JPS6238122B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a veneer. The usual method for manufacturing veneers in the conventional plywood manufacturing process is to grip a raw wood cut into rounds of appropriate dimensions with a veneer lace, and use so-called scoring to align both end faces of the raw wood with the axis of rotation of the veneer lace. While cutting vertically,
This method involves cutting a veneer to a desired thickness, but as is well known, there are many cracks on the end surface of the raw wood due to growth stress, dryness, etc. Even if some of the cracks are removed, most of the cracks remain on the cut end of the veneer, so during the subsequent transportation process, for example, the veneer may be torn from the cracked area, resulting in narrow or irregular shapes. This is a continuous process, which is the biggest factor hindering the rationalization of the treatment process.

In particular, veneers that are cut after the raw wood has become cylindrical, can be automatically rolled up and processed efficiently if they do not tear. Since the width becomes narrow and discontinuous, it is not possible to roll it up well, which not only complicates the subsequent processing process significantly, but also requires the front and back of the veneer to be used to make use of the veneer, which has become narrow due to tearing. The reduction in yield caused by cutting the edges and making the veneer into a rectangular shape is extremely large, and is a negative cause of a significant increase in the cost of plywood.

Therefore, for example, as disclosed in ``Method for preventing cracks in veneers or veneers, etc.'' (Japanese Patent Publication No. 1589/1989), adhesive is filled into the cracks on the end surface of the log, and then adhesive is applied to the end surface of the log. Attempts have been made to prevent the cracks from expanding in the veneer by reinforcing the cracked areas in advance by applying a crack-preventing coating with a chemical or film, but these methods have the following drawbacks: Because of this, it has not yet been put into practical use.

In other words, the problem with the conventional method is that not only is it extremely difficult to fill the cracks with adhesive, but the inner surface of the cracks is covered with dirt and grime that have adhered during transportation.
It is contaminated with mold, etc., and there is rot, secondary cracking, etc. in the vicinity, so even if it were possible to fill it with adhesive, the adhesive effect would be extremely low, and it would be difficult to handle it in the subsequent process. Furthermore, according to the results of numerous past experiments by the present inventors, crack prevention coatings made of adhesive or film applied to cracked areas cannot be achieved with veneer lace. When cutting, the veneer is subjected to external forces from blades, nose bars, etc., or is subjected to intensive external forces due to buckling of the veneer in subsequent processing steps, which forces it to deform, such as bending or compressing, resulting in cracks. The crack-preventing film itself may be destroyed, or the adhesive layer between the crack-preventing film and the wood end surface may peel off, resulting in a loss of reinforcing effect. Since it is not possible to cut the veneer, the end surface of the veneer becomes non-linear and cannot be used as a reference surface when, for example, cutting the veneer to a predetermined size, making it difficult to handle the veneer in the future. However, since it has various disadvantages such as being extremely inconvenient, for example, it deforms only slightly during cutting, such as with a board, and since it is light in weight, it does not require much reinforcing strength. It is almost impossible to put it to practical use except when manufacturing special ultra-thin veneers that do not require a special reference surface in order to be rectangular according to the shape, and furthermore, it requires a large amount of adhesive. Since it is consumed, it also has the disadvantage of increasing the cost required for reinforcement.

The present invention aims to eliminate the drawbacks of the conventional reinforcing methods and solve the various problems in the veneer manufacturing process mentioned at the beginning. To provide a method for manufacturing a veneer that can easily and inexpensively obtain a veneer that is reinforced with necessary and sufficient reinforcement strength and has a substantially straight butt end surface, regardless of deformation, and which can be used at a plywood factory. The aim is to contribute to the automation and rationalization of the veneer manufacturing process.

That is, the reinforcing means that forms the basis of the present invention uses fibrous materials such as natural fibers, synthetic fibers, glass fibers, metal fibers, etc. as reinforcing materials, and preferably uses various adhesives suitable for high moisture content bonding. The above-mentioned fibrous material is attached to the cracked part of the end surface of the log, and since the fibrous material is highly flexible and has strong tensile strength, it is resistant to deformation due to cutting with veneer lace, etc. Not only does it not cause any problems, it can provide the necessary and sufficient reinforcing strength, and in addition to requiring less adhesive, the cost of reinforcing is also lower than in the past. The effect is extremely significant.

The present invention will be described in detail below along with an example of implementation illustrated in the drawings.

The method for manufacturing a veneer according to the present invention includes cracks 2, 2a, 2b, as illustrated in FIGS. 1 to 3, for example.
The fibrous materials 3, 3 are formed so as to include the cracks 2, 2a, 2b on the end surfaces of the logs 1, 1a, 1b having
a and 3b, at least the cracks 2, 2a, and 2b are reinforced in advance, and then the deflection of at least one of the end surfaces of the raw wood relative to the rotational axis of the veneer lace is within an allowable range; That is, centering is done so that the end surface of the one side is approximately perpendicular to the rotation axis of the veneer lace,
After gripping the raw wood with a veneer lace, as illustrated in FIG. 4, the raw wood 1, 1a, 1b is cut into a veneer of a desired thickness without dividing the reinforced butt end surface by marking. 1c is removed,
In FIG. 4, 1d is a single-plate winding ball, 4 is a veneer lace cutter, and 5 is a core of the winding ball.

