JPH1086109A - Composite natural structural material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite natural structural material formed into a rectangle-columnar shape having a large cross section, which can also be used as a structural material such as a column and a beam, by using composite natural structural materials, particularly, wood, as a primary constitution material, and bamboo materials sandwiched therebetween as a reinforcing material. SOLUTION: A plurality of, more preferably, at least three layers of, woody board materials are bonded to one another with bamboo materials thereamong to form a rectangle-columnar shape having a large cross section, so that the rectangular column thus formed can also be used as a structural material such as a column and a beam. In this case, a cedar material is used as a unit wooden board A. A log is first sawed to manufacture the plate-like unit wooden board A with a width W of 10.5cm, a length L of 240cm and a thickness (t) of 3cm. A recess 1 with a depth of 2mm is formed in one of bond faces of this unit wooden board A, leaving marginal portions of 5cm from its end and side faces. Further, a bamboo is split to form a slender, thin sheet-shaped bamboo lath 2 with a length L of 230cm, a width W of 3cm and a thickness (t) of 3mm. It is preferable that this bamboo lath 2 formed into the slender and thin sheet shape is made substantially smooth by shaving completely bamboo joint portions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite natural structural material, in particular, a composite formed by using wood as a main constituent material and a bamboo material as a reinforcing material, and having a large cross section which can be used for columns and beams. It relates to natural structural materials.

[0002]

BACKGROUND OF THE INVENTION In recent years, problems have been pointed out, such as protection of the global environment, especially environmental destruction and global warming due to the cutting of tropical rainforests. From this point of view, effective utilization of domestic timber is desired, and in Japan, protection and fostering of domestic forests is also called out from the viewpoint of securing water resources. However, domestic timber does not win the price competition with imported timber, except for a very small amount of high-quality timber, and as a result, the securing of forestry workers has not remained. It is a fact. In view of the above, the present invention has almost completely achieved the effective use of domestic timber, particularly the use of conventional timber, such as thinned wood, crushed wood (tip after removing pillars or the like), or medium wood. The aim is to make effective use of domestic timber that has a poor supply-demand relationship due to its limited use.
That is, conventionally, for example, thinned wood has almost no use, and is economically unsatisfactory even if cut and shipped, and is not cut, or even if it is cut, it is left as it is. Further, although the intermediate material having a diameter of about 28 to 32 cm is about the size of a pillar, its use is small and it is too much.

On the other hand, wood requires a long time to grow. In the meantime, the forest will not grow sufficiently or become elongated sprouts unless several thinnings are cut down in the meantime. Will be devastated. However,
As mentioned above, domestic timber itself does not win the price competition with imported timber, and in terms of circumstances, thinned timber, etc. is not young enough and has insufficient strength and size to be used as a structural material, so economic value is low. At present, there are very few people who perform thinning work and thinning work of thinned wood.

[0004]

2. Description of the Related Art Conventionally, as a use of domestic timber such as thinned timber as described above, the amount of use is very small at a folk art fine parquet process. In addition, although the intermediate wood can be used as a pillar, its demand is small compared to the supply, and it is not yet fully utilized. On the other hand, imported wood is mainly used, but the raw wood is not used as it is, but it is processed and used as glued lumber (thin or long and thin pieces are glued together with an adhesive to make one wide board Or molded into a columnar shape)
Is known.

[0005]

The conventional amount of parquet fineness used is insufficient in terms of effective use of domestic thinned timber or middle-grained timber. In addition, processing is troublesome with conventional glued lumber, and even if raw materials are inexpensive, product prices are high,
It is used only for special purposes and is not sufficient from the viewpoint of effective use of domestic thinned timber.

The present invention provides a structural material that has a relatively low workability and has sufficient strength to withstand use as a pillar or a beam for domestic thinned lumber or the like, which is relatively weak in strength, and is in great demand. Open the way for the use of timber, and add economic value to thinned timber, pulverized timber, or medium-grained timber that has been left unnecessarily, and at the same time, grow very fast, but use bamboo work etc. The purpose of this project is to protect and cultivate forests by effectively utilizing unused domestic timber by using bamboo which is used only in a limited area.

[0007]

According to the present invention, a bamboo material is sandwiched between a plurality of, preferably three or more layers of woody boards, and the pieces are formed into a prism having a large cross section which can be used as a pillar or a beam. Thus, a composite natural structural material is obtained. Also, a concave portion is provided on at least one of the opposing surfaces where the bamboo materials of the plurality of wooden board members are sandwiched, and the bamboo material is inserted into the concave portion and bonded, so that the bamboo material is not exposed on the bonded side surface or end surface. A composite natural structural material with a beautiful appearance is obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. First, the log used in the present invention is:
For example, cedar or cypress, especially wood, which grows fast, but is weak in strength, but thinning material such as cedar or the remaining material obtained by removing structural materials such as pillars, or intermediate wood, etc. In this case, the material is small in size or weak in strength, so that it has a small number of uses and is sufficient for materials that are slightly surplus.

[0009] The raw wood is preliminarily sawn into a thick plate shape. First, the dimensions of the large-section prismatic product to be formed, for example, the width W
Is 10.5cm, length L is 240cm, thickness T is 18c
When a prismatic product of m is to be formed, a flat unit plate A having a width W and a length LT substantially equal to the prismatic product is manufactured. At this time, the thickness t may be any thickness that can be collected according to the log, for example, 3 cm or 5 cm.

