Stock material or miscellaneous articles – Sheets or webs edge spliced or joined – Sheets or webs coplanar
Patent
1994-05-16
1996-01-23
Bray, W. Donald
Stock material or miscellaneous articles
Sheets or webs edge spliced or joined
Sheets or webs coplanar
144346, 144350, 156264, 1563045, 428106, B32B 314, B27D 100
Patent
active
054863937
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method of manufacturing sheet elements of end-wood type for use as wear surfaces for flooring, counters and the like.
For many many years it has been known to manufacture floor surfaces made up of end-wood pieces in the form of relatively short wood blocks, which can consist of cut-off posts with essentially circular end surfaces or cut-off sawn planks or pieces of lumber with preferably rectangular cross-sectional areas. Such floor surfaces of blocks have a number of advantages. Inter alia, they are very wear-resistant and pleasant to walk on as well as being aesthetically pleasing. For outdoor purposes, impregnated woodblocks of round cross-section are often laid in sand, asphalt or other filler material, which can absorb the natural moisture-induced movements in the wood. For indoor environments, depending on the use, blocks of primarily rectangular cross-sectional shape have been glued together into composite blocks or sheets which are later sawn and sanded into either self-supporting massive block floor-boards or a relatively thin wear-layer for block ply floor-boards, which are tongued and grooved to facilitate laying the boards to make a floor.
In the corresponding manner counters and tables can be made of blocks of rectangular cross-section.
Despite the fact that such end-wood products have often been greatly appreciated due to their wear-resistance and pleasant appearance, they have never come into widespread use due to their tendency to crack or be deformed with changes in moisture. Cracking is due primarily to the fact that the movement of moisture in the wood varies in different directions, i.e. it is about twice as great in the tangential direction of the growth rings as it is radially to the growth rings, so that the internal stresses in the wood will become excessive.
One method of substantially dealing with this problem has been to stabilize the dimensions of the wood with the aid of various chemicals. This is, however, expensive and often unacceptable for environmental reasons.
Another method of reducing the risk of cracking is to saw out pieces of wood with triangular cross-section and glue them together into a composite block, which is in turn sawn up transversely to the fiber direction into sheets or stave or board-like products (see e.g. SE-A-9100830-0). If, when gluing together the sawn-out pieces of wood -- regardless of whether these are triangular or of other shape, e.g. rectangular, in cross-section -- the growth ring direction is oriented in a uniform manner, it is possible to obtain an end-wood product, the moisture movements (and thus the internal stresses) of which will be regular and predictable. However, in this case as well, the movements tangentially to the growth rings can be so great as to cause problems.
The primary purpose of the present invention is to suggest an improved process for manufacturing sheet elements of end-wood type, with which it is possible to obtain end-wood elements with substantially reduced moisture movement in the plane of the wear surface, especially reduced moisture movement tangentially to the growth rings.
According to the invention, this is achieved by virtue of the fact that a longitudinally sawn piece of wood, preferably of triangular or square cross-section, is sawn up with parallel cuts oblique to the longitudinal direction, into plates the cut area of which is greater than the cross-sectional area of the piece of wood, whereafter the plates are laid next to each other and joined together with complementarily shaped edge surfaces to form a sheet end-wood element. This means that the dominant tangential movement of moisture can be given a component which is directed perpendicularly to the plane of the wear surface, and this results in a substantial reduction in the moisture movement in the plane of the wear surface.
Suitably the longitudinally sawn piece of wood is sawn up with oblique cuts within an angular range of about 30-75.degree. to a plane normal to the longitudinal axis of the piece of wood, and t
REFERENCES:
patent: 301068 (1884-06-01), Parmelee
patent: 947001 (1910-01-01), Kertscher
patent: 2544935 (1951-03-01), Orner
patent: 3961654 (1976-06-01), Hasenwinkle
patent: 3969558 (1976-07-01), Sadashige
patent: 3989078 (1976-11-01), Hasenwinkle
patent: 4111247 (1978-09-01), Hasenwinkle
patent: 4122878 (1978-10-01), Kohn
patent: 4897140 (1990-01-01), Opsvik
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