JP2010099942A - Laminated veneer lumber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated veneer lumber reducing absorption of water from its cut surface and also easy to manufacture. <P>SOLUTION: The laminated veneer lumber 1 has a core part 2 keeping 2-4 veneers stacked so that the fiber directions of the respective layers are made parallel to each other, intermediate layers 3 and 3 keeping the veneers stacked to both upper and lower sides of the core part so that the fiber directions of the veneers are allowed to orthogonally cross the fiber directions of the veneers of the core part at a right angle and the surface layers 4 and 4 further provided to the outsides of the respective intermediate layers and keeping veneers stacked so that the fiber directions of the veneers are made parallel to the fiber directions of the veneers of the core part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a veneer laminate.

Conventionally, a widely used plywood is a single plate of about 1 to 4 mm in thickness obtained by cutting wood with a rotary lace or slicer, with the fiber directions of adjacent layers orthogonal to each other and laminated between the layers. It is formed by integrating an adhesive.
It is also known to use a veneer as a veneer laminate called LVL, which is laminated in multiple layers with the fiber directions parallel to each other.
Furthermore, in recent years, a laminated material with improved LVL has also been proposed. For example, Patent Document 1 includes a single plate whose fiber direction is parallel to the longitudinal direction and a single plate whose fiber direction is orthogonal to the longitudinal direction. A single-plate laminated material in which the fiber directions of all single-plate layers appearing on the cut surface in the longitudinal direction are parallel to the longitudinal direction and an efficient manufacturing method thereof have been proposed (see Patent Document 1).

JP-A-6-71608

The conventional general plywood has a problem that when the cut surface is subjected to processing such as actual processing, defects such as burrs and chips are likely to occur in the processed portion, and it takes time to repair the defects. In addition, the plywood also has a problem that it is easy to absorb water from its cut surface.
Furthermore, the conventional LVL, especially those improved as in Patent Document 1, have a problem that they cannot be efficiently manufactured unless a considerable modification is made to the plywood manufacturing facility.

  Accordingly, an object of the present invention is to provide a single-plate laminated material that has little water absorption from the cut surface and is easy to manufacture.

  In the present invention, a core portion composed of a single plate of 2 to 4 layers laminated with the fiber directions parallel to each other, and the fiber direction is orthogonal to the fiber direction of the single plate of the core portion on each of the upper and lower surfaces of the core portion. An intermediate layer made of a single plate laminated and a surface layer made of a single plate laminated with the fiber direction parallel to the fiber direction of the single plate of the core part on the outer side of each of the intermediate layers. The above object is achieved by providing a single-layer laminated material that is characterized.

  The single-plate laminate of the present invention has little water absorption from the cut surface and is easy to manufacture. Also, defects such as burrs and chips are less likely to occur when actual machining is performed.

Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
FIG. 1 is a diagram showing an embodiment of a single-plate laminate of the present invention. .
The single-plate laminated material 1 of the present embodiment is obtained by cutting a face material into a shape that is long in one direction (X direction in the figure), and has a structure in which a total of eight single-layers are laminated. Yes.

  More specifically, as shown in FIG. 1, the single-plate laminate 1 of the present embodiment includes a core portion 2 composed of four-layer single plates 21 to 24 that are laminated with the fiber directions parallel to each other, and the core Intermediate layers 3 and 3 composed of a single plate 31 laminated on the upper and lower surfaces of the portion 2 so that the fiber direction is orthogonal to the fiber direction of the single plate of the core portion 2, and further outside of each of the intermediate layers 3 and 3 The surface layers 4 and 4 are composed of a single plate 41 laminated with the fiber direction parallel to the fiber direction of the single plates 21 to 24 of the core portion 2.

  In each of the single plates 21 to 24 constituting the core portion 2, the fiber direction is oriented in the X direction in the figure, and the fiber directions are parallel to each other. By providing the core portion 2 composed of a plurality of single plates whose fiber directions are parallel to each other, the surface from which the end surface of the single plate is exposed, particularly the two side end surfaces 11 in which the fiber direction of the single plate of the core portion 2 is parallel to the surface. , 12 can suppress the amount of water absorption. Moreover, when performing actual processing etc., it can also suppress that defects, such as a burr | flash and a chip, arise in a processing part by performing actual processing to this core part 2. FIG. Also, when used as a floor plate, floor nails may be driven, but in that case the impact on the real part is also small, and the rate at which defects such as cracks and chips are generated in the real part can be kept low. it can.

