JPS6319204A - Particle board and its preparation - Google Patents

Abstract

PURPOSE:To enhance mechanical strength, especially, bending strength without excessively increasing the density of a board, by setting the thickness of one of skin layers laminated to both surfaces of an inner layer to a predetermined value or less and holding an iron laminate between the skin layer having the predetermined thickness and the inner layer. CONSTITUTION:An iron laminate 4 is held between an inner layer 1 and one skin layer 2 among the skin layers laminated to both surfaces of the inner layer 1 and the thickness of the skin layer 2 holding said iron laminate 4 is set to 6mm or less. Since the iron laminate thus held is present at a position within 6mm from the surface of a board on the side of one skin layer 2 of the board, bending strength when the surface opposite to the skin layer 2 of the board receives stress is markedly enhanced and strength can be enhanced without increasing the wt. of the board due to the holding of the iron laminate to a large extent.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a particle board with improved mechanical strength, especially bending strength, and a method for manufacturing the same.

(Conventional technology and its problems, huge) Since particle board can be made from a wide range of wood materials, it is useful for the effective use of unused wood materials, including waste wood, and its uniform and controlled quality makes it Widely used for furniture woodworking, construction, etc. Particle board 8! Mechanical strength and density have a high correlation, and particle boards with high mechanical strength tend to be dense, that is, heavy. When producing particleboard, increasing the amount of adhesive used increases the strength, but there are problems with economic efficiency, the lifespan of cutting tools during processing, etc., and there is a limit to the amount of adhesive used.

(Means for Solving the Problems) The present invention solves the above-mentioned problems and provides a particle board with improved mechanical strength, especially bending strength, without increasing the particle board density too much; The first object is to provide a particle board that is lighter in weight without reducing its bending strength, and the second object is to provide an industrially advantageous method for manufacturing such a particle board. Therefore, the first object of the present invention is to provide a particle board in which a surface layer is laminated and integrated on both sides of an inner layer according to the first aspect of the present invention, in which the thickness of one of the surface layers is 6 mm.
The above-mentioned second object is achieved by a particle board formed by sandwiching a thin iron layer between a surface layer and an inner layer having this thickness, and according to the second aspect of the present invention (a) Step (b) of continuously scattering small pieces of fine fibers for forming a surface layer onto a moving belt to form a mat (b) Touching the mat formed in step (b) above
Step (c) of forming a mat by continuously scattering small pieces of vegetable fiber for forming the inner layer with an ei agent applied (i) Formed in the step (b) above. - a step of continuously scattering 111 pieces of plant amber material for surface layer formation onto the mat to form a mat (d) a mat obtained in steps (a) to (c) above; (e) At the beginning of the steps (a) and (b) above, iron is applied to one of the mats formed and moving in the step (a). T
Insert the step of laminating the ij layers, and in that case, the amount of small pieces of plant fiber for surface layer formation to be sprinkled in step (a) will be replaced by the heat-pressure medium in step (d) above! ! ! ! When done, 6
Either the thickness is within +s+m, or (f) between the above steps (b) and (c), iron is placed on top of the moving mat that has been shaped in step (b). When a step of laminating the thin layer body is inserted, and in that case, the small pieces of vegetable fiber for forming the surface layer to be sprinkled in step (c) are subjected to heat-pressure treatment in step (2') above. , of particle board characterized by having a thickness within 6III1! 3: Achieved by L method.

The present invention will be explained in detail below.

The first section is a schematic front view of an example of the particle board of the present invention, in which 1 is the inner layer of the particle board, 2 and V3.
4 is the surface layer, and 4 is the thin iron layer.

The plant fiber pieces forming the inner layer 1 include those conventionally used for forming the inner layer (hereinafter abbreviated as inner layer pieces).
Any of these can be used, and as the vegetable fiber pieces forming the surface layers 2 and V3, any of those conventionally used for forming the surface layer (hereinafter referred to as surface layer pieces) can be used.

