JPS5871105A - Method of joining veneer plywood - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bonding force method for veneer plywood (hereinafter referred to as plywood).

Conventionally, as a method for joining plywood, for example, the scarf joint method is partially known.

In this method, as shown in FIG.
Then, at the joint end, a sloped joint surface is formed so that the scarf cut length is approximately 10 to 12 times the plywood thickness t, and both of the joint surfaces are adhesively joined to form a joint surface of unequal thickness. It is intended to obtain no bonded plywood. However, in this method, there is an extremely large amount of roughness in the bonding process to ensure that the respective bonding surfaces match well, and in addition, there is a limit to the accuracy of processing the bonding surfaces, making it difficult to achieve sufficient bonding strength. There was a drawback that (1) could not be obtained stably.

The present invention provides a plywood joining method that can achieve plywood joining by extremely simple means and that can stably obtain sufficient joint strength, in place of such conventional techniques.
The details will be explained based on the illustrated embodiment as follows.

Figures 2 (A) and (B) show two pieces of plywood 1.
3 (A) and (B) are explanatory diagrams showing the state in the joining process of two pieces of plywood described in 1111, and FIG. This is an explanatory diagram showing the joined plywood after joining, and as is clear from the figure, first, of the two sheets of plywood to be joined, the joined end 1a of the plywood 1, and if necessary, the plywood A scarf cut is made on the joint end 2a of 2. The cut length Ll is usually within the range of 2 to 12 t, and preferably 3 to 6 t, where t is the plywood thickness. Also, for 2′, 0
~12t, roughly the same as ρ1.

Of course, the scarf cut of this scale is formed by any suitable means such as cutting with a knife or grinding with a sander.

Then, as shown in FIGS. 2(A) and 2(B), the joint end 1
Apply an appropriate adhesive 3 such as a thermosetting adhesive, a thermoplastic adhesive, or a wet curing adhesive to 2a or both over an appropriate area, and then ), overlap both joint ends 1a and 2a (in this figure, glue 3
(omitted).

Next, as shown in Fig. 3(B), a base plate 4 made of thousand-faced earth
Pressure is applied as shown in the figure by a press device 7 consisting of a press plate 6 having an elastic body 5 such as a lx plate. At this time, the elastic body 5 deforms the plywood 2 toward the base plate 4 while deforming in a state corresponding to the overlapping portion of the plywood 1 and 2. Under this pressure, the adhesive interposed between the joint ends 11j and 11j is cured, and as shown in FIG. 4, the adhesive on the base plate side is i! I
Next, a T8 plywood 8 is obtained which is made into a planar shape.

As described above, the method for joining plywood according to the present invention involves applying a scarf cut to the joining end of one of the two plywood boards to be joined, and cutting the joining end of the other plywood as necessary. Both joint ends are overlapped with adhesive so that at least a part of the overlapping part is thicker than the thickness of the plywood, and the joint end with the scarf cut is flat from the side. Pressure is applied to the overlapped portion by applying pressure to the base plate that maintains the curvature and an elastic body from the opposite side, and under the pressure, the adhesive is cured and the joint ends are joined. Since this is a unique plywood joining method, there is no strict requirement for scarf cutting processing accuracy, and a rough overlapping condition is sufficient, making the joining work extremely easy and the accompanying joining process. The stability of strength is also significantly improved.

3- In addition, the plywood joined by the method of the present invention has a thickness that is not less than the thickness of the plywood at the joint part, but this part exhibits so-called lip lateral progression. Therefore, it has one surface that is favorable in terms of strength, and one side of the bonded plywood can be ensured to be in a continuous and substantially flat state.
For example, when used for plywood to which decorative boards are glued, etc.
This will not cause any problems in applications where only one side of the plywood is required to be flat.

Further, in carrying out the present invention, FIG. 3(A) of the above embodiment
The overlapping of the joined ends can be carried out directly on the base plate that applies the pressure described above or on the elastic body, or after substantial overlapping is performed in any space, or It is also possible to press the above-mentioned pressing member by moving it toward the overlapping portion while performing the above-mentioned operation.
) After being temporarily bonded to a state such as ), the materials may be transported to a press machine that applies the pressure described above.

