JP2003145487A - Uneven foam, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide uneven foams which is formed of a melamine foam, manufactured so as to ensure a large difference in unevenness, i.e., a large depth and prevents the melamine foam of low elasticity and brittle structure from leaving any traces of dent or the like during the manufacture, and a manufacturing method of the foam. SOLUTION: When performing the profiling operation to the melamine foam M, the melamine foam is pressed by projections 64 and 64 with spacers 14 and 14 of the predetermined thickness fitted to a face side and a back side of the melamine foam M to obtain an uneven foam 10 having the unevenness of the depth D of at least 10% of the thickness of the melamine foam M.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concavo-convex foam and a method for manufacturing the same, and more particularly, to the surface of a melamine foam which is heat-resistant and lightweight and can be processed into a required shape in order to increase its surface area. The present invention relates to such a concavo-convex foam and a manufacturing method for obtaining the concavo-convex foam.

[0002]

2. Description of the Related Art Conventionally, glass wool, rock wool,
Materials that are flexible and easy to construct, such as soft urethane foam and melamine foam, are widely used as sound absorbing materials or structural materials. Such sound absorbing materials are widely used as wall members and ceiling members of buildings, automobile interior materials and the like.

In the case of the above-mentioned glass wool, rock wool or soft urethane foam, at least 10 kg / m ³
It is possible to secure sufficient sound absorption required for building materials, etc. by making the density higher or thicker, but in this case, it occupies a lot of installation place, that is, it is bulky and space utilization is required. Is less efficient,
It is pointed out that there is a drawback that the workability and the workability are poor because the weight is heavy and the shape retention property, so-called rigidity is not provided.

On the other hand, in the case of the melamine foam, even if the material has a low density (about 10 kg / m ³ ), it exhibits the same sound absorbing property as the above-mentioned glass wool, rock wool or soft urethane foam. Since it has a suitable hardness and can be handled as a lightweight block body, it is very excellent in workability and workability as compared with the above-mentioned soft urethane foam or glass wool.

However, also in the case of the melamine foam, it is necessary to have a predetermined thickness and / or density in order to secure sufficiently excellent properties such as sound absorption. However, in recent buildings and the like, efficient use of space is required, and in particular, there is a case where a sufficient space cannot be secured in a portion outside a living / activity space such as between an inner wall and an outer wall or inside a vehicle. Therefore, the thickness of the melamine foam is limited, and it is necessary to increase the density in order to obtain sufficient sound absorption.

As a method of ensuring sound absorption with a relatively low density and without increasing the wall thickness, as shown in FIG. 8, the surface area is increased by forming a regular uneven shape on the surface,
Processed foam 50 made of melamine foam that can absorb sound from various directions regardless of the incident angle
Has been produced (see FIG. 8 (a)). Such processing is
Generally referred to as profile processing, this term is also used in the description of the present invention. It should be noted that this profile processing cannot be performed on the lump of fibers such as the glass wool or rock wool.

Explaining the method for carrying out the profile processing, as shown in FIGS. 2 and 9, a pressing pattern is formed on the outer peripheral surfaces 62a, 62a of the projections 64, 64 so that a required pattern of irregularities to be formed on the surface is formed. Roll 62,62
It is manufactured using the processing apparatus 60 (see FIG. 2) having a. Then, the pressing rolls 62, 62 are attached to the protrusions 64, 6
Rotate in opposite directions so that 4 correspond and match
(See FIG. 9A). By supplying melamine foam M, which is a workpiece, between the pressing rolls 62, 62, the front surface side and the back surface side of the melamine foam M are pressed by the pressing roll 6
Narrow pressure is applied by 2,62, whereby the melamine foam M in the compressed / deformed state is cut along the feeding direction by the split blade 66 as a cutting means (see FIG. 9 (b)).
A pair of two concavo-convex foams 50, 50 in which the concavo-convex surfaces 12, 12 of a required pattern are processed on the cut surface are obtained (see FIG. 9C). Concavo-convex foam 5 thus obtained
In the case of 0 and 50, the required pattern corresponding to the protrusion 64 is formed on the uneven surfaces 52 and 52 cut by the split blade 66.

