JP5470976B2 - Three-dimensional wooden molded body and method for producing the same - Google Patents

Description

The present invention relates to a three-dimensionally shaped wooden molded body mainly made of wood and a method for producing the same.

  Products using natural wood are used in various applications such as furniture and indoor lighting. In addition, recently, wood is sometimes used as a housing for home appliances and a material for speakers. The importance of timber products is increasing as the indoor environment becomes more natural and creates a space to relax and relax.

  In general, a three-dimensional processed wood product is produced by cutting and processing solid wood. However, this cutting method uses a lot of wood, which is not preferable from the viewpoint of maintaining forest resources.

  In addition, since machining is performed one by one, it is difficult to reduce the processing cost. Especially, if the shape is complicated, it is necessary to use an NC processing machine instead of a potter's wheel or a lathe. Further, the cost increases. Therefore, methods such as rolling thinly sliced wood or pressing it into a three-dimensional shape have been proposed.

  As one of techniques for three-dimensionally pressing thin wood, a technique for processing a speaker diaphragm using wood with a thin veneer is disclosed (for example, see Patent Documents 1 and 2). In Patent Documents 1 and 2, in order to prevent cracking in the curved surface molding of the veneer, a sheet in which wood and paper are laminated is impregnated with a lubricant to soften the wood and prevent cracking during press molding. .

  Specifically, a tree softened with a soft material (such as sake) is molded with a press to evaporate moisture and temporarily mold it. Thereafter, in order to further stabilize the shape of the tree, the tree is impregnated with a thermosetting resin, and high-temperature press molding is performed in a plurality of times.

JP 2003-158798 A JP 2004-254013 A

  However, in the technique of performing impregnation and high temperature press molding divided into a plurality of times, it takes time and cost to manufacture, and thus it may be difficult to improve productivity. Moreover, there is a limit in softening by a soft material, and when processing a shape with a large curvature, there is a possibility of causing a crack in the tree. Depending on the design of the product to be manufactured, it is necessary to reduce the thickness of the wood and process a shape with a large curvature or a complicated shape, and thus further examination of processing technology has been desired.

  In order to reduce the thickness of the timber in the processed timber product and to process a shape having a large curvature or a complicated shape, a method of thinning the wooden sheet can be considered. However, if the methods of Patent Documents 1 and 2 are used as processing techniques for processed wood products with a thin wooden sheet, the thermosetting resin impregnated into the wooden sheet oozes out to the mold side during press molding and sticks to the mold. It may be attached. As a result, productivity may be reduced.

  Further, in the methods of Patent Documents 1 and 2, it is only possible to three-dimensionally form a thin wood sheet, and for example, it has been difficult to produce a casing made of mainly wood and having sufficient strength.

  Conventionally, there is a particle board as one of thick and strong wood laminates. This is a wood plywood in which wood chips are finely crushed between two thin woods and laminated together with an adhesive. However, such a particle board is generally used as a flat plate, and even if it is bent into a curved surface, it is limited to bend in two directions in one direction. Moreover, since the particle board surface is a laminated material of wood chips, it does not have a unique luster or grid pattern, and is not good in design because it does not have a texture unique to wood. Although it is desirable to stick a thin board to the surface to give a texture of wood, it is difficult to express a grain in a three-dimensional shape because it is limited to bonding to a flat surface or a curved surface in one direction.

In view of the above problems, in the present invention, it can be easily processed large shape or complex shape curvature, high strength, grain appear on the surface, the three-dimensional shape wooden compacts and their manufacture with texture wood grain It aims to provide a method.

In order to achieve the above object, an embodiment of the present invention includes a base material layer made of wood chips, and a solid wood material having a thickness of 140 μm or less laminated on the surface of the base material layer and sliced into a sheet. On the back surface of the base material layer, the resin layer provided on the surface layer as the material, the base material layer and the surface layer, and for adhering the wood chips of the base material layer to each other and for adhering the base material layer and the surface layer and a laminated backing layer, a resin filling amount of the surface side of the surface layer, so that less than the resin filling amount of the back surface side of the surface layer in contact with the substrate layer, the back side of the surface layer resin filling Solid wood characterized in that the resin part is arranged in the surface layer so that the resin filling amount on the surface side of the surface layer is 10 to 50% when the amount (weight ratio) is 100% The gist is that it is a molded body.

Another aspect of the present invention includes a step of impregnating a wood chip with a resin, a step of drying the impregnated wood chip, and a thickness of 140 μm sliced into a sheet having a gap between wood fibers penetrating both surfaces. A step of laminating and stacking wood chips after drying between a surface layer made of the following solid wood of natural wood and a sheet-like back surface layer, and a substrate composed of the laminated surface layer and wood chips A step of softening the surface layer and the back surface layer by exposing them to a water vapor atmosphere, and pressing the softened surface layer, base material layer, and back surface layer once at a temperature of 160 to 220 ° C. The first press step of opening the water vapor and releasing the water vapor, and pressing again at the same temperature, the resin filling amount on the surface side of the surface layer is less than the resin filling amount on the back surface side of the surface layer in contact with the base material layer as such, the back side of the surface layer resin charge When the amount (weight ratio) is 100%, so that the resin filling amount of the surface side of the surface layer is 10% to 50%, is filled with a resin in the substrate layer to the surface layer, through a resin base A second pressing step of bonding the material layer and the surface layer and bonding the base material layer and the back surface layer; and a step of forming the bonded base material layer, the surface layer, and the back surface layer into a predetermined shape. The gist of the present invention is a method for producing a three-dimensionally shaped wooden molded article.

