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Encyclopedia > Plywood
Towers of Hanoi constructed from plywood. Notice the high quality wood veneer (light color) covering the lower quality inner wood (dark color).
Towers of Hanoi constructed from plywood. Notice the high quality wood veneer (light color) covering the lower quality inner wood (dark color).

Plywood is a type of engineered wood made from thin sheets of wood veneer, called plies or veneers. The layers are glued together, each with its grain at right angles to adjacent layers for greater strength.[1] There are usually an odd number of plies, so that the grain on the outside plies runs in the same direction. The plies are bonded under heat and pressure with strong adhesives, usually phenol formaldehyde resin,[2] making plywood a type of composite material. Plywood is sometimes called the original engineered wood.[3] Image File history File links Broom_icon. ... Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... A model set of the Towers of Hanoi The Tower of Hanoi (also called Towers of Hanoi) is a mathematical game or puzzle. ... Engineered wood, also called composite wood, includes a range of derivative wood products which are manufactured by binding together the strands, particles, fibers, or veneers of wood, together with adhesives, to form composite materials. ... In woodworking, veneer refers to thin slices of wood, usually thinner than 3 millimetres (1/8 inch), that are usually glued and pressed onto core panels (typically, wood, particle board or medium density fiberboard) to produce flat panels such as doors, tops and side panels for cabinets, parquet floors and... For the band, see Adhesive (band). ... The earliest commercial synthetic resin is based on a Phenol formaldehyde resin with the commercial name Bakelite, and is formed from an elimination reaction of phenol with formaldehyde. ... A cloth of woven carbon fiber filaments, a common element in composite materials Composite materials (or composites for short) are engineered materials made from two or more constituent materials with significantly different physical or chemical properties and which remain separate and distinct on a macroscopic level within the finished structure. ... Engineered wood, also called composite wood, includes a range of derivative wood products which are manufactured by binding together the strands, particles, fibers, or veneers of wood, together with adhesives, to form composite materials. ...


A common reason for using plywood instead of plain wood is its resistance to cracking, shrinkage, twisting/warping, and its general high degree of strength. It has replaced many dimensional lumbers on construction applications for these reasons. For other uses, see Wood (disambiguation). ... Dimensional lumber is a term used in North America for lumber that is cut to standardized width and depth specified in inches. ... This article does not cite any references or sources. ...

A wall lamp made partially from plywood
A wall lamp made partially from plywood

Contents

Image File history File linksMetadata Download high-resolution version (1010x810, 78 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Plywood Metadata This file contains additional information, probably added from the digital camera or scanner used to create... Image File history File linksMetadata Download high-resolution version (1010x810, 78 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Plywood Metadata This file contains additional information, probably added from the digital camera or scanner used to create...

Types of plywood

average plywood with veneer
average plywood with veneer
good quality concrete pouring plate in plywood
good quality concrete pouring plate in plywood

A vast number of varieties of plywood exist, with many conditions and uses. Softwood plywood is usually made either of Douglas fir or spruce, pine, and fir, and is typically used for construction and industrial purposes.[4] Decorative plywood is usually faced with hardwood, including red oak, birch, maple, lauan (Philippine mahogany) and a large number of other hardwoods. Image File history File linksMetadata Download high-resolution version (2288x1712, 1034 KB) close up picture of plywood with a veneer coat. ... Image File history File linksMetadata Download high-resolution version (2288x1712, 1034 KB) close up picture of plywood with a veneer coat. ... Image File history File links Multiplex. ... Image File history File links Multiplex. ... Despite being fairly hard, cedar is a softwood Softwood is the wood from conifers. ... Species See text Douglas-fir is the common name applied to coniferous trees of the genus Pseudotsuga in the family Pinaceae. ... Species About 35; see text. ... For other uses, see Pine (disambiguation). ... FIR may stand for: finite impulse response (a property of some digital filters) far infrared, i. ... Beech is a typical temperate zone hardwood For the record label, see Hardwood Records. ... Binomial name Quercus rubra L. The Northern red oak, Quercus rubra (Quercus borealis in some older references), is an oak in the red oak group (Quercus section Lobatae). ... Species Many species; see text and classification Birch is the name of any tree of the genus Betula, in the family Betulaceae, closely related to the beech/oak family, Fagaceae. ... For other uses, see Maple (disambiguation). ... Genera Anisoptera Cotylelobium Dipterocarpus Dryobalanops Hopea Marquesia Monotes Neobalanocarpus Pakaraimaea Parashorea Shorea Stemonoporus Upuna Vateria Vateriopsis Vatica Dipterocarpaceae is a family of 17 genera and approximately 580-680 species of mainly tropical lowland rainforest trees with two-winged fruits. ... This article is about the timber. ...