As mentioned above, as a specific means for gripping a log with a veneer race by centering the end face of at least one of the logs with respect to the rotational axis of the veneer race so as to keep it within an allowable range, for example, the method shown in FIG. As illustrated in FIG.
Means for gripping the log 1 by the spindle 10 while bringing one end surface 11 of the log 1 into contact with the centering surface of the centering member 13, or rotation of a veneer race as illustrated in FIG. 10, for example. A centering member 15 having a centering surface perpendicular to the axis is provided at a centering position in front of the veneer race, and the centering member 15
After centering the log by bringing one end surface 16 of the log 1 into contact with the centering surface of the log, the chuck 14 is moved back and forth between the centering position and the spindle 10 of the veneer lace. 1 and transfer the log 1 to the position of the veneer lace spindle 10, and
Various methods can be used, such as re-grasping the grip, but in any case, it is desirable to minimize the vibration as much as possible.

As is clear from the above, the method for manufacturing a veneer according to the present invention involves adhering a fibrous material to the end surface of a log, and then allowing the end surface of at least one side of the log to run out with respect to the rotation axis of the veneer lace. The wood is centered within the range, the wood is gripped with a veneer lace, and then cut into a veneer of the desired thickness.A fibrous material is attached to the end of the wood for reinforcement. Because it is highly flexible, it easily deforms as it passes through the cutting process, so it does not break or peel off from the adhesive layer, and it is firmly attached to the end surface of the cut veneer. In addition to remaining in its original shape, it will not break or peel off from the adhesive layer even when deformed during subsequent processing steps, and because it is a material with strong tensile strength, cracked parts of the veneer can be removed. It exhibits sufficient reinforcing strength to prevent it from expanding when subjected to external forces, and as a result, the veneer cut from the reinforced log is prevented from tearing at the cracked part. Due to the above-mentioned centering, the end surface of at least one side of the raw wood becomes almost perpendicular to the axis of rotation of the veneer lace, and the end surface of the veneer on the centered side The surface is substantially linear regardless of the original shape of the raw wood and even if the markings are omitted, so it is effective as a reference surface when cutting a veneer to a predetermined size, for example.

This simplifies the subsequent veneer processing process, prevents the width of the veneer from becoming narrower due to tearing, eliminates the need to cut out the torn part and mold the veneer, and improves the yield. The veneer, which is machined after the raw wood has become cylindrical, can be formed by simply winding it up into a ball shape as shown in the figure, unwinding it, and then cutting it to the specified size, so the processing is simple and the yield is low. , significantly improved compared to the conventional method. In addition, adhesives do not require any reinforcing strength by themselves, and simply attaching the fibrous material to the end surface of the raw wood is sufficient, so the amount of adhesive used is extremely small, and the cost required for reinforcement is lower than in the past. be.

In addition, when cutting a long log into multiple pieces of veneer at the same time while dividing it with a middle crease, the end surface of the veneer divided by the middle crease will definitely be straight, so please use the standard It can be used as a surface, and the centering buttside surface and the reinforcing buttside surface do not necessarily have to match, but in any case, either one of the buttsides of the veneer When using as the reference plane,
Using methods such as applying paint at appropriate times,
It is advantageous if the reference surface is identified and displayed, as processing work in subsequent steps becomes convenient.

In addition, when attaching a fibrous material to the end surface of logs, in addition to the method of attaching the fibrous material limitedly to the vicinity of cracks, as illustrated in Fig. 1 or 2, there are other methods, such as As shown in Figure 3, if the entire end surface of a log with cracks is reinforced by applying a fibrous material to the entire end surface of the log, cracks cannot be detected with the naked eye. It is effective because it can not only reinforce the cracked parts but also reinforce the parts other than the cracks.

In addition to the general method of attaching the entire surface of the fibrous material to the end surface of the log using adhesive, for example,
As illustrated in the figure, cracks 2 are made on the end surface of log 1 in advance.
After forming a groove 6 of an appropriate width along the crack 2,
The fibrous material 3 is pasted on the end surface of the raw wood 1 having a groove 6 of an appropriate width along the crack 2 and the groove 6, or as illustrated in FIG. The fibrous material 3 is attached by interposing a release material 7 of an appropriate width, or as illustrated in FIG. 7,
Using a pressurizing body 8 having an uneven pressurizing surface, preferably, the concave portion of the pressurizing surface is aligned with the crack 2, and the fibrous material 3 is pressed and adhered to the end surface of the log 1, so that the crack is approximately Adhesion of the fibrous material that can be placed at least in the vicinity of the crack by using a method such as making the adhesion of the fibrous material 3 intermittently stronger or weaker in the orthogonal direction (approximately the same direction as the cutting direction of annual rings or logs) If the restraint associated with cracking is locally released or reduced, the fibrous material near the crack will become even more flexible.
against deformation during cutting or subsequent processing steps.
This is effective because it can be handled more reliably.

