JP2001277212A - Method for manufacturing warp preventive floor board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of not definite warp remedy due to a large unevenness of a warp of a woody material owing to a variable factor as compared with a warp preventive effect even in any of a conventional rear surface sheet sticking method, a rear surface water coating method, a method for regulating a water content of only a base material surface layer to a low content and the like variously tried as a warp preventing method without definite warp remedy from the result of a large irregularity in the warp of the woody material caused by not only temperature and humidity conditions of an environment surrounding the woody material but also a cause for variation due to individual difference of logs in addition to the degree of a moisture gradient in a material, a tree type, a heartwood or a sapwood, a butt end surface of a timber, a cross grain surface or a straight grain surface in a water content change as a main cause for the warp of the woody material. SOLUTION: A method for manufacturing a warp preventive floor board comprises the steps of adhering a thin sheet for preventing a warp to a rear surface of a woody base material such as a woody floor board, a plywood or the like, then giving a moisture to the sheet, and then thermally pressing the sheet. Thus, the warp is extremely reduced in a surface protruding direction. Then, the unevenness can be decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wooden floorboard used for interiors of houses and other buildings, and more particularly, to a wooden floorboard which is extremely unlikely to warp.

[0002]

2. Description of the Related Art Since a wooden floorboard is made of a woody material such as plywood, fiberboard, and chipboard, the wooden material expands and contracts due to a change in water content over time, and the floorboard itself warps, causing a serious problem. . There are two types of warpage, namely, a so-called reverse warp in a surface concave warp direction and a so-called mountain warp in a surface convex warp direction, and a torsion phenomenon that occurs when these are combined may also occur.

[0003] If this reverse warpage occurs in the course of the floorboard manufacturing process, it not only causes a processing trouble in the subsequent steps, but also the construction of the reverse warp floorboard is very difficult, which has been a serious problem. Also, the so-called mountain warpage in the surface convex direction is a cause of a trouble in a manufacturing process and a trouble in construction, though not so much as reverse warpage.

Therefore, conventionally, in order to prevent the warp of the wooden floorboard,
Various methods have been devised, such as using a synthetic resin film, paper, or a composite sheet thereof as a backing material on the back side of a wooden substrate, and applying water to the back side. Also,
In some cases, a low-quality veneer veneer that has defects such as knots and discoloration is used as a backing material. Further, when the wood base material is plywood, the so-called reverse warpage in the direction in which the surface becomes concave is prevented by setting the moisture content of the surface veneer to be considerably lower than that of the other layers.

Japanese Patent Application Laid-Open No. 10-109380 discloses a thin paper or titanium paper weighing about 23 to 30 g / m ² as a backing paper on the back of a wooden board having decorative paper adhered to the surface.
It describes that kraft paper is used.

[0006]

However, the cause of the warpage of the woody material is mainly caused by the fluctuation of the water content. However, the movement of water in the woody material depends on the degree of the water gradient in the material.
It is greatly affected by the type of tree, the type of heartwood sapwood, the type of wood, the woodgrain, plank, and straight-grain, and the temperature and humidity conditions of the environment surrounding the woody material. Not only that, but also due to the variation of individual differences in the raw wood, the warpage of the woody material is a phenomenon with extremely large variations. Therefore, various methods have been tried according to the prior art, such as a back sheet bonding method, a back water application method, and a method in which only the surface layer of the base material is adjusted to have a lower moisture content than other layers. Also in the method (1), the variation caused by the above-mentioned fluctuation causes is larger than the warpage preventing effect, and the method cannot be a decisive warpage measure. The present invention has been made to solve the following problem in order to eliminate the unevenness of the warp due to the fluctuation of the water content specific to these woody materials.

[0007]

The present invention has been accomplished as a result of intensive studies to solve the above-mentioned problems. Claim 1
The invention relates to a wooden floorboard (1) in which a male base is provided at one end of a wooden base material (3) having a predetermined shape and dimensions, and a female base is provided at the other opposite end, and a decorative material (2) is adhered to the surface. ), After attaching a thin sheet (4) for preventing warpage to the back surface of the wooden floorboard (1) or the wooden base material (3), the thin sheet (4) for preventing warping is applied. The above-mentioned problem has been solved by a method for producing a warp-preventing floorboard, characterized in that the above-mentioned method is subjected to hot-press drying after water is applied.