Plywood for indoor use generally uses the less expensive urea-formaldehyde glue which has limited water resistance, while outdoor and marine grade plywood are designed to withstand rot, and use a water resistant phenol-formaldehyde glue to prevent delamination and to retain strength in high humidity. In construction, marine plywood is a specially treated plywood that is designed to resist rotting in a high-moisture environment. ... Delamination is a mode of failure of laminated composite materials. ... Humidity is the amount of water vapor in air. ...


The most common varieties of softwood plywood come in three, five or seven plies with a metric dimension of 1.2 m × 2.4 m or the slightly larger imperial dimension of 4 feet × 8 feet. Plies vary in thickness from 1/10" through 1/6" depending on the panel thickness. Roofing can use the thinner 3/8-inch plywood. Floorboards are at least 5/8-inch depending on the distance between floor joists. Plywood for flooring applications is often tongue and grooved. Two of the edges will have "grooves" notched into them to fit with the adjacent "tongue" that protrudes from the next board. A roof tiled in imitation of thatch at Croyde, north Devon, England Rooftops in Vietnam A roof is the top covering of a building that prevents the ingress of weather into the building interior. ... A joist, in architecture and engineering, is one of the supporting bars that run from wall to wall to support a ceiling (or floor). ... Tongue and groove is a method of fitting similar objects together, used mainly with wood: flooring, panelling etc. ...


High-strength plywood, known as aircraft plywood, is made from mahogany and/or birch. It was used for several World War II fighter aircraft, including the British-built Mosquito bomber. Airplane plywood was adapted for furniture by Alvar Aalto. Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... An A-10 Thunderbolt II, F-86 Sabre, P-38 Lightning and P-51 Mustang fly in formation during an air show at Langley Air Force Base, Virginia. ... The de Havilland Mosquito[1] was a British combat aircraft that excelled in a number of roles during the Second World War. ... “Aalto” redirects here. ...


Plywood production

Plywood production requires a good log, called a peeler, which is generally straighter and larger in diameter than one required for processing into dimensioned lumber by a sawmill. The log is peeled into sheets of veneer which are then cut to the desired dimensions, dried, patched, glued together and then baked in a press at 140 °C (280 °F) and 19 MPa (2800 psi) to form the plywood panel. The panel can then be patched, resized, sanded or otherwise refinished, depending on the market for which it is intended. For the 1922 film starring Oliver Hardy, see The Sawmill. ...


