JP2016030445A - Method for producing hybrid woody core laminate lumber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing hybrid core laminate lumber where water resistance, dimensional stability, flexural strength, elastic modulus and the like are improved.SOLUTION: A method for producing hybrid woody core laminate lumber comprises the steps of: producing a laminated board having predetermined length and width via the bonding of a length so as to become a predetermined length by being bonded with an adhesive in a length direction of a dried lamina or the bonding of a side surface so as to become a predetermined width by being bonded in a width direction after making the lamina by lumbering raw wood to have predetermined length and width and drying the made lamina so as to have a predetermined moisture content; preparing a core layer including one plywood made by bonding a laminate laminated by an odd number of 3 or more so as to cross the fiber directions of a plurality of veneers with the adhesive; and bonding the laminated boards made at the upper and lower sides of the core layer as a face layer and a back layer.SELECTED DRAWING: Figure 2a

Description

  The present invention relates to a method for producing a hybrid wood core laminated timber, and more particularly to a method for producing a hybrid wood core laminated timber supplementing the features and drawbacks of the laminated wood.

  Recently, with the development of luxury homes, return to rural areas, and the declining birthrate and aging population, the market of the timber industry is continually expanding due to increased use of timber products and increased interest in wooden houses. Based on the expansion of demand for wooden houses and the International Climate Convention, the expansion of the wood structure market for reducing carbon emissions has been shown. As a result, the demand for wood structure materials is expanding. In recent years, there has been a demand for building unique houses by many architects due to diversification of design drawings, and there is a tendency that the distance between spans such as beams, joists, etc., which are horizontal members, becomes considerably long. . Since wood as an existing structural material does not have a structural strength that can sufficiently withstand the span distance, there is a reality that the use of laminated wood, which is processed wood, is increasing.

  The laminated timber (10) as shown in FIG. 1a has a length, width or thickness so that the fiber direction is parallel to a laminar (1) adjacent to a single lumber or small-corner lumber having a thickness of about 20 mm. It is a material that is adhesively laminated using an adhesive in the vertical direction. Laminated wood was developed in earnest since the development of resorcinol resin, and construction materials began to spread after the 1960s and structural materials since the 1990s. Glued wood is divided into indoor and outdoor use according to usage conditions, and linear gluing, curved gluing, I-type cross-gluing, box-type gluing, hollow cross-gluing, depending on the shape. Exists. According to the load direction, it is divided into horizontal laminated glulam and vertical laminated glulam. According to the Japanese standard JAS, it is classified into a laminated gluing material, a decorative gluing gluing material, a structural gluing material, and a laminated gluing laminated gland according to the application It is divided. The grades of adhesion and appearance of building glue are the criteria for grade classification, and the structural glue is used as a structural strength member and is used in an important part of the structure, so the performance standards are strict.

  Large cross-section structural lumber for construction and the characteristics of the building are obtained by laminating lamina systematically, resulting in a material with less variation in strength. As a result, the lower limit of the strength distribution increases, so the allowable stress Is up to about 1.5 times that of lumber. In addition, the raw material of lamina is characterized by less twisting and splitting because it uses a desiccant, and the surface ignites and burns, and a charred layer is formed in the burning part, so fire resistance is superior to general wood .

On the other hand, there is also an orthogonally laminated lumber (20, Cross Laminated Timber) as shown in FIG. 1b as processed wood in the form of a plate formed by alternately laminating laminated lamina (1). Orthogonal laminated timber (20) is a processed timber having the advantage that a high-rise wooden building can be built, and is a laminated timber that was developed and used in Europe, North America, Japan, etc. in the 2000s. In Europe and North America, these orthogonal laminated timbers are used to build high-rise wooden buildings. The world's production and scale of orthogonal laminated timber is around 475,000 m ^{3 in} 2011. . Among them, Central Europe accounts for about 95%, and production tends to expand in the UK, Germany and Austria.

  However, when such a conventional cross-laminated timber (20) is exposed to changes in external conditions such as temperature and humidity, problems such as twisting and splitting of lamina occur due to different shrinkage generated in each layer. Sometimes. The lamina twist causes the bonding surface between the lamina to be desorbed, and the drying stress due to the moisture gradient between the lamina surface and the interior causes cracks and splits on the surface of the cross-laminated timber and deformation due to moisture may occur. This causes a strength penalty that is very disadvantageous for use as a structural laminate. In addition, since the orthogonal glulam is a relatively new processed wood, its moisture characteristics have not been properly evaluated, and if the orthogonal glulam that is not protected against precipitation is exposed to high moisture conditions for a long time, Degradation may occur due to moisture or rot.