Regarding the scarf cut to be made at the joint end of the plywood to be joined, the cut is a curved cut such as the joint end shown in Fig. It may have a surface, and there are no particular restrictions on its shape.However, in any case, it is preferable that the thickness of the tip 9 at the joint end is thin, as in the joint end 1a in the same figure. Form a scarf cut so that Therefore, the shape of the scarf cut, the cut length, etc. are determined appropriately according to the degree of flatness required to obtain the desired flatness.In addition, the joint end 2a located at the elastic body extension; In this case, as shown in FIGS. 6 and 7, the described joining can be carried out without scarf cutting the joining end 2a.
Furthermore, as shown in FIGS. 8 and 9, a scarf cut may be made so that the middle plate of the plywood 2 is exposed to the outside.

In particular, in the case shown in Figure 9, the scarf cover exposes the middle plate even if it is attached to the joint end la located on the base plate side.
It has been given a

- force, f in Fig. 1θ] The one shown is the one in which plywood boards of the same thickness are joined in such a manner that the front and back boards of the white board are joined horizontally. In practice, other materials with different thicknesses may be used.

Alternatively, it is also possible to join two sheets of plywood with the fiber Ut directions set in a desired relationship.

Further, the present invention is not limited to the exemplified 3-ply ordinary plywood, but can be made of any other plywood such as A-layer plywood.

In addition, if you place emphasis on the bonding strength of the bonded plywood, the fourth
It is preferable that the overlapping length No. 8 indicated in the figure and Fig. 1 θ is about 4 to IO times the thickness of the plywood, the adhesive is also thermosetting, and the pressing device used for pressing is a hot press type. It is desirable to do so. Of course, if necessary, the overlapping length of mI may be set to be larger or smaller than 8.

However, in any case, when the joined ends are overlapped, the length of the overlapped length j28 is longer than the scarf cut length of the longer scarf cut made on the two joined ends. The basic principle is to make it large.

If specified, it will be 18-1 or 8-1.

Preferably, No. 8 has a plywood thickness of at least 1 or more,
Furthermore, 3 is superimposed so that it becomes larger than 1Ot, and in the example shown in Fig. 4, it is about 7t, and the 1st θ
In the example shown, the joint is made larger than J21 by about 5t.

It is also possible to improve the scarf cut joint method as illustrated in FIG. 1 by using the method of the present invention.

