KR102059557B1 - Lightweight felts - Google Patents

Abstract

(assignment)
It has high sound absorption and flame retardancy and is flexible to provide a lightweight felt material suitable for automobiles or automobile interior materials, industrial materials, and garment materials.
(Solution)
In the lightweight felt material, the two mirror layers are 20 to 80% of ultrafine fibers each having a fineness of 1.1 decitex or less, 10 to 60% of hollow fibers imparting bulkiness, and low melting point fibers 10 to be melted during the entire heat treatment. -60% is mixed, and the fiber diameter in a nonwoven sheet is 2-20 micrometers, and basis weight is 20-100 g / m <2>.

Description

Lightweight felt material {LIGHTWEIGHT FELTS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight felt material having high sound absorption and flame retardancy and which is flexible and suitable for interior materials of automobiles and vehicles, industrial materials, garment materials and the like.

In general, interior materials are adhered to automobiles in trunk rooms, luggage rooms, and the like, and as the interior materials, a velour-like or dilor-like skin texture sheet is often used. Even if the skin sheet is adhered to the plastic or felt sheet on the lower side of the skin material, the sound absorption can be improved, the noise penetrating into the compartment from the trunk room can be reduced, the rigidity and moldability can be increased, and the constant strength can be maintained. In the past, it was very difficult to obtain a desired three-dimensional shape.

In order to obtain a desired three-dimensional shape, the present applicant has already sold the interior material formed by tying the plane type skin material and the felt sheet by needle punching and integrating them and then hot-pressing. Further, in Japanese Patent No. 5027456, a spunbond nonwoven fabric integrated with a felt sheet is used, and granular melts are dispersed by pre-heating treatment on the entire surface of the spunbond nonwoven fabric. When formed, when reheated alone, the spunbond nonwoven fabric is surface melted, and can be bonded to the skin material to be molded. Since the felt material for interior materials can be formed by a cold press, since the surface of a skin material does not heat and pressurize, the interior material which kept the color of a skin and a feeling of hairiness can be obtained.

The said felt sheet is generally blended with normal polyester fiber and low-melting-point polyester fiber, and is integrated and manufactured by needle punching further. Since the fineness of the fiber used is relatively high, this felt sheet cannot improve sound absorption performance very much, and a needle punching makes a fiber transition to a thickness direction, and the overall sound absorption performance tends to fall. On the other hand, Japanese Patent Laid-Open No. 53-41577, Japanese Patent Laid-Open No. 6-212545 and Japanese Patent Laid-Open No. 6-212546 disclose melt-blown using microfine fibers and polyester short fibers. ) Nonwoven fabric (brand name: THINSULATE) is provided, and since this nonwoven fabric has high sound absorption and is flexible and easy to process, it is suitable as an interior material.

Japanese Patent No. 5027456 Japanese Patent Laid-Open No. 53-41577 Japanese Patent Laid-Open No. 6-212545 Japanese Patent Laid-Open No. 6-212546

Meltblown nonwoven fabrics are produced by integrating, for example, microfibers having an average fiber diameter spun by the meltblown method of 10 µm or less and polyester short fibers such as flame retardancy, and generally It is very good in sound absorption and heat insulation. Meltblown nonwoven fabrics are lightweight and have a large volume, and are suitable not only as sound absorbing materials but also as heat insulating materials, but at present, there is a demand from users to propose higher performance interior materials.

Moreover, the melt blown nonwoven fabric adhere | attaches skin materials, such as a spunlace, on the front and back surface, and is used as an automotive roof seat in some vehicle models. In this roof sheet, the spunlace of the front and back surface is adhere | attached, and this spunlace tends to be wrinkled, and it is hard to make it fit in the shape of a built-in surface. It is also pointed out that this loop sheet is more difficult to fit into the shape of the interior surface because the cut end face may be attached to the cutter when the shape is cut out by the Thomson cutter.

The present invention has been proposed in order to further improve the conventional interior materials for automobiles, and an object thereof is to provide a lightweight felt material which is excellent in sound absorption and flame retardancy and in which thickness, weight and density are balanced. Another object of the present invention is to provide a lightweight felt material suitable not only for interior materials of automobiles and vehicles, but also for industrial materials, winter clothing materials, and the like.