[0008] The invention of claim 2, said thin sheet of anti-warpage - DOO (4) is a paper quality material having a basis weight of ^{20g / m 2 ~35g / m 2} , the thin sheet - DOO (4) Water to give 10
A to 100 g / m ^2, pressing temperature of 140 ° C. or higher, the thin sheet by the clamping pressure is hot press at 10.0 kg / cm ² or more conditions - to preparative (4) is thermocompression dried According to a first aspect of the present invention, there is provided a method for manufacturing a warp-preventing floorboard, which solves the above problem.

In the prior art, for example, a backing material such as a simple sheet is stuck to the back surface of plywood or the like, water is applied, or the moisture content is adjusted differently between the surface layer of the plywood and other layers. Or, on the other hand, the present invention, on the other hand,
After attaching a thin sheet (4) for preventing warpage to the back surface of a wooden base (3) such as a wooden floorboard (1) or plywood, moisture is applied to the thin sheet (4) for preventing warping. And then drying by heat-pressing, it becomes possible to obtain a wooden floorboard (1) with extremely small warpage and small warpage variation.

That is, a thin sheet (4) for preventing warpage on the back surface of a wooden base material (3) such as a wooden floorboard (1) or a plywood thereof.
If only water is adhered, the shrinkage balance between the cosmetic material (2) on the front surface and the thin sheet (4) on the back surface is destroyed by the subsequent fluctuation of the water content, and the direction of the surface convex or concave with the passage of time. Warpage often occurred. However, as in the present invention, after the thin sheet (4) on the back surface is adhered, sufficient moisture is given to the thin sheet (4) and then the sheet is hot-pressed, so that the above-mentioned shrinkage balance is restored. Then, even with the subsequent aging, it is possible to adjust the warpage in the convex side of the front surface rather than the warpage in the concave direction of the front surface by the effect of the moisture on the rear surface and the effect of the heat and pressure clamping.

[0011] At this time, if the pressing conditions are as follows: the pressing temperature is about 90 ° C. or more, the pressing pressure is about 7.0 kg / cm ² or more, and the pressing time is about 50 seconds or more, the warp prevention is great. Although the effect can be exhibited, the conditions of the thermal compression are not limited to these. At this time, the basis weight of the thin sheet on the back side is 20 to
May, if 100 g / m ² degree, is insufficient warp preventing effect is about 20 g / m ² or less, there is a risk of inter-sheet peeling exceeds about 100 g / m ^2. The amount of water to be given is about 1
What is necessary is just 0 g / m ² or more. If it is less than about 10 g / m ² , the effect of preventing warpage is insufficient.

[0012] Further, if the heat-pressing condition is further set to a high temperature and a high pressure, the pressing time can be shortened, so that mass production is possible and the economic effect becomes extremely large. Further high-temperature and high-pressure conditions include a pressing temperature of 140 ° C. or higher and a pressing pressure of 10.
0 kg / cm ² or more. At this time, if the pressing time is about 30 seconds, a great effect can be obtained in preventing warpage. Thus, the pressing time can be greatly reduced.

In the case where the warpage prevention treatment is performed under the conditions of high temperature, high pressure and short press as described above, the wooden floorboard (1)
Or back of the thin sheet of plywood, such as wood substrates (3) - preparative (4) a relatively thin paper quality material having a basis weight of ^{20g / m 2 ~35g / m 2} , the thin sheet - providing a preparative (4) The amount of water is 10-10
0 g / m ² is about 3 g under high temperature and high pressure conditions.
It is most suitable for a short press of about 0 seconds. In the short press, the sheet on the back side must be thin. In addition, the amount of water to be given is about 10 to 100 as described above.
When the amount is g / m ² , hot press drying can be sufficiently performed even by pressing for a short time. When the amount of water to be provided is about 10 g / m ² or less, the effect of preventing warpage is small. On the other hand, when the amount of water is 100 g / m ² or more, drying is not sufficiently performed by pressing for a short time.

[0014]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a warp-preventing floorboard manufactured by the method of Examples 1 and 2 of the present invention, FIG. 2 is a schematic view showing a method of applying a water back surface in Example 1, and FIG.
FIG. 4 is a schematic view showing a state of hot pressing and drying at high temperature and high pressure in Examples 1 and 2. In the figure, (1) is a wooden floorboard manufactured by the method of the present invention, (2) is a decorative material, (3) is a wooden substrate,
(4) is a thin sheet, (5) is a shower spray, (6)
Indicates a roll coater, and (7) indicates a hot press.

