Thin sheets of wood with grain parallel to the surface can be sliced, varying in thickness, before use, from 0.25 mm to about 6.4 mm. All decorative veneers produced in Europe are cut into 0.6–0.9 mm, average thickness 0.7 mm (1/40 in) for facial quality. Most veneers produced in the United States and Australia are cut by 0.9 mm (1/28 in). They are made in three basic ways, sawing, rotary peeling and slicing. Those high-value or striking appearance are used for surface decoration, but veneers are also used structurally to make plywood boards and to create bent laminate and molded shapes that are wood without chemical modification. Cannot be obtained in a single thick piece of. The basic method of sawing has been changed to all but saw knife cutting cases for commercial production. Logs made for slicing are cut and examined for shape, grain, texture, and defects before cutting into sections suitable for the production of veneers.
Shredded, quartered or torn log sections are usually soaked in boiled or warm water for one to several days before cutting. The logs made for rotary peeling are treated in a round. In rotary cutting, the log is placed at either end in a large lathe and rotated against the knife, which is pushed forward at each turn to preserve the thickness of the cut. This cutting method is particularly suited for the high volume production of large sheets of veneer used to make plywood. However, it is used in one of its five basic forms or in many other variations, such as bird's eye maple, pinched betula, and lentil birch, to produce many ornamental ornamental veneers, which are used in any other cutting. Can not be removed by the method of.
In slicing, a wooden knife placed in a frame is moved against it. Four different methods of cutting and mounting flitches are used to extract the best figure. Later slices of veneer are placed in order during drying operations so that the figure from one leaf to the other is preserved. They are usually sold as a flitch in this form which can be broken later and sold in books or individual leaves or sheets.
Whether rotary peeling or slicing is used, the cutting action is essentially the same in both. As the knife separates the veneer from the flitch, a separate layer of wood is severely bent and tension builds up in the area near the knife edge. When these stresses exceed the strength of the wood, failure occurs resulting in a series of knives that are veneered against the knife. This side of the veneer is called the loose side and the distal side of the knife is called the tight side. Using a pressure bar to cut the veneer as it is cut is possible in some cases to reduce and eliminate this problem. The extent to which this is possible is determined by species, by the thickness of the cut, by the installation of the machine, and by the temperature of the wood.
Porous hardwoods with diffused rays, such as birch, are more likely to produce tight veneers than oak such as ring porous hardwoods. Holding a piece of veneer with one edge in each hand and flexing it will usually reveal tight and loose sides; The veneers feel strenuous when the veneer is flushed to close the check and more lame when closed in the open. If the veneer feels the same in both directions it is probably tight. Knife checks often appear months or years after the veneer is laid, such as parallel-to-grain cracks through the finish. Whenever possible therefore the tight side (also called face side) should be faced and should not be taken into consideration during refinement.
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