JPS61273942A - Mat for molding and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] ・°ζ Industrial application field゛
The present invention relates to a low specific gravity forming mat suitable for deep drawing processing and a method for producing the same.

Conventional technology 5. 2. Description of the Related Art Molding mats suitable for deep drawing and methods of manufacturing the same have been known.

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゛ For example, in the case of equity [55-40423@, i'□ wood fiber, and
Made pulp fibers, and if desired, fibers with longer fiber lengths111. A method is disclosed in which natural fibers are mixed at °C, a thermosetting resin is added thereto, wet-mixed, and then paper-formed and dehydrated to obtain a low-density soft fiber, a board.

JP-A No. 59-120440 discloses that undried wood fibers that have been defibrated by steaming and then separated from water vapor are mixed with long fibers with high tensile strength, powdered thermosetting synthetic resin, and powdered or fibrous wood fibers. A thermoplastic synthetic resin is added and mixed, the resulting mixture is made into a mat using a cotton-making machine, and the mat is heated at a temperature above the melting point of the thermoplastic synthetic resin but below the curing temperature of the thermoplastic resin. A method of selecting a wooden ta II mat for molding, which is heated and dried in a range and then pressed, is disclosed.

Problems with the Prior Art In the wet papermaking method described above, resin flows out during papermaking and dewatering, so an excessive amount of resin must be added in order to fix the required amount of resin in the mat. Further, thermal energy and time are wasted due to drying after papermaking. Furthermore, since it is wet-formed, the fibers are highly entangled, and cracks tend to occur during deep drawing.

The latter method mentioned above is similar to the dry method, but it also uses steam defibration.
40-50 to use the wood fibers without drying them.
% moisture content, a mixture of wood fibers and long fibers,
Fibers tend to get tangled (, tendency for fiber clumps to occur: N
, :・ri,',;(, It is difficult to obtain homogeneous 7 pieces with the same direction (゛・Also, it takes a long time to dry the pine and kuto, and the moisture content remains high)': '4: When forming, heating and pressing, the contained moisture rapidly evaporates.)'71. This causes a puncture. Also, add powdered resin to 16'162. 1,□,14. It is difficult to obtain mats of uniform quality.

1,1 Particularly when the amount of resin blended is small, uniform dispersion of the resin is difficult.

1.P. Therefore, the present invention aims to provide a method for manufacturing 7 shapes, which eliminates the above-mentioned drawbacks.

3. The applicant has previously filed two patent applications regarding a method for producing a mat for molding that solves the above-mentioned problems.

6. The first application (Japanese Patent Application No. 60-22054) discloses a dry ll1i material consisting of wood fibers, fibers with a stronger tensile strength than the wood fibers, and natural fibers with a longer fiber length. , a liquid or fibrous thermoplastic resin, a thermosetting resin having a curing temperature higher than the melting point of the thermoplastic resin, and a resin material consisting of 5° are uniformly mixed,
The resulting mixture is made into a mat shape using a forming device, and the resulting mat is heated and pressurized within a temperature range that is above the melting point of the thermoplastic resin and below the curing temperature of the thermosetting resin, and then cooled. Then, the above fiber material is fused with a thermoplastic resin and the specific gravity is 0.
01-05 are disclosed.

The above-mentioned second furnace opening (Japanese Patent Application No. 60-22055) does not include laminating sheet-like materials on the front and back surfaces of the mat-like material formed in the forming step in the method of the first application. This patent discloses a method for producing a molding mat similar to that of the first application.

These methods suffer from the above-mentioned drawbacks in the prior art.
tlAM$WiRIJ'#Jt'Lm<, Hv K
There is a tendency for the surface of deep-drawn products to have a smooth finish. Furthermore, the shape retention and strength of the mat for forming are somewhat inferior to the product gravel produced by the method of the second application, and the ease of handling is also somewhat inferior. Again
In the method of the second application mentioned above, sheet-like materials are laminated on both the front and back sides of the mat 5. However,
This matter is out.

k. Through further research by the applicant, it has been found that when using a net-like material, it is not necessarily necessary to laminate the net-like material on both the front and back surfaces of the mat. Ta. That is, ne, zo, . In addition, when using a net-like material, even if only wood fiber is used for the fiber material, it can be formed by deep drawing. 1 1. It was found that the paper has good processability.This is thin paper.

Net-like materials adhere better to textile materials than sheet-like materials such as Japanese paper, and therefore, during deep drawing, the fiber material follows the deformation of the net-like material better. It seems like ta・ゝ・( ).