  Therefore, the present invention has been devised to solve the problems of conventional laminated materials and orthogonal laminated materials, complementing the disadvantages of conventional laminated materials and orthogonal laminated materials, water resistance, dimensional stability, The purpose is to develop a hybrid core laminated material with improved bending strength and elastic modulus.

  Therefore, the present invention can be solved as a conventional orthogonal laminated lumber by producing processed wood (Engineered Wood) having a new feature utilizing low- or low-utilized tree species and medium / small-diameter thinned wood that are easy to supply. Complementing difficult problems, we propose a utilization plan for structural materials for wooden houses (wall materials, pillars, structural materials for beams).

  A method for producing a hybrid wood core laminated lumber according to a preferred embodiment of the present invention is a method of producing a lamina by sawing a raw wood with a predetermined width and thickness, and drying the produced lamina so as to have a predetermined moisture content. After that, the length of the dried lamina is bonded with an adhesive to a predetermined length, or the side is bonded to the width direction to have a predetermined width. A core including a laminated board having a certain length and width, and a single plywood in which a plurality of veneer single boards are laminated in an odd number of 3 or more and bonded with an adhesive so that the fiber directions intersect each other Preparing a layer, and bonding the manufactured laminated board to the upper and lower sides of the core layer as a surface layer and a back layer with an adhesive, thereby improving dimensional stability and bending strength. It is characterized by.

  Further, the core layer is formed by laminating three plywoods.

  Further, the three plywoods for forming the core layer are arranged such that the fiber direction is parallel to the assembly plate.

  Further, the three plywoods for forming the core layer are arranged such that the fiber direction intersects with the laminated plate.

  Further, the core layer is characterized in that the laminated plate is arranged at the center, and plywood is bonded to the upper and lower sides thereof.

  According to the present invention, it is possible to solve the difficulty of functional treatment such as shrinkage / expansion, antiseptic and flame retardant due to temperature / humidity change, which is a problem of conventional laminated materials and orthogonal laminated materials. Compared to the above, a hybrid wood core laminated material with improved physical and mechanical properties such as dimensional stability, bending strength, and elastic modulus is provided.

It is a figure which shows the conventional laminated lumber. It is a figure which shows the conventional orthogonal laminated material. It is sectional drawing of the hybrid wood core laminated material which concerns on the 1st Embodiment of this invention. It is sectional drawing of the hybrid wood core laminated material which concerns on the 1st Embodiment of this invention. It is sectional drawing of the hybrid wood core laminated material which concerns on the 1st Embodiment of this invention. It is sectional drawing of the hybrid wood core laminated material which concerns on the 1st Embodiment of this invention. It is sectional drawing of the hybrid wood core laminated material which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the hybrid wood core laminated material which concerns on the 2nd Embodiment of this invention.

  Below, the hybrid wood core laminated material which concerns on this invention is demonstrated in detail using the manufacturing method. 2a to 2d are cross-sectional views of the hybrid wood core laminated lumber according to the first embodiment of the present invention.

  In the manufacturing method of the hybrid wood core laminated lumber according to the first embodiment of the present invention, a lamina is manufactured by sawing a raw wood with a predetermined width and thickness, and the manufactured lamina has a predetermined moisture content. After drying, the dried lamina is bonded to the length direction with an adhesive so as to have a predetermined length, or the side surface is bonded to the width direction to have a predetermined width. A laminated plate (30) having a certain length and width through a plurality of layers, and a plurality of veneer single plates are laminated with an odd number of 3 or more and bonded with an adhesive so that the fiber directions intersect. And a step of preparing a core layer including three plywoods, and a step of joining the core layer with an adhesive between the surface layer and the back layer of the manufactured laminated plate (30). Hereinafter, each step will be described in more detail.

1) Manufacture of laminated board (30) First, the laminated board (30) which forms the front and back layers of the hybrid wood core laminated material of this invention is manufactured. The assembly board (30) is manufactured in the order of lamina drying, length joining and longitudinal joining, adhesion, and finishing steps.