The lightweight felt material which concerns on this invention integrates the whole through the nonwoven sheet between two mirror surface layers. In this lightweight felt material, in both mirror layers, 20 to 80% of ultrafine fibers having a fineness of 1.1 decitex or less, 10 to 60% of hollow fibers imparting bulkyness, and low melting fibers that melt during the entire heat treatment 10 to 60% is blended, the fiber diameter in the nonwoven sheet is 2 to 20 µm, and the basis weight is 20 to 100 g / m 2.

The lightweight felt material which concerns on this invention integrates the whole by thermocompression bonding through a nonwoven sheet between two mirror surface layers. In this lightweight felt material, in both mirror layers, 20 to 80% of ultrafine fibers having a fineness of 1.1 decitex or less, 10 to 30% of hollow fibers imparting bulkiness, and low melting point fibers to be melted during the entire heat treatment 10 to 60% is mixed, and the fiber diameter in a nonwoven sheet should just be 2-20 micrometers, and 20-100 g / m <2> of basis weights.

In the lightweight felt material of the present invention, the ratio of the thickness of the upper mirror layer to the lower mirror layer is preferably 1: 1 to 1: 4, and the nonwoven sheet is produced by the meltblown method. It is preferable if it is a nonwoven fabric. Moreover, in a mirror surface layer, you may normally contain 10 to 30% of further short fibers or half hair of synthetic fibers of fineness also.

The manufacturing method of the lightweight felt material which concerns on this invention puts a nonwoven sheet following the 1st web which intertwined the ultrafine fiber, the hollow fiber, and the low melting point fiber on the traveling conveyor, and further added the ultrafine fiber, the hollow fiber, and the low melting point fiber. The third web layer is formed by placing the entangled second web, and then, by heat treatment and pressurizing the three-layer laminate at a temperature exceeding the melting point of the low-melting fiber, the entire felting and integration are simultaneously achieved. . In this manufacturing method, it is preferable to more reliably adhere the nonwoven sheet and the first and second webs by fluffing up both sides of the nonwoven sheet by embossing at the low temperature or by brushing the surface.

The light weight felt material which concerns on this invention is a composite material of a mirror layer and a nonwoven sheet, compared with the existing melt blown nonwoven fabric, it is excellent in sound absorption and flame retardancy, and is comparatively cheap. The lightweight felt material of the present invention has flexibility and is easy to fit into the inner surface of a vehicle, and is not only used for interior materials of automobiles and vehicles, but also for industrial materials such as soundproof insulation materials, insulation for ski wear, and cold protection such as filling gloves and hats. Applicable also for garment material.

The lightweight felt material according to the present invention has a high sound absorption performance and flame retardancy suitable for FMVSS302 as long as the basis weight, thickness and density equivalent to that of the existing meltblown nonwoven fabric, and establishes a balanced balance of thickness, weight and density. The lightweight felt material of the present invention is advantageous in terms of cost because no adhesive material or the like is required at the time of manufacture, and can be advantageously used as a substitute for a conventional meltblown nonwoven fabric by appropriately adjusting the sound absorbing performance and the flame retardant performance.

Since the manufacturing method of the lightweight felt material which concerns on this invention integrates by heat-processing and integrating a 1st web, a nonwoven sheet, and a 2nd web, it is possible to collectively produce a lightweight felt material in one line. When the manufacturing method of this invention is used, a lightweight felt material can be manufactured efficiently, and a manufacturing cost can be reduced. Moreover, when both surfaces of a nonwoven sheet are fluffed previously, the peeling strength of the whole said felt material can be raised.

1 is an enlarged cross-sectional view showing a lightweight felt material according to the present invention.
2 is an enlarged cross-sectional view showing a modification of the lightweight felt material.
3 is a schematic side view illustrating a manufacturing process of a lightweight felt material.
Fig. 4 is a partial perspective view showing the three-layer laminated body disassembled.
It is a graph which shows the felt material of Example 2 and Example 3, and the sound absorption rate of Comparative A-C.
It is a graph which shows the sound absorption rate of the felt material of Example 5 and Example 6, and the comparative D.