ζ In addition, the solution to the problem 1.
In the molded mat according to the invention, at least 51;
material, at least one layer of fibrous material consisting of a resin material containing at least a thermosetting resin, and at least one layer of a net-like material. The i-layer body is fused with the resin material. In the laminate, a single layer of a net-like material may be formed on either the front or back of a single fiber material layer, or between a plurality of fiber material layers and/or on either the front or back. One or more layers of net-like material may be laminated on both sides, or vice versa.

In the method for producing a molded mat according to the present invention, a fiber material containing at least woody am and a resin material containing at least a thermosetting resin are uniformly mixed, and the resulting mixture is formed to form at least one IBM material layer. In the forming step □, a small amount of net-like material is applied to at least one of the front and back surfaces of the fiber material layer, or a plurality of miscellaneous materials Wjl111 and/or at least one of the front and back surfaces of the fiber material layer. WA layer, and the obtained laminate is heated at a temperature lower than the curing reaction initiation temperature of the thermosetting resin but at a temperature higher than the temperature at which at least a part of the resin material exhibits plasticity, and then pressurized. After that, the fiber material and the net-like material are fused together by cooling.

;・; The fiber material may be wood fiber alone, or it may be made of wood fiber, or it may be made of wood fiber, or it may be made of hemp, palm, palm, etc., which have a comparatively high rigidity and are comparable to wood fiber. and has strong tensile strength.

"Comparison of natural fibers with long fiber length and recycled fibers." Comparison of natural fibers with long fiber length and recycled fibers. A mixture may also be used.

The resin material is thermosetting resin only, and "4" or "6" or "Z tl C" is used.
@Resin 0 curing temperature I”□ A thermoplastic resin having a low melting point may also be used.

Various materials can be used for the mat, depending on the purpose of the molding mat and the laminated state described above.

,':゛1 ・゛Net Example explanation・ ・
:)! The fiber material used in the present invention is fiber material 82, which is a wood fiber commonly used as a raw material for board. It may be only i. Wood fiber is
For example, conifers.

,, nl Wood chips such as hardwoods are defibrated into fibers of 2 to 15 fibers by a conventional method, and the fibers are dried to a moisture content of 8%.

Dry.

Alternatively, in addition to the above-mentioned wood fibers, long fibers having a stronger tensile strength may be mixed and used. For example, one or both of relatively rigid natural fibers such as hemp, palm, and palm fibers and relatively soft II fibers such as recycled wool may be used in combination.

The length mi of these is preferably about 20 to 80 #1.
: Highly rigid long fibers function as aggregates, and flexible long fibers allow the fibers to intertwine well and provide strength against bending and tension, and the two complement each other to increase the shape-retaining strength of the mat. enhance

The resin material is uniformly mixed into the fiber material as described above. As the resin material, thermosetting resins such as urea resin, melamine resin, and phenol resin are essential. These resins are
It may be in liquid, powder, or fibrous form. However, when a powdered thermosetting resin is used, it can be used together with a liquid thermoplastic resin.

Alternatively, a thermosetting resin as described above and a thermoplastic resin having a melting point lower than its curing temperature may be mixed. Examples of thermoplastic resins include pyryl acetate resin, ethylene vinyl acetate resin, polyethylene, resin, and latex.

These resin materials may be added when the wood chips are defibrated, or they may be added to the fiber material by pouring it into the fiber material using a mixing device. The desired amount is about 3 to 3 Qwt% based on the fiber material.

゛ It's delicious. If it is less than 3 wt%, the strength of the molded product itself will be low, and if it is more than 30 wt%, there will be no problem in terms of quality, but the cost will be high. The amount of thermoplastic resin added is
Approximately 0.5 to 10 wt% of the wire material is desirable;
In this case, the amount of thermosetting resin added is different from that for single use.
The same level is fine. Although it is not critical when the thermoplastic resin reaches the lower limit of 0.5 wt%, the fusion due to the melting of only the thermoplastic resin becomes insufficient, and the fusion due to the thermosetting resin,
It becomes necessary to also use the strength of the combination, and the meaning of mixed use becomes weaker. Also, if more than 10 wt% is added, it will adhere to the hot platen or mold during heating and pressurization or during deep drawing of the product.

”, >t, becomes easy (poor mold releasability), leading to a decrease in productivity and quality.

The mixture thus obtained is formed into a mat shape using a forming device.