  Lamina used in the production stage of laminated board (30) is generally pine, black pine, larch, Douglas fir, cypress, cedar, fir, Tsuga, spruce, Japanese toad, rice tsutsuga, radiata pine, hemlock Coniferous trees such as beech, birch, zelkova, Japanese oak, Abemaki, Mongolinara, chestnut, Mizunara, maple, elm, lawan, etc. are used. The standard of the lamina used for the laminated lumber is a standard with a thickness of 3 mm to 100 mm, a width of 1 cm or more, and a length of 10 cm or more.

  The lamina prepared in this way is dried to a predetermined moisture content using another drying facility. At this time, the moisture content after drying of the lamina is suitably 8 to 15%, preferably 8 to 12% for indoor laminated material and 12 to 15% for outdoor laminated material. Also, the moisture content difference between adjacent laminae must be uniform within 3% and the moisture content difference of all laminaes within 5%. After drying, the sawed lamina is generally processed to a uniform thickness by the process of processing with an industrial planer.

  The laminated lamina is subjected to length joining and side joining by removing defects that deteriorate adhesiveness, strength and appearance with a cross saw or a patching machine. Adhesives used at this time include thermosetting resins such as phenol, melamine, urea and isocyanate, thermoplastic resins such as PVAc, PVA, EVA, PUR and epoxy resins, and hot melt and rubber adhesives. Is included.

  Side surface bonding refers to a step of bonding a narrow lumber plate in the width direction so as to have a predetermined width, and is performed using a butt joint having a strength effective rate of 90% or more.

  Length joining refers to the process of joining the lumber plates in the length direction so that they have a predetermined length. There are butt joints, scarf joints, finger joints, etc. To implement.

  Thus, the laminated plate (30) having a certain length and width is manufactured through length joining or side joining. The manufactured laminated board (30) is cut into a predetermined size by using a double sizer in which two sets of circular saws are combined, and the surface finish is a thickness adjustment and a surface smoothing process. Is carried out by surface polishing. For surface polishing, a wide belt sander or the like is used to polish and remove to a thickness of 0.25 to 0.5 mm.

2) Manufacture of core layer Next, the plywood (40, 41) used with a core is manufactured. Plywood used at this stage is made of domestic timber such as larch, rigid pine, red pine, lily, birch, chestnut, pine, cypress, cedar, and radiata pine, eucalyptus tops, meranti, MLH (mixed local hardwood), It is a mixed species of poplar, Vietnamese acacia, south seawood including KERUING, etc., and adhesives used include thermosetting resins such as phenol, melamine, urea and isocyanate, PVAc, PVA, EVA, PUR, epoxy Thermoplastic resins such as resins, as well as hot melt and rubber adhesives are included.

  The manufacturing process of plywood includes boiling and steaming of raw wood, lying down of raw wood, peeling, cutting of veneer, drying, boarding, repairing defects on veneer, applying adhesive, cold pressure, hot pressure, post-processing process Progress.

  When cutting a single plate, the thickness of the single plate is manufactured to be 0.5 mm or more and 5 mm or less. After the veneer is dried, the moisture content of the veneer is dried at a level of 5 to 10%. In the case of softwood plywood, the moisture content is dried at about 3 to 8%. The moisture content range of the veneer suitable for bonding needs to be adjusted according to the type of adhesive used. When urea and melamine resin adhesives are used, 5-15% phenol resin adhesive should be used. When used, it must be maintained at a moisture content of 8% or less.

  Next, in the process of assembling, there may be a large number of single plates that have been dried and have defects such as splitting, knots, rot, or smaller than a predetermined size. Small scratches scattered around are removed with a patch machine and buried with another healthy veneer of the same size and shape, and the veneer veneer is repaired by taping. A narrow veneer is made into a veneer of the desired width via lateral joining. For horizontal joining, the side surfaces of the single plates are cut smoothly with a veneer joint and brought into close contact with each other, then taped on them, or directly bonded by applying an adhesive to the side surfaces of the single plates to be joined. There is a way to do it. Single plates that have undergone maintenance and transverse bonding are prepared by combining the front plate, core plate, and back plate in consideration of the single plate configuration according to the product specifications.