As the wood base material (3), plywood, fiberboard,
A particle plate, a laminated material, or a composite base material thereof is used. The decorative material (2) is made of wood material such as veneer, rotary veneer, half-floor veneer, sawn veneer, vinyl chloride resin sheet, olefin resin sheet, etc. A decorative sheet in which, for example, a grain of wood is printed on the synthetic resin sheet of
Or, decorative paper in which, for example, woodgrain is printed on paper material such as thin paper, kraft paper, titanium paper, Japanese paper, nonwoven fabric,
Alternatively, resin-impregnated paper in which decorative paper is impregnated with a synthetic resin, metal foil, ceramic material, or the like is used, but other materials may be used.

As the thin sheet (4), thin paper, kraft paper, titanium paper, Japanese paper, non-woven fabric and the like are used, but other paper materials may be used. A thin sheet may be used, but a paper material having a basis weight of about ²⁰ to 100 g / m ² may be used. As described above, the hot pressing conditions of the present invention are such that the pressing temperature is about 90 ° C. or more and the pressing pressure is about 7.0 kg / cm ^2.
As described above, the pressing time may be about 50 seconds or more, but is not limited thereto. Particularly, in consideration of economy, in order to perform the warpage prevention treatment by short-time pressing under high temperature and high pressure conditions, the pressing temperature is 140 ° C. or more and the pressing pressure is 10.0 kg.
/ Cm ² or more. A pressing time of 30 seconds at this time is sufficient.

The thin sheet (4) on the back side is 20 to 100 g /
Any paper material of about m ² may be used. If it is too thin, the tensile stress at the time of contraction of the paper material is small, and the effect of preventing warpage cannot be sufficiently exhibited. On the other hand, in the case of short-time pressing under a high temperature and a high pressure, it is desirable that the pressure is about ²⁰ to 35 g / m ² . The reason is that when the paper material is less than 20 g / m ² , the tensile stress at the time of shrinkage of the paper material is small, and the effect of preventing warpage cannot be sufficiently exhibited, and when it is more than 35 g / m ^2, it is difficult to dry in a short time. Just good is 20g / m ²
It is in a range of ~35g / m ^2.

The amount of water applied to the thin sheet (4) on the back surface of the wooden base (3) such as a wooden floorboard (1) or a plywood is about one.
The condition may be 0 g / m ² or more. However, in short-time pressing under high temperature and high pressure, the amount of water to be applied is preferably about 10 to 100 g / m ² . With such an amount, drying can be sufficiently performed even by pressing for a short time. About 10g /
When it is less than m ² , the effect of preventing warpage is small, and conversely 100 g / m ²
In this case, there is a danger that not only a short press but also insufficient drying may result in poor adhesion of the thin sheet (4) on the back surface. It is desirable that the thin sheet (4) has a large water absorption for the effect of preventing warpage.

Next, the method for producing the warp preventing floorboard of the present invention will be described in detail. First, the thin sheet is placed on the back of the wooden substrate (3).
The sheet (4) is adhered with a woodworking adhesive such as a urea resin adhesive, water is applied thereon, and hot-pressed with a hot press (7) to heat-dry the thin sheet (4). . At this time, a method of simultaneously pressing the thin sheet (4) on the back surface and the surface material (2) may be used. Before applying the surface material (2) to the floorboard which has been actually processed, a thin sheet (4) is attached to the back of the floorboard before applying the surface, water is applied thereon, and then hot pressing (7). Then, it is good also as a wooden floorboard (1) by performing surface painting finish. Also, after attaching a thin sheet to the back surface of the finished wooden floorboard (1) up to the surface coating finish, apply water thereon, and heat-press it with a hot press (7). Is also good.

The amount of water applied to the thin sheet on the back side needs to be at least about 10 g / m ² or more in order to exhibit the effect of preventing warpage. Under a high-temperature and high-pressure condition with a pressing pressure of 10.0 kg / cm ² or more and a pressing time of about 30 seconds.
0 g / m ² is an appropriate amount. If the amount of water given is less than 10 g / m ² , the effect of preventing warpage cannot be sufficiently exerted, and if the amount of water is too large, not only the thin sheet (4) may have poor adhesion but also wood There is also concern about the influence of material deterioration on the base material. In addition, it cannot be dried sufficiently by pressing for a short time of about 30 seconds, and there is a fear of poor drying. In addition, it is preferable that the amount of water to be applied is large when the back surface temperature is relatively high, and is small when the back surface temperature is relatively low. Depending on the material temperature, the optimal water content is 10 to 100 g /
It may be adjusted appropriately within the range of m ² .