At this time, the procedure is changed depending on the number of layers of the fiber material and the number of layers of the net-like material. When each layer is single, the net-like material 2 is fed in advance and the IAI material layer 1 is formed thereon (see FIG. 1C), or vice versa. (see Figure 1C), a single ais
w When laminating two layers of the net-like material 2 on both sides of the material W11 (see FIG. 1C), the net-like material 2 is fed in advance, the fiber material Fm1 is formed thereon, and then After that, the net-like material 2 is placed thereon again. When laminating one layer of net-like material 2 between two fibrous material layers 1 (see Figure 1), after forming the first fibrous material layer 1, the net-like material 2 is layered on top of it. What is necessary is just to mount it and further form the 2nd m fiber material layer 1 on it. Needless to say, it is possible to make the fiber material layer 1 and the net layer 2 into a plurality of layers by using the above-mentioned combinations (see FIGS. 1e and 1f).

The net-like material used in this) desirably has a tensile strength of about 3 Ky/d or more. Tensile strength
If it is less than 3 kg/ci, the net-like material itself will be cut due to the tensile force exerted by the forming die during deep drawing, and the mat will crack and crack as a result.
' This may cause damage or the mat may be torn. However, the above-mentioned strength changes depending on where in the laminate the net-like material is provided. In other words, depth ≧ ゛ If there is no direct contact with the forming surface of the forming die during drawing, the greater the distance between the forming surface and the net layer, the greater the tension of the net-like material itself. It is clear that the lower the strength, the better.

2' The material of the net-like object is synthetic fiber net, glass 1.

,,, Fiber > fft-, cheesecloth/metal fabric 1
etc.・What rt'tb use・Pai get. However, when deep drawing the product, □
．． 1. Things are preferable. For example, the heating temperature used during heating and pressurization at the final stage of the manufacturing process of the molding mat, X.

ST,,7. : Higher than 100°C, and about the same as the curing temperature of thermosetting resin (τ.

*If a thermoplastic resin net with a melting point of Therefore, the net structure can be maintained in the molding mat product.This improves the shape retention strength and handling properties of the product.Furthermore, when the molding mat is deep drawn, the net structure can be maintained. In this case, the net-like material is melted by heating above the curing temperature of the thermosetting resin, and therefore, especially when the net-like material is laminated on the surface of the molding mat,
The surface of the molded product can be made smooth.

Further, when the net-like material is laminated within the layer of the molding mat, the material of the net-like material is preferably set at a temperature higher than the curing temperature of the thermosetting resin. As a result, the net structure is preserved in the product after the molding mat is deep drawn.
Increases the strength of the product.

The laminate obtained as described above is heated and pressed by a hot pressing device to obtain a moldable mat.

:o*omssm°“jla IN (t,i! m
Ill (7)1! (eゝ1, ″mIfJ!f
'rsa, :, = "116・Z (7) jo % m
.

The lower limit of the temperature is that when a thermosetting resin is used alone as the resin material, the temperature must be higher than the temperature at which the resin exhibits plasticity, allowing fusion between fibers and between fibers and the net-like material. becomes.

Also, mixed use of thermoplastic resin as the resin material□゛′□
In this case, the heating temperature mentioned above needs to be at least higher than the melting point of the thermoplastic ζ resin. As mentioned above, if the amount of thermoplastic resin added is small, heating is performed at a temperature higher than the temperature at which the thermosetting resin exhibits plasticity.

By doing so, thermosetting resins can also be used for fusion bonding.

・：0′−・ ,).

- The pressure can be adjusted as appropriate depending on the use of the molding mat, but in the case of a molding mat for deep drawing, it is preferable to set the pressure so that the specific gravity of the product is about 0.01 to 0.5. When the specific gravity is 0.01 or less, the shape retention force□
Even if there is, it is too flexible during transportation and molding.
If it is more than 0.5, deep drawing performance becomes poor.

The molding mat thus obtained has sufficient shape retention and tensile strength to withstand transportation and handling during molding.

“: When molding the molding mat,
Pressure is applied at a temperature higher than the curing temperature of the thermosetting resin. At this time, the thermoplastic resin is once melted, and the disparity between the fibers and between the fibers and the net is removed, allowing their mutual movement. The same applies when a thermoplastic resin is used in combination, since its melting point is selected to be lower than the curing temperature of the thermosetting resin. Thus, when the fibers are compressed by the mold, they conform to the molding surface and follow suit by being pushed or pulled by the deformation of the net-like material.
Therefore, the force applied locally by the deep-drawing die is easily transmitted to the surrounding area, and it conforms well to the die. As the curing reaction progresses, the III material and the net-like material are finally firmly fixed within the mat.