Another aspect of the present invention includes a step of impregnating a wood chip with a resin, a step of drying the impregnated wood chip, and a thickness of 140 μm sliced into a sheet having a gap between wood fibers penetrating both surfaces. A step of laminating a dried wood chip between a surface layer and a back surface layer made of the following solid wood material, a laminated surface layer, a base material layer made of wood chips, and a back surface layer The process of softening by exposing to a steam atmosphere, and the softened surface layer, base material layer, and back layer are pressed once at a temperature of 160 to 220 ° C, and after a predetermined time, the upper and lower molds are opened to release the water vapor. The first pressing step is performed again at the same temperature, so that the resin filling amount on the surface side of the surface layer is less than the resin filling amount on the back surface side of the surface layer in contact with the base material layer, Tree on the back side of the surface layer When the filling amount (weight ratio) is 100%, so that the resin filling amount of the surface side of the surface layer is 10% to 50%, the resin of the base layer causes filled into the surface layer The resin filling amount (weight ratio) on the back side of the back layer is such that the resin filling amount on the front side of the back layer is less than the resin filling amount on the back side of the back layer in contact with the base material layer. Is 100%, the back surface layer is filled with the resin in the base material layer so that the resin filling amount on the surface side of the back surface layer is 10 to 50%, and the resin is inserted through the resin. A second pressing step of bonding the base material layer and the surface layer and bonding the base material layer and the back surface layer, and forming the base material layer, the surface layer, and the back surface layer after bonding into a predetermined shape A method for producing a three-dimensionally shaped wooden molded article, comprising: The gist.

ADVANTAGE OF THE INVENTION According to this invention, the solid shape wooden molded object which can process a shape with a big curvature and a complicated shape easily, has high intensity | strength, a grain appears on the surface, and has the texture of a grain, and its manufacturing method are provided. it can.

It is a section perspective view showing the wooden fabrication object concerning an embodiment of the invention. It is a cross-sectional perspective view which shows the wooden molded object which concerns on the 1st modification of embodiment of this invention. It is a cross-sectional perspective view which shows the wooden molded object which concerns on the 2nd modification of embodiment of this invention. It is explanatory drawing which shows the manufacturing method of the wooden molded object which concerns on embodiment of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. The following embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is to change the structure and arrangement of components to the following. Not specific.

  FIG. 1 is a cross-sectional perspective view showing an example in which a wooden molded body (wood sheet) 1a according to an embodiment of the present invention is produced.

  As shown in FIG. 1, a wooden molded body 1a according to an embodiment of the present invention includes a base material layer 3 made of wood chips, a surface layer 2 laminated on the surface of the base material layer 3, and a base material layer. 3 and a resin part 5 embedded in the base material layer 3 and the surface layer 2 and for bonding the base material layer 3, the surface layer 2 and the back surface layer 4 to each other.

  As the surface layer 2, a material obtained by slicing a natural wood solid material into one sheet is used. As natural wood, most of conifers and hardwoods can be used.

  The surface layer 2 can be formed by applying a rotary blade, ie, so-called wiggling, by applying a cutting blade while rotating a log-like wood. Moreover, you may produce the surface layer 2 by the slice process from a plate board material or a grid board material.

  When using hardwood as the surface layer 2, it is preferable to use sapwood rather than using heartwood. Sapwood has a fine texture and is difficult to break during molding, and is particularly suitable for products that require a certain level of strength (rigidity) and durability.

  In order to make it possible to produce a wooden molded body having a three-dimensional shape with a large curvature and a complicated three-dimensional shape, it is preferable to produce an extremely thin sheet by processing using a superfinished planer.

  The surface layer 2 includes a cell tissue (wood fiber) 21 including a conduit or a temporary conduit of natural wood, and a gap 22a that is discontinuous in the cross-sectional direction of FIG. And have. When the thickness of the surface layer 2 is less than a certain value, the number of wood fibers (conduit) 21 in the thickness direction is reduced, and the minute gaps 22a between the wood fibers 21 are surfaced with a certain probability as shown in FIG. Appears as a gap (through hole) 22b penetrating the back surface. For example, if the thickness of the surface layer 2 is 140 μm or less, through-holes 22b are generated everywhere in the surface layer 2, so that the through-holes are not bent when greatly bent. Since it provides a buffering action and absorbs bending stress and deforms, it becomes a flexible structure that is resistant to cracking even with large bending.

