JP2005153409A - Projected plate original paper and method for producing projected plate-stuck decorative plywood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide projected plate original paper which can control cracking in a projected plate and a method for producing projected plate-stuck decorative plywood. <P>SOLUTION: The projected plate original paper is used in the production of the projected plate-stuck decorative plywood in which the projected plate original paper is placed between plywood and the projected plate. The projected plate original paper at least 1.2 kN/m in lateral tensile strength defined by JIS P-8113 and 5 s or below in water absorption speed and the method for producing the projected plate-stuck decorative plywood in which the paper-making direction of the projected plate original paper and the fiber direction of the projected plate are made to coincide for sticking are provided. The air permeability defined by JIS P-8117 of the projected plate original paper is preferably 30 s or below. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a veneer base paper used for a veneer laminated veneer and a method for producing a veneer veneer using the veneer base paper.

  A veneer-attached decorative plywood is a decorative plywood in which a thin wooden board (decorative board) for decoration is attached to the surface of a plywood obtained by bonding a plurality of veneers, and is used for furniture, building interior materials, etc. . The veneer and the veneer constituting the decorative plywood shrink and expand due to drying and moisture absorption, but the veneer and veneer have different expansion ratios. For this reason, there exists a problem that a protrusion board tends to produce a crack (crack) to a fiber direction by expansion and contraction of the single board on the surface of a plywood.

Conventional techniques for preventing cracking of the veneer include a method in which a medium density fiber board (MDF) is combined with the surface of the plywood so that the plywood is not in direct contact with the plywood, and Japanese paper or cold chill between the plywood and the veneer. There have been proposed a method of interposing a backing material, a method of performing a WPC (synthetic resin injection) treatment on the protruding plate itself, etc.
JP 10-235608 A (paragraph numbers (0002) and (0003))

  In the method of preventing cracking of the veneer by interposing paper (veneer base paper) between the veneer and the plywood, the production direction of the veneer paper drawn from the roll is usually reduced in order to keep the production equipment small and to reduce the production cost. Parallel bonding is performed in which the longitudinal direction of the plywood and the veneer, that is, the fiber direction of the veneer is the same. However, the veneer base paper normally produced by a paper machine has a lower tensile strength in the direction perpendicular to the paper making direction (transverse direction) compared to the tensile strength in the paper making direction (longitudinal direction), which is sufficient to prevent cracking of the veneer. It does not work effectively. Also, in some cases, the paper texture is poor and the water absorption rate is slow, so that the adhesive penetrates unevenly, causing separation between papers (a phenomenon in which separation occurs in the paper layer) after becoming a veneered decorative plywood product. Sometimes.

  Accordingly, an object of the present invention is to provide a veneer base paper that can more reliably reduce cracks and separation between papers generated on the veneer of the veneer laminated veneer, and a method for manufacturing the veneer veneer plywood using the veneer base paper. .

  As a result of diligent research, the present inventor used veneer base paper whose tensile strength and water absorption speed in the lateral direction are within a predetermined range, and manufactured a veneer laminated veneer by overlapping the fiber direction of the veneer and the horizontal direction of the veneer base paper perpendicularly. As a result, it was found that cracking of the protruding plate and separation between papers can be reduced, and the present invention has been completed.

  The present invention for solving the above problems is described below.

  [1] A veneer base paper used for manufacturing a veneer laminated veneer having a veneer base paper interposed between the plywood and the veneer, and having a lateral tensile strength of 1.2 kN / m as defined in JIS P-8113 As described above, a veneer base paper having a water absorption speed of 5 seconds or less.

  [2] The veneer base paper according to [1], wherein the air permeability defined in JIS P-8117 is 30 seconds or less.

  [3] In the method for producing a veneer-laminated decorative plywood, in which a veneer base paper is interposed between the plywood and the veneer, the paper making direction of the veneer base paper and the fiber direction of the veneer are aligned with each other. A method for producing a veneered veneer plywood, wherein the veneer is laminated together.

  The veneer base paper of the present invention has a predetermined range of tensile strength in the lateral direction, and therefore is effective when the paper making direction of the veneer base paper and the fiber direction of the veneer are made parallel in the manufacture of the veneer laminated veneer. In particular, cracking of the veneered veneer can be reduced. In addition, since the water absorption speed is high, the adhesive penetrates uniformly, and peeling between papers of the veneer plywood can be prevented.

  In the veneer base paper of the present invention, the tensile strength in the transverse direction specified in JIS P-8113 is 1.2 kN / m or more, preferably 1.5 kN / m or more. The higher the tensile strength in the transverse direction, the better, so there is no upper limit, but the strength of the veneer base paper that can be manufactured is usually 1.2 to 4.0 kN / m. If the tensile strength in the transverse direction is less than 1.2 kN / m, cracking of the veneer cannot be sufficiently prevented when the veneer base paper is used as a decorative plywood.