A method and apparatus for applying water to the wooden floorboard (1) or the thin sheet (4) on the back surface of the wooden substrate (3) are shown in FIG. ) And the roll coater (6) shown in FIG. 3 can be used, but other methods and apparatuses may be used. The temperature of the water to be applied may be appropriate unless it is extreme. Wood floor board (1)
Is turned over and the back is turned up, and these are put into these water application devices.

It is preferable to use a hot press (7) as the hot press. It is a matter of course that it may be put into a hot press immediately after application of water, but it is preferable to leave it for about 20 seconds and wait until the water has sufficiently permeated before putting it into the hot press. The hot pressing conditions are as follows: when the pressing temperature is about 90 ° C. or more, the pressing pressure is about 7.0 kg / cm ² or more, and the pressing time is about 50 seconds or more, a great effect for preventing warpage can be exerted. By setting the conditions to a higher temperature and a higher pressure, the pressing time can be shortened and mass production can be performed, so that the economic effect is extremely large. The high-temperature and high-pressure that can provide a highly economical warp prevention effect means that the clamping temperature is about 140 ° C or more and the clamping pressure is about 1
0.0 kg / cm ² or more is required. At this time, the pressing time may be about 30 seconds.

[0023]

[Example 1] 12 m as a wooden base material (3)
First, an m5 ply plywood is prepared, and then a backing step is performed. A urea melamine resin adhesive was applied to the back surface of the plywood, and a thin sheet of 30 g / m ² was placed thereon as a thin sheet (4) for preventing warpage. Then, it injected | thrown-in to the water application process. In the water application step, water was applied to the back surface of the plywood by shower spray (5) at 50 g / m ² . The material temperature of the back surface of the plywood before water application was 33 ° C to 38 ° C. After waiting about 20 seconds after the application of the water, it was put into a hot press, hot pressed and dried. The conditions of the hot pressing are a pressing temperature of 90 ° C and a pressing pressure of 7.0 kg / c.
m ² and a pressing time of 50 seconds. Next, a 0.3 mm thick oak veneer was adhered to the surface with a urea resin adhesive as a surface attaching step. Finally, actual processing and painting were performed to produce a wooden floorboard (1) having a width of 303 mm, a length of 1818 mm, and a thickness of 12 mm.

[Example 2] A urea melamine resin adhesive is applied to the back surface of the same plywood as in Example 1, and a thin sheet (4) for preventing warpage is placed on the adhesive. Put into roll coater (6), thin sheet on back of plywood (4)
Was coated with 10 g / m ² of water. The material temperature of the back surface of the plywood immediately before coating was 18 ° C to 23 ° C. About 2 after water application
After waiting for 0 seconds, the mixture was put into a hot press (7), hot pressed and dried. The hot pressing conditions were high temperature and high pressure. Compression temperature 140
° C, a pressing pressure of 10.0 kg / cm ² , and a pressing time of 30 seconds. Others were exactly the same as Example 1.

Comparative Example 1 The same thin sheet as in Example 1 was adhered to the back of the plywood, but the only difference from Example 1 was that the water application and the subsequent hot-pressing step were omitted. . Other than that produced the wood floorboard of Comparative Example 1 exactly like Example 1.

Comparative Example 2 The same thin sheet as in Example 2 was adhered to the back surface of the plywood, but the only difference from Example 2 was that water application and the subsequent hot-pressing step were omitted. . Other than that produced the wood floorboard of Comparative Example 2 exactly like Example 2.

[Results of Warp Test] The following warp tests were carried out using the respective wooden floor boards of Examples 1 and 2 and Comparative Examples 1 and 2.

[0028]

[Table 1] Table 1: Results of warpage test of wooden floorboard * Unit of warpage amount: mm * In the direction of warpage, warpage in the surface convex direction is indicated by +, and reverse warpage is indicated by-.

[Method of Warpage Test] The amount of warpage was measured by using a vernier caliper to measure the warp in the longitudinal direction of the floor plate at a length of 1818 mm and threading the yarn. The number of each specimen was n = 5.

