JPS6147209A - Method of preventing crazing 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 before the center area, resulting in a difference in dryness between the surface area and the center area. As the temperature increases, 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
If the percentage is around 0%, there will be products that are not suitable 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. The narrow grooves (referred to as ring removal) 22 are cut in advance, and when drying, not only the outer peripheral surface of the wood 21 but also the narrow grooves 2
2. Moisture can be released from the inner surface at the same time, 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. was.

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

(1) It is necessary to carve a narrow groove (ring cut) 22 over the entire length of the wood 21, and the process of carving the narrow groove becomes troublesome. In particular, the narrow grooves 22 are created by cutting the surface of the wood 21 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 unsightly parts on the circumferential surface of the wood 21. 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 of the wood will decrease if the thin W422 is added, so it is usually used without adding the thin 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) 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 damage to the otherwise good quality material.

(Object of the Invention) In view of the above-mentioned problems with the conventional method for preventing cracks in wood by cutting thin grooves, the present invention has been developed to prevent the occurrence of cracks without cutting thin grooves into wood. The first purpose of this study is to propose a method for preventing cracking in wood that has been treated with 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 a crack preventive agent is applied to the surface of the wooden board within the width of the grain portion and also over the entire length of the wood, and then the wood is dried.

(Function) The method for preventing cracks in wood according to the present invention is to apply a crack preventive agent to the wood grain parts where cracks are likely to occur (straight grain parts are less likely to crack) before drying the wood. This has the effect of making it difficult for cracks to occur even if the difference in drying degree between the surface layer and the center of the wood increases during drying, and by applying a crack preventive agent in this way, cracks can be prevented. Even if it is designed to prevent cracking,
The moisture in the wood can be released into the outside air through the surface of the straight-grained areas that are not coated with anti-crack agent, preventing moisture from escaping from the grain areas and making drying uniform, thereby preventing cracks. This provides the effect of preventing the quality of wood from deteriorating.

Furthermore, if the anti-crack agent is applied to the entire outer circumference of the wood, the effect of preventing cracks in the wood will be greater; however,
There is a problem in that the moisture absorption and moisture release properties of the wood are stopped, making the wood more susceptible to rot due to moisture.

(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, the wood 1 has a rectangular cross section (
A rectangular piece of wood 11 is shown. Further, in the embodiment shown in Fig. 3, a wood bundle Y is shown in which multiple layers of as-sawn wood 11, 11, etc. are bundled so that each surface of the wood is in close contact with each other vertically and horizontally. There is.

The wood 1 of the embodiment shown in FIG. 1 is sawn from a log so that the center of the annual ring is aligned approximately at its center, and each side (4 sides) of the wood 1 is A board grain 2 with a predetermined width W 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 a raw wood from a portion away from the center of the growth ring, and has two mutually opposing sides on each side of the lumber 11 (in FIG. 2, the top and 12 grains on each side (width Wt) of each bottom side)
．． 12 appears, and the straight grain 13.13 appears on the entire surface (width T) of the two sides (left and right sides) of paternity.

In the method for preventing cracks in wood according to the embodiment of the present invention shown in FIGS. 1 and 2, each of the wood 1. II
Each board grain 2, 2...

On the surface where 12.12 appears, each plate grain 2.2...
12. Width W of the 12th part 1. This is done by applying anti-cracking agent 2 over the entire length of W+. In addition, in this example, the crack preventive agent Z is also applied to the ends 4 and 14 of the lumber 1.11 and the straight grain 3°13 portion near the main end (as appropriate, only within the length range of the small dimension S). . As the anti-cracking agent Z used in this example, there is, for example, a liquid type of radish called "Mizukake Stopper" manufactured by Mizukake Co., Ltd. This anti-crack agent 2
is applied with a brush.

In this way, when wood 1.11 is dried after applying crack prevention agent Z to the grains 2 and 12 of wood 1.11, the moisture in the wood will be removed from the straight grain to which crack prevention agent B has not been applied. 3. It is released into the outside air from the 13 part. At this time, the surface layer of the book (41, 11, where the straight grain 3° 13 appears) is initially drier than the center, but it gradually dries to the inside, and the grain area is coated with a crack preventive agent. Although drying may occur from the inside, the drying process is made uniform by drying through the straight-grained parts, and the anti-crack agent prevents moisture from escaping, and the two effects of solidifying the wood prevent cracks in the wood when it dries. It has the effect of making it less likely to occur.

The method for preventing cracks in wood according to the embodiment 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. . In the wood bundle Y shown in FIG.
．． 11.Is the moisture inside the wood located on the outer periphery? From this exposure, it is released into the outside air,
The moisture in the wood located on the inner layer side of the wooden shed bundle Y gradually penetrates into the wood located on the outer layer side. 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 crack prevention method of the embodiment shown in FIG. This is done by applying the anti-cracking agent Z only to 12 portions of the grains on the surface of the wood located on the outer periphery of the wood Y, which are exposed to the outside. When the crack prevention method shown in Fig. 3 is applied, cracks occur in the wood on the inner layer side of the wood bundle Y because the difference in dryness between the surface layer and the vicinity of the center of the wood does not become large. It piles up, and even the wood on the outer periphery is exposed to the outside (
The effect of the anti-cracking agent Z applied to the grain 12 portion of the plate (where water easily evaporates and cracks) makes it difficult to crack can be obtained.

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

Experimental Examples Each grain of 4 tons of wood (hemlock flat wood) freshly sawn from logs was coated with a crack preventive agent (trade name: Mizukake Stopper) by brush.
When 10 pieces of wood of the same type and shape without any treatment were dried in the sun for 15 days under the same conditions, most of the pieces coated with a crack prevention agent (example of the present invention) showed no cracks. No cracking occurred and none of the 10 samples were disqualified, whereas for those that had not been treated, only 3 out of 10 samples were disqualified due to cracking.

(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. Since we apply a crack preventive agent and then dry the wood, if the difference in dryness between the surface layer and the center of the wood (1° II) becomes large during drying, we will normally Cracks occur even in the grain (2, l2) part of the board that is prone to cracking, making it difficult to drill. The crack preventive agent can now be released into the outside air from the surface of the straight-grained parts (3, 13) where no crack preventive agent has been applied, allowing the drying of the wood to dry from the inside through the straight-grained parts, which are the surface grains that are the easiest to dry. By suppressing the drying of the parts, it has the effect of drying the wood products while making the drying uniform and preventing cracks.

In addition, the method for preventing cracks in wood according to the present invention requires simply applying the crack preventive agent to the grains of the wood. )
It is easier to prevent cracks compared to wood that is machined, and cutting thin grooves (rings) like in conventional wood (Figure 3) reduces strength. In addition, even if the wood is used as is without being processed with fine grooves, it can be dried at the same time as preventing cracks, eliminating the problem of strength loss. so that you can get it

[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. 1.11 ・・・・・・Wood 2.12 ・・・・・・Plant 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,
) Preventing cracks in wood by applying a crack preventive agent (Z) to the width (W_1, W_2) and extending over the entire length, and then drying the wood (1, 11). Method.