Wear. That is, in FIG. 1, the plywood l to be joined,
2 is further overlapped by more than the plywood thickness t than the state shown in the figure, and the overlapping length 8 (not shown) is made larger than the scarf length by 1 or more, thereby reducing the thick part of the joint. The present invention described in detail above can also be put to practical use in cases where the work is facilitated by unevenly distributing the surface on one side and ensuring flatness on the other side.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the conventional plywood joining method, Figure 2 (A
) ・(B) shows the processed state of the edge of the base plate when carrying out the plywood joining method according to the present invention. FIG. 4 is an explanatory diagram showing the joined plywood. Fig. 10 is an explanatory diagram showing an example of changing the processing state of the joint end of plywood.
1 is a plywood, 1a and 2a are joint ends, 3 is an adhesive, 4 is a base plate, 5 is an elastic body, and t is a plywood thickness. Patent applicant Meinan Seisakusho Co., Ltd. Agent Patent attorney Ken Ito- 12d2 ■(29 12, 2 ■, I8 Procedural amendment (voluntary) 1. Indication of the case 1982 Patent Application No. 169829 2- Name of the invention Veneer Plywood joining method 3, relationship with the amended case Patent applicant address: 3-130 Kajita-cho, Obu City, Aichi Prefecture Name: Minami Manufacturing Co., Ltd. Representative: Katsuji Hase 4, Agent: 457 Address: Nagoya 1-18-6 Higashiura-dori, Ichinami-ku Specification to be amended No. 15-1 Bright strip [Title of the invention] Method for joining veneer plywood [Claims] l At the joining end of one veneer plywood If necessary, make a scarf cut at the joint end of the other veneer plywood, and glue both joint ends so that at least a portion of the overlap is thicker than the thickness of the veneer plywood. The two sides of the joint end having the scarf cut are brought into contact with a base plate that maintains flatness, and the opposite side is brought into contact with an elastic body to apply pressure to the overlapping part, and under the applied pressure, A method for joining veneer plywood, which is characterized by curing the adhesive described in 1M1 and joining the joint ends. Regarding a joining method. Conventionally, as a method for joining plywood, for example, the scarf joint method is generally known. This method is shown in FIG. A bonded surface is formed on the part so that the scarf cut length L is about 10 to 12 times the plywood thickness t, and both bonded surfaces are adhesively bonded to obtain a bonded plywood with no thickness variation. However, in this method, there are extremely great difficulties in making the respective joint surfaces match well in the joining process, and in addition, there is a limit to the accuracy of processing the joint surfaces, making it difficult to achieve good results. However, in place of such conventional branching techniques, the present invention has been developed to create a plywood joint that can be achieved by extremely simple means and that can provide stable and good joints. The details of the joining method will be explained based on the illustrated embodiment. Figures 2 (A) and (B) show two sheets of plywood to be joined, and two pieces of plywood. 3 (A) and (B) are explanatory diagrams showing the state of the joint end portions 1a and 2a of...1. This is an explanatory diagram showing the joined plywood after being joined.As is clear from the figure, first, of the two plywood sheets to be joined, the joining end of plywood 1? ill l a,
Also, if necessary, a scarf cut is made on the joint end 2a of the plywood 2. The cut length fLl is usually in the range of 2 to 12 tons, preferably about 3 to 61 tons, where t is the plywood thickness. Regarding L2: dO to 12t, preferably to the same level as il. Of course, this type of scarf cut can be formed by any suitable means such as cutting with a knife or grinding with a sander. Then, as shown in FIGS. 2(A) and 2(B), the joint end 1
a or 2a, or both over a suitable extent, a thermosetting adhesive such as an amino resin adhesive, a thermoplastic adhesive such as a hot melt adhesive, or a wet curing adhesive. Apply an appropriate adhesive 3 such as
Both joining ends 1a and 2a are overlapped as shown in (the adhesive 3 is not shown in this figure). Then, as shown in FIG. 3(B), pressure is applied as shown in the figure using a press device 7 consisting of a flat base plate 4 and a press plate 6 having an elastic body 5 such as a comb plate. At this time, the elastic body 5 deforms the plywood 2 toward the base plate 4 while deforming in a state corresponding to the overlapped portion of the plywood 1 and the plywood 2. Thus, the adhesive interposed between the bonded ends is cured by the pressure F, and a bonded plywood 8 is obtained in which the curve of the base plate continues to form a concavity shape as shown in FIG. 4. As described above, the method for joining plywood according to the present invention involves applying a scarf cut to the joining end of one of the two plywood sheets to be joined, and cutting the joining end of the other plywood as necessary. Both joint ends are overlapped with adhesive so that at least a part of the overlapping part is thicker than the thickness of the plywood, and the joint end with the scarf cut is flat from the side. Pressure is applied to the overlapping part by applying pressure to the base plate that maintains this, and an elastic body from the opposite side, and then hardening the adhesive at the pressurizing groove to join the joint ends. Since this is a plywood joining method that has the special feature of performing the following steps, there is no strict requirement for scarf cutting processing accuracy, and a rough overlapping condition is sufficient, making the joining work extremely easy. In addition, the stability of the joint is also significantly improved. It should be noted that the plywood joined by the method of the present invention has a thickness that is considerably larger than the thickness of the plywood at the joint. However, since this part speeds up the formation of the structure, it has one surface that is favorable in terms of strength, and one side of the bonded plywood can ensure a continuous and substantially flat state.
