JP2022168835A - Manufacturing method of wooden laminate material - Google Patents

Abstract

To provide a manufacturing method of a wooden laminate material capable of manufacturing the wooden laminate material effectively, with reduced loss of material or adhesive agent and at low cost.SOLUTION: A manufacturing method of a wooden laminate material applies composite adhesive to a veneer 11 via a sheet 13 to form the wooden laminate material 10, and comprises the steps of: coating an adhesive agent 14 to the sheet 13; installing the sheet 13 coated with the adhesive agent 14 between the veneers 11; and applying a hot press to a veneer (a laminate veneer 16) laminated via the sheet 13 at a temperature at which the sheet 13 is not melted to apply the composite adhesive.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing laminated wood lumber.

Laminated wood materials such as LVL and plywood, which are formed by stacking multiple veneers, have conventionally adopted a manufacturing method in which plate materials are directly attached to each other with an adhesive to form a composite, as in Patent Document 1. .

Japanese Patent No. 5073085

However, when multiple thin veneers with a thickness of about 0.2 mm are combined, if adhesive is applied to the veneer with a roll coater, the veneer is thin and lacks rigidity, so there is a risk that it will be wrapped around the roll coater. A veneer that is wrapped around like this becomes unusable.

In addition, if the adhesive is applied by spraying, a large amount of adhesive is lost, and there is a risk of contamination of manufacturing equipment. Furthermore, instead of applying an adhesive to the material surface, a method of using an adhesive sheet at room temperature is conceivable, but the adhesive sheet is expensive and is not suitable for use in plywood or other items that require low cost.

The present invention has been proposed in consideration of such circumstances, and its object is to efficiently manufacture a laminated wood material with little loss of materials such as veneers and adhesives, and at a low cost. It is to provide a manufacturing method of

In order to achieve the above object, the method for producing a laminated wood material of the present invention is a method for producing a laminated wood material, comprising: forming a laminated wood material by bonding and combining veneers via a sheet; An adhesive is applied, the sheet coated with the adhesive is placed between the veneers, and the veneers stacked with the sheets interposed are hot-pressed at a temperature at which the sheets do not melt to bond them. It is characterized by combining.

Since the method for manufacturing the laminated wood material of the present invention has the steps described above, it is possible to efficiently manufacture the laminated wood material at low cost with little loss of materials such as veneers and adhesives.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram simply showing a method for manufacturing a laminated wood material according to an embodiment of the present invention; (a) corresponds to A in FIG. 1, (b) corresponds to B in FIG. 1, (c) corresponds to C in FIG. 1, and (d) is an enlarged schematic cross section corresponding to D in FIG. It is a diagram.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, the basic procedure of the method for manufacturing the laminated wood material 10 according to the embodiment (hereinafter referred to as the present manufacturing method) will be described.

This manufacturing method is a method of forming the laminated wood material 10 by bonding and combining the veneers 11 via the sheet 13, and is a procedure in which the following steps are sequentially executed.
(a) Step of applying adhesive 14 to sheet 13 (adhesive application step)
(b) A step of installing the sheet 13 coated with the adhesive 14 between the veneers 11 (sheet installation step)
(c) A step of hot-pressing the laminated veneers 11 (laminated veneers 16) with the sheets 13 interposed therebetween at a temperature at which the sheets 13 do not melt (hot-pressing step).

In the manufacturing method described below, a cutting step of cutting the sheet 13 to a desired length is performed between the adhesive applying step and the sheet placing step.
The manufacturing method will be described in detail below with reference to FIGS. 1 and 2. FIG.

As the wooden laminated material 10 manufactured by this manufacturing method, a laminated material obtained by bonding and combining veneers 11 such as plywood and LVL (laminated veneer lumber) is assumed. The veneer 11 is a plate material obtained by thinly cutting a natural raw wood such as a coniferous tree or a broadleaf tree.

As the veneer 11, a rotary veneer obtained by cutting a raw wood processed into a log shape like peeling a Japanese radish, or a sliced veneer obtained by slicing the surface of a raw wood processed into a square shape, etc. are used. be done. The latter method yields a thinner veneer 11, for example less than 0.1 to 0.6 mm thick. When processing a sliced veneer using a veneer slicer, if the thickness is 0.6 mm or more, there is a risk of curling during slicing.

Various thicknesses can be assumed for the veneer 11 used in this manufacturing method. In this manufacturing method, since the procedure of directly applying the adhesive 14 using the roll coater 30 to the veneer 11 is not used, it is difficult to directly apply the adhesive 14 with the roll coater 30 in the past. This manufacturing method is particularly effective when using the veneer 11 of . As the laminated wood material 10 manufactured using the veneer 11 having such a thickness, a surface decorative material (veneered board) is exemplified. In the case of a long veneer (fibers are oriented in the length direction), even if the thickness is about 0.4 mm, the roll coater 30 can be applied without winding, but if it is a cross veneer (fibers are oriented in the width direction), it will be 0. Even the veneer 11 with a thickness of .4 mm may be wrapped around during application.

