wood resources and optimal use of each tree
- They reduce the greenhouse gases that contribute to global warming by locking up the carbon dioxide naturally removed from the air by trees during their growing cycle
Besides the environmental attributes, what are the benefits of using composite wood products?
- Durability: Composite wood products provide solid, uniform strength that is highly resistant to warping, cracking and splitting
- Quality: The smooth surface composite wood panels offer is critical for today’s decorative surfaces
- Versatility: Composite wood products are engineered to meet specific customer performance requirements
- Workability: Composite wood products can be easily shaped and moulded into almost any design
- Consistency: Composite wood panels are free from the defects and imperfections that may be found in other wood products. Because each panel is uniform and consistent, the products made with composite wood panels are of the same high quality
- Value: Composite wood products typically cost much less than their solid wood counterparts. That means you get a product that provides superior performance at an affordable price!
Quality products that are easy to use and easy on the environment—it’s clear that composite wood products are the natural choice!
Source: Ashley Furniture