JP5787395B2 - Manufacturing method of wood composite board - Google Patents

Description

  The present invention relates to a method for producing a wood composite board in which one wood board and the other wood board are bonded with a water-based adhesive to obtain a wood composite board.

Conventionally, a wood composite board used as a base material such as a wood composite flooring is manufactured by bonding a plywood or a wood fiber board such as LVL and MDF with an adhesive, but warping may occur after bonding. is there. In particular, when a water-based adhesive is used for bonding, the occurrence of warpage becomes significant. This is considered to be due to the fact that the adherend absorbs the moisture of the adhesive and then dries during bonding, causing expansion and contraction, and warping due to the difference in expansion and contraction of the upper and lower layers of the adherend.
As a method of preventing this phenomenon, there is a method of using a non-aqueous adhesive such as a solvent type or a hot melt type as an adhesive. However, there is a problem in terms of workability, environmental aspect, cost, and the like due to the large equipment. It is desirable to bond with the adhesive.

  In order to solve such problems, as a method of manufacturing a wood composite board that uses a water-based adhesive as an adhesive to prevent warping, a plywood and MDF are bonded in advance with a water-based adhesive. There has been proposed a method in which MDF is pretreated under heating and pressure, and thereafter, plywood and MDF are bonded with a water-based adhesive (for example, see Patent Document 1).

JP 2007-98704 A

  However, in the manufacturing method described in Patent Document 1 described above, since MDF is pre-treated under pressure and pressure before bonding, special and expensive equipment is required, and pre-treatment takes time, There was a problem that the manufacturing cost was high.

  As a result of repeated research and studies to solve such problems, the present inventor needs to minimize the influence on the entire board when the water content of the water-based adhesive is absorbed by the wood board, What is absorbed is the very surface of the surface to be bonded, and that part expands and contracts due to the absorbed moisture, so that the distortion affects the entire plate and appears as a warp, and thus absorbs the moisture of this adhesive. It is found that by drying immediately before adhering the very surface, bringing it into a contracted state and then bringing it into contact with the adhesive, the shrinkage is restored to the normal state by absorbing the moisture of the adhesive, and it can be bonded without causing distortion. The present invention has been completed.

  An object of the present invention is to provide a method for producing a wood composite board, which can obtain a wood composite board using a water-based adhesive suitable for building materials without warping, with simple equipment and at low cost. It is in.

In order to achieve the above object, the invention according to claim 1 is characterized in that one wood board made of wood fiber board and the other wood board made of plywood or LVL are bonded and integrated by using an aqueous adhesive. A method for producing a composite board, wherein the adhesive surface side of one wood board made of the wood fiber board is dried, and the aqueous adhesive is applied to the adhesive face of the other wood board made of the plywood or LVL in parallel. Then, after drying on the bonding surface side of the one wood board made of the wood fiber board, the one wood board made of the wood fiber board and the other wood board made of the plywood or LVL are immediately bonded and integrated. Features.

The invention according to claim 2 is characterized in that the adhesion of one wood board made of the wood fiber board and the other wood board made of the plywood or LVL is pressure-bonded at room temperature. And

According to the present invention , by drying the bonding surface side of one wooden board made of wood fiber board , the bonding surface side is in a contracted state, and after drying on the bonding surface side of one wooden board, the bonding surface in parallel Adhering to the other wood board made of plywood or LVL coated with water-based adhesive, the dry adhesion side of one wood board made of wood fiber board is the adhesion surface of the other wood board made of plywood or LVL By absorbing the moisture of the adhesive applied to, the contracted state returns to the normal state, the occurrence of distortion is prevented, and warp does not become a problem, and a wood composite board suitable for building materials can be manufactured.
Further, in this method, it is not necessary to press-dry the whole wood board, and the wood composite board can be manufactured with simple equipment and at low cost. Moreover, since the drying of the bonding surface side of one wooden board made of wood fiber board and the application of the aqueous adhesive to the bonding surface of the other wooden board made of plywood or LVL are performed in parallel, After drying the bonding side of the wood board, one wood board made of wood fiber board and the other wood board made of plywood or LVL can be bonded immediately without taking time, and therefore one side made of wood fiber board Adhesion before considering the moisture absorption in the atmosphere before bonding on the bonding surface side of the wooden board in the dry state of the wooden board, it is possible to reduce the degree of dryness on the bonding surface side of one wooden board consisting of its wood fiber board Thus, the manufacturing time can be shortened.