The measuring time was as follows. 1) At the time of raw plywood, that is, at the time when nothing has been attached to the front and back surfaces. 2) After the back pasting step. That is, a thin sheet (4) was stuck on the back surface of the plywood, water was applied thereon, and the measurement was performed after drying by hot pressing. However, Comparative Example 1,
In No. 2, the measurement was carried out after application of the thin sheet on the back side (4), without application of water and drying under heat and pressure. 3) After pasting the table. In other words, in Examples 1 and 2 after the back pasting step, the back surface was coated with water, dried by hot pressing, and then measured after the decorative material (2) was adhered to the front surface. In Comparative Examples 1 and 2, the measurement was performed after applying the decorative material (2) to the surface without applying water and drying under heat and pressure. 4) After processing and painting. Measured after actual processing and painting finish.

[Consideration of test results] According to the method of Example 1, after applying a backing, applying water, and drying by heat and pressure, about 10 m
m was also greatly warped. However, after pasting the table, it was pulled by the veneer veneer on the table and the warpage was slightly higher on average.
It warped to the surface convex side by 0.2 mm and +0.8 mm at the maximum. Some were -0.3 mm. Although this slight warpage remained in the subsequent measurements after the actual processing and the finish of the coating, slight warpage did not cause any problem during the subsequent construction. The measured value is an average value of +0.3 mm (-0.1 to
+0.8 mm). The difference between the maximum and minimum values is 0.9
mm, and the variation in the amount of warpage was considerably small.

On the other hand, in Comparative Example 1, the thin sheet (4) was adhered to the back surface of the floorboard. However, since the water application step and the subsequent hot-press drying were omitted, the front surface after the front application and the work painting were omitted. I could not correct the pulling to the side, and reverse warpage occurred. The average warpage after work painting is -2.8 mm (-
11.4 to +6.1 mm). The difference between the maximum value and the minimum value is as large as 17.5 mm, and it can be seen that the variation has not been eliminated. This reverse warpage was a major problem in later construction. The effect of Example 2 was similarly confirmed in Example 2 and Comparative Example 2.

[0033]

According to the present invention, after attaching a thin sheet for preventing warpage to the back surface of a wooden base material such as a wooden floorboard or a plywood, the thin sheet is heated and pressed by heat and dried. A stable wooden floorboard in which warpage is extremely small and warpage variation is small can be realized. In addition, the hot pressing condition is set at a pressing temperature of 140 ° C.
As described above, under the pressing conditions of a pressing pressure of 10.0 kg / cm ² or more, the above-mentioned thin sheet for warpage prevention is weighed at 20 g / m ² or more.
By using a paper material of 35 g / m ² and setting the amount of water to be applied to the thin sheet (4) to 10 to 100 g / m ² , pressing can be performed for a short time, and a highly economical warp-preventing floorboard can be obtained. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a warp-preventing floorboard manufactured by the method of Embodiments 1 and 2 of the present invention.

FIG. 2 is a schematic view showing a method for applying a water back surface in Example 1.

FIG. 3 is a schematic diagram showing a method for applying a water back surface in Example 2.

FIG. 4 is a schematic diagram showing a state of drying by hot pressing in Examples 1 and 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wooden floorboard manufactured by the method of this invention 2 Decorative material 3 Wooden base material 4 Thin sheet 5 Shower spray 6 Roll coater 7 Hot press

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B002 AA02 AA03 AA04 BA01 BA18 BB04 BB06 BB10 BB12 DA01 2B250 AA05 BA05 CA11 DA04 EA02 EA13 EA18 FA21 FA28 FA31 FA33 FA37 FA53 GA05 HA01

Claims (2)

[Claims] 1. A wooden floorboard having a male base at one end and a female base at the other end opposite to a wooden base material (3) having a predetermined shape and dimensions, and a decorative material (2) attached to the surface. In 1),
After attaching a thin sheet (4) for preventing warpage to the back surface of the wooden floorboard (1) or the wooden base (3), water is applied to the thin sheet (4) for preventing warpage. A method for producing a floor board with warpage, wherein the floor board is subjected to hot-press drying after the application. Wherein said thin sheet anti-warpage - DOO (4) is a paper quality material having a basis weight of ^{20g / m 2 ~35g / m 2} , wherein,
The amount of water given to the thin sheet (4) is 10 to 100 g / m ²
The pressing temperature is 140 ° C. or higher and the pressing pressure is 10.0
^{2. The} method according to claim 1, wherein the thin sheet (4) is hot-press dried by hot-pressing under a condition of not less than kg / cm < ² >.