As shown in FIG. 1, the lightweight felt material 1 which concerns on this invention is integrated by interposing the nonwoven sheet 5 between two mirror surface layers 2 and 3. As shown in FIG. The mirror layers 2 and 3 are usually of the same thickness, density and basis weight distribution, and the sound absorption performance of the felt material 1 may be further improved by appropriately adjusting both thicknesses and the like as desired. When using it as a interior material, the felt material 1 is further adhere | attached the skin material which has a favorable external appearance, a touch, a hairiness, etc. by normal temperature or heat processing.

The lightweight felt material 1 generally has a three-layer structure as shown, and the mirror surface layer itself may be provided in plural layers. In addition, the lightweight felt material 1 may arrange | position two nonwoven sheets between each of three mirror-layers, and may arrange three nonwoven sheets into each of four mirror-layers, and a nonwoven sheet and In order to raise the adhesive strength of a mirror surface layer, the adhesive powder of the quantity which does not impair sound absorption performance may be sprayed between them, and an adhesive liquid may also be apply | coated.

The mirror layers 2 and 3 are formed by intertwining 20 to 80% of the ultrafine fibers, 10 to 60% of the hollow fibers, and 10 to 60% of the low melting point fibers, and may normally add synthetic fibers of fineness as appropriate. The mirror layers 2 and 3 are usually the same fiber composition, but may be changed depending on the use of the felt material 1. Synthetic fibers of ultrafine fibers, hollow fibers and ordinary fineness are polyester, acrylic, polyamide, rayon, polypropylene, polyvinyl chloride, polyethylene and the like, and may be used by mixing a plurality of kinds with respect to each fiber. In view of cost and heat resistance, polyester, any of ultrafine fibers, hollow fibers, low melting fibers and synthetic fibers of ordinary fineness is preferred.

In the mirror layers 2 and 3, the ultrafine fibers mean fibers having a fineness of 1.1 decitex (1 denier) or less, which are difficult to normal spinning, and include ultrafine fibers, ultrafine fibers, and the like in the present invention. In order to manufacture ultrafine fibers of short fibers, a melt blow method, a centrifugal spinning method, a flash spinning method, a beating method, a mixed spinning method, a tag spinning method, and the like are used. The addition amount of this ultrafine fiber is 20 to 80 weight%, Preferably it is 40 to 80 weight% which is a comparatively large quantity. If the addition amount of the ultrafine fibers is less than 20%, it is difficult to increase the sound absorption performance of the felt material 1, while if it exceeds 80%, it is difficult to make the felt material 1 into a large volume and it is also uneconomical.

In the mirror layers 2 and 3, the hollow fiber is a kind of release cross-sectional fiber, for example, using a spinning nozzle special in melt spinning such as polyester, acrylic, polyamide, or the like. In the case of ray spinning, bubbles can be generated inside the fibers to make a yarn having a hollow cross section. This hollow fiber is thick in apparent fineness, strong in crimp, generally good in heat retention, and light, and makes the elasticity of a felt material strong. The addition amount of a hollow fiber is 10-60 weight%, Preferably it is 10-30 weight% which can impart bulkiness. If only less than 10% of the hollow fiber is added, it is difficult to impart bulkiness to the felt material 1, while if it exceeds 60%, the flexibility of the felt material 1 is impaired.

In the mirror layers 2 and 3, the low melting point fiber has a melting point of about 40 to 70 ° C lower than that of the ultrafine fiber, the hollow fiber and the normal fineness synthetic fiber, and the whole integral and nonwoven sheet 5 as a binder during heat treatment. Contributes to adhesion. Low melting point polyester, low melting point polyamide, polyethylene, polypropylene, etc. can be illustrated to this low melting point fiber, and the copolymer with ethylene or butene may be sufficient. As long as this low melting point fiber is lower than a normal fiber, well-known fiber, resin filament, or these mixed fiber which has a melting point of 90-170 degreeC can also be used, and composite fiber, such as parallel and a sheath core structure, is also preferable. The addition amount of low melting fiber is 10 to 60 weight%, Preferably it is 20 to 50 weight% which makes integration of the whole easy. If the low melting point fiber is less than 10%, the heat treatment will make integration of the felt material 1 or adhesion with the nonwoven sheet 5 difficult, while if it exceeds 60%, the whole felt material 1 will be too hard.