As the iron thin layer body, iron foil (including gAi!i) or a net made of thin iron wires woven into a plate shape is used. Iron foil is 150μ thick
~20μ is known, and any of these can be used, and iron foils plated with tin, zinc, nickel, etc. are preferred from the viewpoint of corrosion resistance. This ironstone may be perforated in a uniformly distributed manner as long as its strength is not significantly impaired. Further, the iron wire net may be thicker than iron foil, for example, iron wire with a thickness of 400 to 800 microns and a mesh of 10 to 4 meshes is used.

In the particle board of the present invention, one of the surface layers placed on both sides of the inner layer 1 (surface layer 2 in FIG. 1)
A thin iron scrap body 4 is sandwiched between the inner layer 1 and the inner layer 1, and it is important that the thickness of the f2JfA2 that holds the thin iron layer body 4 is 6 mm or less, preferably 41 mm or less, and more preferably The preferred value is 211111 or less. The lower limit of the thickness is such that the particle board retains its surface appearance, and is also suitable for attaching decorative plastic to particle board, attaching veneer,
It can be thinned as long as it does not interfere with surface treatments such as oil-impregnated overlays and paint finishes, for example 1.
It is preferable to set it to about mm or more.

The reason why the sandwiching position of the iron thin layer body is shifted to one surface from the thickness center plane of the particle board is as follows. When a bending load is applied to particle board to cause it to break, the breakage occurs on the tensile side (the side that protrudes when curved). Furthermore, when using particle board, the load is usually only applied in one direction.

Therefore, it is effective to reinforce the tensile side with a thin iron layer in one direction where the load is mainly applied, and J! I! Theoretically, the farther away from the point of load application, the more effective it is. In order to suppress the increase in the weight of the particle board itself, it is desirable to use a thin plate, but from the perspective of improving bending strength, a thick plate is advantageous.For example, as shown in Figure 1 In particle board, the thin iron layer 4 exerts a resistance against the load directed from the top to the bottom, and the degree of resistance increases as the thin iron layer 4 becomes thicker and the surface layer 2 becomes thinner. The thin layer body 4 is sandwiched inside the particle board so that the appearance is the same as that of Togo's particle board, and surface treatments such as resin-impregnated paper overlay, veneer pasting, decorative plastic adhesive pasting, and painting finish are possible. This is because particle board can be molded simultaneously during continuous production.

Next, an example of a method for manufacturing the particle board of the present invention will be explained with reference to FIG.

In FIG. 2, reference numeral 5 denotes a homing belt that moves continuously in the direction of the arrow, and surface particles are continuously spread onto this belt 5 from a first spreader 6 to form a pine door. The amount of the surface layer particles to be sprinkled is adjusted so that the particle board has a desired thickness of 6 mm or less in the final step when it is hot-pressed and the particle board is completed. On top of the manodore formed in this way, the iron M9 unwound from the roll 8 wrapped with iron foil is guided by the idle roll 14 and piled up.Next, on top of this iron foil 9, a second scattering of 1filo is applied. Continuously scattering small pieces of the inner layer to form a mat 11,
A mat 13 is formed on the mat 11 by continuously distributing small pieces of the surface layer from a dispersing machine 12.

The laminate of Matsudoor, Iron M9, Mantle 11 and Mat 13 formed as above is cut into predetermined lengths,
It is heated and molded using a hot press. This heat pressure is conventional particle board! This may be carried out under the same conditions as those used in Il construction.

In the above manner, a structure in which the iron'iiN body 4 is sandwiched between the surface layer 2 and the inner layer 1 as shown in FIG. 1 is manufactured. In order to manufacture a particle board having a structure in which the iron thin layer body 4 is sandwiched, the following procedure is performed. That is, to explain with reference to the explanatory diagram of FIG. 2, iron M9 is fed out from a roll 8 wrapped with iron foil 8! The air pressure is not provided between the first sprayer 6 and the second spray amount 10, but is provided between the second spraying rock 10 and the third sprayer 12,
The iron foil 9 may be stacked on the mat 11. In this case, the amount of the surface layer particles sprayed from the third spreader 12 will be as follows: ↑ by 1 so that the thickness is 6+*w or less.