The processing device 60 includes the pressing roll 62.
Is pressed against the melamine foam M, and the melamine foam M compressed and deformed by this pressing is cut to obtain the uneven surface 52 on which the required pattern is formed. The difference in the unevenness, that is, the depth, is determined by the pressing force. For example, in order to increase the surface area in order to improve the sound absorbing property, it is better that the difference between the irregularities is large, that is, the pressing force is large.

[0009]

However, when the melamine foam having a low elasticity and structurally brittleness is processed by increasing the pressing force of the pressing roll 62, the uneven surface 5 is formed.
While the difference between the unevenness of 2 becomes large, the projection 6 is formed on the front surface side and the back surface side of the melamine foam M to be pressed.
The pressure marks 4 and 64 remain as scratches (see FIG. 8B), and in some cases tears occur. Such a structural defect is not only a problem of a decrease in commercial property but also a factor of greatly reducing a yield of products, resulting in a large increase of a manufacturing cost.

Further, it is difficult to eliminate the above-mentioned scar caused by the pressing even if the pressing amount of the pressing roll 62 is small, and a high yield can be maintained even if the melamine foam is processed with a small pressing amount. Was difficult.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks inherent in the above-mentioned prior art, and was proposed in order to suitably solve the above-mentioned drawbacks.
A melamine foam that can be manufactured so as to have a large difference in unevenness, that is, a large depth, and that does not leave a mark such as pressure on the melamine foam that is low in elasticity and structurally brittle during manufacturing. It is an object to provide a foam and a method for manufacturing the foam.

[0012]

In order to overcome the above-mentioned problems and achieve the intended purpose, the concavo-convex foam according to the present invention has projections of a required pattern formed on the outer peripheral surfaces thereof, and the projections rotate in mutually opposite directions. A pair of pressure rolls arranged to face each other, and arranged so as to face the middle of the pair of pressure rolls,
Using a split blade whose blade edge is oriented in the arrival direction of the melamine foam that is the workpiece, in a state in which the melamine foam supplied toward the pair of pressing rolls is greatly pressed by the protrusions of the required pattern. In the concavo-convex foam in which the concavo-convex surface of the required pattern is processed on the cut surface by feeding the melamine foam in the sandwiched state into two pieces along the feeding direction by the split blade while being fed to the downstream side. By pressing the spacers with a spacer having a required thickness on the front surface side and the back surface side of the foam, the unevenness to be processed on the cut surface of each uneven foam is the melamine before the processing. The depth of the foam is at least 10% or more.

In order to overcome the above-mentioned problems and achieve the intended purpose, a method of manufacturing a concavo-convex foam according to another invention of the present application is such that projections of a required pattern are formed on the outer peripheral surfaces of the foams, and the projections are directed in mutually opposite directions. A pair of pressing rolls that are arranged to face each other to rotate, and a split blade that is disposed so as to face the middle of the pair of pressing rolls and has its blade edge oriented in the arrival direction of the melamine foam that is the workpiece, and The melamine foam supplied toward the pair of pressing rolls is fed to the downstream side in a state where it is strongly pressed by the projections of the required pattern, and the melamine foam in the pressing state is fed by the split blade along the feeding direction. When manufacturing a concavo-convex foam in which the concavo-convex surface of the required pattern is processed on the cut surface by cutting into two pieces, the surface side of the melamine foam And a spacer having a required thickness correspondingly applied to the back surface side and supplied toward the pair of pressing rolls, and pinching the melamine foam by the protrusions of the required pattern through the spacer. It is characterized in that it was carried out.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a concavo-convex foam according to the present invention and a method for manufacturing the same will be described below with reference to preferred examples. The inventor of the present application is a state in which the foam is compressed and deformed by pressing from both sides a melamine foam that can be suitably used for building materials and automobile interior materials having excellent properties such as light weight and sound absorption. When performing so-called profile processing, in which a concave-convex foam having a surface pattern of a required pattern is formed by cutting with, the melamine foam is sandwiched by a spacer made of a soft or semi-rigid resin material having a predetermined thickness and hardness. By letting
The inventors have found that profile processing with a larger difference in unevenness can be carried out in the state where there are no pressure marks on the melamine foam.