  The veneer base paper of the present invention has a water absorption rate of 5 seconds or less as measured by the method described in the examples described later. If the water absorption speed exceeds 5 seconds, the adhesive is slow to penetrate and difficult to penetrate uniformly when producing the veneered decorative plywood, and the paper may peel off after the veneered decorative plywood is manufactured.

  In the veneer base paper of the present invention, the air permeability defined in JIS P-8117 (ISO 3687) is preferably 30 seconds or less, and more preferably 20 seconds or less. When the air permeability exceeds 30 seconds, it is difficult for the adhesive to penetrate uniformly when producing the veneered decorative plywood, and the paper may peel off after the veneered decorative plywood is manufactured.

The basis weight of the veneer base paper of the present invention is preferably 14 to 35 g / m ² on a dry mass basis, and more preferably 18 to 30 g / m ² . The thickness of the veneer base paper is preferably about 35 to 55 μm.

  In the veneer base paper of the present invention, the tensile strength ratio (horizontal / longitudinal) in the horizontal direction and the vertical direction is preferably 70% or more, and more preferably 90 to 120%. By setting the tensile strength ratio to 70% or more, even when the veneer base paper is used as a decorative plywood, cracking of the veneer can be more effectively prevented even if the base weight is about the same as that of a normal veneer base paper. In the veneer base paper obtained by a normal paper machine, the fibers are easily oriented in the paper making direction because the paper is made while pulling in the wire traveling direction, that is, the paper making direction. For this reason, the obtained base paper has the property that the tensile strength in the vertical direction is high and the tensile strength in the horizontal direction is low, and the tensile strength ratio (horizontal / longitudinal) is about 40 to 70%.

  The veneer base paper of the present invention is produced by a paper machine used for ordinary paper making. In order to obtain a veneer base paper having a tensile strength, a basis weight, and a tensile strength ratio within the above ranges, at least one of the following methods is used in the production process. It is preferable to adopt.

(1) Method of adjusting paper outflow speed and paper making speed Adjust J / W ratio (ratio of paper outflow speed J jetted from head box to wire and wire speed (paper making speed) W) By doing so, it is possible to prevent the fibers from being oriented in the longitudinal direction of the base paper and to obtain the base paper having a high tensile strength ratio in the lateral direction.

(2) Method of Shaking the Wire Shaking the wire when the paper stock is poured into the wire to form a sheet. By appropriately selecting the frequency and amplitude of the wire according to the conditions such as the fiber length and paper making speed in the paper stock, the tensile strength ratio (width / length) ) Can be adjusted. The frequency of the wire is preferably 100 to 250 rpm, and the amplitude is preferably 10 to 20 mm. In addition, the frequency of the wire in normal operation is less than 100 rpm, and the amplitude is less than 10 mm.

  The method of performing the shaking of the wire is also an effective method in that the texture of the veneer base paper can be more uniformly adjusted and the air permeability and the water absorption speed of the veneer base paper can be within the above ranges.

  A longitudinal sectional view of an example of a veneered decorative plywood using the veneer base paper of the present invention is shown in FIG. 1, and a partially cutaway plan view is shown in FIG.

  The veneer-attached decorative plywood 1 is formed by sequentially laminating a veneer base paper 5 and a veneer 7 impregnated with an adhesive on a plywood 3 as a base material. The plywood 3 and the veneer 7 are attached via a veneer base paper 5 impregnated with an adhesive. In FIG. 2, a indicates the paper making direction (longitudinal direction) of the veneer base paper 5, b indicates the direction perpendicular to the paper making direction of the veneer base paper (lateral direction), and the veneer base paper 5 has a tensile strength in the b direction of 1.2 kN. Paper is made so that it becomes more than / m. The protruding plate 7 is laminated on the protruding plate base paper 5 so that the fiber direction is the same as the paper making direction a of the protruding plate base paper 5. Since the crack of the veneer is likely to occur when a force that expands and contracts in the direction perpendicular to the fiber direction acts on the veneer, the fiber direction a of the veneer 7 and the lateral direction b of the veneer base paper 5 having a predetermined tensile strength are mutually connected. By making them orthogonal, it is possible to reduce cracks in the protruding plate.

  As the plywood 3, one having a thickness of about 5 to 20 mm in which a single plate such as a so-called lauan material is laminated is preferable. As the protruding plate 7, a single plate such as oak or zelkova having a thickness of about 0.2 to 0.6 mm is preferable.

  As the adhesive impregnated into the veneer base paper 5, a known adhesive used for a normal veneer laminated veneer can be used without limitation.

  In the above description, the case where the protruding plate and the protruding sheet base paper are stacked only on one side of the plywood has been described. However, the present invention is not limited thereto, and the protruding plate and the protruding sheet base paper may be stacked on both sides of the plywood.

