JPH05104503A - Bonding method for wood - Google Patents

Abstract

PURPOSE:To make a progress of the bonding process for wood to each other smoothly in a short time, improve product efficiency and manufacture a wood product of excellent finish for which problems such as the deviation of bonded face, oozing-out of a bonding agent and the generation of cracks are solved. CONSTITUTION:A bonding agent is applied to wood, and then predried for 20 to 30 seconds by using a drier (far infrared ray drier) with a drying mechanism of far infrared ray irradiation to the wood just after being coated. Bonding is carried out in the similar way to the regular bonding process after being predried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood-to-wood bonding method, and more particularly to an improved bonding process.

[0002]

2. Description of the Related Art Conventionally, in the process of bonding wood when producing wooden products such as furniture, when applying makeup to adjust the aesthetic appearance of the product, immediately after applying the adhesive to the bonding surface. The method of adhering the timber to each other by applying cold pressure or hot pressure to the is adopted. However, in this case, various problems caused by water contained in the adhesive occur after drying. For example, seepage of the adhesive agent on the surface of the veneer, cracks in the veneer, and displacement of the adhesive surface. In addition, when the laminated core material and the single plate are bonded, after the adhesive is applied to the bonding surface, warpage occurs between the laminated core material and the single plate, so that the bonding surface is displaced or floated after drying.

In order to prevent the above-mentioned displacement and floating,
Conventionally, temporary fixing using paper tape, a high-frequency hand machine, or a stapler has been performed. However, when temporarily fixed with a paper tape, there are problems such as a cost problem such as a tape cost and labor cost, and a decrease in production efficiency due to a loss of work time due to manual work. Further, when the hand high-frequency machine is used, the adhesive layer is partially cured, so that there is a problem that the adhesive strength partially varies when the final product using the wood is completed.

Further, the problems such as the seepage of the adhesive on the surface of the veneer and the cracks in the veneer have not been solved yet.

[0005]

DISCLOSURE OF THE INVENTION The present invention addresses the above-mentioned problems in the wood-to-wood bonding process, and promotes the bonding process to proceed smoothly and in a shorter time than in the past, and improves the production efficiency. It is an object of the present invention to provide a wooden product having a good finish in which problems such as displacement of an adhesive surface, seepage of an adhesive, and cracks are solved.

[0006]

SUMMARY OF THE INVENTION The present invention is a preliminary process using a dryer which irradiates far wood with a far infrared ray after applying an adhesive to the wood in the wood-to-wood bonding process and before the drying process after bonding. The above object is achieved by providing a drying process. Hereinafter, the bonding process of the present invention will be described in detail, taking the case where the wood to be bonded is plywood and veneer as an example.

A necessary amount of adhesive is applied to the adhesive surface of the plywood (for example, in the case of urea-melamine co-condensation resin, preferably 135 g / m ²
Apply). The plywood immediately after coating is subjected to preliminary drying treatment for about 20 to 30 seconds using a dryer having a drying mechanism by far infrared irradiation (hereinafter, far infrared dryer). After the pre-drying treatment, it is carried out in the same manner as the usual adhesion process. That is, after the plywood and the veneer are bonded together, they are bonded by an ordinary method. Note that (if the moisture content from 35 to 70% of the conventional wet veneer, temperature ^110-130. C, pressure conditions 5~8kg / cm ^2, the time of about 2 to 10 seconds) hot press as bonding conditions the process It is preferable to provide. Also,
The adhesive used in the present invention is not particularly limited as long as it is suitable for adhesion of wood.

[0008]

[Function] When far-infrared rays are irradiated onto the adhesive-coated surface of wood, the far-infrared rays having a long wavelength reach the core of the adhesive evenly, so that the surface from the adhesive-coated surface to the inside is uniformly dried. It Further, since far infrared rays are well absorbed by the adhesive coating film, it is efficiently dried in a short time. A wood product is provided by appropriately drying an adhesive using far infrared rays, and then bonding and drying woods.

[0009]

EXAMPLES Next, examples for specifically showing the present invention will be described, but the present invention is not limited to the following examples. Example 1 100 parts of a urea-melamine co-condensation resin adhesive, 100 parts of a vinyl acetate adhesive, 100 parts of flour, and 100 parts of water
And 2 parts of 20% ammonium chloride aqueous solution were added and mixed uniformly. After applying this adhesive to plywood (application amount: 135 g / m ² ), in a far infrared dryer equipped with a far infrared radiation plate having an excellent emissivity over a wide temperature range in the far infrared region, After pre-drying by irradiating far infrared rays for 30 seconds, a wet veneer (thickness: 0.25 mm, water content: 25 to 30%) is attached to the adhesive surface of the plywood, and heat-pressed (use conditions / pressure). : 5kg / c
m ² , temperature: 120 ^. C, time: 2 seconds).

Comparative Example 1 Using an adhesive having the same composition as in Example 1, the adhesive was applied to a plywood (under the same conditions as in Example 1) (application amount: 135).
g / m ^2), after which, a hot-air dryer (Yamato Scientific Co., Ltd., Terms of Use / wind pressure: 16m ^{2, temperature:.} 100 C, time: 30
After pre-drying for 2 seconds, a wet veneer (under the same conditions as in Example 1) was attached to the adhesive surface of the plywood, and heat-pressed (use conditions / pressure: 8 kg / cm ² , temperature: 120) ^. C, time: 30
Seconds).

Comparative Example 2 Using an adhesive having the same composition as in Example 1, the adhesive was applied to plywood (under the same conditions as in Example 1) (application amount: 135).
g / m ² ), the preliminary drying is omitted, a wet veneer (same conditions as in Example 1) is attached to the adhesive surface of the plywood, and heat-pressed (use conditions / pressure: 8 kg / cm ^2). , ^{temperature:.} 120 C, time: 60 seconds) was performed.

The results of Example 1, Comparative Example 1 and Comparative Example 2 are shown in Table 1 below.

[0013]

[Table 1] As shown in Table 1 above, in the bonding of the plywood and the veneer according to Example 1, preliminary drying by far-infrared irradiation is performed, so that a short time (total 22 from preliminary drying to completion of hot pressing).
In seconds) a good product (a product with no bleeding and few cracks) could be obtained.

Example 2 In bonding the laminated core material and the dry type single plate (thickness 1 to 3 mm),
An adhesive having the same composition as in Example 1 was used to apply the adhesive to the laminated core material (coating amount: 135 g / m ² ), and the far infrared ray dryer of Example 1 was used for 28 seconds far infrared rays. As a result of irradiating, it was possible to obtain a product with good dimensional stability in which no deviation occurred between the laminated core material and the adhesive surface of the dry type single plate.

[0015]

According to the present invention, by providing a new bonding process of predrying by irradiation with far infrared rays,
Providing a wood product with a good finish that solves problems such as displacement of the bonding surface, exudation of the adhesive, and cracks, while improving the production efficiency by smoothly and quickly advancing the bonding process. It has become possible.

Claims (1)

[Claims] 1. In a bonding step of laminating wood and wood by using an adhesive, after applying the adhesive to one wood and before laminating and bonding the other wood, a far infrared ray is irradiated for preliminary operation. A method for adhering wood, characterized by being dried.