When this low melting fiber is a sheath core structure polyester fiber, the fiber to sheath should just be a low melting polyester, such as melting | fusing point 110 degreeC, 130 degreeC, 150 degreeC, 160 degreeC, In the Example, the thing of melting | fusing point 110 degreeC is used, The fiber of the core is regular polyester having a melting point of 250 ° C. In the case of the sheath core structure PP / PE fiber, the fiber to be sheathed is polyethylene having a melting point of 130 to 134 ° C, and the fiber of the core is polypropylene having a melting point of 165 ° C. Although the sheath core structure PP / PE fiber is relatively inexpensive and can be used, the binder effect is small and the repulsion is slightly inferior to the sheath core structure polyester fiber.

In the mirror layers 2 and 3, in addition to each of the above fibers, a short fiber or various semi-hairs (recovered and recycled cotton) of synthetic fibers of fineness may be further contained 10 to 30%, and this addition is mainly low in cost. The amount of addition is limited to the range in which the sound absorption performance is not lowered. In terms of cost, it is advantageous to add a half-hair so that the lightweight felt material 1 can be manufactured at a very low cost.

In the lightweight felt material 1, the upper mirror surface layer 2 and the lower mirror surface layer 3 are generally the same in thickness and density. In addition, like the lightweight felt material 6 shown in FIG. 2, the ratio of thickness can be changed to 1: 4, preferably 1: 2.2 in order to further improve sound absorption performance with respect to the mirror surface layers 2 and 3. And even if the ratio of thickness is enlarged more, sound absorption performance hardly improves. If the thickness of the mirror surface layer 2 and the mirror surface layer 3 is different, it is necessary to arrange so that sound may enter from the thinner mirror surface layer 2 side, and for example, if sound enters from the thicker mirror surface layer 3 side, the felt will be felt. The sound absorption performance of the ash 1 will fall.

In the upper mirror surface layer 2, it is normally preferable that thickness is 10-19 mm and basis weight 100-300 g / m <2>, and preferable specifications are thickness about 12 mm and basis weight about 177 g / m <2>. On the other hand, in the lower mirror surface layer 3, it is preferable that thickness is 19-30 mm and basis weight 100-300 g / m <2> normally, and a preferable specification is thickness about 25 mm and basis weight about 123 g / m <2>.

It is preferable to comprise the nonwoven sheet 5 from the ultrafine fiber of 2-20 micrometers in fiber diameters, The said nonwoven sheet can be manufactured by said each method, Preferably it is manufactured by the melt-blown method. The meltblown nonwoven sheet 5 is low density and bulky, and is drape-rich and flexible. With respect to the meltblown nonwoven sheet 5, a plurality of short fibers adjacent to each other in the web are focused together to form a connection portion in which at least a portion of the fiber length direction is bonded to each other. For example, in a melt blown nonwoven sheet, kneading resin is extruded from a nozzle onto a conveyor while blowing hot air, and the fine fibers are entangled with heat to form a sheet. In a meltblown nonwoven sheet, it is preferable that the connecting fiber containing a connection part is adhere | attached at the intersection with the fiber which comprises a meltblown web.

The nonwoven sheet 5 is a relatively thin and drape-rich nonwoven fabric having a thickness of 0.1 to 1.0 mm, preferably a basis weight of 20 to 100 g / m 2, and a preferable specification is about 0.3 mm in thickness, The basis weight is about 40 g / m 2. If the basis weight of the nonwoven sheet 5 is less than 30 g / m <2>, the sound absorption performance of the felt material 1 may not fully be improved, whereas, if it exceeds 100 g / m <2>, the improvement of sound absorption performance will be small and flexibility will fall easily.

The ultrafine fibers constituting the nonwoven sheet 5 are made of polyester, acrylic, polyamide, polypropylene, polyethylene, polyvinyl chloride, or the like, and generally, polyester is preferable in view of cost and heat resistance. This ultrafine fiber may be sprayed with a flame retardant after sheet formation, or immersed in the solution of a flame retardant, and this flame retardation is similarly possible also about the mirror-surface layers 2 and 3.