It is process explanatory drawing which shows the 1st reference example of the manufacturing method of the wood composite board which concerns on this invention. It is process explanatory drawing which shows the 2nd reference example of the manufacturing method of the wood composite board which concerns on this invention. It is process explanatory drawing which shows an example of embodiment of the manufacturing method of the wood composite board which concerns on this invention.

Hereinafter, an embodiment for carrying out a method for producing a wood composite board according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a process explanatory view showing a first reference example of a method for producing a wood composite board according to the present invention.
In this reference example, first, the bonding surface 1a of one wooden board 1 and the bonding surface 2a of the other wooden board 2 are heated by the heating device 3, and the bonding surfaces 1a and 2a side is dried. Drying of the bonding surface 1a side of one wooden board 1 and the bonding surface 2a side of the other wooden board 2 is sufficient for the drying of a slight layer from the surface, and the heating temperature and heating time here are the bonding surface 1a. The temperature and time for drying a slight layer on the 2a side are set. As a result, the layer on the bonding surface 1a of one wooden board 1 and the layer on the bonding surface 2a side of the other wooden board 2 are dried and contracted.

Next, after the adhesive surface 1a side of one wooden board 1 and the adhesive surface 2a side of the other wooden board 2 are dried, the adhesive surface 1a of one wooden board 1 and the other wooden board 2 are immediately bonded. The water-based adhesive 5 is applied to any one of the surfaces 2a by the application device 4, and the adhesive surface 1a of one wooden board 1 and the adhesive surface 2a of the other wooden board 2 are bonded and integrated. In this reference example, the water-based adhesive 5 is applied to the bonding surface 2 a with the other wood board 2.
“Immediately” here means that the dried layer portions on the side of the bonded surface 1a of the dried wooden board 1 and the bonded surface 2a of the other wooden board 2 are affected by moisture in the atmosphere. I mean.

  The dried layer portion in the contracted state on the side of the dried bonding surfaces 1a and 2a of the one wooden board 1 and the other wooden board 2 thus bonded absorbs the moisture of the aqueous adhesive 5 so that the contracted state is normal. Returning to the state, the wood composite board 6 is produced in which the occurrence of distortion is prevented and the warpage is not a problem.

FIG. 2 is a process explanatory view showing a second reference example of the method for producing a wood composite board according to the present invention.
In this reference example, the bonding surface 1a of one wooden board 1 is heated and dried by the heating device 3 out of the bonding surface 2a of one wooden board 1 and the other wooden board 2. The other steps are the same as those in the first reference example. In this example as well, the same woody composite board 6 as in the first reference example is manufactured.

FIG. 3 is a process explanatory view showing an example of a method for producing a wood composite board according to the present invention.
In this example, the bonding surface 1a side of one wooden board 1 made of wood fiber board is heated and dried by a heating device 3, and applied in parallel to the bonding surface 2a of the other wooden board 2 made of plywood or LVL. 4, apply the aqueous adhesive 5.
Next, as soon as the bonding surface 1a side of one wooden board 1 is dried, the bonding surface 1a of one wooden board 1 made of wood fiber board and the other wooden board 2 made of plywood or LVL are immediately bonded. And unite.

Thus, by drying the bonding surface 1a side of one wooden board 1 made of wood fiber board , the bonding surface 1a side is contracted, and the bonding surface 1a side of one wooden board 1 made of wood fiber board After drying, the adhesive surface 2a is bonded to the other wood board 2 made of plywood or LVL coated with the water-based adhesive 5 in parallel, so that one wood board 1 made of wood fiber board is dried. The dry layer portion in the contracted state on the 1a side absorbs the moisture of the water-based adhesive 5, so that the contracted state returns to the normal state, the generation of distortion is prevented, and the wood composite board 6 in which warpage does not become a problem is manufactured. .