  For example, as the surface layer 2 according to the present embodiment, when the birch material is sliced into a sheet shape so as to have a thickness of about 80 μm, the length of the through hole 22b appearing on the surface of the surface layer 2 is At most, it is about 500 μm or less. However, considering the ratio of the area of the through hole 22b to the entire surface area of the surface layer 2, even if a plurality of 500 μm through holes 22b are formed on the surface layer 2, the wood fibers 21 are connected to each other. Since the portion is larger, the sheet-like shape as the surface layer 2 according to the present embodiment can be sufficiently maintained.

  Since wood is a natural product, the fiber density is not always constant. Therefore, for example, when the thickness of the birch material is reduced to 50 μm or less, the wood fibers 21 are separated from each other depending on the place where the surface layer 2 is present, and the sheet-like shape cannot be maintained. There is also an influence of the size of the wood fiber 21 depending on the type of wood, and the optimum thickness varies depending on the material. However, the thickness of the surface layer 2 is generally 50 μm to 140 μm, more preferably 80 to 120 μm. It is preferable to set the degree.

  Thereby, the surface layer 2 which has two or more through-holes 22b which penetrate both surfaces of the surface layer 2 between the wood fibers 21 can be formed, maintaining a sheet | seat shape (refer FIG. 1). This through-hole 22b provides a buffering action when the wooden molded body 1a is molded, and the resin part 5 fills part of the through-hole 22b and the gap 22a, so that the wooden molded body 1a is reinforced without being largely broken, Can be formed into a shape or a three-dimensional shape.

  Further, if the thickness of the solid wood of the surface layer 2 is, for example, 50 to 120 μm, the ratio of the gaps 22a between the wood fibers 21 increases, so the transparency of the resin part 5 filled in the gaps 22a can be increased. For example, it becomes easy to transmit light together with the resin portion 5 in the gap between the wood chips 31 of the base material layer 3 to be described later, and if the wooden molded body 1a is used for, for example, a lamp shade of a lighting fixture, it is thick and sufficiently strong. In spite of this, it is possible to make wood lighting equipment that easily transmits light.

  The base material layer 3 is made of wood chips 31. In the base material layer 3, the separated wood chips 31 are bonded and connected via a resin constituting the resin portion 5. For this reason, even if it is molded in a three-dimensional shape, anisotropic force does not work, so there is little deformation after molding. In addition, spaces between the wood chips 31 are crushed by pressure such as pressing, and resin is embedded in the spaces and the respective wood chips 31 are bonded, so that sufficient strength can be obtained. ing. When producing wooden molded bodies 1a having different thicknesses, the thickness changes if the amount of the wood chip 31 of the base material layer 3 is changed, and the natural wood sheet as the surface layer 2 is the same as the above-described material. Therefore, inventory management of natural wood sheets becomes easy. The thickness of the base material layer 3 can be about several mm.

  The back layer 4 is made of, for example, a non-woven paper having a thickness of about several tens to several hundreds of μm. It may be a resin material such as plastic or a metal material.

  As the resin part 5, a thermosetting resin such as a resol type phenol resin, an epoxy resin, or a urethane resin is preferably used. The resin part 5 is dispersed and enters the inside (gap) of the fibers of the wood chip 31 of the base material layer 3 and the gap between the wood chips 31, and the inside of the wood fibers 21 of the surface layer 2 and the wood fibers 21. The structure is embedded in the gap 22a and the through hole 22b formed therebetween, and the base material layer 3 and the surface layer 2 are bonded so as to be integrated via the resin portion 5. Further, the back surface layer 4 is bonded to the base material layer 3 by the resin of the resin portion 5.

  The resin portion 5 in the surface layer 2 is preliminarily impregnated with resin in a wood chip 31 to be the base material layer 3, and the wood chip 31 is pasted on the surface layer, for example, as will be described in detail by a manufacturing method described later. It is formed so as to be gradually infiltrated into a part of the gaps 22a and 22b of the surface layer 2 by spreading in a shape and sandwiching between the back layer 4 and hot pressing. For this reason, the inside of the surface layer 2 is resin from the back surface side (the lower surface in FIG. 1) of the surface layer 2 toward the surface side (the upper surface in FIG. 1) of the surface layer 2 facing the one surface. The resin filling amount of the part 5 is gradually reduced.

  According to the cross-sectional observation result of the wooden molded body 1a according to the present embodiment, when the resin filling amount (weight ratio) on the back surface side (surface on the side in contact with the base material layer 3) of the surface layer 2 is 100%. The resin filling amount on the surface side of the surface layer 2 is preferably 60% or less, more preferably about 10 to 50%.