  The number of laminated single plates is 3 ply or more in the case of plywood (40, 41), the thickness of the single plate is 0.5 mm or more and 5 mm or less, and the total thickness of the plywood (40, 41) is 2.4 mm, 2.7 mm. Standards determined by international standards for plywood, such as 3.6 mm, 4.8 mm, 5.2 mm, 6 mm, 7 mm, 7.5 mm, 9 mm, 11.5 mm, 12 mm, 15 mm, 18 mm, 22 mm, 24 mm, 30 mm, 40 mm, and 50 mm Is included. The laminated plywood (40, 41) is different from the conventional plywood lamination, and can be alternately laminated using only a single core plate having a constant thickness without distinguishing between Face and Back (see FIG. 2). At this time, the plywood (40, 41) used as the core is manufactured only in the core layer having no surface layer and no back layer.

3) Manufacture of hybrid wood core laminated material As described above, the produced laminated board (30) is used as a front layer and a back layer, and the core layer produced as described above is joined with an adhesive between them to produce a hybrid. Manufacture wood core laminated timber. 2a to 2d are views showing the hybrid wood core laminated lumber according to the first embodiment, and FIG. 2a shows three plywoods in which the fiber direction of the uppermost floor is parallel to the laminated plate (30) as a core layer. 40) is performed by laminating, and FIG. 2b is obtained by laminating three plywoods (41) in which the fiber direction of the top floor intersects the laminated board (30), and FIG. In the middle as the core layer, a plywood (40) whose uppermost fiber direction is parallel to the laminated board (30) and a plywood (41) whose uppermost fiber direction intersects the laminated board (30) on the upper and lower sides thereof. 2d is a plywood (41) in which the fiber direction of the uppermost floor intersects the laminated board (30) in the middle as the core layer, and the fiber direction of the uppermost floor on the upper and lower sides thereof. The plywood (40) parallel to the laminated board (30) is joined.

  Adhesives used in all laminations include thermosetting resins such as phenol, melamine, urea and isocyanate, thermoplastic resins such as PVAc, PVA, EVA, PUR, and epoxy, and hot melt and rubber An adhesive is included.

  The produced hybrid wood core laminated timber is cut into a predetermined size using a double sizer that combines two sets of circular saws, and the surface finish is surface polishing with thickness adjustment and surface smoothing treatment To implement. For surface polishing, a wide belt sander or the like is used to polish and remove to a thickness of 0.25 to 0.5 mm.

  As described above, the hybrid wood core laminated material of the present invention uses a plywood as a core, so that the conventional laminated laminar is joined in length or width and parallel or orthogonally laminated. Thus, by having a relatively dimensional stability and having a thin multilayer adhesive structure, it is possible to improve the bending strength and the elastic modulus. In addition, the use of thermosetting water-resistant adhesives such as phenol formaldehyde adhesives, melamine formaldehyde adhesives, and isocyanate adhesives used as plywood adhesives can improve water resistance and other absorption rates. is there.

  In addition, by replacing the core with plywood through the hybrid wood core laminated lumber of the present invention, the amount of lamina used can be reduced. , That amount does not increase. Thereby, it is possible to manufacture even if the supply of raw materials is disadvantageous. In addition to this, unlike conventional laminated lumber, dimensional stability is complemented by the core plywood, and a plate-like material with a wide surface can be easily created. Maintaining the same MOE and MOR as the material, the appearance has the advantage of maintaining through the lamina.

  These hybrid wood core laminated timbers can be economically effective. That is, the lamina used as the core of the laminated lumber and the orthogonal laminated lumber cannot avoid incidental losses accompanying production such as sawdust loss rate due to lumbering and dimensional loss due to shrinkage. However, the use of plywood for the core can not only reduce sawdust loss, but also minimize dimensional loss. In particular, as a laminar material for laminated wood, it is necessary to supply raw materials from excellent large-diameter wood, but when plywood is used, a defective material of small-diameter wood can also be used.

  In addition, the hybrid wood core laminated timber of the present invention is more economical than the conventional laminated timber, but the plywood that enters the core layer is a more affordable core than the face and back. As an advantage, and there is an advantage that the manufacturing cost can be reduced.

