JP2009226813A - Plywood and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a highly strong plywood at superior productivity by using afforestation wood veneers such as radiata pine and falcata that have light property with an air-dried specific gravity of ≤0.5 and a lot of shortcomings including loose knots and by using conifer veneers such as Sakhalin fir, larch, and cedar grown in Japan. <P>SOLUTION: The plywood is obtained by laminating and bonding a plurality of veneers and, among the veneers, at least those comprising the top side layer and the rear side layer have formation of recessed parts by applying brushing and shot blasting on the surface to remove soft portions, with resin like an adhesive filled in the recessed parts. By using such plywood as a base material and sticking a wood fiberboard thereto, it is possible to obtain a highly strong woody composite board. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plywood suitable for use as a base material such as a flooring material or a wall material of a building such as a house, and a method for producing the same, and in particular, uses a light afforestation tree veneer having many defects such as cutouts. The present invention relates to a plywood and a manufacturing method thereof.

  Conventionally, as a single board that constitutes plywood, southern hardwood such as lauan wood, which has a small and uniform density difference between early and late wood, and has no defects such as omissions, has been widely used. As a result, logging has progressed, and in recent years it has been rapidly depleted and has been cited as one of the causes of global environmental problems. Therefore, development of plywood, etc. that uses light wood with an air-dry specific gravity of 0.5 or less and afforestation tree veneers such as Radiata Pine, Falkata, etc. and conifer veneers such as domestic Todomatsu, larch, and cedar Is progressing. For example, as described in Patent Document 1, a laminated composite wood material in which thin plate materials having an absolute dry specific gravity of 0.6 or more and thin plate materials (Falkata) having an absolute dry specific gravity of 0.4 or less are alternately laminated and integrated has been proposed. ing. As a result, it is said that a laminated composite wood material using a southern wood material that was difficult to use as a building material can be obtained.

  However, in the method of Patent Document 1, it is necessary to prepare tree species having different specific gravities, and the characteristics such as the moisture content and the dimensional change rate are different for each tree species, so that warping and twisting do not occur. It was necessary to design and was troublesome.

In addition, when using plywood made of planted wood, which is light and has many omissions, as a base material, and using a thermal press such as a hot press device when manufacturing wood composite boards such as flooring, the plywood can be quickly There was also a problem that the material part and the loose joint part were compressed and deformed, and the surface of the wood composite board was likely to be swollen or dented.
WO2003 / 035541

  The present invention has been made in view of the above-mentioned problems, and has a light dry specific gravity of 0.5 or less and a lot of defects such as radiata pine, planted trees such as falkata, domestic todomatsu, larch, cedar, etc. The purpose is to obtain a high-strength plywood with good productivity by using the softwood veneer.

  In order to achieve the above object, a plywood according to a first aspect of the present invention is a plywood formed by laminating and bonding a plurality of single plates, and the single plate constituting at least a front surface layer and a back surface layer of the single plates. The plate is characterized in that the concave portion after the soft portion is removed is filled with resin.

  Thereby, a veneer in which only a hard portion having strength remains is obtained, and a plywood is constituted by this veneer, so that a high-strength plywood is obtained.

  Further, the plywood of the invention according to claim 2 is the plywood of the invention of claim 1, wherein at least one layer of the single plate, other than the surface layer and the back layer (inner layer or core layer), is provided. The single plate to be formed is characterized in that a resin is filled in the concave portion after removing the soft portions on both the front and back sides. Thereby, a higher strength plywood can be obtained.

  The manufacturing method of the invention according to claim 3 is the method for manufacturing a plywood of claim 1 or claim 2, wherein the single plate is subjected to brushing treatment and / or shot blasting treatment on one side or both sides thereof. The concave portion is formed by removing the soft portion, and then, the adhesive is filled into the concave portion and penetrated into the single plate by laminating and bonding with a plurality of adhesives.

  Thereby, the high-strength plywood comprised by the single board | plate with which the concave part which removed the soft part on the single side | surface or both surfaces of the single board was filled with resin can be manufactured.

