Mdf

Medium-density fibreboard (MDF or MDFB) is an engineered wood product formed by breaking down softwood into wood fibres, often in a defibrator, combining it with wax and resin, and forming panels by applying high temperature and pressure. It is a building material similar in application to plywood but made up of sawdust. It is denser than normal particleboard. Large-scale production of MDF began in the 1980s. Its name derives from the distinction in densities of fibreboard. MDF typically has a density of 600-800 kg/m³. Particle board is a low-density fibreboard and has a density of 160-450 kg/m³, while hardboard, also called high-density fibreboard, has a density of 500-1,450 kg/m³. Similar manufacturing processes are used in making all types of fibreboard. One contentious issue is the use of formaldehyde resins and the associated health risks. Thus, other resins are being introduced. Contents 1 Uses and applications 2 In media 3 Manufacturing 4 See also 5 References 6 External links Uses and applications MDF is useful in many applications such as architrave or skirting board in the home, particularly where particleboard was previously used. It is not the most ideal product for outdoor use because it may swell up on contact with water - several grades of MDF are available; nonetheless, it has better moisture tolerance than particleboard. Because MDF is fibre-based, it has a remarkably consistent structure. This quality makes it easy to machine or employ in woodworking applications. MDF is often used with melamine or wood veneers. MDF is a good material for cabinetry, particularly including acoustic enclosures such as loudspeakers or subwoofers due to its high sound insulative and damping properties. MDF can be dangerous to use if the correct safety precautions are not taken. MDF contains a substance called urea formaldehyde, which may be released from the material through cutting and sanding. Urea formaldehyde may cause irritation to the eyes and lungs. Proper ventilation is required when using it and facemasks are needed when sanding or cutting MDF with machinery. The dust produced when machining MDF is very dangerous. Masks and goggles should always be worn at all times. In media Famously, MDF was used often on the British TV's Changing Rooms, leading to "YMDF", a YMCA parody. Alan Partridge said "MDF's banned in America" in one episode of the program I'm Alan Partridge, which lead to his friend Dan's wife saying "So's that" and pointing to a video of her and Dan having sex (not seen). (Note however that MDF is not actually banned in America.) Manufacturing To meet Wikipedia's quality standards, this article or section may require cleanup. Please discuss this issue on the talk page, or replace this tag with a more specific message. Editing help is available. This article has been tagged since August 2006. MDF is a piece of wood formed by wood fibre from softwood, which is mixed with wax and resin. This is then formed by applying high temperatures to the MDF products to create the finish. In Australia the main species for MDF is plantation grown radiata pine. However a variety of other products have also been used including other woods, waste paper and fibres. However to acquire MDF, the company must first get rid of a number of trees to create the MDF which in turn makes the environment unhealthy and a decrees of Australia’s natural resources. After the company has acquired their tree/s, they will go though the debarking progress. This progress involves the stripping of the bark from the wood that creates a bark free log. This bark can then be reused by selling it for landscaping or be used to power on site furnaces. Alternatively a factory may buy their logs debarked or chipped. After debarking the log will be sent to the MDF plant where it will go though the chipping process. This process involves a disk chipper, which contains between 4-16 blades, which chip the log. The chips if they are not the desired size may be re-chipped but those undersized may be used as fuel. They will then be washed and checked for defects. After chipping the MDF will be compacted using a screwfeeder and will be heated for 30-120 seconds to soften the wood then fed into a defibrator. The defibrator that maintains high pressure and temperature, which upon existing the pulp is light, fine, fluffy and light in colour. After the defibrator the pulp will enter a blow line where the pulp will be joint with wax to improve moisture resistance and resin. If this were not added the pulp would form bundles, which would be a waste of materials. The material then expands in diameter and is then heated by heating coils. When it comes out it may be stored in bins for an unspecified length of time. After this drying period the board will go thou the Pendistor process (above) which will create 230-610mm thick boards. . After the Pendistor the board will be cut and will continue to the Pressing. It will then be pressed to supply greater strength and required size for a few seconds. For example it will be 330 seconds (5 ½ minutes) to bring a board down to 16mm. After pressing the MDF are cooled in a star dryer, trimmed and sanded. If the company wishes they may be laminated. The Environmental Impact of MDF has greatly improved over the years. Today many MDF boards are made from a variety of materials. These include other woods, scrap, recycled paper, bamboo, carbon fibres and polymers, steel, glass, forest thinning and sawmill off cuts. See also Engineered wood Fiberboard Glued laminated timber Hardboard Masonite Oriented strand board Particle board Plywood Pressed wood References Lignocellulosic Composites External links Children's furniture, on the safety issues of MDF Medium Density Fibreboard Search Term: "Medium-density_fibreboard" Categories: Cleanup from August 2006 | Composite materials | Wood | Engineered wood

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