EP2573244B1 - Sound absorbing material - Google Patents

Description

Technical area

The present invention relates to the field of textile products and their applications in the field of sound insulation, in particular the soundproofing in vehicles, aircraft and trains, in the construction industry and in small appliances.

The invention relates to a sound absorption material of a nonwoven fabric containing at least two polymers, wherein the melting point of at least one first polymer is above the melting point of at least one second polymer, and a process for its preparation. The invention further relates to the use of such a sound absorbing material for the production of lining parts used in the interior of automobiles and the use of this nonwoven fabric for producing a composite material.

Nonwovens are textile fabrics made of individual fibers and can be obtained by a wide variety of manufacturing processes, such as carding (dry laid), meltblowing (spunbonding) or aerodynamic nonwoven laying (air laying).

In melt spinning, a polymeric substance is heated in an extruder and pressed by spinning pumps through a spinneret. The polymer emerges from the nozzle plate as a filament (continuous filament) in molten form, is cooled by an air flow and stretched from the melt. The air stream conveys the endless filaments onto a conveyor belt, which is designed as a sieve. By suction under the wire, the threads can be fixed to form a fiber fabric. The solidification of the fiber fabric can be done by heated rollers (calender), by a vapor stream, by hot air or by mechanical or chemical bonding. When solidified by calender, one of the two rolls may be engraved, which may consist of dots, short rectangles or diamond-like surfaces.

Nonwovens are used for a variety of purposes. Nonwoven fabrics with high strength can be used alone or as a reinforcing layer in fiber composites. In the packaging field, single-layer constructions are usually made using meltblown or meltblown-like material structures, i. Fiber structures used from only one domain. Nonwoven fabrics are also used as sound absorption materials.

In the search for a suitable sound absorbing material is the choice not only by the sound absorption ability but also by other factors, such as. As price, weight, thickness, fire resistance, etc. influenced. Usually used as sound damping felts, foams, Pressfasem, glass powder or "stone powder" and recycled materials are used. These can, for example, be treated with the hammer mill and synthetic resin and thermo-treated in order to adapt the properties of the materials to the respective fields of application.

In particular, the present invention seeks to broaden the conventional field of nonwoven applications by imparting sound insulating properties in combination with a small thickness, making them particularly suitable for use in demanding environments such as the interior of automobiles.

State of the art

Sound absorption materials of the type mentioned are basically known. In principle, the sound absorption is based on a disturbance or redirection of the sound energy. For this purpose, the energy can be converted into heat on the one hand or there is a reflection of the energy. The expert speaks at a power diversion of insulation. The sound is thus damped.

Usually reflective materials / walls are used for sound insulation, such as. B. capsule walls, partitions or screens, which engage in the propagation path of the sound energy. Due to their porous structure, conventional sound absorption materials convert the sound energy into heat in the medium to high-frequency range.

Also suitable for sound insulation are synthetic mineral fibers, open-cell foams, porous inorganic bulk materials or natural fibers.

In the course of increasing demands on sound absorbing materials, these materials must not only be able to dampen the sound, but they must also meet other requirements in terms fire resistance, thickness, weight, hydrophobicity, etc. and material properties.

Especially with regard to the room acoustics, a small material thickness is advantageous, as this reduces the space requirement. Especially in the automotive sector, the suppliers are asked for car accessories to make the lining parts such that they are designed to save space.

In addition, these parts should be recyclable, high color and lightfastness, in particular a high heat-fastness, a low tendency to fouling, high abrasion resistance, moisture resistance, flame resistance, Having cleanability and good Heißverformbarkeits- or thermoforming capabilities. It is also of great interest to increase the sound insulation in terms of comfort for the automobile occupants.

In the automotive sector, it is customary to produce sound absorption materials as composite materials from a textile carrier with a damping layer and optionally a cover layer. In this case, the absorption property is achieved in particular by combining the textile carrier with the soundproofing layer.

Good soundproofing can be achieved with microfiber nonwovens made of melt spun nonwoven composite filaments which are at least 80% split into elementary filaments and solidified. These nonwovens are in the DE 100 09 281 A1 described and have multi-component endless filaments. Their preparation comprises the following steps: First, multicomponent continuous filaments are spun, drawn and deposited directly into a nonwoven. Subsequently, a pre-consolidation and the deposited web is then split by means of high-pressure fluid jets in elementary filaments and solidified. Such soundproofing layers have a uniform thickness and an isotropic thread distribution and show excellent soundproofing properties.

Other nonwovens are used in the US2008 / 085679 described.

A disadvantage of these sound absorption materials is that their production process is time-consuming and expensive.

Presentation of the invention

The invention therefore an object of the invention to provide a sound absorbing material and a method for its production, which avoids the disadvantages mentioned above. In particular, it should be easy, inexpensive and time-saving can be produced.