  If the resin filling amount on the surface side of the surface layer 2 is greater than 60%, the resin that has entered the through holes 22b may wrap around the surface of the surface layer 2, and the entire surface of the surface layer 2 may be covered with the resin. As a result, the resin that wraps around the entire surface of the surface layer 2 may adhere to the mold during press processing, and the wooden molded body 1a may be broken or torn. Alternatively, when the entire surface of the surface layer 2 is covered with the resin portion 5, an artificial luster appears, and an appearance that uses natural wood as it is may not be obtained. On the other hand, if the amount is less than 10%, the outermost surface layer of the surface layer may not be sufficiently hardened with resin, and the tree may be peeled off or cracked due to rubbing of the surface during long-term use.

  Even if the resin filling amount on the surface of the surface layer 2 is larger than 60% (for example, about 70%), it is not impossible when only a small number of wooden molded bodies 1a are molded. However, when the number of presses increases due to mass production, the cured resin adheres to the mold surface, which may affect the final shape of the wooden molded body 1a. Moreover, since sticking to the metal mold | die surface of the wooden molded object 1a becomes easy to occur, the wooden molded object 1a may be damaged.

  Conventionally, in order to obtain a three-dimensional processed wood product having a curved surface shape, solid wood has been cut out and produced. In addition, for simple and curved curved wood products such as cylindrical shapes, processing costs and use of wood can be achieved, for example, by attaching a thinly sliced plate (veneer) to the surface of a housing such as plastic. The amount has been reduced.

  However, the method of cutting out solid wood takes time for processing and uses a large amount of wood, so that productivity is low. In addition, a large amount of wood is consumed, and a large amount of scraped wood is generated.

  Further, even a material generally called a veneer has a thickness in the range of 150 μm to 500 μm, and slicing it thinly to 140 μm or less is not common in terms of yield and processing accuracy. When wood having a thickness of 140 μm or more is press-molded into a shape with a sharp curved surface or a complicated shape, cracks may occur.

  There is also a method of preventing cracking during curved surface processing by laminating a plurality of composite sheets of thinly sliced wood sheets and nonwoven fabric made of adhesive resin (Japanese Patent Laid-Open No. 5-83792). However, the adhesive layer increases and the weight increases due to the weight of the adhesive, and by stacking multiple sheets of wood, the difference in strength depending on the fiber direction of the wood also occurs, so cracks are likely to occur. It was difficult to form a three-dimensional shape having a large curved surface shape.

  On the other hand, the wooden molded body 1a according to the present embodiment is embedded in the surface layer 2 made of natural wood having a thickness of 140 μm or less, and in the gaps existing in the surface layer 2 and the base material layer 3, so that the surface layer 2 And a resin portion 5 integrated with the base material layer 3. As a result, a lightweight and high-strength molded body can be obtained even though most of the whole is natural wood, so that a shape with a large curvature and a complicated shape can be easily processed.

  Further, the resin portion 5 of the resin that has permeated the surface layer 2 of the wooden molded body 1a decreases in the resin filling amount toward the surface (surface opposite to the base material layer 3) (or the base material layer of the surface layer 2). Since the resin filling amount is lower on the surface side than on the third side), the resin oozes out over the entire surface of the surface layer 2. For this reason, seizure of the resin part 5 to the mold during press working is suppressed, and workability is improved. Further, since the surface layer 2 is prevented from being artificially glossed by covering the entire surface with the resin portion 5, an appearance closer to that of natural wood can be obtained.

  Further, in the wooden molded body 1a according to the present embodiment, the resin part 5 is embedded from the base material layer 3 side to the surface layer 2 side by press molding, whereby the resin part 5 is interposed between the base material layer 3 and the surface layer 2. Are intertwined, and the base material layer 3 and the surface layer 2 are firmly bonded. Therefore, the wooden molded body 1a is less likely to be peeled off than a conventional composite sheet or the like in which a plurality of layers are bonded via a resin film, and the strength is increased by embedding the resin portion 5, and thus the wooden molded body 1a is hardly broken.

(First modification)
As shown in FIG. 2, the wooden molded body 1b according to the first modified example is made of a natural wood solid material obtained by slicing the back surface layer 4 into a single sheet, with respect to the wooden molded body 1a shown in FIG. It is the structure replaced with the back surface layer 6 used as a material. That is, the back surface layer 6 is made of the same material as that of the surface layer 2, from the cell tissue (wood fiber) 61, the gap 62 a formed inside and between the cell tissues 61, and the surface of the back surface layer 6. And a gap (through hole) 62b penetrating the back surface. The thickness of the back surface layer 6 is preferably 50 μm to 140 μm, more preferably about 80 to 120 μm, similarly to the surface layer 2.

  The resin part 5 penetrated into the surface layer 2 and the back surface layer 6 so as not to ooze out on the entire surface of the surface layer 2 (surface on the uppermost side of the paper) and the surface of the back surface layer 6 (surface on the lowermost side of the paper). As the resin moves from the front surface (surface opposite to the base material layer 3) to the base material layer 3 side, the filling amount of the resin increases (or the surface layer 2 and the back surface layer 6 are on the base material layer 3 side. Embedded in the gaps 22a and 22b of the surface layer 2, the entire interior of the base material layer 3, and the gaps 62a and 62b of the back surface layer 6 so that the resin filling amount increases from the side). 3 and the back surface layer 6 are integrated and bonded.