As shown in FIG. 1, a concavo-convex foam 10 according to a preferred embodiment of the present invention is made of a melamine resin foam (hereinafter referred to as melamine foam), and one side of which has at least a melamine foam M as a workpiece. Thickness of 10
The melamine foam M is provided with the uneven surface 12 having a required pattern having a difference of not less than%, and is manufactured by subjecting the melamine foam M manufactured by a conventionally known method or commercially available to profile processing.

The concavo-convex foam 10 is specifically shown in FIG.
It is manufactured by the processing apparatus 60 shown in. The processing device 60 includes an outer peripheral surface 62 on which projections 64 having a required pattern are formed on the uneven surface 12 of the uneven foam 10.
and a pair of pressure rolls 62, 62 having a, 62a, and arranged immediately downstream of the pair of pressure rolls 62, 62,
A split blade 66 that divides the melamine foam M compressed and deformed corresponding to the pattern of the uneven surface 12 to be obtained by being pressed by the pair of pressing rolls 62 and 62 into the narrow pressure state, and the pair of pressing members. The uneven foam 1 obtained by feeding the melamine foam M into the rolls 62, 62
It basically comprises a transfer mechanism 68 for sending 0, 10 to a predetermined position.

[0017]

[Manufacturing Method] A manufacturing method for obtaining the pair of concavo-convex foams 10, 10 from the melamine foam M using the processing apparatus 60 will be described with reference to FIGS. 3 and 4. Basically, the manufacturing method of the present concavo-convex foam 10 comprises a preparatory step S1 of preparing a melamine foam M which is a base of the concavo-convex foam 10 to be manufactured, and the melamine foam M prepared with a required pattern by the processing device 60. Processing step S2 for obtaining a pair of processed concave-convex foams 10,10
And a final step S3 in which post-processing such as polishing or punching into a predetermined shape and a predetermined inspection are performed on the obtained concavo-convex foam 10 (see FIG. 3).

The preparation step S1 is a step of obtaining a melamine foam M which is a workpiece of the processing apparatus 60. Although a description of a specific method for producing the melamine foam M is omitted, it is generally performed by a conventionally known method such as microwave irradiation to prepare a raw material or a commercially available product, and obtain the melamine foam M by the processing device 60. Pre-processing such as cutting is performed according to the width and length of the uneven foam 10 to be formed.

The processing step S2 is a spacer placement step S.
21, a pressing step S22, a narrow pressure / cutting step S23, and a spacer removing step S24 (see FIG. 3). Each step S21 to S24 of the processing step S2 will be described step by step with reference to FIG. 4. First, a predetermined spacer 1 is formed on the front surface and the back surface of the melamine foam M so as to cover the entire surface.
4 and 14 are applied correspondingly (spacer placement step S21:
See FIG. 4 (a). The pair of pressing rolls 62, 62 that rotate the melamine foam M applied with the spacers 14, 14 in opposite directions at a predetermined speed so that the projections 64, 64 have corresponding projections and depressions corresponding to each other. Is supplied by the transfer mechanism 68 (see FIG. 4B).

The melamine foam M supplied between the pair of pressing rolls 62, 62 is made up of the spacers 14, 14
It is compressed and deformed by being pressed by the pressing rolls 62, 62 through (pressing step S22: see FIG. 4 (c)).
Then, the split blade 6 is provided at the approximate center in the thickness direction of the melamine foam M, which is compressed to a required pattern by this compression.
6 cuts along the feed direction of the melamine foam M (narrow pressure / cutting step S23: see FIG. 4 (d)). Finally, the spacers 14, 14 applied to the melamine foam M are removed (spacer removing step: S24 FIG.
(See (e)).