As the adhesive 14 used in this manufacturing method, it is desirable to use, for example, a reactive adhesive 14 such as urethane, epoxy, or acrylic in order to avoid deformation or puncture. An adhesive containing water or a solvent is not desirable because the water may migrate to the veneer 11 in the sheet installation step, and deformation or puncture may occur. may be used as long as it is allowed to evaporate almost completely. For example, any adhesive 14 having a solid content of 90% or more can be used.

As the sheet 13 used in this manufacturing method, it is desirable to use a material that allows the adhesive 14 to easily permeate, that is, a porous material having voids inside. I wish I could.

In particular, it is more desirable to use a non-woven fabric that is entangled with fibers and contains sufficient voids. For example, if inexpensive materials such as PET spunbond, PP spunbond, and PE spunbond are used, the manufacturing cost can be kept low. The nonwoven fabric is not limited to spunbond, and may be manufactured by various methods such as meltblown, thermal bond and spunlace.

The thickness of the sheet 13 is not particularly limited, but since the sheet 13 is arranged in a compressed state in the adhesive layer 12 between the veneers 11 of the laminated wood material 10, the basis weight is 10 to 25 g/m. About ² is desirable. Further, the planar dimensions of the sheet 13 are generally the same as those of the single plate 11, that is, the sheet is hidden by the single plate 11 in the sheet installation step. This is because deformation (planar elongation) of the sheet 13 due to hot pressing is considered.
The method illustrated in FIG. 1 will now be described in detail for each of the steps described above.

<Adhesive application step>
In this step, a rolled sheet 13 is used.

As the adhesive 14, for example, a two-component urethane adhesive containing a curing agent is preferably used. The main agent of this adhesive 14 is liquid at room temperature. The two-component type is a combination of polyol and polyisocyanate with hydroxyl groups at the ends, or urethane prepolymer with isocyanate groups at the ends. can be done. In addition, it is desirable to bond in a heated state in order to increase the bonding strength.

In the method illustrated in FIG. 1, the liquid adhesive 14 is applied to one surface of the sheet 13 using a roll coater 30 . In this case, a roll of the sheet 13 is used, and while the sheet 13 is pulled out by the roll 31 on the bonding line 32, the sheet 13 is maintained in a flat shape, and the sheet 13 is pulled and held by another roll or the like. It is desirable to apply adhesive 14 .

Although other methods such as brushing and spraying may be used to apply the adhesive 14, cutting can be performed continuously and efficiently on the downstream side of the adhesive line 32 with little application loss. It is desirable to use a coating method using a roll coater 30 . Also, bead coating may be performed.

The amount of the adhesive 14 to be applied may be such that it covers substantially the entire surfaces of the two veneers 11 that are in contact with the sheet 13 when the sheet 13 is thermally compressed in the subsequent hot press step. The adhesive 14 may be applied to only one side of the sheet 13, but may be applied to both sides.

At the stage where the adhesive 14 is applied to one surface of the sheet 13 in this way, as shown in FIG. permeates the

<Cutting step>
It is desirable to form the adhesive sheet 15 by cutting to match the length dimension of the longitudinal sides of the veneer 11 . For cutting, a cutting device 33 provided on the downstream side of the bonding line 32 may be used. Alternatively, the sheet 13 may be formed in advance so as to match the shape and dimensions of the veneer 11, and then the adhesive 14 may be applied.

<Seat installation step>
The sheet 15 with adhesive is placed between the two veneers 11 . In the example of FIG. 1, the laminated wood material 10 is manufactured by stacking three veneers 11, and therefore two sheets 13 are used to form the laminated veneer 16. FIG. For example, as shown in FIG. 2B, the adhesive-coated sheet 15 may be placed between the veneers 11 with the surface coated with the adhesive 14 facing upward, but the reverse is also possible.

<Heat press step>
This step is a step of hot-pressing the laminated veneers 16 with the sheets 15 with adhesive between the veneers 11 by the hot press machine 34 . As the hot press 34, a multi-stage press is used, but various machines such as a roll press may be used.

The hot press conditions differ depending on the thickness of the veneer 11 used, the type and amount of the adhesive 14, the type of the sheet 13, the basis weight, and the like. For example, if the sheet 13 is PET spunbond and the adhesive is urethane, the press pressure should be 5-20 kg/cm ² and the press temperature should be 100-190°C.

