JPH03278904A - 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 a polyvinyl butyral 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. polyvinyl butyral are incorporated with 5 pts.wt. or more modified polyolefin having a polar group. A belt-like veneer 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 [Field of Industrial Application] The present invention relates to a sheet for adhering plywood, which has good synthesis productivity and enables improvement of the working environment and labor saving in its production.

[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: 180X90CI, 240X12
It is cut to a size slightly larger than the architectural module, such as 0 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
Place the veneer a cut to the required size on the board, and manually
Each sheet is sent to the gluing roll 4 in the adhesive glue tank 1, coated with glue, and sent to the other glue lid 3. This sent-out veneer a is again manually moved to the lifter 3.
When the required number of veneers a are stacked with wood fibers crossed over them, veneers a to which glue is not applied are stacked on top of the veneers a to form a single plywood structure. From then on,
Similar operations are repeated to stack stationary 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 assembled into one body at a temperature of 125 to 130°C, 18 to 10 kgf/c-
At 3.5 to 5 times, the pieces are heated and pressed together to form a plywood base, which is then subjected to decorative cutting, sanding, etc. to produce plywood as a commercial product.

[Problem to be solved by the invention]

However, the above-mentioned conventional adhesive paste application operation 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 working environment and reduce the cost of the adhesive 1fq coating operation.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, first, in manufacturing the conventionally known plywood as described above, adhesion is performed using a heat-press adhesive sheet; The sheet is made of a material in which 5 parts by weight or more of a modified polyolefin having a polar group is added to 100 parts by weight of polyvinyl butyral.

The reason why the amount of the modified polyolefin is 5 parts by weight or more is that if it is less than 5 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. The composite is produced by bonding and integrating.

At this time, the interposition of this sheet prevents the wood fibers from tearing, so there is no need to run the reinforcing tape along them.

〔Example〕

First, sheets (Example 1.2 and Comparative Examples) consisting of the blending ratio of polyvinyl butyral and modified polyolefin shown in Table 1 below were made using the conventionally known example molding method, and each sheet was molded by the process shown in Figure 2. I made plywood A.

Modified polyolefin: UBEBOND M-1000
(Ube Industries ■Product name) To manufacture the plywood A, as shown in the figure, first, a strip-shaped veneer strip 21 with a thickness of 211I11 is formed from raw wood W by peeling with a cutter 20, and the veneer strip 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. For this reason, the winding roll 22
A sheet 12 is interposed between the eyebrows, and the adhesiveness of the sheet 12 prevents the wood fibers from tearing.

These take-up rolls 22 include one with a width of 90 cm 22a, one with a width of 1801 cm 22b, and one with a width of 1 without the sheet 12 attached.
80 cm pieces 220 are made, and they are sent to the next cutting and stacking process by Hawklit 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, heat and pressure is applied from above and below on the stacking table 24, 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
It is dried for 20 hours at a temperature of °C, immersed in boiling water for 4 hours, and further dried for 3 hours at a temperature of 60 °C ± 3 °C.

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 the sheet eliminates the scattering of glue and improves the working environment.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an embodiment of plywood using the sheet according to the present invention, FIG. 2 is an explanatory diagram for manufacturing plywood, and FIG.
The figure is an explanatory diagram of conventional plywood manufacturing. 10.11.13...Plywood, 12...Plywood adhesive sheet, 20...Cutter 21...Veneer strip, 22.22a, 22b , 22C... Winding roll, A... Plywood, B...
Plywood structure, W... Log, H...
...Hawkrit.

Claims (1)

[Claims] (1) In a plywood adhesive sheet interposed between the wood veneers of a plywood formed by stacking and bonding a plurality of wood veneers with their fibers intersecting, polyvinyl butyral 1
A plywood adhesive sheet made of a material in which 5 parts by weight or more of a modified polyolefin having a polar group is added to 00 parts by weight.