  When the wooden molded body 1b is subjected to a heat press process or the like, the resin is deformed and cured by heat, and can maintain a curved surface shape and a three-dimensional shape. In addition, the intermittent gaps between the fibers formed on the front surface layer 2 and the back surface layer 6 are not largely broken because they give a buffering action when the wooden molded body 1b is bent. Furthermore, since the resin part 5 is embedded in the gap between the front surface layer 2, the base material layer 3 and the back surface layer 6 and penetrates deep inside each layer, the portion cured by the resin part 5 is a wooden molded body 1b. Across almost the whole. Therefore, the three-dimensional shape becomes stronger and is resistant to deformation.

  Since the surface of the wooden molded body 1b is wood on both sides, a beautiful wooden pattern appears on both sides as if a solid wood had been cut out, so that the design value is high. For example, it is suitable for a device (such as a vessel) that requires a visual effect on both sides of a three-dimensional shape.

(Second modification)
As shown in FIG. 3, the wooden molded body 1c according to the second modified example is obtained by adding a reinforcing layer 7 between the base material layer 3 and the surface layer 2 to the wooden molded body 1b shown in FIG. The reinforcing layer 8 is added between the material layer 3 and the back surface layer 6. The reinforcing layers 7 and 8 are made of a fibrous material such as nonwoven paper.

  The resin part 5 also penetrates into the inside (gap) of the fibers of the reinforcing layers 7 and 8, and integrally bonds the surface layer 2, the reinforcing layer 7, the base material layer 3, the reinforcing layer 8, and the back surface layer 6.

  As shown in the manufacturing method described later, the reinforcing layers 7 and 8 are impregnated into the reinforcing layers 7 and 8 in advance before the reinforcing layers 7 and 8 are laminated with the surface layer 2, the base material layer 3, and the back layer 6 and subjected to hot pressing. By placing, the resin forming the resin portion 5 can be infiltrated into the reinforcing layers 7 and 8. Alternatively, the resin impregnated in the wood chip 31 constituting the base material layer 3 oozes out and penetrates into the reinforcing layers 7 and 8 during hot pressing, and the resin is also applied to the surface layer 2 and the back surface layer 6 made of wood sheets. May penetrate.

  Especially when the pulverization size of the wood chip 31 of the base material layer 3 is large, the corners of the wood chip 31 may be sharp, so when the surface layer 2 and the back surface layer 6 are laminated on the base material layer 3, The front surface layer 2 and the back surface layer 6 may be broken at the corners of the wood chip 31. Therefore, as in the wooden molded body 1c of FIG. 3, for example, sheets of nonwoven paper having a high fiber density are used as the reinforcing layers 7 and 8, between the base material layer 3 and the surface layer 2, and the base material layer 3 and the back surface. When sandwiched between the layers 6, the surface layer 2 and the back layer 6 are protected from the corners of the wood chip 31, so that the surface layer 2 and the back layer 6 can be prevented from being broken.

  In addition, you may provide the reinforcement layers 7 and 8 similarly to the wooden molded object 1c of FIG. 3 to the wooden molded object 1a shown in FIG.

  Moreover, although it is preferable to provide both the reinforcement layers 7 and 8, you may abbreviate | omit one.

  Next, the manufacturing method of the wooden molded object 1a which concerns on embodiment of this invention is demonstrated with reference to FIG.

  First, as shown to Fig.4 (a), the sheet-like surface layer 2, the wood chip 31 used as the origin of the base material layer 3, and the sheet-like back surface layer 4 are prepared.

  As the surface layer 2, there is a single sheet obtained by slicing a solid hardwood (birch) having a gap of wood fibers penetrating both surfaces and having a thickness of 140 μm or less, more preferably about 50 to 120 μm. Used.

  The wood chip 31 may be the same as the tree species of the surface layer 2, but may be other types. In particular, the use of wood ends, thinned wood, grinding scraps, etc. is also suitable for the environment. Further, the size of the wood chip 31 may be equal to the size used for the laminated material such as particle board or MDF. However, since the corners of the wood chip 31 may break through the wood sheet portion of the surface layer 2, it is more preferable to have a fine shape or a shape with more rounded corners.

  As the back layer 4, for example, non-woven paper is used.

  As shown in FIG. 4B, among the prepared surface layer 2, wood chip 31, and back layer 4, only the wood chip 31 is placed in a container 9 containing the resin solution 12 for a certain period (for example, 10 minutes). Soak the resin to the inside of the wood chip 31 sufficiently. When the surface layer 2 is impregnated, the resin adheres to the entire surface, and the cured resin sticks between the surface layer 2 and the mold 10 at the time of press molding, and the mold 10 and the surface layer 2 cannot be released from each other. Therefore, it is preferable not to impregnate the surface layer 2.

