Woodworking – Wood bending steamer
Patent
1991-08-01
1993-09-28
Bray, W. Donald
Woodworking
Wood bending steamer
144 2R, 144361, 144380, B25H 100, B27M 102
Patent
active
052479757
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a wood treating method and apparatus for treating woods which are slender or curved, for example, soft woods, such as Japanese cedars, Japanese larches, poplars and albizias, or woods from thinning, such as Japanese cedars and Japanese cypresses removed during growth, for strengthening, straightening and free-form shaping, to achieve high added values and effective utilization of woods.
Soft woods, such as Japanese cedars, though utilized as building materials, are limited in use because of their low strength. Further, woods left unused, such as Japanese larches, poplars and albizias, and woods from thinning, such as Japanese cedars and Japanese cypresses removed during growth, are small-diameter woods and, moreover, curved and excessively soft; thus, they are either left unused or discarded.
Accordingly, it has been usual practice to inject a resin, such as phenol resin, into woods, to strengthen the latter by the curing of the resin. However, since a large amount of resin has to be injected into wood, the resin cost is high and so is the treating cost. Further, a special injection device, a period of time (about one day) and substantial labor are required in order to inject resin uniformly into wood. At present, injection of resin into wood is very difficult. Further, since resin is injected into wood for strengthening purposes, the water absorption property which is characteristic of wood is lost, resulting in the wood assuming the plastic property, while losing its performance, functions and properties. Furthermore, if such treated wood is discarded as a waste material, a problem of pollution is raised by the resin during incineration (smoke from harmful materials, influences of high temperature on the incinerator, etc.).
Studies have been made for strengthening wood without using resin; for example, a study of compacting process based on heat treatment using microwaves has been made. However, no effective method has been found as yet for fixing a deformation produced by compaction. That is, absorbing an amount of water corresponding to compaction, the wood is restored to its original shape. Further, microwaves are limited in penetration depth, so that it is difficult to treat thick wood, and the cost is high.
SUMMARY OF THE INVENTION
The present invention is the result of an intensive study to solve the above-mentioned problems, finding that softening wood in a high temperature high pressure water vapor atmosphere and compression-molding and fixing it, is very effective means for strengthening wood.
Thus, an object of the invention is to provide a wood treating method and apparatus, based on softening wood in a high temperature high pressure water vapor atmosphere and compression-molding it to any desired shape and fixing it in this state, thereby strengthening wood and doing away with lumbering.
A wood treating method according to the present invention to achieve said object is characterized by softening wood in a high temperature high pressure water vapor atmosphere, compression-molding it, and fixing the resulting deformation by placing it in a high temperature high pressure water vapor atmosphere.
Placing wood in a high temperature high pressure water vapor atmosphere results in the wood absorbing the water vapor to increase its temperature (when wood is left to stand for several seconds to tens of minutes, the wood temperature rises to 130.degree.-200.degree. C.), whereby the wood is softened. In this state, mechanical compression forces are applied to the wood, thereby compressing the latter until it is reduced to about 1/2 to 1/3 in terms of cross-sectional area ratio while squeezing absorbed water, with the result that the voids formed in the wood are decreased in size and the wood is hardened and strengthened; thus, curved wood is straightened or wood can be freely treated without lumbering. As a result, the use of resin becomes unnecessary, reducing the treating cost to a great extent, enabling the strengthening process to be e
REFERENCES:
patent: 1403722 (1922-01-01), Turnbull
patent: 1644801 (1927-10-01), Van Der Werff
patent: 2218897 (1940-10-01), Skutl
patent: 2567292 (1951-09-01), Lundstrom
patent: 2586308 (1952-02-01), Curtis
patent: 4017980 (1977-04-01), Kleinguenther
Soviet Inventions Illustrated, Mar. 1964, Derwent Publications Ltd., London, GB: and 2B: 157097 & SU-A-157 097; Jan. 1964, Abstract.
Fukada Syuzo
Inoue Masafumi
Kimoto Senji
Ota Chikayoshi
Tanahashi Mitsuhiko
Bray W. Donald
Hisaka Works Limited
Tanahashi Mitsuhiko
LandOfFree
Wood treating method and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Wood treating method and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wood treating method and apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2185849