  As described above, according to the first aspect of the present invention, the concave portion is formed by removing the soft portion of the single plate by brushing or shot blasting on one side or both sides of the single plate, so that only the hard portion having strength is formed. Is obtained, and a plywood is constituted by this single plate, so that a high-strength plywood is obtained. Further, by applying and impregnating a resin on the front surface or back surface of the single plate, the concave portion from which the soft portion has been removed and the interior of the single plate are filled, so that a single plate having a high specific gravity can be obtained. Furthermore, since they are laminated, a high-strength plywood can be obtained.

  In addition, by applying the brushing process and shot blasting process, fine scratches and irregularities are attached to the entire surface of the veneer, making it easier for the resin to penetrate into the veneer from that location, and a veneer with a higher specific gravity. can get. Since it is a plywood having a high specific gravity constituted by a single plate having a high specific gravity, one having a high strength can be obtained. Among the single plates constituting the plywood, since the front layer and the back layer are single plates having high strength, a high strength plywood can be obtained.

  According to the invention of claim 2, the single plate as at least one of the layers other than the front surface layer and the back surface layer (inner layer or core layer) is formed in the concave portion after removing the soft portions on both the front and back surfaces. Since the resin is filled, a plywood with higher specific gravity and strength can be obtained.

  According to the invention of claim 3, a high-strength plywood composed of a single plate in which a concave portion obtained by removing a soft portion on one side or both sides of a single plate is filled with resin is obtained. In addition, since the soft part is filled with resin, even when making a composite board as a base material such as flooring, it is not affected by hot pressure such as hot press, so deformation such as warping and twisting occurs. Hateful.

  In this way, the present invention uses light aerial trees such as Radiata Pine, Falkata, etc., and softwood veneers such as Japanese Todomatsu, Larch, and Sugi to produce high-strength plywood. Can get well.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

(Embodiment 1)
FIG. 1 shows a 5-ply plywood A according to the present invention.

  In FIG. 1, 1, 1 ′, 2, 2 ′, and 3 are rectangular single plates constituting the plywood A, and the fiber directions in the single plate 1, 1 ′ of the front and back layers and the single plate 3 of the core layer are as follows. The plywood A is configured to be substantially in the length direction. The fiber direction in the single plates 2, 2 ′ of the inner layer is configured to be substantially the short side direction of the plywood A.

  The single plate 1, 1 ′ is subjected to a brushing process or a shot blast process on one side, and a soft part is removed to form a concave part P. Here, the soft part is mainly a conduit part. The single plates 2, 2 ′ and 3 are not subjected to brushing or shot blasting. The plywood A is obtained by sequentially laminating these single plates 1, 2, 3, 2 ', 1' through an adhesive and solidifying them.

  At this time, it is preferable that the front and back layer single plates 1 and 1 ′ have the surfaces on which the concave portions P are formed facing the inner layer single plates 2 and 2 ′, respectively. The veneer 1 and 1 'of the front and back layers are subjected to brushing treatment and shot blasting treatment, so that fine scratches and irregularities are given to the entire surface of the veneer. Can easily penetrate into the veneer. By filling the concave portion P with the anchoring effect, the adhesive strength between the single plates is increased, and the adhesive is filled into the concave portion P so that the front and back layers become a single plate having a higher specific gravity. Higher strength plywood A is obtained.

  Note that filling and impregnation of the adhesive to the veneer and its concave portion P proceed almost simultaneously, but the adhesive filling and laminating and bonding of the veneer do not necessarily have to be performed simultaneously. In other words, the soft part of the single plate is removed by performing a brushing process or a shot blasting process, and the single plate 1, 1 'on which the concave portion P is formed is preliminarily coated with resin, filled and impregnated, and then laminated and adhered. The plywood A may be formed. It is possible to design the process appropriately according to the properties of the equipment and the adhesive.

  There are no particular limitations on the wood species of the veneer constituting the plywood A, and various types can be used. In particular, in the present invention, the wood species that are light and not high in hardness, the wood species that are liable to warp or twist, the omission nodes, etc. Conifers and early-planted trees, such as tree species with many defects and large hardness differences between early and late wood, such as domestic todomatsu, larch, cedar, spruce, radiata pine, northern larch, poplar, acacia hybrid A veneer made of a tree species such as acacia mangeum, falkata, eucalyptus, rubber or the like can be used as a veneer constituting the plywood A or as a veneer constituting a part of the plywood A.