In addition, as the fibrous material, various single fibers such as natural fibers, synthetic fibers, glass fibers, metal fibers, etc., or a combination thereof can be used.
If necessary, they may be processed into woven or non-woven fabrics to improve the workability of pasting, but in any case, as shown in Figure 2 or 3. As shown in the example, the fibers of a fibrous material, such as a thin film made of a non-woven fabric or the like, or a linear fiber made of a single yarn or twisted yarn, are aligned in the same direction as the cutting direction of the log. It is effective to increase the strength against tension if the adhesive is attached with the adhesive.

Experiments have also confirmed that the purpose can be achieved by using a thermoplastic adhesive called hotmelt, but thermoplastic adhesives cannot be used when drying veneers at high temperatures. Since there is a risk of melting, from a practical point of view polyvinyl alcohol (hereinafter referred to as PVA) used in other experiments is recommended.
The water-soluble synthetic resin adhesive was good.
That is, in the experiment, the PVA powder was placed between the end surface of the log and a fibrous material and then pressurized and heated, or water was added to the PVA powder and slightly preheated to form a paste. After that, the fibrous material was placed between the end surface of the log and the fibrous material, and the fibrous material was applied with pressure and heat to adhere the fibrous material, but neither of them melted even when the veneer was dried at high temperatures. However, since it cured to a somewhat flexible state, it did not impair the flexibility of the fibrous material and was suitable as an adhesive for use in the practice of the present invention. Of course, the adhesive used in carrying out the present invention is not limited to the above two types of adhesives, and various known adhesives can be used, but preferably, like the above-mentioned PVA,
It is preferable to use an adhesive that can be bonded to the end surface of a log in a wet state and that can be cured to a somewhat flexible state, and also from the viewpoint of cost and not impairing the flexibility of the fibrous material. It is desirable to use as little as possible.

In addition, if the end surface of the log is poor, for example, as illustrated in FIG. There is no problem in trying to flatten the adhesive surface by deforming it, or if you want to efficiently adhere a fibrous material, the adhesive itself or other pressure-sensitive adhesives or cuttable fasteners, etc. Temporarily fix the fibrous material to the end surface of the log using
Then, if necessary, heat and pressure may be applied to perform main bonding.

As is clear from the above, according to the present invention, the veneer is reinforced with the necessary and sufficient reinforcement strength regardless of the deformation caused by external force during cutting with veneer lace, and the end surface of the veneer is substantially straight. , can be obtained easily and relatively inexpensively, and greatly contributes to the automation and rationalization of the veneer manufacturing process in plywood factories of the present invention.

[Brief explanation of the drawing]

The drawings are for explaining the present invention, and FIGS. 1 to 3 are perspective explanatory views for explaining the state of pasting the fibrous material to the butt end surface of logs, and FIG. 4 is a butt end surface. 5 to 8 are cross-sectional explanatory views to explain the state in which a fibrous material is attached to the end surface of the log. Figure 10 is a front explanatory diagram to explain the state of centering the log with veneer lace, and Figure 10 is a front explanatory diagram to explain the state of centering the log at the centering position in front of the veneer lace. It is a diagram. 1, 1a, 1b... Log, 1c... Veneer, 1d
...rolled ball, 2, 2a, 2b...cracked, 3, 3a,
3b... Fibrous material, 4... Veneer lace cutter, 6... Groove, 7... Release material, 8, 8a... Pressure body, 9... Veneer lace, 10... Veneer lace spindle, 11, 16... One end surface of the raw wood, 12... The rotation axis of the veneer lace, 13, 1
5...Centering member.

Claims (1)

[Scope of Claims] 1. By attaching a fibrous material made of natural fibers, synthetic fibers, glass fibers, metal fibers, etc., including the cracks, to the end surface of a log having cracks,
After reinforcing at least the cracked portion in advance, and then centering the log so that the deflection of the end surface of at least one side of the log with respect to the rotation axis of the veneer race is within an allowable range, and gripping the log with the veneer race, A method for producing a veneer characterized by cutting a reinforced wood end surface without dividing it by scoring. 2. A method for manufacturing a veneer according to claim 1, comprising adhering a fibrous material to the end surface of a raw wood having grooves of appropriate width along the cracks in a manner that includes the cracks. 3. A method for manufacturing a veneer according to claim 1, which comprises adhering a fibrous material with a release material of an appropriate width interposed along the cracks. 4. The method for producing a veneer according to claim 1, wherein the fibrous material is adhered by intermittently varying the strength of the fibrous material in a direction substantially perpendicular to the crack. 5 Thin film-like fibers made of non-woven fabric, etc. whose fiber directions are aligned in the same direction, or linear fibers made of single threads, twisted threads, etc., are pasted approximately in the cutting direction of the raw wood. A method for manufacturing a veneer according to claim 1 or 2 or 3 or 4.