On the other hand, a bamboo material is cracked, and an elongated and thin plate-shaped bamboo eluate 2 is formed in advance. The length of the elutriation 2 is desirably substantially equal to the flat unit plate A, but it is not necessarily equal to the length, and may be shorter. When the length is shorter than the unit plate body A, it is desirable to bond them so that joints do not overlap at the time of bonding described later. According to the dimensions (thickness T) of the prismatic product having a large cross section in which the plurality of unit plate bodies A are to be formed, a thin thin plate-like bamboo material 2 is sandwiched therebetween and bonded with an adhesive, as shown in FIG. Prismatic product B with a large cross section that can be used as a structural material for columns, beams, etc.
To form

[0011]

EXAMPLE A cedar wood was used as a unit plate A. First, a raw wood was sawn, and a width W was 10.5 cm and a length L as shown in FIG.
Is produced, and a flat plate-shaped unit plate A having a thickness of 240 cm and a thickness t of 3 cm is manufactured. On one of the bonding surfaces of the unit plate A, a concave portion 1 having a depth of 2 mm leaving 5 cm of an end surface and an edge of a side surface.
To form The concave portion 1 is for embedding the bamboo material 2 between the unit plate bodies A so that the bamboo material 2 is not exposed on the end face of the molded product when the bamboo material 2 is sandwiched between the unit plate bodies A and bonded together. This is unnecessary if the bamboo material 2 can be exposed on the end face of the molded product B without any problem. In addition, the unit plate body A located in the middle of the molded product B may have concave portions formed on both sides of the bonding surface.

Further, the bamboo is split, and as shown in FIG.
Is 230 cm, the width W is 3 cm, and the thickness t is 3 mm. It is desirable that this elongate thin plate-shaped elutriation 2 is substantially smooth with the nodes removed neatly.

The thin plate-shaped bamboo material 2 is inserted into the concave portion 1 of the unit plate A, and a room temperature-curable resorcinol resin adhesive, PHENOLITEMD-
3003 (trade name of Dainippon Ink and Chemicals, Inc.), alternately piled up 6 sheets, and dried while applying a pressing force of 2 kg per 1 cm of heiho centimeter. As shown in FIG. 5cm, length L is 240cm, thickness T
Formed a prismatic product B having a size of 18 cm. At this time, the thickness (3 mm) of the bamboo material 2 formed into a long thin plate to be inserted therein is thicker than the depth (2 mm) of the concave portion 1 of the unit plate body A. The bamboo bites into the tree (unit plate A) under pressure, and no bamboo material appears on the bonding surface in appearance, and the appearance is similar to that obtained by bonding multiple pieces of wood.

As shown in FIG. 4, the thus formed large-section prismatic product B was subjected to a bending test in which a load of 5 Ton was applied to the center of the upper surface with both ends of the lower surface being supported. It deflects about 15 cm when it is
When the load was released, it returned to its original state.

For comparison, a bending test was conducted on a U.S.-made toga wood having the same cross-sectional shape under the same conditions. As a result, a crack was formed at the center of the bent lower surface, and even when the load was released, it returned to the original state. Did not.

[0016]

According to the present invention, there are few conventional uses,
Even if it is cut down, thinned wood, powdered timber, or intermediate wood that has been left untreated can be used as a structural material that is in great demand. In addition, by effectively utilizing the domestic timber, protection and cultivation of forests can be achieved, and an effect of nature protection can be expected.

[0017]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a large-section rectangular column-shaped product of the present invention.

FIG. 2 is a perspective view showing an example of a unit plate body A of the present invention.

FIG. 3 is a perspective view showing an example of the bamboo material of the present invention.

FIG. 4 is a schematic view of a bending test of the prismatic product having a large cross section according to the present invention.

[Explanation of symbols]

 A, unit plate B, large cross-section prismatic product 1, recess 2. Elutriation (bamboo material formed into a long thin plate)

Claims (5)

[Claims] 1. A composite natural structural material characterized in that a bamboo material is sandwiched between a plurality of wooden boards and bonded to form a prism having a large cross section which can also be used for columns and beams. 2. The composite natural structural material according to claim 1, wherein a plurality of wooden board members are formed in three or more layers, and bamboo materials are sandwiched between the respective layers. 3. A concave portion is provided on at least one of the opposing surfaces where a plurality of wooden board bamboo materials are sandwiched therebetween, and the bamboo material is inserted into the concave portion and adhered, so that the bamboo material is adhered to the attached side surfaces and end surfaces. The composite natural structural material according to claim 1 or 2, wherein the composite natural structural material is not exposed. 4. A bamboo material sandwiched between a plurality of wooden boards and adhered is a long thin plate-shaped bamboo eluate obtained by crushing a hollow cylindrical bamboo in the longitudinal direction. The composite natural structural material according to claim 2, 3 or 4. 5. A bamboo material which is sandwiched between a plurality of wooden boards and is a bamboo long fiber obtained by crushing a hollow cylindrical bamboo and separating only a bamboo fiber. ,
The composite natural structural material according to claim 3 or 4.