  The brushing treatment applied to the single plate can be performed by a known method, for example, a wire brush. This is done by adjusting the wire diameter, waist strength, and contact pressure of the wire brush according to the tree species and thickness of the veneer. The shot blasting is a method of spraying small diameter steel balls or high hardness mineral particles. The treatment conditions are not particularly limited, and may be changed as appropriate according to the tree species and thickness of the veneer. Note that either the brushing process or the shot blasting process performed on a single plate may be used, or a combination thereof may be used.

  The type of resin to be filled or impregnated into the concave portion P from which the soft portion has been removed by brushing treatment or shot blasting treatment may be known, for example, thermosetting resin, modified thermosetting resin, or a mixture thereof. Preferably used. Specific examples include melamine resins, urea resins, urea / melamine resins, phenol resins, polyester resins, epoxy resins, acrylic resins, vinyl acetate resins, or modified products and mixtures of these resins. .

  Although it is desirable in terms of productivity that the kind of the adhesive for adhering the veneer is the same as the resin filled or impregnated into the concave portion P from which the soft part is removed, it may be different. In addition, for resins or adhesives, antioxidants, UV absorbers, UV stabilizers, anti-blocking agents, flow control agents, charge control agents, color pigments, dyes, fillers, curing accelerators, plasticizers as necessary. Various commonly used additives such as an agent, a low shrinkage agent, and an elastomer may be included.

  As another example of the plywood A according to the present invention, as shown in FIG. 2, the front and back surfaces of the veneer 2 and 2 ′ forming the inner layer are subjected to a brushing process or a shot blasting process so that the soft part of the veneer It is also possible to use the one in which the concave portion P is formed by removing. Since fine scratches and irregularities are also given to both surfaces of the single plate 2 or 2 ′, the adhesive easily penetrates into the single plate from the portion when laminated. By filling the concave portion P with the adhesive, the anchoring effect further increases the adhesive strength between the single plates, and the adhesive is filled in the concave portion P so that the front and back layers and the core layer have a higher specific gravity. As a result, a plywood A having higher strength can be obtained.

  Further, as shown in FIG. 3, in addition to the inner layer single plates 2 and 2 ′, the plywood A is made using a material in which both surfaces of the single layer 3 of the core layer are subjected to brushing processing and shot blasting processing. Of course, as shown in FIG. 4, as shown in FIG. 4, the inner layer single plate 2, 2 ′ is untreated, and the both sides of the core layer single plate 3 are subjected to brushing processing and shot blasting processing. You may comprise the plywood A using what was given.

In addition, as shown in FIG. 5, it is also possible to bond the wood fiber board 4 to the plywood A to make the wood composite board B. In that case, as the single plate 1 in contact with the wood fiber board 4, one in which both sides are subjected to a brushing process or a shot blasting process in advance to remove a soft part and form a concave part P can be used. After that, for example, a melamine resin adhesive is applied between each layer, and laminated adhesion is performed by hot pressing at a temperature of 110 to 120 ° C. and a pressure of 5 to 7 kg / cm ² with a hot press for about 30 to 50 seconds. it can.

  As the wood fiber board 4, those having a thickness of 1.0 to 3.0 mm can be suitably used. When the thickness of the wood fiber board 4 is less than 1.0 mm, the strength such as hardness is insufficient, which is not preferable. When the thickness exceeds 3.0 mm, the influence of the wood fiber board 2 becomes too large, and the wood material formed. Since deformation such as warpage is likely to occur in the composite plate A, it is not preferable. By setting the thickness of the wood fiber board 4 to 1.0 to 3.0 mm, good hardness can be imparted and deformation such as warpage can be prevented.

  In addition, when using a thin fiberboard 4 having a thickness of less than 2.0 mm, for example, the wood fiberboard 2 having a thickness of 3.0 mm is divided into two in the thickness direction to be approximately 1.5 mm. It is also possible to use a thicker layer, or to further reduce the thickness by sanding the divided surface.