  As the resin solution 12 in FIG. 4B, for example, a phenol resin which is a thermosetting resin can be used. When the amount of the resin is too large, it may be used after being dissolved in a solution such as methanol. The optimum concentration of the resin varies depending on the amount of the wood chip 31 and the thickness of the surface layer 2, but generally, the smaller the amount of the wood chip 31 to be impregnated (the thinner the finished wooden molded body is), the more the concentration. Is preferably thinner.

  Next, as shown in FIG. 4C, the wood chip 31 is taken out from the container 9 and dried with warm air or naturally dried. Once the wood chip 31 is dried, the wood chip 31 can be easily handled as compared with the case where the wood chip 31 is not dried, and the efficiency of the manufacturing work can be improved. The wood chip 31 after the resin impregnation may be dried after being laid on the front surface layer 2 or the back surface layer 4 and then proceeded to the next step.

  Next, as shown in FIG. 4 (d), a press die 10 in which a dried wood chip 31 is laid on the back surface layer 4, the surface layer 2 is stacked thereon and laminated, and these are set at a predetermined temperature. Place in. Note that the wood layer 31 may be laid on the surface layer 2 and the back surface layer 4 may be overlaid. The amount of the wood chip 31 is adjusted according to the thickness after being compressed by molding.

  The press die 10 has a male die 10a and a female die 10b. At this time, it is desirable that the surface of the male mold 10 a and the female mold 10 b be subjected to a mold release treatment so that the surface layer 2, the resin solution 12, and the back surface layer 4 are not easily attached to the mold 10. Examples of the mold release treatment include a method of applying a mold release agent on the surface of the mold 10 and affixing a film such as Teflon (registered trademark). Thereby, for example, resin that has exuded to the surface from a minute gap (gap 22 b in FIG. 1) passing through both surfaces of the surface layer 2 can be prevented from sticking to the surface of the mold 10. In addition, as described above, when the resin is excessively oozed out on the outermost surface, the cured resin sticks even if the mold release process is performed, so it is necessary to repeat the mold release process every several presses. Yes, productivity becomes worse. As described above, if pressing is performed under the condition that the resin on the outermost surface layer is 10% to 50% with respect to the inner layer, 100 or more presses are required for one mold release treatment. Number of times is possible. The temperature of the mold 10 needs to be a temperature at which the resin is sufficiently cured, and for example, about 160 to 220 ° C. is appropriate.

  Subsequently, the front surface layer 2, the wood chip 31, and the back surface layer 4 are exposed to a water vapor atmosphere to soften the whole. “Exposing to a steam atmosphere” means, for example, spraying steam on the mold 10 by spraying steam or mist-like water, or adding moisture to the surface layer 2, the wood chip 31, and the back surface layer 4. It can be produced by a method such as steaming with the heat of the mold 10. Considering the ease of processing into a molded product having a large curvature, the higher the water content, the more preferable it is.

  Next, as shown in FIG. 4 (e), the laminated front surface layer 2, the base material layer 3 formed by the wood chips 31, and the back surface layer 4 are pressed and deformed with a predetermined pressure.

  When the surface layer 2 which is a natural wood is bent as shown in FIG. 4 (e), the gap portion penetrating both surfaces of the surface layer 2 acts as a buffer region together with the softening of the wood by water vapor. It is easy to form a curved surface shape without being largely broken. The base material layer 3 has a stable shape because the separated wood chips 31 are press-compressed and resin-cured into a molded shape, so that curved surface shape stress is unlikely to occur.

  In addition, as press conditions, it is preferable to mutually adjust temperature, time, and pressure conditions, for example. For example, when the temperature is fixed at 220 ° C. and the time is fixed at 30 seconds, the pressure is preferably 0.2 to 1.5 MPa. If the pressure is higher than 1.5 MPa under the above-described conditions, the mold surface can be subjected to the mold release treatment, but the resin oozes out on the surface layer 2 and sticks to the mold 10, so that the mold 10 can be molded. There is a case where it is not possible to release from the torn and torn. On the other hand, when the pressure is made smaller than 0.2 MPa, it has been confirmed by the present inventors that the resin does not sufficiently penetrate into the surface layer 2 and tends to be deformed after molding. When the processing temperature is lower than 220 ° C., the upper limit of the pressure is less than 1.5 MPa, and the lower limit is controlled to be greater than 0.2 MPa so that the resin does not ooze out over the entire surface on the surface layer 2. Could be controlled.

  Once a predetermined time has passed after pressing, the mold 10 (male mold 10a, female mold 10b) is opened to release water vapor as shown in FIG. 4 (f). Thereby, the gas of the water | moisture content and resin solvent component enclosed in the base material layer 3, the surface layer 2, and the back surface layer 4 is open | released. As a result, accumulation of gas in each layer can be suppressed. The optimum opening time varies depending on the pressure value and the mold temperature. Specifically, for example, when the temperature of the mold 10 is 200 ° C. and the pressure is 0.5 MPa, the pressing time is about 10 seconds after pressing. When it was opened only once for about 10 seconds, the water and solvent components in each layer were sufficiently evaporated.