The spacer 14 is one that sufficiently relieves the stress caused by the compression / deformation applied to the melamine foam M to be processed by the pressing rolls 62, 62, for example, an inexpensive polyurethane having a predetermined thickness. Foam such as foam, whose hardness is JIS K
In the measuring method prescribed by 6401 (“soft urethane foam for cushion”), a solid body such as a polypropylene sheet or a soft PVC sheet having a weight of 1 kg or less is preferably a solid body having an ASKER A hardness of 80 or less. Adopted by. If the hardness exceeds the above-mentioned value, sufficient stress relaxation cannot be expected even with the thickness described below, and there is a possibility that a pressing mark will be formed. In the present invention, the solit body is treated as including a porous body (microcellular plastic) made of a resin such as polypropylene as a raw material.

If the material of the spacer 14 is a foam such as urethane foam, the thickness of the spacer 14 is at least 3 which is the difference between the irregularities of the irregular surface 12 formed, that is, the depth D.
It is set to 0% or more, and in the case of a solid body such as a polypropylene sheet, it is set to at least 1.5% or more. If it is less than this, the force applied from the pressing roll 62 cannot be sufficiently relaxed, and a pressing mark is left.
When the thickness of the solid body exceeds 0.4 mm, it is important that the hardness described above, that is, the ASKERA hardness is 80 or less. Therefore, for example, soft PVC is suitable as the material. Is.

It should be noted that the spacer 14 made of a material such as the urethane foam is compressed in the same manner as the melamine foam M in actual use, and it is clear that the spacer 14 exhibits the stress relaxation ability in a state where its effective thickness is small. And
At the time of compression, it is considered that the stress is relaxed in a state of being compressed to 1.5% or more of the depth D to be obtained, which is the thickness of the above-mentioned polypropylene sheet or the like, that is, about 1/50 of the normal state. To be

The difference in the unevenness of the required pattern formed on the uneven surface 12 of the uneven foam 10 obtained by the above-described processing method, that is, the depth D is set to 90% or less of the thickness of the melamine foam M before processing. . This is because the spacers 14 required at the time of processing are formed when a depth D larger than this is formed.
Is too thick, and as a result, the stress relaxation of the spacer 14 acts too strongly so that the required pattern due to the protrusions 64 on the pressing roll 62 cannot be formed sufficiently. Further, in actual use, unless the depth D is set to about 90% or less of the thickness of the melamine foam M as a workpiece, the self-supporting property when the uneven surface 12 is turned sideways is greatly impaired, and It is necessary to be careful because it will significantly deteriorate the sex

By the preparatory step S1 and the processing step S2 which have been performed up to this point, the unevenness in which the unevenness of the required pattern from the melamine foam M is at least 10% or more of the thickness of the melamine foam M before processing. Form 10
Can be obtained. Then, in the final step S3 that is finally performed, post-processing such as polishing or punching into a predetermined shape and a predetermined inspection are performed on the concavo-convex foam 10, and a final product is completed.

The melamine foam thus obtained, which has been processed according to the present invention and has an uneven shape capable of exhibiting a high sound absorbing property, does not have a pressing mark at the time of processing.
And since it is possible to express a good sound absorbing property by forming a pattern having a large difference in the unevenness, a sound absorbing cover of a device that causes noise, a lightweight property of an automobile interior member, etc. are required,
Further, it can be suitably used in a portion where sound absorption is required while the installation place is subject to space restrictions and the like. Further, it can be suitably used also in a part such as a wall or a ceiling of a building, which is required to have excellent sound absorbing properties and high flame retardancy.

Furthermore, the skeleton may be used as a cleaning tool for kitchen sponges, for example, by taking advantage of another feature of melamine foam, which has a fine skeleton, that is, a high scraping property for foreign matter adhering to fine gaps. In this case, by increasing the surface area in a so-called semi-oval shape, that is, a semi-oval shape, a more convenient cleaning tool can be obtained.

[0028]

[Experimental Example] The processability and the commercial property of the concavo-convex foam obtained by the method for processing a melamine foam according to the present invention and the concavo-convex foam obtained by the conventional profile processing are compared below. Further, suitable experimental examples of sound absorption and the like will be shown, but the present invention is not limited to these experimental examples.

