JPS61152402A - Crazing preventive method of wood - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for preventing cracks in wood.

(Prior art) Wood (for example, pillar materials, beam materials, girder materials, etc. for construction) is sawn into a predetermined shape from raw wood and then dried (dried in the shade or in the sun). However, when the wood dries, the surface layer of the wood dries earlier than the center, resulting in a difference in dryness between the surface layer and the center. As the wood becomes larger, cracks will appear in the dry surface layer.These cracks tend to occur particularly in the surface layer where the grain of the wood is exposed.

In addition, if wood products are left to dry naturally, most products will have large cracks, and depending on the tree species, the cracks will be 30 to 4
At around 0%, some products become unsuitable for use as products.

Conventionally, in order to prevent the occurrence of cracks in the wood as described above, before drying the wood, as shown in FIG. A narrow groove (referred to as a ring cutter) 22 with a depth of
At the same time, the inner surface of the wood 21 is made to be able to release moisture, so that there is no large difference in dryness between the surface layer and the center of the wood 21, thereby making it difficult for the wood 21 to crack. I was doing it.

However, the conventional method for preventing cracks in wood shown in FIG. 4 has the following problems.

(1) Thin grooves (ring cutting) 22 over the entire length of the wood 2I
This requires cutting and processing, and the fine cutting process becomes troublesome. In particular, the narrow grooves 22 are created by cutting the surface of the tree 121 that is brought into contact with a wall or the like after construction and becomes invisible from the outside, and therefore has many knots, scratches, and other parts that impair the aesthetic appearance of the wood 121. However, when machining the narrow groove 22, it is necessary to search for the surface to be machined.

(2) Since the narrow grooves 22 are formed in the wood 21, the wood 21
1 strength decreases. In addition, in the case of wood used for girders and beams of buildings, the strength decreases if the narrow grooves 22 are inserted, so it is usually used without the narrow grooves 22, but as it dries, large cracks occur and the strength decreases significantly. Therefore, it was uneconomical to use a large piece of wood in advance to ensure the specified strength.

(3) The internal stress of the raw wood before sawing was evenly distributed during its growth, and as a result, it maintained the shape of a single straight log.
When $22 is formed, the balance of the internal stress up to that point is disrupted, and the wood becomes bent over time after being sawn, making it unusable or deformed after use (gaps occur between pillars and shoji after construction) Things that cause architectural defects such as

(4) Even if the product is clean with no defects on all four sides, the narrow grooves 22 must be cut into one of the surfaces, resulting in scratches on the otherwise good quality material.

(Object of the Invention) In view of the problems of the above-mentioned conventional method for preventing cracks in wood by cutting fine grooves, the present invention has been developed to prevent the occurrence of cracks without cutting thin grooves in wood. The first purpose of this study is to propose a method for preventing cracks in wood.

A second object of the present invention is to propose a method for preventing cracks in wood such as girders and beams, which were conventionally allowed to crack.

(Means for Achieving the Object) The method for preventing cracks in wood of the present invention focuses on the fact that cracks occur only in the grain areas of wood, and the grains in the wood appear before the wood is dried. The wood is characterized in that the surface of the lumber is subjected to an appropriate moisture diffusion suppression treatment within the width of the grain portion and also over the entire length thereof, and then the wood is dried.

(Function) The method for preventing cracks in wood according to the present invention includes applying an appropriate moisture wicking suppression treatment to the grain portions where cracks are likely to occur (straight grain portions are less likely to crack) before drying the wood. This method has the effect of preventing the occurrence of cracks from the grain of the wood during wood drying, and even if the moisture wicking control treatment is applied to prevent cracks, the wood The moisture inside can be radiated into the outside air from the surface of the straight-grained portion that has not been treated to suppress moisture diffusion, and an appropriate wood drying effect can be obtained.

Furthermore, if moisture wicking control treatment is applied to the entire outer periphery of the wood, the effect of preventing cracks in the wood will be greater, but the wood's ability to absorb and release moisture will be stopped, making the wood more susceptible to rot due to moisture. There is a problem.

(Embodiment) A preferred embodiment of the present invention will be described with reference to FIGS. 1 to 3. In the embodiment shown in FIG. In the embodiment shown in FIG. 2, a piece of wood 1 is shown, for example, a piece of wood Ill having a rectangular cross section (flat angle) used for beams. In the embodiment shown in FIG. 3, a large number of as-sawn timbers t1. lt
A wood bundle Y is shown in which the wood bundles Y are bundled so that their respective surfaces are in close contact with each other vertically and horizontally.

The lumber l of the example shown in Fig. 1 is formed by sawing from raw wood so that the center of the annual ring is aligned approximately at the center of the lumber l, and each side (four sides) of the lumber l is A board grain 2 with a predetermined width WI appears at the middle portion in the width direction, and straight grain 3.3 portions with a predetermined width T, , T, appear on both sides thereof.

The lumber 11 of the embodiment shown in FIG. 2 is formed by sawing from a portion of the raw wood that is away from the center of the growth ring, and the lumber 11 is formed by sawing from a portion of the log that is away from the center of the annual ring. , each lower side), each side has 12 grains on the entire surface (width W, ).
．． 12 appears, and straight grain 13.13 appears on the entire surface (width T) of the other two surfaces (left and right surfaces).

In the embodiment of the present invention shown in FIGS. 1 and 2, each grain 2.2 of each lumber 1.11 shown in FIGS. 1 and 2 is・
, 12.12 appear on the surface, each plate grain 2.2-
, 12.12 width wI.

