JPH03278902A - Adhesive sheet for plywood - Google Patents

Abstract

PURPOSE:To improve the working environment of adhesive application and to reduce the cost by constituting a sheet used for adhesion in manufacturing a plywood of a material wherein an ethylene-vinyl acetate(EVA) is incorporated with a modified polyolefin having a polar group. CONSTITUTION:A sheet 12 for adhering a plywood consists of a material wherein 100 pts.wt. EVA are incorporated with 7 pts.wt. or more modified polyolefin having a polar group. A belt-like veneer belt 21 with a thickness of 2mm is formed from a raw wood (w) by wig peeling using a cutter 20 and on the way of the veneer belt 21 to a winding roll 22, the sheet 12 is attached to the whole surface. A product wherein the sheet 12 is placed between layers of the veneer belt 21 is prepd. thereby, on the winding roll 22, split of wooden fiber is prevented by adhesiveness thereof. In addition, as placing the sheet between the veneer belts is easy in comparison with coating with an adhesive, the productivity of plywood is remarkably improved while the working environment being improved without flying of an adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a plywood bonding sheet that has good plywood productivity and enables an improved working environment and labor saving in the production thereof.

[Conventional technology]

Plywood is made by gluing thin veneer sheets of wood together with adhesive. Conventionally, plywood is manufactured by first slicing the raw wood along the outer circumferential direction to the required thickness. The veneer is made into a sheet-like veneer, and reinforcing tape (thread) is attached to both edges of the veneer to prevent it from tearing in the direction perpendicular to the wood fibers, and then it is wound up into a roll. This rolled veneer has length and width: 180X90cal, 240X1
It is cut to a size slightly larger than the building module, such as 20 cm, and adhesive glue is applied to it.

This adhesive glue application work is carried out by placing lifters 2.3 on both sides of the adhesive tank 1 and lifting the lids 2 and
A sheet of paper cut to a required size is placed on the sheet, and each sheet is manually fed into the gluing roll 4 of the adhesive gluing tank 1, where the glue is applied and fed to the other glue lid 3. The sent out veneers a are again manually stacked on the lifter 3 with the wood fibers crossed, and when the required number of veneers a are stacked, a veneer a to which no glue has been applied is placed on top of it. They are stacked together to form a single plywood structure. Thereafter, similar operations are repeated to stack a certain amount of plywood structures on the lifter 3.

Once a certain amount of plywood is stacked in this way, it is fed to a heating press using a transport vehicle, and the certain amount of stacked plywood structure is integrated into a 125-130°C 18C18-1O/ct.
The material is heated and pressed for 3.5 to 5 times to create a plywood base, which is then subjected to decorative cutting, sanding, etc., to produce plywood as a commercial product.

[Problems to be Solved by the Invention] However, the conventional adhesive paste application operation described above requires a large number of workers, which poses a problem in terms of cost. Also,
Due to the rotation of the roll 4, the glue is scattered around, and each time the veneer a is handled, wood powder is scattered from the veneer a.
Since a large number of them are handled, there is also a large amount of them floating around, leading to a deterioration of the working environment.

The present invention takes the above points into consideration and aims to improve the work environment and reduce costs for the adhesive application work.

[Means to solve the problem]

In order to solve the above-mentioned problems, in the present invention, first, in manufacturing the conventionally known plywood mentioned above, adhesion is performed using a heat-press adhesive sheet, and the sheet is made of ethylene vinyl acetate (hereinafter referred to as EVA). The structure is made of a material in which 7 parts by weight or more of a modified polyolefin having a polar group is added to 100 parts by weight (100 parts by weight).

The reason why the amount of the modified polyolefin is 7 parts by weight or more is that if it is less than 7 parts by weight, the desired adhesive strength cannot be obtained. Incidentally, if the amount of the modified polyolefin increases, a negative economic effect will occur, so the amount added to achieve the desired adhesive strength with as little amount as possible is appropriately selected through experiments and the like. In particular, since wood is made of cellulose, good results can be obtained using polar groups such as hydroxyl and carboxyl groups.