History

Plywood output in 2005

Plywood has been made for thousands of years; the earliest known occurrence of plywood was in ancient Egypt around 3500 BC when wooden articles were made from sawn veneers glued together crosswise. This was originally done due to a shortage of fine wood. Thin sheets of high quality wood were glued over a substrate of lower quality wood for cosmetic effect, with incidental structural benefits. This manner of inventing plywood has occurred repeatedly throughout history. Most high quality English furniture makers working in the eighteenth and nineteenth centuries (and since) have used veneering as a technique. In addition to making the most out the highest quality materials available, it reduces prices and improves stability of construction. The irregularities of grain which confer decorative interest often result in uncontollable warping and cracking if any attempt is made to use the wood in thicknesses much greater than those characterising cabinet-making veneers (typically 1-2mm). Image File history File links Size of this preview: 800 × 351 pixelsFull resolution (1425 × 625 pixels, file size: 58 KB, MIME type: image/png)This bubble map shows the global distribution of plywood output in 2005 as a percentage of the top producer (China - 21,797,000 cu. ... Image File history File links Size of this preview: 800 × 351 pixelsFull resolution (1425 × 625 pixels, file size: 58 KB, MIME type: image/png)This bubble map shows the global distribution of plywood output in 2005 as a percentage of the top producer (China - 21,797,000 cu. ... Khafres Pyramid and the Great Sphinx of Giza, built about 2550 BC during the Fourth Dynasty of the Old Kingdom,[1] are enduring symbols of the civilization of ancient Egypt Ancient Egypt was a civilization in Northeastern Africa concentrated along the middle to lower reaches of the Nile River...


Modern plywood in which the veneer are cut on a rotary lathe from softwood logs is of relatively recent origin, invented by Immanuel Nobel. The first such lathes were set up in the United States in the mid 19th century. Plywood has been one of the most ubiquitous building products for decades. For other uses, see Lathe (disambiguation). ... Immanuel Nobel ( 1801- 1872), Swedish engineer, architect, inventor and industrialist. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ...


Compare to OSB (Oriented strand board) and MDF (Medium-density fibreboard). OSB-production before the press Oriented strand board, or OSB, is an engineered wood product formed by layering strands (flakes) of wood in specific orientations. ... Medium-density fiberboard output in 2005 Medium-density fiberboard (MDF or MDFB) is an engineered wood product formed by breaking down softwood into wood fibers, often in a defibrator, combining it with wax and resin, and forming panels by applying high temperature and pressure. ...


One of the earliest applications of mass-produced modern plywood manufacturing in the United States was recorded in Portland, Oregon by the Portland Manufacturing Company. The owner, Thomas J. Autzen helped develop a bonding technology, which greatly shortened the drying and manufacturing process. His early engineering contribution played an important role in making plywood one of the most abundant and affordable building products ever produced. Thomas J. Autzen (1888 – 1958) was a German-American pioneer in the plywood industry, best known for establishing a philanthropic foundation to support the construction of a football stadium at the University of Oregon. ...


Plywood grades

Plywood grades are determined by the veneer quality on the face and back of each panel. The first letter designates quality of face veneer (best side), while the second letter denotes the surface quality of the back of the panel.[5] The letter "X" simply indicates the panel was manufactured with exterior type adhesive.


"A": Highest grade quality available. Can be defect free or contain small knots, providing they are replaced with wooden plugs (the fillers having a "boat" or a "football" shape) or repaired with synthetic patch. This grade may contain occasional surface splits that are repaired with synthetic filler. The surface is always sanded and provides for smooth paintable face quality.


"B": Second highest quality veneer grade. Normally a by-product of downgraded "A" quality veneer. Solid surface, but may contain small diameter knots and narrow surface splits. Normally repaired with wooden plugs or synthetic filler. Surface normally sanded smooth.


"C": Considered to be a lower end face quality, but a reasonable choice for general construction purposes. May contain tight knots up to 1½ inches diameter, some open knot holes, some face splits, and discoloration. Some manufactures may repair the defects with synthetic filler. Panels typically not sanded.


"D": Considered to be the lowest quality veneer and often used for the back surface for construction grade panels. Allows for several knots, large and small, as well as open knots up to 2½ inches diameter. Open knots, splits, and discoloration are acceptable. "D" grade veneers are neither repaired nor sanded. This grade is not recommended for permanent exposure to weather elements.