Effects Since the method of the present invention is a completely dry method, there is no need to dry the mat after forming, which saves thermal energy and time. In addition, in the wet method, the mini fiber material and resin material are uniformly mixed in a liquid state.

□,・: 1, j, By appropriately using resins such as powder, 1lli, etc., and by using different mixing methods, layers can be created. The bond between the net and □ becomes even stronger, especially when laminating net-like objects on 11!1m of fiber material, the fibrous material layers on both sides pass through the mesh of the net and Fusion also occurs between the fibers, making it even stronger. As a result, the molding mat according to the present invention does not cause cracks or cracks during deep drawing processing.
When a net-like material is laminated on the surface of the laminate.
The material of the net-like material is the hardened part of thermosetting resin!
□ By using a thermoplastic material with a melting point similar to that of 100%, it is possible to give the product a smooth surface after deep drawing.

When a net-like material is laminated within the layers of a laminate, □
has a melting point higher than the curing temperature of the thermosetting resin.
The selection of materials preserves the net structure of the product after deep drawing, thus increasing the strength of the product.

By using a net-like material, a mat for deep drawing can be obtained using only wood fibers without mixing long fiber materials.

A wide variety of molding mats can be provided by selecting the fiber material, resin material, net-like material, and lamination arrangement.

[Brief explanation of the drawing]

Figures 1a to 1f show some examples of variations in the laminated structure of the molding mat according to the present invention. Explanation of symbols

Claims (15)

[Claims] (1) A laminate of at least one fibrous material layer consisting of a fibrous material containing at least wood fibers and a resin material containing at least a thermosetting resin, and at least one layer of a net-like material is formed by using the above resin material. A molding mat characterized by being fused. (2) In the molding mat according to claim 1, the fiber material is made of a mixture of relatively short wood fibers and relatively long long fibers that have a stronger tensile strength than the wood fibers. A molding mat characterized by: (3) The molding mat according to claim 2, wherein the long fibers are natural long fibers such as hemp, hemp, palm, etc. (4) The molding mat according to claim 2, wherein the long fibers are recycled fibers. (5) The molding mat according to claim 2, wherein the long fibers are a mixture of natural fibers such as hemp, hemp, palm, etc., and recycled wool. (6) Any one of claims 1 to 5
3. The molding mat according to item 1, wherein the resin material is a mixture of a thermosetting resin and a thermoplastic resin having a melting point lower than the curing temperature of the resin. (7) Uniformly mixing a fibrous material containing at least wood fibers and a resin material containing at least a thermosetting resin, forming the resulting mixture to form at least one fibrous material layer, and in the forming step: , at least one net-like material is laminated on at least one of the front and back sides of the fiber material layer or between multiple fiber material layers, and the resulting laminate is heated at a temperature lower than the curing reaction initiation temperature of the thermosetting resin. A method for producing a mat for molding, which comprises heating the resin material at a temperature higher than the temperature at which at least a portion of the resin material exhibits plasticity, applying pressure, and then cooling to fuse the fiber material and the net-like material. . (8) In the method according to claim 7, the fiber material is a mixture of relatively short wood fibers and relatively long long fibers having a higher tensile strength than the wood fibers. A method for producing a molding mat, characterized in that it is used. (9) A method for producing a molding mat according to claim 8, characterized in that the long fibers are natural fibers such as hemp, hemp, and coconut. (10) A method for producing a molding mat according to claim 8, characterized in that recycled hair is used as the long fibers. (11) Production of a molding mat according to the method according to claim 8, characterized in that the long fibers are a mixture of natural fibers such as hemp, hemp, palm, etc., and recycled wool. Law. (12) In the method according to any one of claims 7 to 11, the resin material includes a thermosetting resin and a thermoplastic having a melting point lower than the curing temperature of the resin. production of a molding mat, characterized in that the heating temperature of the laminate is lower than the curing reaction start temperature of the thermosetting resin and higher than the melting point of the thermoplastic resin. Law. (13) In the method according to any one of claims 7 to 12, the net-like material has a tensile strength of 3 Kg/cm^2 or more at room temperature. A method for producing a molding mat, characterized by: (14) In the method according to any one of claims 7 to 13, as a net-like material laminated on the surface of the laminate, the net-like material is A method for producing a molding mat, characterized by using a net-like material made of a thermoplastic material having the same melting point. (15) In the method according to any one of claims 7 to 14, the net-like material to be laminated on the inner surface or back surface of the laminate is used during the molding process of the molding mat. A method for producing a molding mat, characterized by using a net-like material made of a material having a melting point higher than the heating temperature used.