A decorative sheet material may be attached instead of the wood fiber board 4. In this case, the surface of the plywood A may be adjusted by lightly grinding with a paper sander or the like. Thereafter, for example, a melamine resin-based adhesive is applied, and hot pressing is performed at a temperature of 110 to 120 ° C. and a pressure of 5 to 7 kg / cm ² for about 30 to 50 seconds. As the decorative sheet material to be attached, a veneer having a thickness of about 0.15 to 0.60 mm, a synthetic resin decorative sheet such as polyolefin resin, decorative printing paper, resin-impregnated decorative printing paper, or the like can be used.

Next, specific examples will be described.
Example 1
A larch rotary single plate having a thickness of 2.4 mm was prepared, and two of the surfaces were subjected to shot blasting. Two treated veneers are used for the front and back layers, three untreated veneers are used for the inner layer and the core layer, and the treated veneers for the front and back layers are so that the treated surface faces inward, The veneer was constructed so that the fiber directions intersected in order from the top, and a phenolic resin adhesive was applied to each interface and laminated to obtain a 5-ply plywood. When the cross section of the plywood was observed, it was confirmed that the concave portion formed by the shot blasting process was filled with the adhesive.

(Example 2)
A larch rotary single plate having a thickness of 2.4 mm was prepared, and shot blasting was performed on both of the front and back surfaces. Three treated veneers and two untreated veneers are constructed so that the fiber directions intersect in order from the top, and a phenolic resin adhesive is applied to each interface and laminated and bonded to form a 5-ply plywood. I was able to get it. When the cross section of the plywood was observed, it was confirmed that the concave portion formed by shot blasting was filled with the adhesive.

(Comparative Example 1)
A 2.4 mm thick larch rotary veneer is prepared, and 5 veneers are left untreated so that the fiber directions intersect in order from the top. A phenolic resin adhesive is applied to each interface and laminated. As a result, a 5-ply plywood was obtained. When the cross-section of the plywood was observed, it was confirmed that the adhesive did not penetrate into the veneer.

  The present invention relates to a technique for manufacturing a strong plywood with good productivity using planted trees, which are light and renewable resources, and can be industrially used in terms of contributing to the global environment. High nature.

FIG. 1 is an example of a plywood A which is an embodiment of the present invention and is constituted by a single plate whose front and back layers are filled with resin in concave portions. FIG. 2 is an example of a plywood A which is an embodiment of the present invention and is composed of a single plate whose front and back layers and inner layer are filled with resin in a concave portion. FIG. 3 is an example of a plywood A which is an embodiment of the present invention and is composed of a single plate in which front and back layers, an inner layer, and a core layer are filled with resin in concave portions. FIG. 4 is an example of the plywood A according to the embodiment of the present invention, in which the front and back layers and the core layer are filled with resin in the concave portions. FIG. 5 is an example of a wood composite board B configured by sticking a wood fiber board to the plywood A of the present invention.

Explanation of symbols

A Plywood B Wood composite board P Concave part 1 Single board (surface layer)
1 'veneer (back layer)
2, 2 'veneer (inner layer)
3 Single plate (core layer)
4 Wood fiberboard

Claims (3)

  It is a plywood formed by laminating and bonding a plurality of single plates, and among the single plates, the single plate constituting at least the front surface layer and the back surface layer is filled with a resin in the concave portion after removing the soft portion. Plywood characterized by   It is a plywood formed by laminating and bonding a plurality of single plates, and among the single plates, the single plate constituting at least one of the layers other than the front surface layer and the back surface layer is soft on both the front and back sides. The plywood according to claim 1, wherein the concave portion after removing the portion is filled with resin.   In the method of manufacturing a plywood in which a plurality of single plates are laminated and bonded, at least one of the single plates is subjected to brushing and / or shot blasting on one side or both sides thereof, and the soft portion of the single plate The plywood is formed by forming a concave portion and then laminating and bonding a plurality of single plates with an adhesive so that the adhesive is filled into the concave portion and penetrated into the single plate. Production method.

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