This object is achieved according to the invention with a sound absorption material a nonwoven fabric containing at least two polymers wherein the melting point of at least one first polymer is above the melting point of at least one second polymer and wherein the first polymer is in the form of elemental segments distributed in a matrix of the second polymer.

Surprisingly, it has been found according to the invention that nonwovens of the abovementioned type have outstanding sound absorption properties. In particular, such nonwovens show an airborne sound absorption coefficient α (0), measured in the impedance tube according to DIN EN ISO 10354-1, of ≥ 0.8 at a frequency of 1000 Hz to 4000 Hz.

Sound absorption tests have shown that the sound absorption material according to the invention is particularly suitable for sound insulation in the sound frequency range of 100 to 5000 Hz.

In particular, it has surprisingly been found that the sound absorption materials according to the invention show excellent sound absorption properties even at low thicknesses. Practical experiments have shown that the sound absorbing materials according to the invention already at a thickness of the nonwoven fabric of 0.01 mm to 1 mm, preferably from 0.05 mm to 0.5 mm, in particular from 0.1 mm to 0.2 mm, the above achieved airborne sound absorption levels and singular values.

Depending on the desired sound absorption properties, the thickness of the sound absorbing materials according to the invention may vary. Preferably, the sound absorbing materials according to the invention have a thickness of 0.01 mm to 1 mm, more preferably from 0.05 mm to 0.5 mm, in particular from 0.1 mm to 0.2 mm.

Likewise, the air permeability of the sound absorption materials according to the invention measured according to DIN EN ISO 9237 at 20 cm ² and 50 Pa vary. Preferably, the sound absorption materials according to the invention an air permeability measured according to DIN EN ISO 9237 at a basis weight of 100 g / m ² of 20 l / m ² sec to 120 l / m ² sec, more preferably from 40 l / m ² sec to 100 l / m ² sec, in particular from 60 l / m ² sec to 90 l / m ² sec, on.

Accordingly, the nonwoven fabric may have a low basis weight and still exhibit good sound absorption properties. Nevertheless, the basis weight of the nonwoven fabric can vary widely and be selected, for example, according to the requirements of a composite material. Preferably, the basis weight is from 30 g / m ² to 400 g / m ² , more preferably from 35 g / m ² to 200 g / m ² , even more preferably from 40 g / m ² to 150 g / m ² , especially from 40 g / m ² to 120 g / m ² .

In addition, the nonwoven fabric is characterized by further advantageous properties, such as a good hot workability or thermoformability. Because of this, it can be processed very easily and adapted to a wide variety of room requirements. The nonwoven fabric is extremely stable at room temperature.

The nonwoven fabric may have a film-like character over the fused domains, but without the weaknesses of a film or paper. So it is easily possible to design the surface of the nonwoven fabric smooth and wet-strength. Such a nonwoven fabric may be considered a "fiber reinforced film".

The nonwoven fabric can have a high strength with low weight. This allows easy processing and handling. Furthermore, a high strength is very advantageous when using the sound absorption material according to the invention as a lining part for the interior of automobiles, in particular as a car roof, doormat, door trim, pillar trim, parcel shelf and / or trunk lining and wheel housing lining.

In addition, the nonwoven fabric is characterized by isotropic mechanical properties, such as an isotropic ratio of maximum tensile force or additional tensile force Machine to transverse direction, off. Isotropy in the sense of the invention denotes the independence of a property from the direction. Isotropic strength properties are advantageous in particular for the use of the nonwoven fabric as a reinforcing layer, since in this way a particularly uniform stabilization is achieved.

Under isotropic machine direction / Querrichtungs Verhättnis the maximum tensile force and / or tear propagation force in the context of the invention is understood that the machine direction / transverse direction ratio of the maximum tensile force and / or tearing force in the range of 0.7 to 1.6, preferably from 0.8 to 1.5, in particular from 0.9 to 1.1, is located.

Maximum tensile force is the force that must be used to rupture a fiber layer. By tear propagation force is meant the force that is necessary to tear down an already cracked fiber layer or further tear. The higher these values are, the more stable a situation is. The maximum tensile force is measured in the machine direction or transversely to the machine direction. The machine direction is understood to mean the direction under which the fibers are deposited longitudinally on a conveyor belt moving in the longitudinal direction. The direction transverse thereto or orthogonal thereto is the transverse direction.

The nonwoven fabric is further characterized by excellent strength properties. Thus, the tear propagation force measured in accordance with ASTM D5733 in the machine and / or transverse direction can be 10 N to 190 N, preferably 60 N to 180 N, in particular 120 N to 180 N. The maximum tensile force measured according to ASTM D5034 in the machine and / or transverse direction may be 70 to 400 N / 50 mm, preferably 100 to 350 N / 50 mm, in particular 150 to 300 N / 50 mm.