For example, when used for plywood to which decorative boards are glued, etc.
This does not cause any problem in applications where only a portion of the plywood is required to be flat. In addition, in carrying out the present invention, FIG. 3 (A
) The overlapping of the joined ends can be performed on the base plate 1- which applies the pressure described above, or directly on the elastic body, or it can be done after substantially overlapping in any space. Alternatively, it is also possible to press the above-mentioned pressing member by moving it toward the overlapping portion while performing the above-mentioned operations.Furthermore, it is also possible to apply the above-mentioned pressure after temporarily adhering it in the state shown in Fig. 3(A) in advance. It may also be carried into the press equipment where it will be carried out. Also, regarding the scarf cut formed at the joint end of the plywood to be joined, the cut may have a curved surface or a cut surface, such as the joint ends 1a+ and 2a shown in FIG. There are no particular restrictions on its shape. However, in any case, the scarf force y) is preferably created such that the thickness of the tip 9 at the joint end becomes thinner, as shown at the joint end la in the drawings. In particular, for the joint end located on the base plate 11 that maintains flatness during pressurization, the thickness of the tip has a large effect on the flatness of the joint plywood 8, so the flatness is The shape, cut length, etc. of the scarf cut are appropriately determined according to the degree of request to obtain the desired flatness. Furthermore, for the joining end portions 2a placed f on the elastic body side, as shown in FIGS. 6 and 7, the described joining may be performed without scarf-cutting the joining end portions 2a. Furthermore, as shown in FIGS. 8 and 9, the plywood 2 may be scarf cut so that the middle plate is exposed to the outside. Particularly in the case shown in Fig. 9, the joint end la located on the heath board side
Even when lined up, the scarf cut 5- exposes the middle plate. The example shown in FIG. 10 is one in which plywood boards of the same thickness are joined together in such a manner that the front and back plates of the plywood boards are joined in a horizontally serpentine manner. Well,
It is also possible to join two sheets of plywood with different thicknesses or with the fiber directions in a desired relationship. Further, the present invention is not limited to the exemplified 3-ply ordinary plywood, and any other plywood such as parallel plywood can be used. In addition, if you place emphasis on the bonding strength of the bonded plywood, the fourth
The overlapping length 8 indicated in the figure and the first θ diagram is
It is desirable that the thickness be about 4 to 10 times the thickness of the plywood, that the adhesive be thermosetting, and that the press device used for pressurization be of a hot press type. Of course, the overlapping length L8 described in 01j can be made larger or smaller as necessary. However, in any case, when the joined ends are overlapped, the overlapped length L8 is longer than the scarf cut length of the longer scarf cut made on the two joined ends. The basic principle is to make it large. If you specify it! 8-inch L1 or 18-inch L2. Preferably, 18 is at least the plywood thickness t,
Furthermore, 3 is superimposed so that it becomes larger than lOt, and in the example of Fig. 4, it is about 7t, and the 1st θ
In the example shown in the figure, the joint is made larger than 11 by about 5t. The method of the present invention can also be used to improve the scarf cut joint method as illustrated in FIG. That is, in FIG. 1, the plywood sheets 1 and 2 to be joined are overlapped by 1 more than the plywood thickness t compared to the state shown in the figure, and the overlapping length 18 (not shown) is the scarf cut length. The following can also be used in cases where the thickness is made larger than L by more than t, and the resulting thick part of the joint is unevenly distributed on one side, ensuring flatness on the surface on the other side of the force and facilitating work. The present invention described in detail can be put into practical use. [Brief explanation of the drawings] Figure 1 is an explanatory diagram showing the conventional plywood joining method, and Figure 2 (A
) ・CB) is an explanatory diagram showing the processing state of the plywood end when carrying out the plywood joining method according to the present invention. FIG. 3 (A) ・(B) is an explanatory diagram showing the joining process. FIG. Figures 5 to 9 are explanatory diagrams showing plywood. Figures 5 to 9 are explanatory diagrams showing examples of changes in the processing state of the joint ends of plywood to be joined. Figure 10 is an explanatory diagram showing another example of joining. 1.2
is plywood, la and 2a are joint ends, 3 is an adhesive, 4 is a base plate, 5 is an elastic body, and t is a plywood thickness. Patent applicant Meinan Seisakusho Co., Ltd. Agent Patent attorney Ken Imaki −

Claims (1)

[Claims] l. Make a scarf cut at the joint end of one veneer plywood, and if necessary, make a scarf cut at the joint end of the other veneer plywood so that at least a part of the overlapping part is thicker than the veneer joint thickness. Both joint ends are overlapped with an adhesive interposed so as to increase the thickness, and a base plate is applied from the side of the joint end with the scarf cut to maintain the instep properties, and an elastic body is applied from the opposite side. Pressure is applied to the overlapping portion of the curves in contact with each other, and the adhesive described in iI'II is cured at the pressure,
A method for joining plywood veneers, with the special feature of joining the joint ends.