JP2010115888A - Processing method for preventing dry crack of wood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a processing method for preventing dry crack of a wood capable of surely preventing dry crack, while improving workability and designability in using as a building material and shortening a drying time by forming a through-hole as an alternative to a back split with respect to the wood after being sawed. <P>SOLUTION: The through-hole 2 along the axial direction running through both the cut end faces 3, 3 is formed with respect to the columnar wood 1 after being sawed, the whole faces of both the cut end faces 3, 3 are coated with a seal material 4 for preventing dry with the through-hole 2 opened, and the seal material 4 is removed by cutting off near both the cut end faces 3, 3 of the wood 1 after artificially drying or naturally drying the wood 1 in that state. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a processing method for preventing dry cracking of wood mainly used for building materials such as columns and beams.

  Timber immediately after cutting has a high water content and has a property of drying and shrinking over time. When such lumber is lumbered and used as it is as a building material such as a pillar or beam, there is a problem that dry cracks occur in unexpected portions of the mouth end surface or the outer peripheral surface due to strain accompanying drying shrinkage. In addition, if the construction is performed without being sufficiently dried, there is a problem that a gap is generated in the joint portion with another member due to drying shrinkage after the construction.

  Therefore, conventionally, by using a saw or the like from the outer peripheral surface of the lumber after sawing to the vicinity of the shaft center, a back split (a cut along the axial direction straddling between the two muzzle surfaces) is made. Measures are taken to prevent dry cracking by releasing strain associated with drying shrinkage (absorbing dimensional changes) and to ensure that the product is dried by artificial drying before construction as a building material.

  However, when the back is split as described above, the back split is exposed on the outer peripheral surface of the wood, so when using wood as a building material and joining other members to the outer peripheral surface, the vicinity of the back split where nailing is difficult There is a problem that the handling on the construction becomes troublesome, such as it is necessary to join while avoiding. Moreover, if the back split is exposed on the outer peripheral surface of the wood, it is not preferable in terms of design, and there is also a problem that it is difficult to use as a building material that looks like a large black pillar. Furthermore, with wood having a large cross-sectional area, there is a problem that the inside of the wood does not easily dry if a cut like a split is made, and it takes a long time to sufficiently dry the wood.

Therefore, instead of splitting the back, by forming a through-hole along the axial direction that spans between the center parts of both lumber surfaces of the lumber, the strain associated with drying shrinkage is released (the dimensional change is reduced). And a processing method that promotes drying inside the wood (see, for example, Patent Documents 1 and 2). This makes it possible to improve the workability and design when wood is used as a building material, eliminating the need for splitting the back, and shortening the drying time by artificial drying and realizing the efficiency of processing work. it can.
JP-A-8-313153 Japanese Patent Laid-Open No. 11-247357

  Generally, timber after sawing is not only distorted due to the difference in shrinkage between the outer peripheral surface and the shaft center, but also due to the difference in shrinkage between both ends and the middle part. Occurs. That is, both ends of the timber (near both ends of the wood) are apt to dry due to the transpiration of moisture from both ends of the wood, and the drying shrinkage proceeds faster than the middle portion. The degree of shrinkage differs and distortion occurs.

  When such a sawn wood is split back from the outer peripheral surface to the vicinity of the shaft center as described above, both strains can be released, but the shaft center portion as described above is penetrated. If the through hole is formed, the strain caused by the difference in shrinkage between the vicinity of the outer peripheral surface and the shaft center can be released, but the degree of shrinkage between both ends and the middle It is difficult to release strain caused by the difference between the two, and dry cracks are likely to occur particularly at both ends of the wood.

  Therefore, the present invention eliminates the above problems and forms a through-hole instead of splitting the back of the lumber after lumbering, improving workability and design in use as a building material, and improving the drying time. An object of the present invention is to provide a method for preventing dry cracking of wood, which can reliably prevent dry cracking while shortening.