In order to manufacture the lightweight felt material 1 continuously, you may use the felt manufacturing apparatus 7 of the combined arrangement schematically illustrated in FIG. The conveyor 8 usually has a net-like structure through which hot and cold air can pass, and travels over the entire length of the felt manufacturing apparatus 7. In the adjacent first and second card cross wrappers 10 and 12, a fine card, a hollow fiber, a low melting point fiber, and the like are mixed with a known carding machine to form an integrated layer. Webs 14 and 16 (see Fig. 4) are obtained.

The long nonwoven sheet 5 installs the sheet winding rolls 18 horizontally between the card cross wrappers 10 and 12 and sends them out on the conveyor 8 from the winding rolls. On the other hand, the long nonwoven sheet 5 can also be sent from the outside of an apparatus via the some roller 20. FIG. Both surfaces of the nonwoven sheet 5 can be more reliably adhered to the nonwoven sheet and the first and second webs if they are fluffed in advance by embossing at a low temperature or by brushing the surface.

The heat treatment machine 22 is provided at the rear of the second card cross wrapper 12, and the second web 16, the nonwoven sheet 5, and the first web () are formed by hot air circulating in the machine. The three-layer laminate 24 (see FIG. 4) of 14 is uniformly heated on the conveyor 8. This heating temperature needs to exceed the melting point of the low melting fiber in the webs 14 and 16, thereby melting the low melting fiber. Behind the heat treatment machine 22, a pair of pressure roller 26 and the cooler 28 are further provided one by one. The lightweight felt material 1 is obtained from the three-layer laminated body 24 by the heat processing machine 22 and a pair of pressure rollers 26.

In the felt manufacturing apparatus 7, the first card cross wrapper 10 first binds the ultrafine fibers, the hollow fibers, the low melting point fibers, and the like, and then forms the first web 14 corresponding to the lower mirror surface layer 3. Export on the conveyor (8). Subsequently, on the conveyor 8, the long nonwoven sheet 5 is continuously mounted on the first web 14. In the second card cross wrapper 12, a predetermined amount of ultrafine fibers, hollow fibers, low melting point fibers, etc. are intertwined, and the second web 16 corresponding to the upper mirror surface layer 2 is placed on the conveyor 8. It is put out on the nonwoven sheet 5 continuously, and it is set as the 3-layer laminated body 24.

The three-layer laminate 24 (see FIG. 4) passing through the second card cross wrapper 12 is uniformly heated on the conveyor 8 in the heat treatment machine 22, and further, a pair of pressure rollers ( It is pressurized by 26) and achieves the whole felting and integration simultaneously, and produces the lightweight felt material 1 continuously. The obtained lightweight felt material 1 is cooled by the cold air which descends in the said cooler by passing through the inside of the cooler 28. As shown in FIG.

It is preferable that the obtained lightweight felt material 1 is usually 8-50 mm in thickness and basis weight 300-500 g / m <2>, and a preferable specification is thickness about 38 mm and basis weight about 340 g / m <2>. In special applications, the thickness may be up to about 100 mm, the basis weight may be about 3000 g / m 2 at the upper limit, the density may be at least 0.005 g / cm 3, and the upper limit may be at least 0.043 g / cm 3.

As an example of the general specification of the lightweight felt material 1, when it is 8 mm in thickness and basis weight is 340 g / m <2>, it is set as density of 0,0425 g / cm <3>. If the thickness is 10-40 mm and the basis weight is 340 g / m 2, the thickness is 10 mm, the density is 0.0340 g / cm 3, the thickness is 15 mm, the density is 0.0227 g / cm 3, the thickness is 20 mm, the density is 0.0170 g / cm 3, the thickness is 25 mm, and the density is 0.0136 g. / Cm 3, thickness 30 mm, density 0.113 g / cm 3, thickness 35 mm, density 0.10097 g / cm 3, thickness 40 mm, and density 0.10085 g / cm 3. In addition, a thickness of 50 mm, basis weight 425 g / ㎡, thickness 60 mm, basis weight 510 g / ㎡, basis weight 510 g / ㎡, basis weight 595 g / ㎡, thickness basis weight 595 g / ㎡, basis weight 680 g / ㎡, thickness basis 100 mm, basis weight 850 g / In the case of m 2, the density becomes 0.0085 g / cm 3.

