Particleboard - also known as particleboard , low density fiber board ( LDF ), and chipboard - is an engineered wood product made from wood chips, sawmill, or even sawdust, and other suitable synthetic or binder resins, pressed and extruded. Oriented strand board, also known as flakeboard , waferboard , or chipboard , is similar but uses wood chips that offer more power. These are all composite materials included in the fiberboard product spectrum.
Video Particle board
Characteristics
Particle boards are cheaper, denser and more uniform than conventional wood and plywood and are replaced for them when cost is more important than strength and appearance. However, the particle board can be made more attractive by painting or using wood veneer to the surface that will be visible. Though more dense than conventional wood, it is the lightest and weakest type of fiberboard, except the insulating board. Fibreboard and medium density hardboard, also called high-density fiberboard, is stronger and denser than particleboard. Different particle board levels have different densities, with higher densities connoting greater strength and greater resistance to screw fastening failure.
The main disadvantage of particle board is that it is very susceptible to expansion and color change due to moisture, especially when not covered with paint or other sealer. Therefore, it is rarely used outdoors or in places where there is a high level of humidity, with the exception of some bathrooms, kitchens and hand-washers, where it is usually used as an underlayment - in moisture resistant variants - under sheet vinyl continuous floor.
The advantage of using particleboard on veneer core plywood is more stable, (unless it is wet), much cheaper to buy, and somewhat more comfortable to use.
Maps Particle board
History and development
Particleboard comes from Germany. It was first produced in 1887, when Hubbard made so-called "artificial wood" from wood flour and adhesive based on albumin, which was consolidated under high temperature and pressure.
Despite the use of two or three layers of ancient wood veneer, a modern 4 'x 8' plywood sheet with 5-11 layers of veneer core was created at the beginning of the 20th century, and began to become commonplace by the Second World War. During the war, phenolic resins were more accessible than high-end wood veneers in Germany, and the Luftwaffe pilot and inventor Max Himmelheber played a role in making the first sheet of particle board, which was little more than the sweeping of floor sweeping, wood chips, and underlining pieces and glue. The first commercial section was produced during World War II at a factory in Bremen, Germany. For its production, waste materials are used - such as planer shavings, offcuts or sawdust - hammer-milled into chips and fastened together with phenolic resins. Hammer-milling involves smashing material into smaller and smaller pieces until they can pass through the screen. Most early particle board manufacturers use similar processes, though often with slightly different resins.
It was found that the strength, appearance, and economy of the better resin can be achieved by using more uniform and manufactured chips. Manufacturers begin processing birch, beech, alder, pine, and solid pine into consistent flakes and flakes; these finer layers are then placed on the outside of the board, essentially comprising rougher and cheaper chips. This type of board is known as a three-layer particle.
Recently, densely graded particle board has also evolved. It contains particles that gradually become smaller as they get closer to the surface
Manufacturing
Particleboard or chipboard is produced by mixing wood particles or flake together with resin and forming the mixture into the sheet. The raw materials to be used for particles are inserted into a disc chipper with between four and sixteen blades arranged radially (chips of disk pieces are more uniform in shape and size than from other wood chipper types). The particles are then dried, after the particles that are too large or small are filtered out.
The resin is then sprayed with mist through the fine nozzle to the particles. There are several types of resins commonly used. Amino-formaldehyde based resin is the best performance when considering cost and ease of use. Urea Melamine resins are used to offer water resistance with melamine enhancement that offers enhanced durability. This is typically used where panels are used in external applications due to the increased water resistance offered by phenolic resins as well as resin colors resulting in darker panels. Phenolic formaldehyde resins Melamine Urea exists as a compromise. To improve panel properties further the use of rescinol resins typically mixed with phenolic resins are used, but these are typically used with plywood for marine applications and rare occasions in panel production.
Panel production involves a variety of other chemicals - including waxes, dyes, wetting agents, release agents - to make waterproof, fireproof, insect resistance, or other quality products.
The particles then pass through a resin mist sufficient to coat all surfaces and then coated, first being carpet continuously. These 'carpets' are then separated into separate 'rectangular' quilts that will then be solidified in cold pressure. Weighers note the weight of the flakes, and they are distributed to the position by rotating the rakes. In densified particleboard density, the fragments are propagated by an air jet that throws the finer particles than the coarse ones. The two jets are like that, reversed, allowing particles to build from smooth to rough and back to fine.
The formed sheets are then cold compressed to reduce the thickness and make it easier to transport. Then, they are compressed again, under pressure between 2 and 3 megapascals (290 and 440 psi) and temperatures between 140 and 220 Â ° C (284 and 428 Â ° F). This process creates and solidifies the glue. All aspects of the whole process must be carefully controlled to ensure the correct size, density and consistency of the board.
The boards are then cooled, trimmed and sanded. They can then be sold as raw boards or enhanced surfaces through the addition of wood veneer or laminate surfaces.
Furniture design
Particle board has a major influence on furniture design. In the early 1950s, particle board kitchens began to be used in furniture construction but, in many cases, it remained more expensive than solid wood. Kitchen particle board is only available for the very rich. After more technology develops, particle board becomes cheaper.
Some big companies base their strategy to provide furniture at low prices. To do this, they use the cheapest material possible. In almost all cases, this means particle board or MDF or the like. However, manufacturers, to maintain a quality reputation at low cost, can use high-value particle board, for example, higher-density particleboard, thicker particle board, or particle board using higher-quality resins. One can record the number of slides on the shelf from the width given to draw the difference.
In general, lower cost sheets (particle board, medium density fiberboard, and other engineered wood products) have helped move solid wood from many cabinet applications.
Security
The safety issue is two parts, one of which is fine dust and chemicals released when the particle board is worked (eg, sawing or routing). Occupational threshold values ​​exist in many countries that recognize the dangers of wood dust. Cutting the particle board can release formaldehyde, carbon monoxide, hydrogen cyanide (in the case of amino resins) and phenol (in the case of phenol-formaldehyde resins). Another concern is the slow release of formaldehyde over time. In 1984 concerns about early indoor formaldehyde levels led the US Department of Housing and Urban Development to set standards for the construction of production houses. Particleboard (PB), medium density fiberboard (MDF), oriented strand board (OSB), and laminated flooring have been a major source of formaldehyde emissions. In response to the many pressures of consumers and timber workers in the industry, PB and MDF are at least now available in the "no additional formaldehyde" (NAF) version, which is not commonly used in 2015. Many other building materials such as finished furniture, carpets and caulking formaldehyde, as well as Urea-formaldehyde foam insulation, which is prohibited in Canada for mounting in closed cavity walls of housing. Formaldehyde is classified by WHO as a known human carcinogen.
See also
- Embedded laminated wood
- Masonite
- Melamine resin, a substance used to glue the particle board
- Wood pressed
- Waferboard
References
External links
- Association of Composite Panels: Particleboard
- European Panel Federation: Particleboard
Source of the article : Wikipedia
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