The number of laminated single plates that constitute the core portion 2 and whose fiber directions are parallel to each other may be two layers or three layers instead of the four layers shown in FIG. FIG. 2 shows an example of a single plate laminated material having a core part 2 made of two layers of single plates, and FIG. 3 shows an example of a single plate laminated material having a core part 2 made of three layers of single plates. Indicated.
The single plates 21 to 24 constituting the core part 2 preferably have a thickness of 2 to 4 mm, particularly 3 to 4 mm, from the viewpoint of securing the thickness of the entire core part 2. Moreover, it is preferable that the thickness T2 (refer FIG. 1) of the core part 2 whole is 30 to 80% with respect to thickness T1 of the single-plate laminated material 1, More preferably, it is 35 to 65%, More preferably. 50-65%. Moreover, it is preferable that thickness T2 of the core part 2 is at least 4 mm or more, More preferably, it is 5-16 mm, Most preferably, it is 6-16 mm.

  The single plates 21 to 24 constituting the core portion 2 are preferably those having a low specific gravity obtained from a low specific gravity material. For example, the specific gravity of the low specific gravity material is preferably 0.45 or less, more preferably 0.05 to 0.4, and still more preferably 0.05 to 0.35. Low specific gravity materials include Falcata (specific gravity 0.37), balsa (specific gravity 0.27), dronoki (poplar) (specific gravity 0.42), gmelina (specific gravity 0.44), cedar (specific gravity 0.38), and chamele. (Eucalyptus) (specific gravity 0.37 to 0.64) and the like are preferably used, and among these, Falcata, which is a fast-growing tree and an afforestation tree, and balsa are preferable. Specific gravity values were obtained from the Japan Wood Information Center. The plurality of single plates constituting the core part 2 are preferably obtained from the same tree species, but single plates obtained from different tree species can also be used in combination.

The intermediate layers 3 and 3 are provided on both the upper and lower surfaces of the core portion 2. As for the single plate 31 which comprises the intermediate | middle layer 3, as for all, the fiber direction is orthogonal to the fiber direction of the single plates 21-24 of a core part. That is, in the single plate 31 constituting the intermediate layer 3, the fibers are oriented in the Y direction in FIG.
By interposing the intermediate layer 3 having different fiber orientation directions between the core portion 2 and the surface layers 4 and 4, it becomes possible to reduce warpage (so-called width warpage) of the material in the Y direction. The preferred thickness of the single plate constituting the intermediate layer 3 is the same as the preferred thickness of the single plates 21 to 24 constituting the core portion 2. Further, the single plate constituting the intermediate layer 3 is preferably obtained from a low specific gravity material like the single plates 21 to 24 constituting the core portion 2, but male processing or female processing is performed. In consideration of the above, the one using a falcater is particularly preferable.

The surface layers 4 and 4 are provided on the outer sides of the two intermediate layers 3 and 3 respectively. As for the single plate 41 which comprises the surface layer 4, as for all, the fiber direction is parallel to the fiber direction of the single plates 21-24 which comprise the core part 2. FIG. That is, in the single plate 41 constituting the surface layer 4, the fibers are oriented in the X direction in FIG.
Minimizing reduction in bending strength and bending Young's modulus in the X direction by making the orientation direction of the single plate fibers of the surface layers 4 and 4 parallel to the fiber direction of the single plate constituting the core 2 It becomes possible to prevent to the limit.