Example 1

Next, although this invention is demonstrated based on an Example, this invention is not limited to an Example. In order to manufacture the lightweight felt material 1 shown in FIG. 1, using the felt manufacturing apparatus 7 shown in FIG. 3, 40% of ultrafine polyester fibers of 0.75 denier fineness, and 15% of hollow polyester fibers of fineness 15 denier 25% of low-density polyester fibers having a fineness of 4 deniers and 20% of polyester short fibers having a fineness of 3 deniers are mixed to form two webs 14 and 16 having a basis weight of 150 g / m 2. As the nonwoven sheet 5, a polyester melt blown sheet having a basis weight of 40 g / m 2 (trade name: Guraflex BTS0040EM, manufactured by Kuraray) is used.

The nonwoven sheet 5 is sandwiched between the webs 14 and 16 above and the whole is heat bonded. The obtained lightweight felt material 1 places the nonwoven sheet 5 at the center of a felt material, and the thickness and basis weight distribution of the upper and lower mirror surfaces 2 and 3 are equal. This lightweight felt material 1 is thickness 38mm and basis weight 340g / m <2>.

Example 2

The lightweight felt material 1 of the fiber composition similar to Example 1 is manufactured using the tester and using polyester semi-fiber instead of the polyester short fiber of the fineness 3 denier in Example 1. In this lightweight felt material 1, the upper mirror layer 2 has a thickness of 19 mm and a basis weight of 155 g / m 2, while the lower mirror layer 3 has a thickness of 19 mm and a basis weight of 155 g / m 2. to be.

The obtained lightweight felt material 1 is thickness 38mm and basis weight 350g / m <2>. Considering the cost, if it is about 20%, a polyester half hair may be added instead of the polyester short fiber.

Example 3

Using the felt manufacturing apparatus 7 shown in FIG. 3, the webs 14 and 16 are of the same fiber formulation as in Example 1, and both webs 14 and 16 sandwich the same nonwoven sheet 5 as in Example 1. The whole is heat-bonded, and the lightweight felt material 1 is manufactured. The obtained lightweight felt material 1 is thickness 38mm and basis weight 407g / m <2>.

About the lightweight felt material 1 which is Example 2 and Example 3, it compares with the following product.

Comparative A: Meltblown nonwoven fabric having a thickness of 38 mm (trade name: Sinsula TC3303 300)

         (Basic weight 356 g / ㎡)

Comparative B: Meltblown nonwoven fabric having a thickness of 38 mm (Product Name: Synthetic Regular 300)

Comparative C: Felt material in which the nonwoven sheet 5 is not interposed by the same fiber formulation as in Example 3.

         (Thickness 38 mm and basis weight 386 g / m 2)

The lightweight felt material 1 and Comparative A-C of Example 2 and Example 3 are all 38 mm in thickness. About these products, the sound absorption data by a perpendicular incidence method is measured, and the result is shown in following Table 1.

5 shows the results of Table 1 in a graph. From this graph, it is evident that the lightweight felt material 1 of Examples 2 and 3 has a sound absorption rate equal to or higher than that of Comparative A and B, which are known meltblown nonwoven fabrics (trade name: Sinsula). Moreover, from the sound absorption rate of the comparative C, the nonwoven sheet 5 is essential in the lightweight felt material of this invention.

Example 4

Using the felt manufacturing apparatus 7 shown in FIG. 3, the webs 14 and 16 are of the same fiber formulation as in Example 1, and both webs 14 and 16 sandwich the same nonwoven sheet 5 as in Example 1. The whole is heat-bonded, and the lightweight felt material 6 (FIG. 2) is manufactured. In the lightweight felt material 6, the upper mirror layer 2 has a thickness of 12 mm and a basis weight of 202 g / m 2, while the lower mirror layer 3 has a thickness of 26 mm and a basis weight of 165 g / m 2. .