(Experiment 1) The difference between the unevenness of the uneven surface (depth D),
Relationship with Spacer Thickness A commercially available melamine foam is processed into a melamine foam having a thickness of 45 mm, the processing apparatus 60 is used, and the profile processing is performed on the melamine foam under the conditions described in Table 1 below. Specimens A to E according to E and Comparative Examples F to I deviated from the content of the present invention by, for example, not sandwiching a spacer.
The test bodies FI related to were produced. Then, the appearances of the unevenness foam and the appearance of pressing marks, etc. of the concavo-convex foams obtained for the respective test bodies A to I of the obtained Examples A to E and Comparative Examples F to I were visually confirmed.
Example E in which the thickness of the solid body is 0.5 mm
In the case of, soft PV with a high degree of flexibility with particular emphasis on hardness
Uses C sheet.

[0030]

[Table 1]

(Supplement to Table 1) Roughness ratio: As shown in FIG. 5, it is the ratio between the highest part and the lowest part of two concavo-convex foams obtained by profile processing. The position of the other uneven foam corresponding to the highest position of the uneven foam of
It is the lowest place, and the sum of these irregularities is equal to the thickness of the melamine foam before processing. Depth D: The highest part-the lowest part.

(Results of Experiment 1) As can be seen from Table 1, in Comparative Example F in which pressing was performed without interposing a spacer, even when the depth D was as shallow as 5 mm, the pressing trace by the pressing was generated. confirmed. When polyurethane foam (foam) is used as the spacer, as shown in Examples A to C and Comparative Example G, a spacer thickness of 10 mm and a depth D of about 30 mm can be supported, that is, a depth to be obtained. It was confirmed that about 30% of D could be used. When a solid body such as a polypropylene sheet is used as the spacer, Examples D and E and Comparative Example H are used.
And as shown in Comparative Example I, the spacer thickness is 0.08 mm.
It was confirmed that a depth D of about 10 mm and a depth D of about 30 mm at 0.5 mm, that is, about 1.5% of the depth D to be obtained can be dealt with.

(Experiment 2) Influence of the shape of the uneven surface obtained through the spacer (confirmed by the difference in the unevenness (depth D) and the sound insulation (noise level)) A commercially available melamine foam was processed. The melamine foam having a predetermined thickness is used, and the processing device 60 is used, and the profile processing is performed on the melamine foam under the conditions described in Table 2 below. Comparative Example N to which the surface is not uneven and deviates from the contents of the present invention
Specimens N to O related to O were produced. Then, the respective test bodies J to O of the obtained Examples J to M and Comparative Examples N to O
In the case where the test body is not installed, that is, for the blank comparative example P, the noise level (dB
(A): Sound pressure level measured with a sound level meter) was measured, and the sound insulation was evaluated based on the comparative example P.

(Evaluation of Sound Insulation) The sound insulation was evaluated basically by the noise level obtained in each Example and Comparative Example with reference to the noise level obtained in the blank Comparative Example P in Experiment 2. It was carried out by calculating the difference with each.
Specifically, the following method is used.

As a method for measuring the noise level, a reverberation room method is usually adopted. However, this method is large-scaled. Therefore, instead of the method, an acrylic closed box is prepared and a sound source is provided inside the box. State in which each of the test bodies J to O according to the present Experiment 2 is used as a lid in a state where the
In (Comparative Example P), the external noise level was measured as dB with the indicated sound level meter (A characteristic) (measurement frequency: 31.5 Hz, 6).
3Hz, 125Hz, 250Hz, 500Hz, 100
0 Hz, 2000 Hz and 4000 Hz). Then, the Ap (all pass) value (dB (A)) which is the logarithmic (log) arithmetic average at all frequencies of the measured examples and comparative examples.
Respectively, and the Ap value of Comparative Example P was compared with the Ap value of each Example and Comparative Example as described above. Specifically, it can be evaluated that the larger the difference in Ap value, the higher the sound insulating property.

