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Cabinetry - Materials/Finishes Engineered Wood for Cabinetry Wood in its natural form is beautiful and makes attractive cabinetry and furniture. But only a small fraction of the lumber supply is suited to this purpose, and the demand far outstrips the supply. To satisfy this demand, the forest industry has developed methods of producing high quality lumber out of wood that once would have been scrapped. Many manufactured products are suitable for furniture and cabinets. Others are more suitable for use in construction projects. In cabinetry, engineered wood is used as substrate (an underlying layer, covered with another material such as a laminate or wood veneer).
Particleboard, flakeboard and other engineered lumbers are composite products made from wood flakes, chips, splinters, etc., formed into layers and held together by resin glues and heated under pressure. Being layered and consisting of larger chunks, particle board does not have the uniform texture of MDF. It is used widely in the manufacture of furniture, cabinets and floor underlayment. Particle geometry, resin levels, board density, and manufacturing processes are altered to produce products designed for specific uses. Additives are used to provide greater dimensional stability, better fire resistance, or to impart additional characteristics Whereas solid wood (lumber) suffers from the swelling and shrinking of wood due to environmental changes such as humidity, particleboard's stability, flatness, smoothness, lack of knots or voids, and ease of laminating make it the major substrate material used in countertops, meeting the ANSI A161.2 performance standard. Particleboard is preferred by laminators because of its uniform density and thickness tolerance, as well as surface smoothness. Its dimensional stability, strength, stiffness, flatness, and workability enhance performance.
SHELVING Many kitchen cabinets have laminated particleboard shelves, sides, backs, drawers, doors and/or other parts because of particleboard's superior performance and economy. Shelves are usually designed for specific applications with typical loads. For example, kitchen shelves are designed for a uniform load of 15 pounds per square foot (psf); closets, 25 psf; bookshelves 40 psf. Particleboard grades M-S, M-2, and M-3 as described in ANSI A208.1 are used in kitchen and vanity cabinets. Refer to ANSI Standard A161.1, Recommended Performance and Construction Standard for Kitchen and Vanity Cabinets, sponsored by the Kitchen Cabinet Manufacturers Association (KCMA), phone 703-264-1690.
OVERLAYS Industrial particleboard grades used in office and residential furniture, kitchen cabinets, case goods and other applications are typically ANSI A208.1 grades M-S, M-2, or M-3.
Medium Density Fiberboard is used increasingly in the manufacture of kitchen cabinets, furniture, door parts and moldings. Cabinetmakers use MDF when they require a shelf or panel free of defects. The surface of MDF is flat, smooth, uniform and free of knots and grain patterns, which simplifies finishing operations, especially for thin laminates. The consistent density of MDF allows for intricate and precise machining and finishing techniques. Its stability and strength hold to close tolerances in accurately cut parts. MDF is a composite panel product typically consisting of lignocellulosic wood fibers combined with a synthetic resin or other suitable bonding system and joined together under heat and pressure. Additives may be introduced during manufacturing to impart additional characteristics. MDF belongs to the hardboard family of products, but it is designed for a density range of 31-55 lb/cu. ft. As its density implies, MDF is very heavy and thus potentially difficult to handle. MDF has many qualities that make it an ideal upgrade from plywood or particleboard. It is dense, flat, and stiff, free from knots and is easily machined. Its fine particles provide dimensional stability without the grain common to lumber. Unlike most plywood, MDF contains no voids, and will deliver sharp, clean edges. A prime attribute of MDF is its sharp, clean edge machining requiring minimal treatment prior to finishing. Edge banding or molding is eliminated with proper finishing. It can be machined into intricate patterns as easily as natural wood, thus is an excellent substitute for solid wood in many interior applications. MDF is used as core material for paneling with veneers, printed surfaces, vinyl and low pressure laminates. It is stable, flat, smooth, has no grain to telegraph through the overlay, and can be installed quickly and easily MDF is easily shaped into almost any form and is commonly available in lengths up to 20 feet. This makes MDF an excellent material for vinyl, veneer or paper wrapped and pre-primed interior moldings. Manufacturers often use embossing-pressing cast die patterns into the MDF surface-to produce three-dimensional designs. A number of manufacturers produce laminates that are commonly used in conjunction with MDF. Some of the more popular brands are Wilsonart, Abet Laminati, Formica, Nevamar, Pionite, Micarta and Laminart. While woodworking joints such as butt, miter, rabbet, dovetail, spline, and dado are preferred over mechanical fasteners, some common fasteners are frequently used with caution, such as staples, nails and screws. Note however that fasteners alone cannot be relied on to securely join components, and they increase the risk of splitting and separation of the material. MDF is very porous. glues typically used are gap-filling glues such as polyvinyl acetate (PVA) typically known as white (paper) and yellow (wood) glues, or modified PVA glues like Titebond II. Epoxy, urea, polyurethane and hot melt glues are also often used. MDF from different sources will vary in texture, density, color, etc. Physical and dimensional tolerances for MDF are specified in ANSI A208.2-1986 This standard classifies MDF by density and use (interior or exterior) and identifies product grades. Specifications identified in the standard include physical and mechanical properties, dimensional tolerances and formaldehyde emission limits. Copies of the ANSI Standard for MDF are available from the CPA.
Finishes that work best at controlling formaldehyde emissions are solid add-on surfaces such as high pressure laminates, vinyl covering, and finished wood veneers. Less effective at controlling emissions are simple seal coats, oil and latex paints, Danish oil, and wax. Plywood Plywood is available in many grades using various lumber species, depending on the purpose for which it will be used. It is used in cabinetry to fabricate the side panels. and has an excellent reputation for durability and screw-holding power. To learn more about the use of plywood in cabinetry, see our article
Hardboard (Hard Density Fiberboard - HDF) The "wet" process produces panels 1/8 or 1/4 inch thick that have one smooth side and a screen pattern on the backside, and are designated S1S. The "dry" manufacturing process produces a panel that is smooth on both sides, or S2S. Hardboard was first produced in 1924 by W. H. Mason, founder of Masonite Corp. The term Masonite is therefore often used to denote hardboard products, High Density Fiberboard (HDF) has a density that ranges between 50 and 80 pounds per cubic feet. Standard hardboard has excellent machining and finishing properties suitable for numerous interior uses such as paneling, partitions, furniture, toys, packaging, flush doors, garage doors etc. Tempered hardboard is impregnated with special oil that is polymerized by heat treatment. It is particularly suitable in applications where there is a need for extra water resistance, surface hardness, rigidity, bending and tensile strength. It is often used in construction siding.
Medium Density Overlay and High Density Overlay Strandboard/ Waferboard Waferboard has been used in North American construction for over twenty years, for interior and exterior and for structural and non-structural applications. Laminated Veneer Lumber (LVL)
Plywood is available in many grades using various lumber species, depending on the purpose for which it will be used. Construction grade lumber has knotholes, repaired or un-repaired depending on grade, and voids where holes exist in the various plies. "Void-free" plywood uses plies with supposedly no holes, but this is not always reliable. Baltic birch plywood is sometimes sold as void-free plywood, and is often used in furniture construction for sidewalls and shelving. Other high-grade plywood such as oak and maple are likewise available for use in cabinet work.
See Also:
Other Links to Related Websites: EPA: Sources of Indoor Air Pollution - Formaldehyde
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