JP3133470U - Sound absorbing material - Google Patents

Abstract

An object of the present invention is to provide a melt-blown nonwoven fabric and a short-fiber nonwoven fabric by using a spider web-like nonwoven fabric having heat-fusibility and wire-bonding to ensure the joining of both nonwoven fabric fibers and increase the peel strength between layers with a low basis weight. Provided is a sound absorbing material which can improve sound absorbing performance without blocking between layers.
A melt-blown nonwoven fabric 1 having a basis weight of 10 to 100 g / m ² , a thickness of 0.05 to 0.3 mm, and an air permeability of 0.1 to 100 cc / cm ² / sec, comprising an ultrafine fiber having a fiber diameter of 6 μm or less, Adhering a short fiber nonwoven fabric 2 having a fiber diameter of 7 to 50 μm, a basis weight of 70 to 250 g / m ² , and a thickness of 5 to 30 mm by wire bonding through a spider web-like heat-fusible nonwoven fabric 3 having a basis weight of 5 to 50 g / m ² It is an integrated sound absorbing material.
[Selection] Figure 1

Description

  The present invention relates to a nonwoven fabric sound-absorbing material that is lightweight and has excellent sound-absorbing properties regardless of its thickness.

Short fiber nonwoven fabrics are widely used as sound absorbing materials for automobiles and construction applications. In order to increase the sound absorption performance of these nonwoven fabrics, methods such as reducing the fiber diameter to increase the air passage resistance and increasing the basis weight have been adopted. As a result, when high sound absorption performance is required, a relatively thin fiber having a fiber diameter of about 15 μm is used, and a thick and heavy short fiber nonwoven fabric having a basis weight of 500 to 5000 g / m ² is used.

  On the other hand, non-woven fabrics containing ultrafine fibers by meltblown have excellent properties such as sound absorption properties, filter properties, and shielding properties, and have been used in many applications, but problems such as low strength and poor form stability In order to improve this, it has been used by being laminated and composited with another nonwoven fabric. However, as a method of laminating and integrating the nonwoven fabric at this time, a method of applying a resin as a binder by spraying or transfer or a method of using a heat-bonding fiber has been performed. Heat treatment is necessary for the purpose, and there are problems from the viewpoint of environmental pollution and energy saving, and there is also a problem that the binder resin forms a film at the interface between the nonwoven fabrics and the sound absorption is reduced.

  It is known that superfine fiber non-woven fabrics and long fiber non-woven fabrics are laminated and integrated, commonly known as S / M / S. Laminate melt-blown non-woven fabrics, which are ultra-fine fibers, between spunbonded non-woven fabrics and join them by hot embossing. However, these nonwoven fabrics have a problem in that they lack a sense of volume as a whole, have a hard texture, and have limited applications.

In order to achieve these improvements, the basis weight of 30 to 200 g / m ² nonwoven fiber diameter containing the following ultrafine fibers 6μm earlier, fiber diameter of basis weight in 7~40μm of 50 to 2000 g / m ² A sound-absorbing material in which a short fiber nonwoven fabric is integrated by entanglement of these fibers and has a short fiber loop outside the nonwoven fabric containing ultrafine fibers (see, for example, Patent Document 1), or an apparent density of 0.01 ~ 0.10 g / cm ³ , a base layer made of a fiber aggregate having a basis weight of 50 to 2000 g / m ² , and a thermoplastic polymer having a melting point of 200 ° C. or higher, and fibers having an average fiber diameter of 10 μm or less are substantially flat. A sound-absorbing material (for example, see Patent Document 2) composed of a laminate of a melt-blown nonwoven fabric having an apparent density of 0.1 to 0.4 g / cm ³ and a basis weight of 5 to 300 g / m ² has been proposed.
Japanese Patent No. 3705212 JP 2002-69823 A

  However, each of the above sound-absorbing materials has difficulty in joining the laminated nonwoven fabric or fiber assembly and the melt-blown nonwoven fabric, and sufficient joining cannot be obtained only by integration by entanglement, resulting in durability and sound absorption. It had some difficulties.

  The present invention uses a spider web-like nonwoven fabric with heat-fusibility to eliminate such difficulties, and by wire bonding, it ensures the bonding of each fiber constituting the sound absorbing material, and the interlayer is peeled off with a low basis weight. The purpose is to increase the strength and improve the sound absorption performance without interlaminar barriers.