[0036]

[Table 2]

(Supplement to Table 2) Split ratio: As shown in FIG. 6, it is the ratio of the projecting portion and the non-protruding portion of the two concavo-convex foams obtained by profile processing. The addition of both values gives the maximum thickness of the relief foam (equal to the convexity of the relief ratio). From this split ratio, the ratio of the depth D in the obtained concavo-convex foam can be known, and the larger the ratio,
It can be said that the depth D is deep.

(Results of Experiment 2) The results obtained (differences between Ap value and Comparative Example P) are shown in Table 2 together with
FIG. 7 shows a graph (noise level dB (A) at each frequency). For reference, an example showing the relationship between the noise level and specific examples is given in the margin of FIG. As can be seen from Table 2 and FIG. 7, the Ap value of the melamine foam flat plate shape of Comparative Example N having a thickness of 25 mm is 48.8 dB (A), and the split ratio of the thickness of 25 mm is 2/3 (depth D = 10 m).
It was found that the Ap value of Example J (m) was 48.9 dB, and that the sound insulation rate was equal to or higher than that. With reference to the split ratio of Example J, split ratio 1/1 (depth D = 1
Example K of 2.5 mm, split ratio 3/1 (depth D = 24 m
m) of Example L and 1/4 (D = 5 mm) of Example M, the Ap values were 48.4 dB (A) and 47.5, respectively.
It is dB (A) and 50.4 dB (A), and it is confirmed that the split ratio, that is, the surface area varies depending on the depth D, and the depth D = 5 mm is an uneven foam. In the test body M according to the example M, the comparative example N
Test body N (melamine foam flat plate shape 25 mm thick)
It was also confirmed that the sound insulation was inferior.

From these sound insulation data, in order to obtain a concavo-convex foam capable of exhibiting sound insulation equal to or higher than that when using a flat plate-shaped 25 mm-thick melamine foam, the split ratio is larger than 1/3. That is, it was confirmed that the depth should be deeper when the depth D is considered.

[0040]

As described above, according to the concavo-convex foam and the method for producing the same according to the present invention, even when a melamine foam having low elasticity and structurally brittleness is used as a material, It is possible to manufacture a concave-convex foam made of melamine foam, which is capable of leaving no trace of pressure or the like and having a large difference in concave-convex, that is, a large depth.

[Brief description of drawings]

FIG. 1 is a perspective view showing an uneven foam according to a preferred embodiment of the present invention.

FIG. 2 is a schematic view showing an example of a processing apparatus for manufacturing a concavo-convex foam according to an example.

FIG. 3 is a flow chart showing a method for manufacturing an uneven foam according to an embodiment.

FIG. 4 is a process drawing showing the method for manufacturing the uneven foam according to the example.

FIG. 5 is a term related to experiment 1, “depth D and unevenness ratio”.
FIG.

FIG. 6 is a schematic diagram schematically showing the term “ratio” according to Experiment 2.

FIG. 7 is a graph showing a frequency-noise level relationship for each of Examples J to L and Comparative Examples M to P in Experiment 2.

FIG. 8 is a perspective view showing a concavo-convex foam according to a conventional technique ((a) shows a front surface side, and (b) shows a back surface side).

FIG. 9 is a process drawing showing a method for producing a concavo-convex foam according to a conventional technique.

[Explanation of symbols]

10 Concavo-convex foam 12 uneven surface 14 Spacer 62 pressure roll 62a outer peripheral surface 64 protrusions 66 split blade M melamine foam D depth

Continued front page    (72) Inventor Hideo Suzuki             Stock No.5, 380, Horiyamashita, Hadano City, Kanagawa Prefecture             Inoac Technical Research Institute (72) Inventor Souko Nakajo             Stock No.5, 380, Horiyamashita, Hadano City, Kanagawa Prefecture             Inoac Technical Research Institute (72) Inventor, Ohta bile             Aichi Prefecture Anjo City Imaikecho 3 1-336 Stock             Inoac Corporation Anjo Business             In-house F-term (reference) 2E001 DF04 FA03 FA14 GA17 HD01                 3C027 EE06                 5D061 AA06 AA40

Claims (9)