The light weight felt material 6 having different thicknesses of the mirror surface layers 2 and 3 has a basis weight distribution, and the total weight becomes about 50 g / m 2, but the light weight felt material 1 having the same thickness of the mirror surface layers 2 and 3 is the same. Compared with), the sound absorption performance is greatly increased.

Example 5

The lightweight felt material 1 is manufactured by the fiber mix similar to Example 1. However, the obtained lightweight felt material 1 is 20 mm in thickness and basis weight 327 g / m <2>.

Example 6

The lightweight felt material 1 is manufactured by the fiber mix similar to Example 2. However, the obtained lightweight felt material 1 is 20 mm in thickness and basis weight 333 g / m <2>.

About the lightweight felt material 1 which is Example 5 and Example 6, it compares with the following product.

Comparative D: Meltblown nonwoven fabric having a thickness of 20 mm (trade name: Sinsula TC3303 300)

        (Basic weight 326 g / ㎡)

The lightweight felt material 1 and the comparative D of Example 5 and Example 6 are all 20 mm in thickness. About these products, the sound absorption data by a perpendicular incidence method is measured, and the result is shown in following Table 2.

6 shows the results of Table 2 in a graph. From this graph, it is clear that the lightweight felt material 1 of Examples 5 and 6 has a sound absorption rate equivalent to or more than the comparison D which is a well-known meltblown nonwoven fabric (brand name: synthrate) also in thickness 20mm.

1: lightweight felt material
2: upper mirror layer
3: downward mirror layer
5: nonwoven sheet

Claims (7)

A lightweight felt material which integrates the whole by interposing a nonwoven sheet between two mirror layers, and in both mirror layers, 20 to 80% by weight of ultrafine fibers having a fineness of 1.1 decitex or less, and 10 to 60 hollow fibers to impart bulkiness. A lightweight felt material having 10% to 60% by weight of a low melting point fiber having a weight% and a melting point of 90 to 170 ° C, being mixed, and having a fiber diameter of 2 to 20 µm and a basis weight of 20 to 100 g / m 2 in the nonwoven sheet. A bulky, lightweight felt material that integrates the whole by thermal compression by interposing a nonwoven sheet between two mirrored layers. In both mirrored layers, 20 to 80% by weight of ultrafine fibers having a fineness of 1.1 decitex or less are imparted. 10 to 30% by weight of the hollow fiber, 10 to 60% by weight of the low melting point fiber having a melting point of 90 to 170 ° C are blended, and the fiber diameter of the nonwoven sheet is 2 to 20 µm and the basis weight is 20 to 100 g / m 2. Lightweight felt material. The method according to claim 1 or 2,
The light weight felt material of the ratio of the thickness of an upper mirror layer and a lower mirror layer below 1: 1-1: 4. The method according to claim 1 or 2,
Lightweight felt material in which a nonwoven sheet is a nonwoven fabric manufactured by the melt blown method. The method according to claim 1 or 2,
Lightweight felt material which contains 10-30 weight% of short fibers or a half hair of a synthetic fiber further in a mirror layer. On the running conveyor, the first web intertwined with 20 to 80% by weight of ultrafine fibers having a fineness of 1.1 decitex, 10 to 60% by weight of hollow fiber, and 10 to 60% by weight of low melting point fiber having a melting point of 90 to 170 ° C. A nonwoven sheet having a fiber diameter of 2 to 20 µm and a basis weight of 20 to 100 g / m 2 was placed thereon. Further, 20 to 80 wt% of ultrafine fibers having a fineness of 1.1 decitex or less, 10 to 60 wt% of hollow fibers, and a melting point of 90 to 170 By placing a second web intertwined with 10 to 60% by weight of the low melting point fiber, which is in degrees Celsius, a three-layer laminate is formed, and then the three-layer laminate is heat treated and pressurized at a temperature exceeding the melting point of the low-melting fiber. The manufacturing method of the lightweight felt material which achieves the whole felting and integration simultaneously. The method of claim 6,
A manufacturing method of more reliably bonding the nonwoven sheet and the first and second webs by fluffing both surfaces of the nonwoven sheet by embossing or brushing the surface.

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