That is, the features of the present invention suitable for the above-mentioned object are that the basis weight is 10 to 100 g / m ² , the thickness is 0.05 to 0.3 mm, and the air permeability is 0.1 to 100 cc / cm. ^{A 2} / sec melt blown nonwoven fabric and a short fiber nonwoven fabric having a fiber diameter of 7 to 50 μm and a basis weight of 70 to 250 g / cm ² are bonded to each other via a spider web-like heat-fusible nonwoven fabric having a basis weight of 5 to 50 g / m ^2. It is a sound-absorbing material that is bonded and integrated.

  The sound-absorbing material of the present invention has a sound insulation effect by using a dense melt-blown nonwoven fabric made of ultrafine fibers, and also has a sound-absorbing effect by a short-fiber nonwoven fabric, and between layers by wire bonding with a spider web-like heat-fusible nonwoven fabric. There is no interruption, the sound is smoothly absorbed between the layers, and the adhesion point is line-bonded, so that it has a remarkable effect as a sound-absorbing material that is efficiently bonded, has excellent peel strength, and is thin and lightweight. In particular, it can be used as a lightweight and excellent sound-absorbing material for improving fuel efficiency and comfort in automobile applications, and is also suitably used as a sound-absorbing material in a wide range of industrial applications.

  Hereinafter, specific embodiments of the sound absorbing material of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view of a sound absorbing material of the present invention. 1 is a melt blown nonwoven fabric, 2 is a short fiber nonwoven fabric, and 3 is a web-like heat-weldable nonwoven fabric used for joining the two. Here, the meltblown nonwoven fabric is a sound insulating material, and is preferably an ultrafine fiber having a fiber diameter of 6 μm or less, and most preferably about 1.5 to 3 μm.

Further, that the melt-blown nonwoven fabric having a basis weight is 10 to 100 g / m ^2, and preferably air permeability is 0.1~100cc / cm ² / sec, when the basis weight is less than 10 g / m ^2, microfine fibers The effect of improving the shielding properties, felt performance, softness, sound insulation properties, etc. is not so good, and it is not so appropriate from the viewpoint of cost reduction and weight reduction. A thickness of 0.05 to 0.3 mm is suitable for practical use.

  The material constituting the melt blown nonwoven fabric is not particularly limited, but polyester or polyolefin, particularly polypropylene is preferable from the viewpoint of recyclability. In particular, the same material as the laminated short fiber nonwoven fabric is particularly advantageous because it is easy to recycle. Of course, there is no problem even if fibers made of a plurality of materials are mixed.

  On the other hand, the relatively thick short fiber nonwoven fabric laminated and integrated with the melt blown nonwoven fabric composed of the above ultrafine fibers is a sound absorbing material, and the fiber diameter is preferably 7 to 50 μm, particularly preferably 7 to 20 μm. A fiber diameter smaller than 7 μm does not directly cause a big problem, but in the case of a short fiber nonwoven fabric, it is not preferable in view of productivity such as spinning performance from a card machine. On the other hand, when the fiber diameter is significantly smaller than 7 μm, the lamination effect according to the present invention is reduced, and another problem may occur such that the nonwoven fabric is easily fuzzed. If the fiber diameter is larger than 50 μm, the contribution to the sound absorbing performance is reduced, which is not preferable. Although there is no limitation in particular as a raw material which comprises this short fiber nonwoven fabric, it is preferable that it is the same material as the said meltblown nonwoven fabric, and polyester and a polypropylene are generally used. It is also preferable to mix a low melting point short fiber of the same material in part.

  In the present invention, the short fiber non-woven fabric as the sound absorbing material is laminated with the melt blown non-woven fabric made of ultra fine fibers as the sound insulating material, so that the ultra-fine fiber melt blown non-woven fabric has low form stability (easy to sag or fluff) and bulky It is possible to improve the point that it is likely to cause a problem in maintaining a high degree of fashion and to exhibit high fashionability and vibration control. In addition, it is considered that the sound absorbing material is generally capable of obtaining higher performance as the thickness is larger, and the effect of performing lamination is also large for the purpose of controlling the thickness, but in the present invention, the sound absorbing performance can be obtained with low weight The effect is great.