[Claims] 1. A pair of pressing rolls (62, 62), which are formed with protrusions (64) of a required pattern on each outer peripheral surface (62a) and are arranged so as to rotate in opposite directions, and the pair of pressing rolls. Arranged to face the middle of the rolls (62, 62), using a split blade (66) whose blade edge is oriented in the direction of arrival of the melamine foam (M) to be processed, the pair of pressing rolls ( 62,62) said melamine foam (M)
Is fed to the downstream side with a large pressure being applied by the protrusions (64, 64) of the required pattern, and two melamine foams (M) in this pressure state are fed by the split blade (66) along the feeding direction. By cutting into a concave-convex foam (10) in which the concave-convex surface (12) of the required pattern is processed on the cut surface, spacers (14, 14) having a required thickness on the front surface side and the back surface side of the melamine foam (M). ) Under the condition that the protrusions (64, 64) are clamped,
The concavo-convex foam processed on the cut surface of (10) has a depth (D) of at least 10% or more of the thickness of the melamine foam (M) before the processing. 2. The depth (D) of unevenness processed on the cut surface.
Is at least 10% of the thickness of the melamine foam (M)
The concavo-convex foam according to claim 1, which is suitable for use as a sound absorbing material. 3. A pair of pressing rolls (62, 62), which are provided with protrusions (64) of a required pattern on each outer peripheral surface (62a) and are arranged so as to rotate in mutually opposite directions, and the pair of pressing rolls. Arranged to face the middle of the rolls (62, 62), using a split blade (66) whose blade edge is oriented in the direction of arrival of the melamine foam (M) to be processed, the pair of pressing rolls ( 62,62) said melamine foam (M)
Is fed to the downstream side with a large pressure being applied by the protrusions (64, 64) of the required pattern, and two melamine foams (M) in this pressure state are fed by the split blade (66) along the feeding direction. By cutting into a concave-convex surface (12) of the required pattern on the cut surface, when manufacturing the concave-convex foam (10), a spacer of the required thickness on the front surface side and the back surface side of the melamine foam (M) ( 14,14) is supplied toward the pair of pressing rolls (62, 62) under a correspondingly applied state, and the melamine foam (M) is formed by the protrusions (64, 64) of the required pattern. A method for manufacturing a concavo-convex foam, characterized in that clamping pressure is carried out via the spacers (14, 14). 4. The cutting of the melamine foam (M) by the split blade (66) is performed under the condition that the spacers (14, 14) are applied to the front surface side and the back surface side of the melamine foam (M). The method for producing a concavo-convex foam according to claim 3, which is carried out by. 5. The split blades are clamped by the protrusions (64, 64) under a state where the spacers (14, 14) are applied to the front surface side and the back surface side of the melamine foam (M). The unevenness processed on the cut surface of each uneven foam (10) cut by (66) has a depth (D) of at least 10% or more of the thickness of the melamine foam (M) before the processing.
The method for producing an uneven foam according to claim 3 or 4, wherein 6. The depth (D) of the unevenness formed on the uneven foam (10) is the melamine foam (M) before processing.
The method for producing a concavo-convex foam according to claim 3 or 4, wherein the thickness is set to 90% or less. 7. When the spacer (14) is a foam such as polyurethane foam, the thickness thereof is at least 30% of the depth (D) of the unevenness formed on the uneven foam (10).
The method for producing a concavo-convex foam according to any one of claims 3 to 6, wherein the hardness is set to the above and the hardness thereof is set to 1 kg or less in the measuring method defined in JIS K6401. 8. When the spacer (14) is a solid body such as a polypropylene sheet, the thickness thereof is at least 1.times. The depth (D) of the irregularities formed on the irregular foam (10).
The method for producing a concavo-convex foam according to any one of claims 3 to 6, wherein the hardness is set to 5% or more and the hardness thereof is set to 80 or less in ASKER A hardness. 9. The thickness of the spacer (14) is such that, even if the melamine foam (M) is largely pressed by the protrusions (64, 64) of the required pattern, pressure marks are applied to the front surface side and the back surface side of the melamine foam (M). The method for producing a concavo-convex foam according to any one of claims 3 to 8, wherein the dimension is set so as not to attach.