DE202009011197U1 - Sound absorption material - Google Patents

Abstract

Sound absorption material consisting of a obtained by a mechanical bonding process nonwoven fabric, characterized in that a starting fiber mixture with a cleavable staple fiber component (primary fiber) and optionally a second staple fiber component z. B. Viscose is present, with only the first fiber component (primary fiber) is fiber-split and the other fiber component is maintained in its titer.

Description

The The invention relates to a sound absorbing material consisting of a nonwoven fabric obtained by a mechanical consolidation process according to the preamble of claim 1.

From the EP 1 261 766 B1 is a sound absorbing material consisting of a microfilament nonwoven fabric with basis weights of 40 to 300 g / m ² previously known.

According to the local method for producing the sound absorption material multi-component continuous filaments are spun from the melt, stretched and placed directly to a fleece. It is done afterwards a pre-consolidation. The nonwoven fabric is then subjected to high-pressure fluid jetting finally solidified, while micro-continuous filaments be split with a titer of 0.1 to 1.2 dtex.

From the DE 197 08 188 A1 For example, a soundproofing material made of nonwoven fabrics containing thermoplastic fibers is previously known. The nonwoven fabric is permanently densified in two stages by a mechanical consolidation process and subsequent pressure / heat treatment into a material having a predetermined flow resistance.

The Indian DE 197 08 188 A1 Concretely, nonwoven fabric disclosed consists of natural and / or synthetic organic or inorganic primary fibers which are mixed with 10 to 90% thermoplastic secondary fibers. In the first stage of densification of the nonwoven fabric is a needling by barbs needles, a needling by hydroentanglement or by a Nähwirkverfahren by Kuliernadeln. The basically necessary pressure / heat treatment as a second stage can be designed batchwise or continuously, with heated presses or heatable calenders being used. The temperature range to be selected must be within the softening temperature of the secondary fibers, which in turn is below the softening or decomposition range of the primary fibers. The basic need to carry out two technological processes in a correspondingly concatenated form, disadvantageously results in higher costs in the production process and thus higher costs of the product thus produced.

Ultimately, the shows EP 0 909 680 B1 a sound insulation structure, in particular for a vehicle interior of a motor vehicle, wherein the materials used are formed predominantly of polyester fibers. By changing the surface density of the fibers, which is done by a variation of the fiber diameter, certain frequency ranges can be selectively absorbed. A first sound insulating material shown therein comprises a mixture of major fibers having a diameter ranging from 10 to 50 μm. The mixture further comprises binder fibers in a similar diameter range. The individual components of the sound insulation structure must be produced separately due to the different output quantities of the binder fibers or the main fibers and then combined into a complex structure, resulting in higher production costs.

Out The above, it is therefore an object of the invention, an evolved Specify sound absorption material, with the help of which in very cost effective Manner and with reproducible properties a nonwoven fabric for acoustic applications, in particular in vehicle construction, can be obtained.

The Solution of the object of the invention is achieved by the teaching according to claim 1, wherein the subclaims are at least expedient Embodiments and developments include.

It is therefore of a method for producing a sound absorbing material, consisting of a through a mechanical consolidation process assumed nonwoven fabric, according to the invention first a Starting fiber mixture of a splitable primary fiber and / or a secondary fiber is created.

According to the invention both the splitable primary fiber and the possibly blended Secondary staple fiber by (hydro) mechanical needling solidified into a nonwoven. By treatment with a water pressure up to 250 bar, the splitable primary fiber in up to decomposed into 20 individual staple fiber segments. The possibly admixed secondary fiber (Staple fiber) remains untreated.

at The primary fiber is so-called split-bifurcated fibers consisting of PES / CoPES, PES / PP, PES / CoPA, PP / CoPP. Structure of split fibers z. B. consists of PES / PA 10 mutually adjacent arranged segments or so-called. Hollow fibers s. Sketch. The possibly. admixed secondary fiber consists z. B. of viscose or depending on the application of any thermoplastic.

The Mixing ratio of two thermoplastic components existing primary fiber z. B. PES / PA is in the range between 20:80 or 80:20, preferably around 50:50. The proportion of evtl. blended secondary fiber is preferably between 10% and 50% between 20 and 30%.

The Fiber fineness of the primary fiber is in the range of 1.7 to 3.3 dtex, preferably 2 to 2.7 dtex and consists of up to 20 Individual segments. The individual segments point after the split process the primary fiber fiber titer ranges between 0.1 and 05 dtex, preferably 0.2 and 0.3 dtex. The fiber fineness of the secondary fibers is in the range between 1.0 and 6.7 dtex, preferably between 1.7 and 3.3 dtex.

