JP2002018807A - Laminated material and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated material 20 utilizing a light and soft material like a poplar and a method for manufacturing the same. SOLUTION: A warp or a bend of a veneer 10 due to a difference of water content ratios is suppressed by alternatively superposing root side ends each having a large water content ratio of the veneer 10 and branch side ends each having a small water content ratio. In a cold pressing step, pressing and pressure releasing are repeated, temporarily tightened, a moisture in an adhesive is entirely uniformly impregnated by the pressing, and a stress generated by the impregnation of the moisture is released by the pressure releasing, and the warp or the bend of the veneer 10 due to the moisture in the thermosetting resin adhesive is suppressed. In a hot pressing step, pressing is conducted at a lower pressure than the pressing pressure of the cold pressing step, thermosetting of the adhesive is expedited by suppressing the stress generated due to the pressing, and hence the warp or the bend of the veneer 10 is prevented more accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laminated material and a method for producing the same.

[0002]

2. Description of the Related Art In general, a laminated material is manufactured by peeling raw wood thinly with a rotary lace to produce a veneer, laminating a plurality of veneers such that the fiber direction of each layer is the same, and bonding them with an adhesive. . Most of the laminated materials are used for building structural materials, fittings, floors,
It is used for interior materials such as walls and ceilings, as well as building materials such as door frames, skirting boards, and stair handrails. Conventionally, conifers such as hinoki, sawara, hiba, and spruce and broadleaf trees such as kamba, mizuna, zelkova, walnut, shioji, yachidamo have been used as the raw materials for such laminated materials.

[0003]

By the way, poplar, which is widely distributed in the temperate region of the Northern Hemisphere, is used as a pulp material because it grows quickly, can be supplied stably, and is easily processed with a light soft material. It is used for materials such as plywood, matchwood, boards, potter's wheel, and boxes. However, a light soft material such as poplar is liable to be warped or bent, and has not been used as a material for a laminated material. An object of the present invention is to provide a laminated material using a light soft material such as poplar as a material, and a method for manufacturing the same.

[0004]

According to a first aspect of the present invention, in a laminated material, a plurality of single sheets are laminated such that a branch end of one veneer is overlapped with a root end of another veneer. The plate is laminated and bonded. The invention according to claim 2 is the laminate according to claim 1, wherein the wooden back surface of the other veneer is superimposed on the wooden back surface of the single veneer, and the wooden surface of the other veneer is further laminated on the wooden surface. It is characterized in that a plurality of veneers are laminated and bonded so that the wooden surfaces of other veneers overlap. According to a third aspect of the present invention, in the laminated material according to the first aspect, poplar is used as a log of the veneer. The invention according to claim 4 is a method for manufacturing a laminated material, wherein a plurality of veneers are combined so that a branch end of one veneer overlaps a root end of another veneer. A bonding step, an adhesive application step of applying a thermosetting resin adhesive to the front and back surfaces of the veneers constituting the even-numbered layer when laminated, and a plurality of veneers that have undergone the combination step and the adhesive application step. A cold press process in which lamination is performed and temporary tightening is performed at least twice at normal temperature by pressing and releasing, and a plurality of veneers temporarily tightened in the cold press process are heated to a predetermined temperature and pressed in the cold press process. It is characterized by including a hot press step of performing pressure clamping at a pressure lower than the pressure. According to a fifth aspect of the present invention, in the method of manufacturing a laminated material according to the fourth aspect, in the combining step, a wooden back surface of the other single veneer is superimposed on a wooden back surface of the single veneer, and It is characterized in that a plurality of veneers are combined so that the wooden surface of another veneer overlaps the wooden surface of another veneer. According to a sixth aspect of the present invention, in the method for manufacturing a laminated material according to the fourth aspect, poplar is used as the log of the veneer.

