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Plywood is a sheet material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which includes medium-density fibreboard (
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The most commonly used thickness range is from 1⁄8 to 3.0 inches (3.2 to 76.2 mm). The sizes of the most commonly used plywood sheets are 4 x 8 feet (1220 x 2440 mm) which was first used by the Portland Manufacturing Company, who developed what we know of as modern veneer core plywood for the 1905 P
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Different varieties of plywood exist for different applications:Softwood plywood[edit]Softwood plywood is usually made either of cedar, Douglas fir or spruce, pine, and fir (collectively known as spruce-pine-fir or SPF) or redwood and is typically used for construction and industrial purposes.[7]The
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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 laid horizontally and rotated about its long axis while a long blade is pressed into it, causing a thin laye
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plywood grading rules differ according to the country of origin. The most popular standards are the British Standard (BS) and the American Standard (ASTM). Joyce (1970), however, list some general indication of grading rules:GradeDescriptionAFace and back veneers practically free from all defects.A/
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In 1797 Samuel Bentham applied for patents covering several machines to produce veneers. In his patent applications, he described the concept of laminating several layers of veneer with glue to form a thicker piece – the first description of what we now call plywood.[3] Bentham was a British naval e
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Plywood is used in many applications that need high-quality, high-strength sheet material. Quality in this context means resistance to cracking, breaking, shrinkage, twisting and warping.Exterior glued plywood is suitable for outdoor use, but because moisture affects the strength of wood, optimal pe
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The latest CNC rotary cutting equipment not only improves the quality and precision of veneer production, but also improves the production efficiency and the degree of automation of the whole machine.
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A typical plywood panel has face veneers of a higher grade than the core veneers. The principal function of the core layers is to increase the separation between the outer layers where the bending stresses are highest, thus increasing the panel's resistance to bending. As a result, thicker panels ca