In the above method, the surface layer pieces and the inner layer pieces used are selected from those in the form of dust, fibers, strands, seven rakes, shavings, splinters, etc. used in conventional particle board manufacturing,
It can be used alone or mixed in proportions. When spraying from a spreader, all
M is applied as an adhesive.
7 E/-le υ (fat, tannin resin, lignin υ (Ill
? or isocyanate resin.

These adhesives may contain curing agents such as soot, which is its main component, and may also contain conventionally used waterproofing agents, flame retardants, and preservatives to improve the general quality of particleboard. , a termiticide, etc. may be added.

Furthermore, in order to strengthen the bond between the iron layer sandwiched between the surface layer and the inner layer, the contact 3' is used for bonding wood and metal. It is advisable to apply an adhesive (for example, a water-based polymer incyanate adhesive) in advance.

In addition, fine plant fiber particles (e.g. dust, fibers, etc.) may be attached to the thin iron layer in advance.
Or, by attaching paper, textile fabric, or non-woven fabric, that is, by interposing something that is easy to adhere to both the iron layer and the particle board layer, to increase the adhesive strength between the two. Good too.

Next, Examples and Comparative Examples for manufacturing the particle board of the present invention will be described, but the particle board of the present invention is not limited to that obtained by the Examples shown here.

Example 1 Particle board was manufactured in the manner shown in FIG. First, on a homing belt with a width of 198 cm, 2 to 4 pieces of surface layer small pieces coated with 9% urea junum (on a dry matter basis for small pieces, the same applies in the following cases) from the first spreader.
A first mat is created by continuous application at a rate of 100 kg/m”.

On top of the first mat formed as described above, the rolled iron is unwound and spread at the same speed as the advancing speed of the mat. The iron foil used at this time was 60μ thick.
, two rolls of foil with a width of 95cm+* are unwound from parallel rolls, and both sides of the foil are coated with a water-based polymer incyanate adhesive (Koyo Sangyo Co., Ltd.! 11 KR-).
10) was applied by spraying approximately -55 g/injection.

On top of the iron foil, spread 4.7 kg of inner layer small pieces coated with 7% area resin from a tpJ2 small piece spreader.
Spray at the rate of 1jS3 on top of that,
2.4 kg/piece of surface layer coated with 9% area resin
Spray m2. After cutting the mat continuously formed in this way into a length of 377 cm, it was loaded into a hot press and heat-pressed at a heating platen temperature of 155°C and a maximum press pressure of 20 kgf/c for 7 days to a thickness of 20 kgf/c. ■ Obtained particle board. Both surfaces of this material were polished with a wide belt sander to obtain a finished particle board with a thickness of 18 strands. In the particle board thus finished,
The surface layer thickness was approximately 2 mm for both the upper and lower layers, and the inner layer thickness was 14 mm.

Bending strength of this product [When stress is applied to the upper center with the surface layer in contact with the iron foil facing down (this is called bending strength test 1), and when stress is applied to the upper center with the surface layer in contact with the iron foil facing upward. (This is referred to as bending strength test 2)] and peel strength were measured.

Both bending strength and peel strength are JIS-As2O3.
In addition, the strength measurements in Examples and Comparative Examples described later are also based on the same measuring method.

The above measurement results are shown below.

Bending strength (Test 1) 99 kgf/am2 Bending strength (Test 2) 47 kgf/am" Peeling strength 1,6 kgf/cm" (Fracture at inner circle)
Example 2 Spreading of surface particles from the first spreader was 2.2 kg/cI.
A laminated mat was formed in the same manner as in Example 1, except that the scattering of surface particles from the spreader No. 413 was changed to a ratio of 2.6 kg/cwa: Further, both sides were polished with a wide belt Sangu to obtain a particle board finished to a thickness of 18 II. The thickness of the surface layer in contact with the iron foil is approximately 1
．． 51, the thickness of the other surface layer was about 2.5 mm, and the thickness of the inner layer was about 14 mm. The results of measuring the bending strength of this product were as follows.