[Action and Effect of the Invention]

According to the first aspect of the present invention, the root end of the veneer having a high water content and the branch end of the veneer having a low water content are alternately overlapped with each other. Bending can be suppressed. Therefore, it is possible to manufacture a laminated material from a veneer made of a light soft material such as poplar. When the veneer is peeled thinly using a rotary lace to make a veneer, the front side of the veneer, which is the bark side of the veneer, is convexly curved, and the back of the marrow, which is the side of the marrow, is concavely curved. According to the second aspect of the invention, the wooden surfaces of the veneers and the wooden back surfaces are alternately overlapped with each other, so that the curved directions of the laminated veneers are opposite to each other. Therefore, when manufacturing a laminated material by overlapping, warpage or bending of the veneer can be further suppressed. According to the third aspect of the present invention, it is possible to save forest resources by effectively using poplars that can grow quickly and can be supplied stably. According to the invention as set forth in claim 4, in the assembling step, the root end portion having a high moisture content of the veneer and the branch end portion having a small moisture content are alternately overlapped. Warpage and bending can be suppressed. Also, in the cold press process, temporary tightening is performed by repeatedly pressing and releasing, so that the moisture in the adhesive permeates the entire veneer uniformly by pressing, and the stress caused by moisture penetration by the releasing pressure is reduced. It can be opened, and warping and bending of the veneer due to moisture contained in the thermosetting resin adhesive can be suppressed. Furthermore, in the hot press process, the press is performed with a pressure lower than the press pressure in the cold press process, so the stress generation due to the press is suppressed as much as possible, and the thermosetting of the adhesive can be promoted, and the warping of the veneer more reliably. And bending can be prevented. According to the invention described in claim 5,
Since the veneers are laminated such that the directions of the curved veneers are opposite to each other, warpage and bending of the veneers can be further suppressed when the laminated materials are produced by lamination. According to the invention described in claim 6, forest resources can be saved by effectively utilizing poplars that can be stably supplied.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a method of manufacturing a laminated material according to an embodiment of the present invention. The manufacturing method is for manufacturing a laminated material from raw wood of Italian poplar, cutting process, primary drying process, secondary drying process, combination process, coating process, cold pressing process, hot pressing process, curing,
It consists of each step of cutting.

[0007] In the cutting process, a log of Italian poplar is subjected to rotary lace, a blade is applied while rotating and supporting both ends of the log at the center, and the log is peeled off in order from the bark side of the log to have a thickness of 1.8 mm ± 0.1 mm. Process into long veneer.

In the primary drying step, a long veneer is fed into a dryer and dried until the water content becomes 28% ± 3%, and cut into single plates at the outlet of the dryer.
Subsequently, in a secondary drying step, each veneer is dried until the moisture content becomes 7% or less.

In the assembling step, as shown in FIG. 2, the root-side end of the veneer 10b overlaps the branch-side end of the veneer 10a, and the wooden back of the veneer 10b overlaps the wooden back of the veneer 10a. ,
The branch-side end of each veneer and the root side are so arranged that the branch-side end of veneer 10c overlaps the root-side end of veneer 10b and the wooden surface of veneer 10c overlaps the wooden surface of veneer 10b. Combine the edge, the back of the wood and the wood surface. At this time, the veneers 10 of even layers are turned upside down so that the wooden surface of the veneer 10 forms the surface of the laminated material,
The odd-layer veneers 10 are arranged with the wooden surface facing upward. The lowermost veneer, which forms the bottom surface of the laminated material, faces down. The number of combined veneers 10 is preferably 15 to 30.

In the coating step, a thermosetting resin adhesive such as alkali phenol is applied to both the front and back surfaces of the veneer 10 constituting the even layer of the veneer 10 combined. Application amount is 33
0 ± 10 g / m 2 is preferred.

In the cold pressing step, as shown in FIG. 3, the laminated veneers are pressed at a pressure of 10 kg / cm 2 for about 10 minutes, and then decompressed for about 2 minutes.
After repeating this process, the veneer 1 was pressed and clamped at a pressure of 10 kg / square centimeter for 15 minutes or more until it was temporarily hardened.
Perform a temporary tightening of 0.