In particular, it is desirable to set the press temperature to a temperature at which the sheet 13 does not melt. For example, when PET spunbond is used as the sheet 13, the melting point of PET is about 260° C., so the press temperature may be set lower than that. desirable. Since PP spunbond has a melting point of about 160° C. and PE spunbond has a melting point of 120° C., it is desirable to use PET spunbond, which has a higher melting point, as the sheet in order to use an adhesive with a high curing temperature.

During the hot press, the sheet 13 is compressed by the hot press 34. As shown in FIG. spread to The adhesive 14 on the upper surface side of the sheet 13 spreads over substantially the entire lower surface of the upper veneer 11, while on the lower surface side of the sheet 13, the adhesive 14 that moves downward in the sheet 13 and protrudes to the lower surface side is located on the lower surface. spread over substantially the entire upper surface of the veneer 11. In short, between the veneers 11, the state is such that the sheet 13 is arranged in the middle of the adhesive 14 in the thickness direction.

The press temperature should be set in consideration of the curing temperature of the adhesive 14 . In other words, the heat pressing may be performed at a temperature at which the sheet 13 is sufficiently compressed without being melted, the adhesive 14 spreads over the surfaces of both the upper and lower veneers 11, and then hardened.

After the adhesive 14 is cured in this way, the pressure is released, and the laminated veneer 16 is taken out from the heat press 34 . When the laminated veneer 16 is taken out, as shown in FIG. 2(d), the adhesive layer 12 including the sheet 13 and the cured adhesive 14 is formed between the veneers 11. As shown in FIG. It is also possible to use an adhesive 14 that cures at room temperature after the laminated veneers 16 are taken out from the hot press after spreading the adhesive 14 over the required areas by hot pressing.

When the sheet 13 is made of paper (paper), the adhesive 14 is more difficult to permeate than the nonwoven fabric. The adhesive 14 may be permeated into the inside by hot-pressing at a high pressure. Since Japanese paper has more voids than Western paper, the adhesive 14 penetrates easily.
According to this manufacturing method, the following effects can be expected.

First, since the adhesive 14 does not have to be applied directly to the very thin veneer 11 using the roll coater 30, the veneer 11 cannot naturally wind around the roll coater 30 during the bonding process. . Therefore, waste of the material (single plate 11) can be suppressed, and the bonding composite process can be performed efficiently. In particular, if the adhesive 14 is applied only to one side of the sheet 13, the sheet setting process can be performed more efficiently than if both sides are used as adhesive surfaces.

Furthermore, since the procedure is such that the adhesive 14 is supplied to the adhesive surface of the veneer 11 through the sheet 13, it can be applied to almost the entire surface of the veneer 11 without leakage. In addition, the loss of the adhesive 14 can be reduced and contamination of the manufacturing equipment can be suppressed as compared with the application by spraying.

In addition, since the sheet 13 is not melted by the heat press in this manufacturing method, it is possible to prevent the molten resin of the sheet 13 from being mixed with the adhesive 14 to cause an adhesion failure (such as a decrease in the adhesiveness of the adhesive). Furthermore, if the temperature is high enough to melt the sheet 13, deterioration of the veneer 11 and deterioration of the adhesive 14 may occur. It can also be evaded. If, for example, PET spunbond is used as the sheet 13 and the sheet 13 is hot-pressed at a melting temperature of 260° C. or higher, there is a high possibility that some kind of failure will occur due to the high temperature.

Further, since the sheet 13 does not melt, the molten resin of the sheet 13 can naturally be prevented from leaking out to the outside. Furthermore, if a portion of the sheet 13 is melted by heat pressing and a portion of the sheet 13 retains its shape while remaining solid, the laminated wood material 10 may not be formed to have a uniform thickness. You can avoid such situations. In addition, even if the sheet 13 is completely melted and the melted resin is arranged in a biased position, there is a possibility that the sheet 13 cannot be formed to have a uniform thickness.

The sheet 13 of the laminated wood material 10 and the adhesive 14 are bonded together by hot pressing to set the coating amount of the adhesive 14 to about 75 g/m ² and the basis weight of the sheet 13 to about 15 g/m ² . The adhesive layer 12 can have a thickness of about 0.05 to 0.07 mm. Since this adhesive layer 12 includes the sheet 13, it may be thicker than the adhesive layer 12 when only the adhesive 14 is used, but the veneer 11 can be made thinner to reduce the cost. can be achieved. Moreover, if a cheaper sheet 13 is used, further cost reduction can be achieved.

Next, an adhesive strength test using PET spunbond as the sheet 13 and a urethane-based adhesive as the adhesive 14 will be described.

<Purpose of the test>
Check the bonding strength of the laminated wooden material after hot pressing under plane tension.