[Effect]

The plywood adhesive sheet according to the present invention constructed in this way is, for example, wound around the entire surface of a peeled veneer, cut to a size that matches the building module, stacked on top of each other, and heated and pressed. They are then glued together to produce plywood.

At this time, the presence of this sheet prevents the wood fibers from tearing, so there is no need to add the above-mentioned reinforcing tape 6 [Example] Sheets (Example 1.2 and Comparative Example) were made by a conventionally known sheet forming method, and plywood A was made from each sheet according to the steps shown in FIG.

Modified polyolefin: UBEBOND M-1000
(Ube Industries ■Product name) As shown in the figure, the production of the gou viA is as follows: First, a strip-shaped veneer strip 21 with a thickness of 211 II and 11 is formed from log W by cutting with a cutter 20, and then the veneer strip is 21 is being sent to the take-up roll 22, the sheet 12 according to Example 1.2 and Comparative Example is attached to the entire surface thereof. Therefore, the winding roll 22 has the sheet 12 interposed between the layers of the veneer strip 21, and the adhesiveness of the sheet 12 prevents the wood fibers from tearing. This take-up roll 22 has a width of 90c+o 22a.
Then, a sheet 22b with a width of 180 cm and a sheet 220 with a width of 180 cm without the attached sheet 12 are made, and these are sent to the next cutting and stacking process by the Hawk Grit H.

In this process, each veneer strip 21 is sent from each winding roll 22a, 22b, 22C to a cutting machine 23, and
cm, cut into lengths of 90 cm and veneer 11.10.1
3 and sent to the overlapping table 24. That is, the veneer 10, the veneer 11, the veneer 10, the veneer 11, and the veneer 13 are fed to form a five-layer plywood structure B. When an appropriate amount of this plywood structure B is stacked, the upper and lower sides of the stacking table 24 are heated and pressurized so that each veneer 10.11
．． Integrate 13. This heating and pressing is performed on the stacking table 2.
It is also possible to move from step 4 to a dedicated process. After being integrated, decorative cutting, sanding, etc. are performed in the same manner as before to form plywood A.

The plywood A according to Example 1.2 and Comparative Example manufactured in this manner was subjected to the following Japanese Agricultural Standards for Plywood: Class 1 immersion peeling test, and the results are shown in the lower column of Table 1.

The following part is ``After immersing the test piece in boiling water for 4 hours, 60℃±3
℃ temperature for 20 hours, immersed in boiling water for 4 hours, and further dried at a temperature of 60℃±3℃ for 3 hours.

From the above results, plywood according to the example, each veneer 10.11.
It can be seen that no peeling occurred between the samples of 13 and 13, and that the sample was sufficiently usable.

〔Effect of the invention〕

Since the present invention is constructed as described above, if it has heat-pressure adhesive properties and is used when winding a veneer that has been peeled, there is no need to add a reinforcing tape as in the past. Since the interposition of sheets is much easier than applying glue, the productivity of plywood is greatly improved.

In addition, the use of sheets prevents glue from scattering (and improves the work environment).

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of plywood using the sheet according to the present invention, FIG. 2 is an explanatory diagram of manufacturing plywood, and FIG. 3 is an explanatory diagram of conventional plywood manufacturing. 10.11.13...Plywood, 12...Plywood adhesive sheet, 20...Cutter 21...Veneer band, 722.22a, 22b , 22c...Take-up roll, A...Plywood, B...
・Plywood structure, W... Log, H.
...Hawklit.

Claims (1)

[Claims] (1) In a plywood adhesive sheet interposed between the wood veneers of a plywood made by stacking and bonding a plurality of wood veneers with their fibers intersecting, ethylene vinyl acetate 10
A plywood adhesive sheet made of a material in which 7 parts by weight or more of a modified polyolefin having a polar group is added to 0 parts by weight.