In the hot pressing step, the plurality of veneers 10 temporarily tightened in the cold pressing step are heated to 135 ± 2 ° C., and are pressed at a pressure of 7 kg / cm 2 for about 14 minutes as shown in FIG. The pressure is reduced to 3.5 kg / square centimeter, and pressing is continued for 7 minutes to promote thermosetting of the adhesive and bond the veneer 10.

Following the hot pressing step, the bonded veneer 10 is cured and cooled to room temperature. Then, it is cut into rectangular pieces shown in FIG. After that, if necessary, the surface cracks and holes are filled with putty, and repairs such as sanding are performed.

As described above, the method of manufacturing the laminated material according to the present embodiment and the laminated material 20 manufactured by the manufacturing method include the veneer end of the veneer 10 having a high water content and the branch side having a low water content. Since the end portions are alternately overlapped, warping and bending of the veneer 10 due to a difference in moisture content can be suppressed.

When the veneer is peeled thinly using a rotary lace to make the veneer, the front side of the veneer, which is the bark side surface, is convexly curved, and the back side, which is the pith side, is concavely curved. However, in the manufacturing method and the laminated material 20 according to the present embodiment, the wooden surfaces of the veneers 10 and the back surfaces of the veneers are alternately overlapped with each other. Therefore, the warp and bending of the veneer 10 can be further suppressed when the laminated material 20 is manufactured by overlapping.

In particular, in this embodiment, forest resources can be saved by effective use of Italian poplar, which is fast growing and can be supplied stably.

Further, in the cold press step, since the temporary tightening and the pressure release are repeated to perform the temporary tightening, the water in the adhesive permeates the entire veneer 10 uniformly by the pressure tightening, and the moisture is permeated by the pressure release. The generated stress can be released, and warping and bending of the veneer 10 due to moisture in the thermosetting resin adhesive can be suppressed.

Furthermore, in the hot pressing step, since the pressing is performed at a pressure lower than the pressing pressure in the cold pressing step, the generation of stress due to the pressing can be suppressed as much as possible, and the thermosetting of the adhesive can be promoted. The board 10 can be prevented from warping or bending.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for manufacturing a laminated material according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a combination step of the manufacturing method.

FIG. 3 is an explanatory view of a cold press step of the manufacturing method.

FIG. 4 is an explanatory diagram of a hot press step of the manufacturing method.

FIG. 5 is a perspective view showing a laminated material manufactured by the same manufacturing method.

[Explanation of symbols]

 10, 10a, 10b, 10c: single plate, 20: laminated material

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B200 AA01 AA07 BA04 BB01 BB02 BB05 BB06 BB07 BB20 CA20 DA04 EA06 EC18 EE13 EF05 EF11 FA24 FA31 HA03

Claims (6)

[Claims] 1. A laminated material comprising a plurality of veneers laminated and bonded such that a branch end of one veneer is overlapped with a root end of another veneer. 2. A plurality of single veneer boards so that the other veneer wood surface overlaps the other veneer wood surface and the other veneer wood surface overlaps the other veneer wood surface. The laminated material according to claim 1, wherein the veneers are laminated and bonded. 3. The laminated material according to claim 1, wherein poplar is used for the log of the veneer. 4. A combining step of combining a plurality of veneers so that a branch end of one veneer is overlapped with a root end of another veneer, and forming an even layer when laminated. An adhesive application step of applying a thermosetting resin adhesive to both the front and back surfaces of the veneer, and laminating a plurality of veneers having undergone the combination step and the adhesive application step, and pressing and releasing at room temperature at least. A cold press step of performing twice and temporarily tightening; and a hot press step of heating a plurality of veneers temporarily tightened in the cold press step to a predetermined temperature and performing pressure tightening at a pressure lower than the pressure in the cold press step. A method for producing a laminated material, comprising: 5. In the combining step, a wooden back surface of the other veneer is superimposed on a wooden back surface of the one veneer, and a wooden surface of another veneer is further superposed on the wooden surface of the other veneer. 5. The method for manufacturing a laminated material according to claim 4, wherein a plurality of veneers are combined so as to overlap. 6. The method for producing a laminated material according to claim 4, wherein poplar is used as the log of the veneer.