W, and has been subjected to appropriate water dispersion suppression treatment over its entire length. Methods for suppressing moisture loss suitable for carrying out the present invention include, for example, applying various liquid or solid coating agents, or applying adhesive tapes. I am applying anti-cracking agent Z. In addition, in this example, the wood end 4.14 of the wood 1.11 and the straight grain 3, 1 near the wood end
3 parts (only the length range of the standing dimension S) are also subjected to moisture dispersion suppression treatment (coating with anti-cracking agent Z). The anti-cracking agent Z used in this embodiment is, for example, a liquid product manufactured by Mokken Co., Ltd. under the trade name "Mokuken Stopper." This anti-cracking agent Z is applied with a brush.

In addition, as coating agents for suppressing moisture diffusion, examples of solid materials include wax, and examples of liquid materials include various adhesives, varnishes, paints, and the like. Also,
Examples of adhesive tapes include cellophane tape with adhesive and paper tape.

In this way, when wood 1.11 is dried after applying moisture wicking control treatment to the grain 2.12 portion of wood 1 and 11, the moisture in the wood is removed from straight grain 3, which has not been subjected to moisture wicking control treatment. .13 part into the outside air. At this time, the surface layer where the straight grain 3.13 of the 1.1 ton wood appears is initially drier than the center, but it gradually dries to the inside, and the grain part is dried by the moisture wicking suppressing material. However, by drying from the inside through the straight-grained portions, the drying process becomes uniform and prevents the wood from cracking when drying.

The method of preventing cracks in wood shown in the example shown in Fig. 3 is suitable for cases where a large number of pieces of wood, such as imported wood, are tied together and kept as they are for a relatively long period of time. ing. In the wood bundle Y shown in FIG.
．． It... The moisture in the wood located on the outer periphery is exposed to the outside and is radiated into the outside air, and the moisture in the wood located on the inner layer side of the wood bundle Y is sequentially located on the outer layer side. It penetrates into the wood. Therefore, the drying speed of the wood located on the inner layer side becomes extremely slow, and the difference in dryness between the surface layer and the vicinity of the center of each inner layer side wood becomes small, so the wood on the inner layer side 11.11.・
It has the characteristic that cracks are less likely to occur. In the embodiment shown in FIG. 3, each lumber 11. The water dispersion suppressing treatment (coating of anti-cracking agent Z) is applied only to the grain 12 portion and the end portion (symbol S) of the surface of the wood exposed to the outside.

In the case of the embodiment shown in FIG. 3, the difference in dryness between the surface layer and the center of the wood in the inner layer of the wood bundle Y does not become large, so cracks are less likely to occur. In addition, the wood on the outer periphery side also has the effect of being less likely to crack due to the effect of moisture wicking control treatment applied to the 12 grains of the surface exposed to the outside (where water easily wicks and cracks). It will be done.

In addition, when the wood subjected to these moisture diffusion suppression treatments is used, the surface is scraped by appropriate means (for example, planing), and the applied moisture diffusion inhibitor and adhesive tape are removed.

Furthermore, the moisture wicking inhibitor and adhesive tape may be removed before use, once the wood has completely dried (usually after 6 to 12 months).

Furthermore, if the wood is used before it has been completely dried, it is advisable to grind the surface of the wood (for example, by planing) and then reapply an appropriate moisture wicking inhibitor only to the grain areas. In this case, the use of a transparent varnish or wax as the moisture diffusion inhibitor provides a good design effect.

Experimental examples of the method for preventing wood cracking of the present invention are shown below.

Experimental Examples Ten pieces of wood (cypress square lumber) that had just been sawn from logs were brushed with a crack preventive agent (trade name: Mokken Stopper) on the surface of each grain part. When 10 pieces of wood of the same type and shape were dried in the shade under the same conditions for 3 months, none of the pieces coated with a crack preventive agent (products implemented in accordance with the present invention) developed cracks and were deemed unsuitable. None of the 10 pieces received any treatment, whereas all of the pieces that had not been treated developed cracks and were no longer usable at the same grade as before the experiment.

(Effects of the Invention) The method for preventing cracks in wood according to the present invention applies to the surface where the grains (2, 12) appear before wood drying treatment, and the width of the grain portion as well as the entire length thereof. The wood has been treated to suppress moisture wicking, and the moisture in the wood is allowed to evaporate into the outside air from the surface of the straight-grained parts (3, 13) that have not been treated to suppress moisture wicking. It is effective in drying wood products by passing through the straight-grained parts from the inside and by suppressing drying of the surface grained parts, which are the easiest to dry, to make drying uniform and prevent cracks.

In addition, the method for preventing cracks in wood of the present invention simply requires applying an appropriate moisture diffusion suppression treatment to the grain portion of the wood. The work to prevent cracks is easier than when machining (cutting) is required. Furthermore, as with conventional wood (Figure 4), the strength is reduced due to the cutting of thin grooves (ring cutting), and the strength is due to cracks that occur when the wood is used as is without thin groove processing. There is no deterioration, and as a result, the desired strength can be obtained even if the thickness of the wood is made thinner than that of conventional wood, which is also economically effective.

In addition, with the conventional crack prevention method using thin grooves (ring cutting), it was common for wood to become deformed due to loss of internal stress balance after use, but this method does not use thin grooves (ring cutting). The method of the present invention does not cause such deformation of wood.

[Brief explanation of the drawing]

1 to 3 are perspective views of wood subjected to a crack prevention method according to an embodiment of the present invention, and FIG. 4 is a perspective view of wood subjected to a conventional crack prevention method. t4t...wood 2.12...grain 3.13...straight grain

Claims (1)

[Claims] 1. Before the wood drying process, the surface of the wood (1, 11) where the grains (2, 12) appear,
) A method for preventing cracks in wood, which comprises applying an appropriate moisture diffusion suppressing treatment to the width (W_1, W_2) and the entire length thereof, and then drying the wood (1, 11).