JPH0132042B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for joining cracks in the end of a log.

Conventionally, in plywood factories, veneer veneer (hereinafter referred to as
It is simply called a veneer. ), there is a risk that the veneer will tear from the crack, so normally, bonding tape is attached to the surface of the veneer to reinforce the cracked area and prevent the veneer from tearing. We are trying to
With this type of reinforcement, the veneer is completely defenseless until the tape is applied, and in reality, many veneer tears occur before that, resulting in a mathematical increase in the number of veneers to be processed. Therefore, many people and equipment are required for the processing, which is a major obstacle to streamlining the veneer processing process.

Therefore, an attempt was made to join the cracks in advance while the wood is still in the raw state, and to remove the veneer that has already been reinforced at the cracks.
(Japanese Patent Application No. 50-134300), specifically, this method uses a cutting tool to create a groove in the crack at the end of the log, and inserts wood into the groove. By filling with adhesive, the cut veneer is prevented from tearing.

However, when using this method on logs where the width of the crack is not constant, it is necessary to change the width of the groove created with the cutting tool and the size of the filler depending on the width of the crack. In each case, it is necessary to provide a groove corresponding to the width of the crack, and to make a wood filler of a size corresponding to the groove.

This is an extremely complicated task as it requires buried trees of countless sizes.

Furthermore, even if several sizes of buried wood are selected, the following problems still occur.

In other words, while the groove and buried wood are required to be slightly wider than the width of the crack,
In reality, the groove must be large enough to accommodate a larger buried tree than the width of the crack.

As a result, the buried trees and trenches are larger than necessary, and valuable materials are wasted.

The present invention was developed to eliminate the drawbacks of the conventional crack reinforcing methods, and by providing a method that can effectively join cracks, it is intended to contribute to streamlining the veneer processing process. Specifically, the crack is closed in advance in a sealed or nearly sealed state using an appropriate closing means, a new bonding surface is formed near the crack, and the adhesive or the adhesive and the filling material 5 are closed. This is a method of joining the joint surfaces using This is extremely beneficial as it makes it possible to mill effectively reinforced veneers.

Hereinafter, the present invention will be described in more detail with reference to an example of implementation illustrated in the drawings.

The method according to the present invention is more effective for logs 1 in which cracks 2 with relatively wide gaps exist at the end of the wood, as illustrated in FIG. 1, for example, and as illustrated in FIG. In this way, the outer periphery of the log is tightened with the rope 6 wound around the outer circumference of the log 1 to close the crack 2 in a sealed or nearly sealed state, and then the crack is cut into an appropriate shape that encompasses the closed crack 2. A new bonding surface 3 is formed by locally removing the vicinity, and the bonding surface 3 is bonded using an adhesive or an adhesive and a filler material 5.

According to such a method, regardless of the gap width and internal shape of the original crack 2, it is possible to form a bonding surface more accurately in accordance with the closed crack 2, and the width to be removed can be narrowed. It is also possible to make it constant.

Moreover, since the adhesive or the adhesive and the filling material are used to bond the new bonding surface 3, which is not related to the dirt on the inner surface of the original crack 2, a good bonding effect can be obtained.

Therefore, as illustrated in FIG. 3, by using a veneer lace having a veneer cutting blade 8, a scoring blade 9, etc., and performing the marking process in the usual manner, the raw wood 1 after joining is turned. , a veneer 7 whose end face is formed into a straight line by the separation of the line scraps 10, and which is bonded and reinforced with an adhesive with the cracks 2 closed or with an adhesive and a filler material 5. This is extremely effective in streamlining the post-treatment process for veneers, as it prevents tearing and significantly reduces the incidence of troubles such as catching in cracked areas.

As a closing means for closing the crack, it is easy to use cables to tighten the cracks as in the above embodiment, and if necessary, rollers may be inserted between the outer periphery of the log and the cables to reduce the resistance. There is no harm in trying to reduce the risk, but
The closure is not limited to this, and the closure can also be done using a press, for example, and any means that is sufficient for closure may be used.

In addition to the rectangular groove shown in FIG. 2, various shapes such as trapezoidal grooves and wedge grooves can be used as the shape for removing the vicinity of the crack, and it is also possible to remove the area from the butt end side. Therefore, it can be formed not only in a straight line, but also in a non-linear shape along the crack, and in short, any shape that can encompass the crack is fine, but in order to save on the amount of adhesive used, a narrow width is better. In addition, when a filling material is used in combination, a shape that allows easy molding of the filling material is preferred.

In addition, as for the adhesive, a wet curing adhesive is most convenient, but if necessary, it is possible to apply a partial drying treatment such as hot air to the joining surface of the raw wood, or even use a dry filler material, to make a thermosetting adhesive. It is also possible to use adhesives such as adhesives and thermoplastic adhesives.

In addition, various materials such as wood powder, veneer, wood chips, fiberboard, and rubber can be used as filler materials. It is preferable to use a material that conforms to the shape or is easy to mold and is inexpensive. For example, if a piece of wood or a veneer made of fibers with a drying shrinkage rate higher than that of the fibers of the raw wood is used, the difference in shrinkage rate will cause This is effective because the cracks tend to become denser as the veneer dries.

Furthermore, the adhesive and filling material do not necessarily need to be filled until the removal marks are completely filled; in short, it is sufficient to fill them up to the extent that the veneer can be reinforced.As is clear from Figure 3, the removal marks are There is no problem even if there is a void in a part of the veneer, but if the removed area is filled in completely, as shown in Figure 4, the veneer can be used without having to cut out the cracked part. This is preferable because it increases the probability and leads to an improvement in yield, and it is more effective if the shape of removal, the amount of adhesive used, the material and color tone of the filling material, etc. are selected with this point in mind.

Also, considering that the crack has been closed, it is even more meaningful to replenish the adhesive and filling material until the removed area is completely filled, and in this way, it is possible to remove the crack from the veneer. The probability that the product can be used without any problems becomes extremely high, and a significant improvement in yield can be expected.

As is clear from the above, according to the method of the present invention, it is possible to effectively join the cracks in the logs, which have been an impediment to process rationalization. This is extremely beneficial as it allows you to

[Brief explanation of drawings]

The drawings are for explaining the present invention, and FIG. 1 is a partial perspective explanatory view for explaining the raw wood before treatment, and FIG. 2 is a partial perspective view for explaining the state in which the method according to the invention is carried out. FIG. 3 is a partial perspective view for explaining a state in which processed logs are turned, and FIG. 4 is a partial perspective view for explaining another joining form. 1... Raw wood, 2... Crack, 3... New joint surface, 4... Removal trace, 5... Replacement material, 6... Cable,
7... Veneer, 8... Cutting tool for cutting veneer lace veneer, 9... Cutting tool for cutting veneer lace, 10... Scrap cutting.

Claims (1)

[Scope of Claims] 1. In order to join cracks at the end of a log, the cracks are closed in advance in a sealed or nearly sealed state using an appropriate closing means, and then the vicinity of the cracks at the end of the log are closed by the closing method. The adhesive, such as a wet curing adhesive, a thermosetting adhesive, or a thermoplastic adhesive, or the adhesive agent and
A method for joining cracks in the end of a log, characterized in that the joining surfaces are joined using wood flour, veneer veneer, wood chips, fiberboard, or a filler material such as rubber. 2. A method for joining cracks in the end of a log as set forth in claim 1, which uses a closing means that tightens the outer periphery of the log using cables. 3. A crack in the end of a log as described in claim 1 or 2, which is made by using a piece of wood or a veneer veneer made of fibers with a drying shrinkage rate larger than that of the fibers of the log as a filling material. How to join.