  Next, as shown in FIG. 4G, pressing is performed again, and a predetermined time and pressure are maintained until the resin hardens while gradually penetrating into the surface layer 2. For example, at the above temperature and pressure, the resin is sufficiently cured in about 30 seconds. The wood chip 31 of the base material layer 3 is compressed and the gap space is crushed by the pressure of the press. The resin penetrates into the remaining space and the wood chips 31 are bonded to each other, and the resin is applied to the surface layer 2. Penetrate and harden. Moreover, the base material layer 3 and the back surface layer 4 are adhere | attached with resin. The temperature and pressure conditions of the press are such that the resin impregnated in the wood chip 31 of the base material layer 3 does not exude to the entire surface side of the surface layer 2 and the resin is embedded in a part of the gap of the surface layer 2. It is preferable to control in such a manner.

  When the resin is infiltrated into the surface layer 2 from the beginning, it is difficult to change the resin concentration from the back surface to the surface of the surface layer 2, and the resin component on the surface side may stick to the mold during pressing and be torn. There is. In the present embodiment, as described above, by appropriately controlling the temperature, pressure, and time at the time of press molding so that the resin in the base material layer 3 gradually permeates into the surface layer 2 side, The gradient of the filling amount of the resin inside the surface layer 2 can be provided so as to decrease from the surface on the side in contact with the base material layer 3 toward the surface on the side not in contact with the base material layer 3. It is possible to control the amount of the resin leaching into the surface layer and to control the resin filling amount of the surface layer 2 within a certain range. Thereby, since the quantity of resin adhering to the metal mold | die 10 can also be reduced, adhesion of resin can be prevented and workability improves. As a method of providing a gradient of resin concentration inside the surface layer 2 made of a wood sheet, hot pressing can be most easily realized.

  Next, as shown in FIG. 4 (h), the molded body 11 is taken out from the mold 10 and cooled. Thereafter, as shown in FIG. 4 (i), the wooden molded body 1 a according to the present embodiment can be manufactured by cutting a portion protruding from the frame to form a predetermined shape.

  According to the method for manufacturing a wood molded body according to the present embodiment, the surface layer 2 and the substrate are softened while the surface layer 2 is softened with water vapor and the wood chip 31 of the substrate layer 3 is compression-molded by press heating. Since the layer 3 and the back surface layer 4 can be attached and molded, the pressing process is simplified and the productivity is greatly improved. Further, in the pressing step shown in FIGS. 4D to 4G, while controlling so that the resin portion 5 does not ooze out to the entire surface side of the surface layer 2 (the entire upper surface in FIG. 1). Since the resin impregnated in the base material layer 3 is embedded in the gap 22b penetrating both surfaces of the surface layer 2, the resin part 5 does not adhere to the mold during pressing, and the molded product is processed without cracking or breaking. Can be done and work efficiency can be improved. Furthermore, since the entire surface layer 2 of the manufactured wooden molded body 1a is not covered with the resin, it is possible to more effectively exhibit the advantageous properties inherent to the wood.

  In the example shown in FIG. 4, the case where a thermosetting resin is used as the resin has been described. However, when a thermoplastic resin is used, for example, the state is maintained for a certain period of time while being pressed with a heated mold 10. The mold 10 may be cooled and the molded body 11 taken out.

  Moreover, in FIG. 4, although the case where the wooden molded object 1a shown in FIG. 1 was manufactured was demonstrated to the example, when manufacturing the wooden molded object 1b shown in FIG. 2, it replaces with the back surface layer 4 in FIG. The back layer 6 made of the same material as the layer 2 may be used.

  In this case, the resin penetrates into the back surface layer 6 as well as the surface layer 2, and the surface layer 2, the base material layer 3, and the back surface layer 6 are integrally bonded, and the back surface layer 6 contains the base material layer 3. A gradient of the resin concentration is formed so as to decrease from the surface on the side in contact with the substrate layer toward the surface on the side not in contact with the base material layer 3.

  When the wooden molded body 1c shown in FIG. 3 is manufactured, the reinforcing layers 7 and 8 made of a fibrous material such as non-woven paper are also impregnated with a resin before the hot pressing, similarly to the wood chip 31. And let it dry. Then, the surface layer 2, the reinforcing layer 7, the base material layer 3 (wood chip 31), the reinforcing layer 8, and the back surface layer 6 are laminated in this order from the top, and the same press as in FIGS. 4 (d) to 4 (g). By performing the process, a wooden molded body 1c is obtained.

  The step of impregnating the reinforcing layers 7 and 8 with a resin in advance and drying is omitted, and the wood chip 31 constituting the base material layer 3 is formed by the same pressing step as in FIGS. 4 (d) to 4 (g). The impregnated resin may ooze out and penetrate into the reinforcing layers 7 and 8, and the resin may also penetrate into the front surface layer 2 and the back surface layer 6.