To hydroentanglement may be the absorbent material thus prepared equipment.

These Equipment can be a two-sided or one-sided coating include with functional components.

The Functional components can be flame retardant, water and / or oil repellent or specified depending on the application specified.

additional there is the possibility of the surface of the manufactured Material with a thermoplastic or reactive or thermosetting adhesive layer, both via a scattering coating and a polymer film (Hotmelt)

According to the invention In addition, a sound absorption material in split fiber nonwoven form, prepared according to the method explained.

Of the The aforementioned nonwoven fabric of microfibers is suitable according to the task in particular for acoustic applications, here Again, especially for the exterior and interior of motor vehicles, or even in the construction sector for sound insulation. Furthermore, applications are both in the field of gas as well Liquid filtration possible.

at the split fiber fleece realized according to the invention made of staple fibers results in an applicative advantage due to the higher elongation due to the staple fibers used, so that the subsequent processing z. Punching, embossing or pinchen is facilitated in the automotive parts manufacturing.

One Another advantage is the arbitrary mixability of the fibers, for. B. with fine viscose fibers to the Pinchkanten the ultimately to optimize realized pressed parts. Through the targeted mixing can the degree of air permeability quasi set arbitrarily, since according to the invention only the Split fibers are split into finer fibers, however, the mixed Fibers are retained in their titer and the air permeability increase. Furthermore, there is the possibility by equipment or coating with thermoplastic, thermosetting binders or so-called fillers the air permeability if necessary in addition to reduce.

It So there is the possibility, by variation of the presented To respond flexibly to different customer requirements.

The Invention will be described below with reference to an embodiment be explained in more detail.

At the inventive embodiment is made from fissile staple fibers (primary fiber) with 2.2 dtex, with the fiber fineness of the individual segments after the mechanical splitting in the range between 0.2 to 0.3 dtex is. Through the fiber core or the individual segments arises a fiber blend consisting of 50% PES fibers and 50% polyamide fibers (PA 6.6).

The Staple length of splitable staple fiber (primary fiber) averaged 51 mm.

The fleece thickness is after the (simultaneous) fiber cleavage and water jet needling at about 0.6 mm at a total basis weight of 85 g / m ² .

The set air permeability was 300 l / m ² xs (pre-pressure at 200 Pa).

The finishing agent used was a commercially available fluoroalkyl acrylate (FAA, fluorocarbon, FC), flame retardants or pigment dyes having a total dry coverage of about 20 g / m ² .

An alternative coating with a thermoplastic adhesive based on a thermoplastic polymer mixture or a reactive phenolic resin (duroplastic) was realized with a dry application amount of, for example, 15 g / m ² .

The The carded nonwoven first becomes a process Water jet needling with pressures up to approx. 250 bar subjected. In the same production line is then one or both sides an equipment with functional components made, z. B. to ensure the desired flame retardancy.

Also On the procedural side there is the possibility of a coating with a thermoplastic adhesive or the like means in-line perform.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1261766 B1 [0002]
• - DE 19708188 A1 [0004, 0005]
• EP 0909680 B1 [0006]

Claims (10)

Sound absorption material consisting of a obtained by a mechanical bonding process nonwoven fabric, characterized in that a starting fiber mixture with a cleavable staple fiber component (primary fiber) and optionally a second staple fiber component z. B. viscose is present, with only the first fiber component (primary fiber) is fiber-split and the other fiber component is maintained in its titer. Material according to claim 1, characterized that the carded web is water jet needled. Material according to claim 2, characterized that waterjet needling (solidification) and fiber cleavage in one operation at pressures up to 250 bar. Material according to one of the preceding claims, characterized in that the fiber fineness of the fiber components in the range between 0.1 to 0.5 dtex, preferably between 0.2 and 0.3 dtex lies. Material according to one of the preceding claims, characterized in that the splitable bicomponent fiber (primary fiber) made of polyester and polyamide fibers, or PES / CoPES, PES / PP, PES / CoPA, PP / CoPP exists, with the mixing ratio in the range between 20:80 to 80:20, preferably 50:50. Material according to one of the preceding claims, characterized in that the staple length of the fibers in the range between 30 and 70 mm, preferably about 50 mm. Material according to one of the preceding claims, characterized in that after the Wasserstrahlvernadelung the Material is subjected to equipment. Material according to claim 7, characterized that the equipment has a one- or two-sided coating comprising functional components. Material according to claim 8, characterized that the functional components flame retardant, water and / or oil repellent Contain funds. Material according to claim 8 or 9, characterized that the surface is a thermoplastic or thermosetting Has adhesive layer.