<Materials used in the test>
Sheet 13: PET spunbond (about 15 g/m ² ) Melting point: about 260°C
Adhesive 14: Two-component urethane adhesive (approximately 75 g/m ² )
In addition, the veneer 11 was not used as the adherend, and two plywoods with a thickness of 3 mm were used.

<Hot press conditions> (see Table 1)
Pressing temperature: 4 types of about 105°C, about 120°C, about 160°C, about 200°C Pressing pressure: 3 types of about 3.5 kg/cm ² , about 7 kg/cm ² , about 14 kg/cm ² Combination of these Twelve tests were performed. The pressing time was 5 minutes.

<Test results> (see Table 1)
(1) When the press pressure is about 3.5 kg/cm ² At any of the temperatures of about 105°C, about 120°C, about 160°C, and about 200°C, the adhesive layer 12 does not change and the plywood breaks (material breaks). )did. That is, the adhesive strength was good.

(2) When the press pressure is about 7 kg/cm ² At any temperature of about 105° C., about 120° C., about 160° C., and about 200° C., the plywood was broken (material failure) without any change in the adhesive layer 12. . That is, the adhesive strength was good.

(3) Press pressure of about 14 kg/cm ² At temperatures of about 105°C, about 120°C, and about 160°C, the adhesive layer 12 did not change and the plywood was broken (material failure). Therefore, the adhesive strength at these temperatures was good. At about 200° C., the adhesive layer 12 broke.

According to the above test results, when the sheet 13 is PET spunbond, the pressing temperature is 105 to 200° C., and the pressing pressure is 3.5 to 7 kg/cm ² , the adhesive strength is almost certainly good. can be determined to be obtained. Moreover, even if the press pressure is more than 7 kg/cm ² and 14 kg/cm ² or less, it can be judged that good adhesive strength can be obtained if the press temperature is 105 to 160°C.

Thus, it was confirmed that a combination of the pressing pressure and the pressing temperature within the numerical ranges described above provides sufficient adhesive strength. The adherend in this test was not the single plate 11 but a plywood with a thickness of 3 mm. Even if it is 11, it is naturally assumed that the material will break. Therefore, it can be judged that the bonding strength is excellent even when the single plate 11 is used.

This test uses PET spunbond as the sheet 13, and if this material is used, the melting point is higher than that of PP spunbond or PE spunbond. The selection range of the agent 14 is wider. Moreover, since PET spunbond is inexpensive, the manufacturing cost of the wood laminate 10 can be reduced.

PP spunbond is also inexpensive and may be used as the sheet 13 . Since the melting point is about 160.degree. C., the sheet 13 does not melt even with a heat press of about 120.degree. In addition, since PE spunbond and hot melt spunbond have a melting point of about 120° C., the adhesive 14 that cures at a temperature lower than 120° C. is used, and the heat press is performed at that temperature. A sheet 13 can also be used.

The laminated wood material 10 manufactured by this manufacturing method is used as a surface decorative material for interior building materials such as floor materials, ceiling materials, and wall materials. Of course, plywood can also be manufactured by this manufacturing method. By using this manufacturing method, it is possible to inexpensively and efficiently manufacture a surface decorative material having a thickness of about 2 to 2.5 mm using ten veneers 11 having a thickness of about 0.2 mm.

REFERENCE SIGNS LIST 10 wood laminate 11 veneer 12 adhesive layer 13 sheet 14 adhesive 15 sheet with adhesive 16 laminated veneer 30 roll coater 31 roll 32 adhesive line 33 cutting device 34 heat press

Claims (7)

A method for manufacturing a laminated wood material, comprising bonding and combining veneers via a sheet to form a laminated wood material,
applying an adhesive to the sheet;
The sheet coated with the adhesive is placed between the veneers,
A method for producing a laminated wood material, wherein the veneers laminated with the sheet interposed therebetween are hot-pressed at a temperature at which the sheet does not melt to be bonded and combined. In claim 1,
A method for producing a laminated wood material, wherein the sheet has voids therein and is deformed by the heat press. In claim 1 or 2,
A method for producing a laminated wood material, wherein the sheet is a nonwoven fabric. In any one of claims 1 to 3,
A method for producing a laminated wood material, wherein the adhesive has a solid content of 90% or more. In any one of claims 1 to 4,
A method for producing a laminated wood material, wherein the veneer has a thickness of 0.1 mm or more and 0.5 mm or less. In any one of claims 1 to 5,
A method for producing a laminated wood material, wherein the sheet is PET spunbond, and the temperature of the hot press is 105°C to 200°C. In claim 6,
A method for producing a laminated wood material, wherein the press pressure of the heat press is 3.5 Kg/cm ² to 7 Kg/cm ² .

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