DESCRIPTION OF SYMBOLS 1a, 1b, 1c ... Wooden molded object 2 ... Surface layer 3 ... Base material layer 4, 6 ... Back surface layer 5 ... Resin part 7, 8 ... Reinforcement layer 31 ... Wood chip

Claims (7)

A base material layer made of wood chips,
A surface layer made of a solid material of a natural wood having a thickness of 140 μm or less laminated on the surface of the base material layer and sliced into a sheet;
A resin part that is provided on the base material layer and the surface layer, adheres the wood chips of the base material layer, and adheres the base material layer and the surface layer;
A back surface layer laminated on the back surface of the base material layer,
The resin filling amount (weight ratio) on the back surface side of the surface layer is set so that the resin filling amount on the surface side of the surface layer is smaller than the resin filling amount on the back surface side of the surface layer in contact with the base material layer. The three-dimensional wooden molded body, wherein the resin portion is arranged in the surface layer so that the resin filling amount on the surface side of the surface layer is 10 to 50% when the surface layer is 100%.   2. The three-dimensional wooden molded body according to claim 1, wherein the surface layer is made of a solid material of a natural wood having a thickness of 50 to 120 [mu] m sliced into a sheet.   The three-dimensional wooden molded body according to claim 1 or 2, wherein the resin portion is obtained by filling the surface layer with a resin in the base material layer by hot pressing. The back layer is made of a solid material of natural wood having a thickness of 140 μm or less sliced into a sheet,
The base material layer and the back surface layer are bonded via the resin portion, and the resin filling amount on the surface side of the back surface layer is the resin filling amount on the back surface side of the back surface layer in contact with the base material layer. So that the resin filling amount (weight ratio) on the back side of the back layer is 100% so that the resin filling amount on the surface side of the back layer is 10 to 50%. The three-dimensionally shaped wooden molded body according to any one of claims 1 to 3, wherein the resin portion is disposed on a back surface layer. A step of impregnating wood chips with resin;
Drying the wood chips after impregnation;
Between the surface layer made of a solid material of a natural wood having a thickness of 140 μm or less and having a gap between wood fibers penetrating both surfaces and sliced into a sheet shape, and the sheet-like back surface layer, the dried state A process of sandwiching wood chips and stacking,
Exposing the laminated surface layer, the base material layer made of wood chips, and the back surface layer to be softened by exposing them to a water vapor atmosphere;
A first pressing step in which the surface layer after softening, the base material layer, and the back surface layer are pressed once at a temperature of 160 to 220 ° C. and after a predetermined time, the upper and lower molds are opened to release water vapor;
Press again at the same temperature, and the amount of resin filling on the surface side of the surface layer is less than the amount of resin filling on the back side of the surface layer in contact with the base material layer. When the resin filling amount (weight ratio) is 100%, the surface layer is filled with the resin in the base layer so that the resin filling amount on the surface side of the surface layer is 10 to 50%. A second pressing step for adhering the base material layer and the surface layer through the resin and adhering the base material layer and the back surface layer;
And a step of forming the base material layer, the front surface layer, and the back surface layer after bonding into a predetermined shape. A step of impregnating wood chips with resin;
Drying the wood chips after impregnation;
The dried wood chips are sandwiched between a surface layer and a back layer made of a solid wood material having a thickness of 140 μm or less and having a gap between wood fibers penetrating both surfaces and sliced into a sheet shape. Laminating steps;
Exposing the laminated surface layer, the base material layer made of wood chips, and the back surface layer to be softened by exposing them to a water vapor atmosphere;
A first pressing step in which the surface layer after softening, the base material layer, and the back surface layer are pressed once at a temperature of 160 to 220 ° C. and after a predetermined time, the upper and lower molds are opened to release water vapor;
Press again at the same temperature, and the amount of resin filling on the surface side of the surface layer is less than the amount of resin filling on the back side of the surface layer in contact with the base material layer. When the resin filling amount (weight ratio) is 100%, the surface layer is filled with the resin in the base layer so that the resin filling amount on the surface side of the surface layer is 10 to 50%. In addition, the resin filling amount (weight ratio) on the back surface side of the back layer is such that the resin filling amount on the front surface side of the back layer is less than the resin filling amount on the back surface side of the back layer in contact with the base material layer. ) Is 100%, the resin in the base material layer is filled into the back surface layer so that the resin filling amount on the surface side of the back surface layer is 10 to 50%, Adhering the base material layer and the surface layer, the base material layer and the back surface layer A second pressing step of bonding,
And a step of forming the base material layer, the front surface layer, and the back surface layer after bonding into a predetermined shape. In the first pressing step, the surface layer, the base material layer, and the back surface layer after softening are hot-pressed at a temperature of 160 to 220 ° C. and a pressure of 0.2 to 1.5 MPa for about 10 seconds, and then the mold is opened. The process of releasing water vapor,
The said 2nd press process is a process of performing a heat press again for about 30 seconds at the same temperature and the same pressure as the said 1st press process, The manufacture of the solid shape wooden molded object of Claim 5 or 6 characterized by the above-mentioned. Method.

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