In order to reduce warpage, the thickness T4 of the single plate 41 constituting the surface layer 4 is thinner than the thickness of the single plates 21 to 24 constituting the core portion 2 in order to reduce the warpage (parallel: orthogonal) ) Is preferable from the viewpoint of approaching 50:50. For example, the thickness of the single plate 41 constituting the surface layer 4 is 10 to 30%, particularly 10 to 20% of the average thickness of the single plates 21 to 24 constituting the core portion 2. %, And more preferably within this range with respect to all the individual thicknesses of the single plates 21 to 24.
The average thickness of the single plates 21 to 24 constituting the core portion 2 is obtained by dividing the total thickness of the individual single plates 21 to 24 constituting the core portion 2 by the number of layers of the single plates constituting the core portion 2. Ask.

  Further, the single plate 41 constituting the surface layer 4 preferably has a higher specific gravity than the single plates 21 to 24 constituting the core portion 2. For example, the ratio (b / a) of the specific gravity b of the single plate 41 constituting the surface layer 4 to the specific gravity a of the single plate constituting the core portion 2 is preferably 2 to 4, particularly 3 to 4. Further, as the single plate 41 constituting the surface layer 4, one obtained from a relatively high specific gravity material can be preferably used. For example, Meranti (specific gravity 0.47), Radiatapine (specific gravity 0.45) Teak (specific gravity 0.63), acacia mangium (specific gravity 0.63), chamelele (eucalyptus) (specific gravity 0.37 to 0.64), etc. are preferably used. Particularly preferred is teak because of its higher specific gravity.

Single plates constituting the core portion, the intermediate layer, and the surface layer can be obtained by cutting wood with various known cutting devices such as a rotary lace and a slicer.
In addition, various known adhesives conventionally used in the production of plywood, LVL, and the like can be used for bonding between layers without any particular limitation. Preferred adhesives include urea resin adhesives, urea-melamine resin adhesives, phenol resin adhesives, phenol-melamine resin adhesives, and the like. The veneer laminate 1 is obtained by hot pressing or cold pressing a desired number of veneers laminated with an adhesive interposed between layers.

  The single-plate laminated material 1 of the present embodiment can be preferably used for various applications. For example, furniture such as ceilings, floors, furniture such as joinery, desks (top plates, etc.), box shelves, chests, beds, It can be used as a base material such as a flooring material, a decorative flooring material, a step board for a staircase, and a partition wall. Moreover, it can also be used for the interior of a ship, a motor vehicle, etc. which need to be lightweight. When used for furniture, flooring, etc., a decorative sheet made of resin film, decorative paper, veneer, etc. is pasted on the surface layer 4 on both the front and back surfaces or on the surface layer 4 on the side touching the human eye. Is also preferable.

As described above, the single plate laminated material 1 of the present embodiment has reduced water absorption from the surface from which the end surface of the single plate is exposed, particularly from the two side end surfaces 11 and 12 described above. Therefore, decorative materials and protective materials (for example, edge tapes fixed around the top of the table top, major materials, major tapes, etc., which are bonded to the side surfaces of the joinery) are attached to these surfaces via an adhesive. When sticking, these cosmetics can be fixed with a small amount of adhesive.
In addition, since the amount of water absorption from the surface where the end face of the single plate is exposed, particularly from the two side end faces 11 and 12 described above, is suppressed, the water absorption even when the side end faces 11 and 12 are actually processed. It is difficult to cause knuckles in dimensions due to, for example.

  It is also preferable that the single plate laminated material of the present invention is subjected to actual processing for connecting the single plate laminated materials to the surface where the end surface of the single plate is exposed. As actual processing, for example, as shown in FIG. 4, a convex portion (protruding portion, etc., male) 5 is formed on one of a pair of side surfaces parallel to each other, and a concave portion (corresponding to the convex portion 5 is formed on the other side. Grooves, female berries) are formed. As the cross-sectional shapes of the male and female berries, various known ones can be employed without particular limitation. In actual processing, only one of a male fruit and a female fruit can be provided on a single laminated sheet material.