Example 1
Raw material kraft pulp (hereinafter referred to as LKP) and softwood kraft pulp (hereinafter referred to as NKP) mixed at a ratio of 1: 1 on a dry mass basis, with a J / W ratio of 100%, wire shaking (frequency 200 rpm, (Amplitude 20 mm) and paper making was performed to obtain a veneer base paper.

Example 2
Paper was made in the same manner as in Example 1 except that the frequency of the shaking of the wire was 150 rpm to obtain a veneer base paper.

Example 3
Paper was made in the same manner as in Example 1 except that LKP was used as a raw material and the beating was rougher than in Example 1 to obtain a veneer base paper.

Example 4
A veneer base paper was obtained by making paper in the same manner as in Example 1 except that NKP was used as a raw material.

Example 5
Using LKP as a raw material, a J / W ratio of 105% and wire shaking (frequency of 150 rpm, amplitude of 20 mm) were made to obtain a veneer base paper.

Example 6
Using LKP as a raw material, the paper was shaken with a J / W ratio of 100% (frequency: 200 rpm, amplitude: 20 mm) to make a paper to obtain a veneer base paper.

Comparative Example 1
A raw material obtained by mixing LKP and NKP at a ratio of 1: 1 on a dry mass basis was subjected to wire shaking (frequency: 100 rpm, amplitude: 10 mm) at a J / W ratio of 96% to obtain a veneer base paper.

Comparative Example 2
A raw material in which LKP and NKP are mixed at a ratio of 1: 1 on a dry mass basis is subjected to paper shaking with a J / W ratio of 100% (frequency 200 rpm, amplitude 10 mm), and then saponified rosin size. A veneer base paper was obtained by adding 1% by mass of the agent in a mass ratio of pulp.

Comparative Example 3
Paper was made in the same manner as in Example 1 except that LKP was used as a raw material to obtain a veneer base paper.

Comparative Example 4
Paper was made in the same manner as in Example 1 except that LKP was used as a raw material and beating was made finer than in Example 1 to obtain a veneer base paper.

  Tensile strength, air permeability, water absorption rate, and rice tsubo were measured using the veneer base paper produced in Examples 1 to 6 and Comparative Examples 1 to 4. Further, using the obtained veneer base paper, a veneered decorative plywood (300 × 600 cm) was manufactured by making the paper making direction of the veneer base paper the same as the fiber direction of the veneer, and subjected to a JAS cold heat repeat test and a knife peel test. The results are shown in Table 1.

  The tensile strength of the veneer base paper was measured according to JIS P-8113, and the air permeability was measured according to JIS P-8117. The measurement of the water absorption rate, the JAS cold heat repetition test, and the knife peel test were performed according to the following procedure.

[Water absorption speed]
A sample of 3 cm square was floated on 23 ° C. water, and the water was sucked in. The time from when the sample floated on the water surface until the water completely penetrated the entire sample was measured.

[JAS Cold Repeat Test]
The decorative plywood was left at 60 ° C. for 2 hours, then left at −20 ° C. for 2 hours, and this was performed for 2 cycles. Thereafter, the total length of cracks generated on the veneer on one side of the decorative plywood was measured.

[Knife peel test]
Make a notch from the veneer bonding surface to the plywood layer at a right angle to the fiber direction of the veneer with a knife with a blade length of 3 cm, width of 1.8 cm, and maximum thickness of 0.5 mm, and then between the veneer and veneer of the decorative plywood The insertion veneer was peeled off. Based on the length of the peeled veneer, the strength between the veneer papers was evaluated according to the following criteria, and 4 or more points were accepted.

Evaluation criteria 5: The knife blade is difficult to enter and the protruding plate hardly peels off 4: The protruding plate peels off from 1 mm to less than 15 mm 3: The protruding plate peels from 15 mm to less than 30 mm 2: The protruding plate peels from 30 mm to less than 50 mm 1: The protruding plate peels from 50 mm or more

It is a longitudinal cross-sectional view which shows an example of the veneered decorative plywood using the veneer base paper of this invention. It is a partially notched top view of the veneered decorative plywood shown in FIG.

Explanation of symbols

1 Veneer plywood 3 Plywood 5 Veneer base paper 7 Veneer

Claims (3)

  A veneer base paper used for manufacturing a veneer laminated veneer with a veneer base paper interposed between the veneer and the veneer, and having a tensile strength of 1.2 kN / m or more in the lateral direction as defined in JIS P-8113 Veneer base paper characterized in that the speed is 5 seconds or less.   The veneer base paper according to claim 1, wherein the air permeability defined in JIS P-8117 is 30 seconds or less. In the manufacturing method of a veneer-laminated decorative plywood, in which a veneer base paper is interposed between the plywood and the veneer, the paper making direction of the veneer base paper and the fiber direction of the veneer are aligned and bonded together. A method for producing a veneered veneer plywood, characterized in that

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