  In addition, in the case of domestic timber, a large area veneer cut from a small diameter log of less than 50 cm is used, so it is possible to produce a plate-like product with a larger area compared to the cut log, which makes wood resources more efficient. Thus, the size and strength anisotropy for mutually laminating the single plates can be improved.

  Next, the manufacturing method of the hybrid wood core laminated material which concerns on the 2nd Embodiment of this invention is demonstrated. 3a and 3b are hybrid wood core assemblies according to the second embodiment of the present invention.

  The difference from the first example of the hybrid wood core laminated material according to the second embodiment of the present invention is that the core layer disposed between the laminated plate (30) as the front and back layers is the laminated plate (30). At the center, plywood (40, 41) is joined to the upper and lower sides, respectively. FIG. 3a is a view in which a plywood (41) in which the fiber direction of the uppermost floor intersects the laminated plate (30) is joined to the upper and lower sides of the laminated plate (30) formed at the center of the core layer. 3b is formed by bonding a plywood (40) whose uppermost fiber direction is parallel to the assembled plate (30) to the upper and lower sides of the assembled plate (30) formed at the center of the core layer.

  In addition, the core layer of the hybrid wood core laminated timber includes, as other embodiments, an oriented strand board (OSB) other than plywood, a particle board (PB), a medium density fiber board (MDF, medium density). It can be performed by parallel or cross lamination of wood board materials such as fiberboard) and parallel strand lumbar (PSL). The use of OSB, PB, MDF, PSL, etc. for the core layer of the hybrid wood core laminated timber has the advantage that various physical and mechanical properties can be improved, for example, the production stage of each wood material When functional chemicals such as flame retardants, preservatives, dimensional stabilizers, insecticides and fire retardants are treated, the effect can be doubled.

  Therefore, the hybrid wood core laminated lumber of the present invention is a general wood board material and shaft material used for wooden construction such as plywood, laminated lumber, orthogonal laminated lumber, etc. through the above process. It has the dimensional stability of plywood and the advantages of a wide plate-like material, the excellent strength performance of conventional wood with conventional and cross-laminated timber, and the advantage of fire resistance for forming a carbonized layer. Hybrid wood core laminated timber uses plywood to make the core, so it is suitable for the domestic forest environment where timber supply is harsh and uses less lamina than conventional laminated timber and orthogonal laminated timber. Yes.

  The hybrid wood core assembly produced in this way can be used in various ways for pillars, beams, wall materials, furniture materials, or floors of wooden buildings.

  All the embodiments described above are illustrative of the present invention and are not intended to be limiting, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

1 Lamina 10 Glulam 20 Cross Glue 30 Glulam 40, 41 Plywood

Claims (6)

Lumber is produced with a predetermined width and thickness to produce a lamina, and the produced lamina is dried to have a predetermined moisture content, and then the dried lamina is joined in the length direction with an adhesive to give a predetermined Manufacturing a laminated plate having a certain length and width through joining of the length to be equal to the length or joining of the side faces that are joined in the width direction to obtain a predetermined width;
Preparing a core layer including one plywood formed by laminating a plurality of veneer single plates with an odd number of three or more and joining with an adhesive so that the fiber directions intersect;
A hybrid wood core laminated material characterized in that it includes a step of using the produced laminated board as a surface layer and a back layer, and joining the core layer with an adhesive therebetween, so that dimensional stability and bending strength are improved. Manufacturing method.   The method of manufacturing a hybrid wood core laminated material according to claim 1, wherein the core layer is formed by laminating three plywoods.   The method for producing a hybrid wood core laminated material according to claim 2, wherein the three plywoods for forming the core layer are arranged such that the fiber directions of the uppermost layer of the plywood are parallel to the laminated board.   The method for producing a hybrid wood core laminated material according to claim 2, wherein the three plywoods for forming the core layer are arranged such that the fiber direction of the uppermost layer of the plywood intersects with the laminated board.   The said core layer arrange | positions the said laminated board in the center, and the plywood is joined to the upper and lower sides, respectively, The manufacturing method of the hybrid wooden core laminated material of Claim 1 characterized by the above-mentioned.   The core layer is made of at least one of a woody plate-like material group composed of an oriented strand board (OSB), a particle board (PB), a medium density fiber board (MDF), and a parallel strand lumber (PSL). The method for producing a hybrid wood core laminated timber according to claim 1, further comprising:

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