Bending strength (test 1) 105 kgf/c theory 2
Bending strength (test 2) 49 kgf/as
2 Example 3 Spreading of surface particles from the first spreader at 2.6 kE/C
1+2, spreading small pieces of surface layer from the third spreader 2.2
kg/am". Except for cutting, the rest was the same as in Example 1 to obtain a particle board with a surface polishing finish of 18I thick. The thickness of the surface layer in contact with the iron was about 31s. The thickness of Table An was approximately 1-thickness.The bending strength measurement results of this material were as follows.

Bending strength (test 'J 1) 89 kgf/
cm” bending strength (test 92) 41k
gf/cm2 Comparative Example A particle board was produced in the same manner as in Example 1, without sandwiching the iron foil. The bending strength measurement results of this product were as follows.

Bending strength (test Wa 1) 45 kgf
/ c+m' bending strength (LK92) 42
kgf/c+*2 Effects of the Invention) (a) In the particle board of the present invention, the iron thin layer books held between the boards are biased toward one surface of the board, and the particle board of the present invention is 6Ie higher than the surface.
Since the particle board is located at a position within Ia, the 11111 strength is significantly improved when stress is applied from the opposite side of this surface 1. When particle board is actually used and is subjected to stress from one direction It is extremely effective when used in cases where there are many In other words, the strength can be increased without increasing the weight due to the sandwiching of the thin iron layer body.

(b) Has magnetic shielding properties.

(c) Has electromagnetic wave shielding properties.

(d) Since the thin iron layer is near the surface, bulletin boards, blackboards (
A fastener made of raIi works effectively when used on white boards, etc.

The particle board of the present invention has the above-mentioned effects and can be used as general building materials (ceiling materials, wall materials, partition materials, etc.), house Jt-
Effectively used for (tables, top boards, kotatsu boards, etc.), bulletin boards, blackboards, whiteboards, magnetic shielding materials, electromagnetic shielding materials, etc.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of an example of the particle board of the present invention;
FIG. 2 is an explanatory diagram showing one embodiment of the method for manufacturing particle board of the present invention. In the figure, 1 is the inner layer of the particle board, 2 and &3 are the inner layers, 4 is the iron thin layer, 5 is the homing belt, and 6
．． Reference numerals 10 and 12 are devices for dispersing small pieces forming each layer of particleboard.

Claims (2)

[Claims] (1) In a particle board formed by laminating a surface layer on both sides of an inner layer, the thickness of one of the surface layers is within 6 mm, and a thin iron layer is sandwiched between the surface layer and the inner layer having this thickness. particle board (2) (a) Step of continuously scattering small pieces of vegetable fiber for forming the surface layer with adhesive onto a moving belt to form a mat (b) Formed in the step of (b) above A step of forming a mat by continuously scattering small pieces of vegetable fiber for forming an inner layer with adhesive applied onto the mat (c) Applying adhesive onto the mat formed in step (b) above. A step of continuously scattering the attached small pieces of vegetable fiber for forming a surface layer to form a mat (d) A step of heat-pressing the mat obtained in steps (a) to (c) above to produce particle board. In the method, (e) between the above steps (a) and (b), inserting a step of laminating a thin iron layer on the mat formed in step (a) and moving; And in that case, the amount of small pieces of vegetable fiber for forming the surface layer to be sprinkled in step (a) will be such that when heat-pressure treated in step (d) above, the thickness will be within 6 mm, or or (f) between the steps (b) and (c) above,
Insert a step of laminating a thin iron layer on the mat formed and moving in step (b), and in that case, (c)
Production of a particle board characterized in that the amount of small pieces of vegetable fiber for forming the surface layer to be sprinkled in the step (d) is such that the thickness becomes 6 mm or less when subjected to heat-pressure treatment in the step (d) above. law