Basis weight of the staple fiber nonwoven fabric, 70 g / m ² or more, preferably 70~250g / m ^2. When the basis weight is less than 70 g / m ² , the lamination effect is small, which is not preferable in terms of bulkiness and soft texture of the nonwoven fabric. On the other hand, if the basis weight is larger than 250 g / m ² , the thickness becomes too large to take up space and the weight becomes unfavorable. In addition, in the said short fiber nonwoven fabric, about 5-30 mm is suitable for thickness.

  Next, when the melt blown nonwoven fabric and the short fiber nonwoven fabric are integrated in the present invention, especially when they are combined using the needle punch method, the melt blown ultrafine fiber nonwoven fabric has holes and the sound absorption performance is lowered, so that the nest-like heat fusion It integrally joins using an adhesive nonwoven fabric. The web-like heat-fusible non-woven fabric is produced by a spunbond method or the like, and is line-bonded, and the bonding point is efficiently bonded for line bonding.

Adhesion with a heat-fusible film may result in loss of air permeability and sound absorption performance. If the film is thin, there will be no problem, but if it is thicker than about 30 μm, the air flow is blocked and sound waves are reflected on the surface. This is not preferable because the sound absorption rate may decrease. When the point heat-fusible nonwoven fabric is used, the strength of adhesion is high, and peeling at the interface is less likely to occur. The spider web-like heat-fusible nonwoven fabric preferably has a basis weight of 5 to 50 g / m ² , particularly preferably a basis weight of 10 to 15 g / m ² . If it exceeds 50 g / m ² , it will become thick and may affect the sound absorption effect. The heat-fusible nonwoven fabric is generally composed of polyamide and polyester, and in particular, the same material as that of the short fiber nonwoven fabric is preferably polyamide, polyester, or polypropylene. Fiber may be mixed in.

  The total thickness of the sound absorbing material of the present invention is suitably 5 to 50 mm. If the thickness is less than 5 mm, it is preferable in terms of sound absorbing performance, but when used as a sound absorbing material, its set space becomes excessive, which is desirable for product design. Absent. Furthermore, since it becomes difficult to handle in terms of processing such as cutting and molding, it is not preferable, and it is not economical to provide excessive performance.

  Thus, the sound absorbing material of the present invention obtained in this way is heat resistant by joining the melt blown nonwoven fabric, which is a sound insulating material, and the short fiber, which is a sound absorbing material, by wire bonding with a heat-fusible spider web. It has excellent sound insulation properties and sound absorption performance such as noise. It is used as a sound absorbing material for engine rooms of automobiles and home appliances, as well as for building wall coverings, house wraps, etc. Can be used effectively. Examples of the sound absorbing material of the present invention will be shown below.

The average fiber diameter of 3 [mu] m, and a polypropylene meltblown nonwoven fabric having a basis weight of 25 g / m ^2, short fibers 50% of fiber diameter 24.5μm polyester fibers having a basis weight of 200 g / m ^2, 40% short fiber having a fiber diameter of 14.1, a composite A 10 g / m ² spider web-like heat-sealable length of 10 g / m ² of a short fiber nonwoven fabric obtained by uniformly mixing 10% of short fibers having a fiber diameter of 20.0 μm of an adhesive fiber (core-sheath fiber polyester fiber). It was bonded at 140 ° C. with a fiber nonwoven fabric (polyamide: melting point 120 ° C., trade name Dynac). Even if the obtained nonwoven fabric was bent 20 times, the problem of peeling did not occur, and the sound absorption coefficient was as high as 80%.

It is sectional drawing of the sound-absorbing material which concerns on this invention.

Explanation of symbols

1: Melt-blown nonwoven fabric 2: Short fiber nonwoven fabric 3: Spider web-like heat-fusible nonwoven fabric

Claims (1)

A melt-blown nonwoven fabric having a basis weight of 10 to 100 g / m ² , a thickness of 0.05 to 0.3 mm, and an air permeability of 0.1 to 100 cc / cm ² / sec, and a fiber diameter of 7 to 50 μm. A short fiber nonwoven fabric with a basis weight of 70 to 250 g / m ² and a thickness of 5 to 30 mm is bonded and integrated by wire bonding through a spider web-like non-woven fabric with a basis weight of 5 to 50 g / m ^2. Sound absorbing material.

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