  In order to solve the above-described problem, the method for preventing dry cracking of wood according to the present invention has a through-hole 2 along the axial direction straddling between both mouth end surfaces 3 and 3 of a columnar wood 1 after sawing. After forming and covering the whole face of the both mouth end surfaces 3, 3 with a sealing material 4 for preventing drying with the through-hole 2 open, in this state after the wood 1 is artificially dried or naturally dried, The sealing material 4 is removed.

  Further, the sealing material 4 is made of a tape-like material to be applied to the both mouth end surfaces 3, 3 or a coating material to be applied to the both end face surfaces 3, 3. Specifically, the tape-like material is made of butyl rubber. A material having an adhesive layer is used, and an epoxy resin is used as a coating material.

  Furthermore, the sealing material 4 is removed by cutting off the vicinity of the both mouth end surfaces 3 and 3 of the wood 1 after artificial drying or natural drying.

  According to the dry crack prevention processing method of the present invention, in the state in which through holes are formed in the lumber after lumbering, both ends of the wood are covered with a sealing material, and rapid drying at both ends is suppressed. As it is artificially dried or naturally dried, it is not necessary to split the back as in the past, while improving the workability and design when using the timber after lumbering as a building material, and reducing the drying time Can be reliably prevented.

  Also, when using a tape-like material as a sealing material, by sticking this tape-like material dry on both ends, for example, using a coating material as a sealing material, compared to the case of applying wet, It is possible to easily take measures for drying both ends of the wood, and to improve the work efficiency.

  In addition, the use of tape-like material with butyl rubber with high moisture permeability resistance as an adhesive layer or coating material made of epoxy resin with high moisture permeability resistance prevents moisture from evaporating from both ends. Thus, drying of both ends of the wood can be sufficiently suppressed, and thereby dry cracking can be more reliably prevented.

  Furthermore, since the sealing material is removed from the wood by cutting off the vicinity of the both ends of the wood, the sealing material is easier and more reliable than when the sealing material firmly adhered to both ends is peeled off. Can be removed, and work efficiency can be improved.

  A method for preventing dry cracking of wood according to an embodiment of the present invention will be described in detail with reference to the drawings. First, lumber is cut into a prismatic shape. The lumber 1 after sawing is used as, for example, a solid large black pillar of a house, and its cross-sectional shape is a substantially square of about 250 mm square. The lumber 1 after sawing is not limited to a prismatic shape, and may be, for example, a cylindrical shape.

  Next, as shown in FIG. 1 and FIG. 2, the through-hole 2 having a substantially circular cross section along the axial direction straddling between the central portions of the both ends 3 and 3 of the wood 1 after sawing. Form. That is, the through hole 2 is formed so as to cut out the axial center portion of the wood 1. The through hole 2 is not limited to a substantially circular cross section, and may be a substantially square cross section or a substantially triangular cross section, for example.

  Then, as shown in FIG. 3, the entire surfaces of the both mouth end surfaces 3, 3 of the wood 1 are covered with a sealing material 4 for preventing drying while the through-hole 2 is opened. Thereby, the transpiration | evaporation of the water | moisture content from both the end surfaces 3 and 3 is suppressed, and the rapid drying of the both ends of the timber 1 is prevented. The through hole 2 is opened in order to prevent the drying of the vicinity of the axial center of the wood 1, that is, the inside.

  As the sealing material 4, a tape-like material having an adhesive layer made of butyl rubber having a high moisture permeability resistance is used. By sticking this tape-like material to both the end surfaces 3 and 3 in a dry manner, both ends of the wood 1 are used. While easily taking measures against drying of the wood, it is possible to reliably prevent the moisture from evaporating from the both ends 3 and 3 and to sufficiently prevent the drying of both ends of the wood 1. The sealing material 4 is not limited to a tape-like material having butyl rubber as an adhesive layer, but may be a tape-like material having an adhesive layer made of another material having high moisture permeability resistance, or a tape-like material. Not limited to this, for example, a coating material such as an epoxy resin having a high moisture resistance may be used, and the both ends may be applied wet.