Plywood applications

Plywood is used in any application that needs high quality wooden sheet material. High quality in this context means resistance to cracking, breaking, shrinkage, twisting and warping. Plywood is also used as an engineering material for stressed-skin applications. Plywood has been used in this fashion for marine and aviation application since the WWII era. Most notable is the British De Havilland Mosquito bomber, which was primarily made out of wood. Plywood is currently used in stressed-skin applications quite successfully[citation needed]. The American designers Charles and Ray Eames and Phil Bolger are world famous for their furniture designed with plywood. The de Havilland Mosquito[1] was a British combat aircraft that excelled in a number of roles during the Second World War. ... Charles Eames (June 17, 1907 – August 21, 1978) (pronounced ) was an American designer, architect and filmmaker who, together with his wife Ray, is responsible for many classic, iconic designs of the 20th century. ... Ray-Bernice Alexandra Kaiser Eames (December 15, 1912 - August 21, 1988) was an American artist, designer, architect and filmmaker who, together with her husband Charles, is responsible for many classic, iconic designs of the 20th century. ... Philip C. Bolger Philip C. Bolger (1927- ), prolific boat designer, was born and lives in Gloucester, Massachusetts. ...


See also

Engineered wood, also called composite wood, includes a range of derivative wood products which are manufactured by binding together the strands, particles, fibers, or veneers of wood, together with adhesives, to form composite materials. ... Fiberboard is a type of engineered wood product that is made out of wood fibers. ... Glued laminated timber or Glulam is a structural timber product composed of several layers of dimensioned lumber glued together. ... A type of manufactured sheet material akin to particle board, but much harder and denser because it is made out of exploded wood fibers. ... Masonite is an a type of hardboard formed using the Mason method (invented by William H. Mason) by taking wooden chips and blasting them into long fibres using steam and then forming it into boards. ... In construction, marine plywood is a specially treated plywood that is designed to resist rotting in a high-moisture environment. ... Medium-density fibreboard (MDF), 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. ... OSB-production before the press Oriented strand board, or OSB, is an engineered wood product formed by layering strands (flakes) of wood in specific orientations. ... Particle board is a material manufactured from wood particles (e. ... Pressed wood is any engineered wood building and furniture contruction material made from wood veneers, particles, or fibers bonded together with an adhesive under heat and pressure. ...

References

  1. ^ O'Halloran, M.R. 1989. Plywood. In Concise Encyclopedia of Wood and Wood-based Materials, ed. Arno Schniewind. Oxford: Pergamon. p. 221-226.
  2. ^ Handbook of Finnish Plywood, Finnish Forest Industries Federation, 2002, ISBN 952-9506-63-5 [1]
  3. ^ "Milestones in the History of Plywood", APA - The Engineered Wood Association. Accessed October 22, 2007. "Plywood is often called the original engineered wood product because it was one of the first to be made by bonding together cut or refashioned pieces of wood to form a larger and integral composite unit stronger and stiffer than the sum of its parts."
  4. ^ O'Halloran, p.221.
  5. ^ http://www.timber.org.au/NTEP/menu.asp?id=104#Veneer_quality

is the 295th day of the year (296th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ...

Further reading

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  Results from FactBites:
 
Plywood / Design/Designer Information (1046 words)
PLYWOOD was invented in the 1850s as a combination of three or more layers of wood.
Plywood consists of at least three layers or veneers of wood which have been plied together with the grain running crosswise to add strength and resilience.
Both Breuer and Aalto’s plywood experiments were admired by young US furniture designers, notably Eero Saarinen and Charles Eames: as were the multi-dimensional plywood designs of Gerald Summers, a British designer and manufacturer whose chairs were sold in the US during the late 1930s.
Making plywood scarf and butt joints (698 words)
As shown in the sketch, the two plywood panels to be scarf-joined are aligned on the edge of a flat table or a sheet of 3/4" plywood.
Align the edges of the two plywood panels to be joined, the table or work surface, and the clamping block, so they are precisely parallel.
Both plywood panels are tapered simultaneously with a hand or power plane, or a disc sander for preliminary rough cutting.
  More results at FactBites »

 
 

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