Next, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the examples.
〔Example〕
As the four single plates constituting the core part 2, a single plate having a thickness of 3.0 mm derived from Falcata, as the two single plates constituting the intermediate layers 3 and 3, a single plate having a thickness of 3.0 mm derived from Falcata, As the two single plates constituting the surface layers 4 and 4, single plates having a thickness of 0.7 mm derived from Meranti are used, and the fiber directions of the single plate of the core portion 2 and the surface layers 4 and 4 are parallel to each other. The intermediate layers 3 and 3 were laminated so that the fiber directions of the single plates were perpendicular to each other. A urea resin adhesive was interposed between the single plates to be laminated, and these laminates were integrated by hot pressing with a hot press.
The obtained single-plate laminated material had a thickness of 18 mm and a vertical and horizontal length of 244 cm × 122 cm.

[Comparative Example]
A total of five single plates having a thickness of 3.55 mm derived from Falcater were laminated so that the fiber directions of adjacent single plates were orthogonal to each other. Further, a single plate having a thickness of 0.9 mm derived from Meranti was laminated on both upper and lower surfaces of the laminate. The single plates derived from Meranti were laminated so that their fiber directions were orthogonal to the fiber directions of the single plates on which they were stacked. A urea resin adhesive was interposed between the single plates to be laminated, and these laminates were integrated by hot pressing with a hot press. The obtained plywood had a thickness of 18 mm and a vertical and horizontal length of 244 cm × 122 cm.

[Evaluation of water absorption]
The water absorption was evaluated for the single-plate laminates obtained in the examples and the plywood obtained in the comparative examples.
About the single board laminated material of an Example, it cuts into the dimension (thickness is 18 mm) of 10 cm in length and width, and is orthogonal to the fiber direction of the single board which comprises the front and back 2 surfaces which consist of the surface layers 4 and 4, and the core part 2 The surface coated with paraffin was used as a test sample, and the plywood of the comparative example was also cut into a size of 10 cm in length and width (thickness: 18 mm), and the two front and back surfaces made of a single plate derived from Meranti and the other two parallel to each other A sample whose surface was coated with paraffin was used as a test sample.
And about those test samples, the water absorption was measured based on ASTM C-272. Specifically, the test sample is immersed in water at 20 ° C. for 24 hours, and the water absorption (%) according to the following equation is calculated from the weight W1 before immersion and the weight W2 after immersion for 24 hours (after water absorption). ) Was calculated. Water absorption rate (%) = [(W2-W1) / W1] × 100
For each of the examples and comparative examples, 10 test samples were prepared and the water absorption rate was determined. Table 1 shows the average value of water absorption of 10 samples.

  From the results shown in Table 1, it can be seen that the single plate laminated material of the example has a lower water absorption rate than the plywood of the comparative example.

1A and 1B are diagrams showing an embodiment of a single-plate laminate of the present invention, in which FIG. 1A is a schematic perspective view, and FIG. 1B is an enlarged view of a part of a side end surface. FIG. 2 is a view showing another embodiment of the single-plate laminate of the present invention. FIG. 3 is a view showing still another embodiment of the single-plate laminate of the present invention. FIG. 4 is a diagram showing an example in which actual processing is performed on the single-plate laminated material of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Single board laminated material 2 Core part 21-24 Single board which comprises a core part 3 Intermediate layer 31 Single board which comprises an intermediate layer 4 Surface layer 41 Single board which comprises a surface layer 5 Male 6 Female

Claims (5)

  A core part composed of 2 to 4 single plates laminated with the fiber directions parallel to each other, and laminated on the upper and lower surfaces of the core part with the fiber direction perpendicular to the fiber direction of the single plate of the core part. An intermediate layer made of a single plate, and a surface layer made of a single plate laminated with the fiber direction parallel to the fiber direction of the single plate of the core part on the outer side of each of the intermediate layers, Single plate laminate.   The single-plate laminated material according to claim 1, wherein the single-plate laminated material has a long shape in one direction, and a fiber direction of the single plate of the core portion is parallel to a longitudinal direction of the single-plate laminated material.   The veneer laminate according to claim 1 or 2, wherein the veneer of the core part is a veneer derived from a plantation tree having a specific gravity of 0.1 to 0.4.   The single plate laminated material according to any one of claims 1 to 3, wherein actual processing is performed.   The single plate laminated material according to any one of claims 1 to 4, wherein a thickness of the core portion is 30 to 80% of a thickness of the single plate laminated material.

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