  Subsequently, the through hole 2 is formed in the axial center portion in this way, and the wood 1 in a state of covering both the end surfaces 3 and 3 is artificially dried by the drying device 5. In this artificial drying, as shown in FIG. 4, the wood 1 is accommodated in the drying pot of the drying device 5, and the moisture contained in the wood 1 is evaporated by filling the drying pot with steam. ing. Note that the drying of the wood 1 is not limited to the artificial drying as described above, and natural drying may be employed although the drying time becomes longer.

  Since the through hole 2 is formed in the wood 1 at the time of such drying, drying not only near the outer peripheral surface of the wood 1 but also around the axial center portion proceeds in the same manner. The difference in the degree of contraction with the vicinity can be reduced, and the strain caused by the difference in the degree of contraction in the through hole 2 can be released. Further, since both the mouth ends 3 and 3 of the wood 1 are coated, moisture from the both ends 3 and 3 is prevented from being evaporated, and rapid drying of both ends of the wood 1 is suppressed. It is possible to make the degree of contraction between the both ends and the intermediate portion of the plate uniform and to prevent distortion between them. Thereby, the dry crack of the wood 1 at the time of artificial drying can be prevented reliably. In addition, the drying time can be shortened by promoting the drying of the wood 1 by the through holes 2.

  Then, as shown in FIG. 5, the seal material 4 is removed from the wood 1 by cutting off the vicinity of the both mouth end surfaces 3 and 3 of the wood 1 that has been artificially dried. Thereby, the sealing material 4 can be removed easily and reliably, for example, rather than peeling off the sealing material 4 firmly adhered to the both mouth end surfaces 3 and 3.

  The processed wood 1 after the sealing material 4 is removed is, for example, subjected to antiseptic treatment on the outer peripheral surface and built as a large black pillar. At this time, since there is no spine exposed on the outer peripheral surface as in the prior art, it is possible to improve the workability and design without complicating handling on the construction or impairing the appearance. .

  In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of this invention. For example, the wood processed by the processing method of the present invention is not limited to one used as a large black pillar, but may be used for other pillars, beams, etc., and further used as wood other than building materials. May be.

In the processing method which concerns on one Embodiment of this invention, it is a perspective view which shows the state which formed the through-hole in the timber. It is a side view which shows the state which formed the through-hole in wood. It is a perspective view which shows the state which coat | covered the both ends of wood with the sealing material. It is a perspective view which shows carrying in to the drying apparatus of wood. It is a perspective view which shows the cutting | disconnection state of the both ends of wood of wood.

Explanation of symbols

1 ・ ・ Wood 、 2 ・ ・ Through hole 3 ・ ・ Kip surface 4 ・ ・ Seal

Claims (5)

A through-hole (2) along the axial direction straddling between the two mouth surfaces (3) and (3) is formed in the columnar wood (1) after sawing, and the both mouth surfaces (3) ( 3) The entire surface of 3) is covered with a drying prevention sealing material (4) with the through-hole (2) open, and the wood (1) is artificially dried or naturally dried in this state, and then the sealing material A method for preventing dry cracking of wood, characterized in that (4) is removed. The said sealing material (4) consists of a tape-like material affixed on the said both-muzzle surfaces (3) (3), or a coating material applied to the said both-muzzle surfaces (3) (3). Drying prevention processing method. 3. The method for preventing dry cracking of wood according to claim 2, wherein the tape-like material has an adhesive layer made of butyl rubber. The wood coating crack prevention processing method according to claim 2, wherein the coating material is made of an epoxy resin. The sealing material (4) according to any one of claims 1 to 4, wherein the sealing material (4) is removed by cutting off the vicinity of the both mouth ends (3) and (3) of the wood (1) after artificial drying or natural drying. Wood crack prevention processing method.