In this example, in the heat drying on the side of the bonding surface 1a of the one wood board 1 made of the wood fiber board , as in the first reference example, it is sufficient to dry a few layers from the surface. Since the drying of the bonding surface 1a side of one wooden board 1 made of wood fiber board and the application of the aqueous adhesive 5 to the bonding surface 2a of the other wooden board 2 made of plywood or LVL are performed in parallel, the wooden fiber board after one adhesive surface 1a side of the wood board 1 consisting of drying, it is possible to bond the other wood board 2 consisting of one of the wood board 1 and the plywood or LVL consisting immediate wood fiber board without leaving a time, thus Adhering before considering the moisture absorption in the atmosphere before adhering to the bonding surface 1a in the dry state of one wood board 1 made of wood fiber board , adhesion of one wood board 1 made of that wood fiber board It becomes possible to reduce the dryness of the surface 1a side Than the first reference example can shorten the manufacturing time.

Examples of the present invention will be given below to illustrate the features of the present invention. However, the present invention is not limited to the examples.
A 9 mm thick 5 mm-bonded MDF having a thickness of 2.7 mm as one wooden board 1 made of wood fiberboard and a urea melamine co-condensation resin adhesive as the other wooden board 2 made of plywood or LVL. A plywood layer was used and a 49% solid vinyl acetate emulsion adhesive was used as the aqueous adhesive 5.

First, the MDF is placed on a heating plane on a planar heater, which is the heating device 3 adjusted to a temperature of 105 ° C., and measurement of the time for drying the bonding surface side of the MDF is started. Next, an aqueous adhesive is applied to the upper surface of the plywood at a coating amount of 20 g / square scale.
When the measurement time is 30 seconds, the MDF with the bonded surface dried is transferred from the sheet heater onto the plywood coated with water-based adhesive, and compressed at room temperature at 5 kgf / cm ² for 30 minutes. A wood composite board was manufactured by curing the aqueous adhesive.

  The moisture content of MDF before processing was 8.3%, and the moisture content of plywood was 11.2%. Moreover, the moisture content of MDF after a heating was 8.1%. The moisture content of this MDF and plywood is the estimated moisture content due to weight change. Therefore, it can be estimated that the moisture content of the heated adhesive surface in the heated MDF is lower than 8.1%.

The wood composite board produced in this way is subdivided into 300 mm x 300 mm, cured by cold pressure at 20 kgf / square scale for 24 hours, allowed to stand without load, and the standard (50% humidity) on the first day after curing is released. The warpage of the wood composite board was measured after 2 days in high humidity (humidity 65%, temperature 22 ° C) and 2 days in low humidity (humidity 45%, temperature 20 ° C). .
As a result, warpage that becomes a concave of about 0.1 mm was observed only after 2 days in low humidity, but the displacement of the warpage is close to zero, and it is possible to manufacture a wood composite board that does not cause warp that causes problems Was confirmed.

1 wood board made of 1 wood fiber board 1a adhesive surface 2 plywood or other wood board made of LVL 2a adhesive surface 3 heating device 4 coating device 5 aqueous adhesive 6 wood composite board

Claims (2)

A method for producing a wood composite board in which one wood board made of wood fiber board and plywood or the other wood board made of LVL are bonded and integrated using an aqueous adhesive,
One side made of the wood fiber board is made by drying the adhesive surface side of one wood board made of the wood fiber board, and applying the aqueous adhesive to the side of the other wood board made of plywood or LVL in parallel. A method for producing a wood composite board, comprising: immediately after drying an adhesive surface side of a wood board, the one wood board made of the wood fiber board and the other wood board made of the plywood or LVL are bonded and integrated. . 2. The method for producing a wood composite board according to claim 1, wherein the wood board made of the wood fiber board and the wood board made of the plywood or the LVL are pressure-bonded at room temperature .

Images