Practical experiments have shown that a nonwoven fabric with particularly good strength properties can be obtained if it is used in its production multicomponent fibers comprising a first polymer component and a second polymer component, wherein the first polymer component in a first zone and the second polymer component in a second zone over the cross-section of the multicomponent fibers, both polymer components extending in the length direction of the multicomponent fibers, the first polymer component having a melting point above the melting point of the second polymer component, and wherein the first zone is the first polymer component in the form of at least two separable elementary segments. PIE fibers, hollow-PIE fibers, core / sheath fibers, multilobal fibers, islands-in-sea fibers or side-by-side fibers have proven particularly suitable. Very particular preference is given to PIE fibers, which preferably comprise 4, 6, 8, 10, 14, 16, 18 or 32 elementary segments. The multicomponent fibers may be formed as staple fibers. Preferably, the multicomponent fibers are formed as continuous filaments and composed of at least two polymers.

PIE fibers are understood as meaning fibers of elementary segments which are arranged in the form of cake pieces or circular segments in cross section.

The effect of reflowing a PIE fiber is the incorporation of stable pie-shaped segments that function as reinforcing filaments in the polymer matrix. As a result, a stabilization is achieved in the manner of a reinforced concrete. In the case of PIE filaments in particular, a marked change in the geometry of the original filament structure is noticeable.

Particularly advantageous in the use of PIE fibers is that the cake-piece-shaped segments have a very small diameter in cross-section and therefore the matrix can prevail in a particularly large number. In addition, the alternating arrangement of the individual core segments in the fibers causes a particularly homogeneous distribution of the various polymers. This leads to an extremely uniform melting with formation of the matrix.

When using core / sheath fibers, it is preferred that the sheaths be made of the lower melting polymer. In this way, the cores are embedded in the matrix polymer matrix in the form of stable circular segments. An advantage of the use of the core / sheath fibers is that due to the circular cross section of the core segments, a particularly dense structure, analogous to a spherical packing, is formed.

The multicomponent fibers may comprise two or more polymers, provided that at least one polymer has a higher melting point than at least one further polymer. Practical experiments have shown that already with the use of two polymers (bicomponent fibers) nonwovens having a stable matrix structure can be obtained.

Structurally, the nonwoven fabric is characterized in that it comprises at least two polymers, wherein the melting point of at least one first polymer is above the melting point of at least one second polymer. The first polymer is in the form of elemental segments distributed in a matrix of the second polymer.

The difference between the melting point of the first and second polymers can vary widely. Conveniently, the difference is at least 15 ° C, in particular at least 20 ° C. Preferably, polymers having a temperature difference of from 15 ° C to 450 ° C, more preferably from 15 ° C to 200 ° C, even more preferably from 20 ° C to 150 ° C, especially from 70 ° C to 150 ° C are used.

As polymers, a wide variety of materials can be used. Preferred combinations for multicomponent fibers include, in particular, thermoplastic polymers, in particular selected from the group consisting of nylon 6, nylon 6.6, nylon 6.10, nylon 6.11, nylon 6-12, polypropylene or polyethylene. Further possible polymers are selected from the group consisting of polyester, polyamide, thermoplastic copolyetherester elastomers, polyolefins, polyacrylates and thermoplastic liquid crystals. Also conceivable is the use of Copolyetheresterelastomeren from long-chain and short-chain ester monomers. If elemental segments of polyethylene terephthalate are used, they can preferably be produced from recyclable polyethylene terephthalate.

By choosing the polymers used, the wetting behavior of the nonwoven fabric can be influenced. For this purpose, in particular the following thermoplastic polymers are used: polyamides, polyvinyl acetates, saponified polyvinyl acetates, saponified ethylene vinyl acetates and other hydrophilic polymers.

Alternatively, elastic polymers can also be used. These polymers are preferably selected from the group consisting of: styrene / butadiene copolymers, elastic polypropylene, polyethylene, metallocene-catalyzed α-olefin homopolymers, as well as copolymers having a density of less than 0.89 g / cm ³ . In addition, the use of amorphous polyalphaolefins having a density of less than 0.89 g / cm ³ , ethylene vinyl acetate, and ethylene-propylene rubber and propylene-1-butene copolymer and terpolymers is conceivable.

According to a particularly preferred embodiment of the invention, the multicomponent fibers comprise polypropylene, polyethylene, polyamide, syndiotatisches polystyrene, polyester, and / or mixtures of these polymers, preferably polyethylene terephthalate.

According to a further preferred embodiment of the invention, the first polymer is selected from the group consisting of: polyester, preferably polyethylene terephthalate and / or the second polymer selected from the group consisting of: polypropylene, polyethylene, polyamide and / or polyester, preferably polyethylene terephthalate.

If core / sheath fibers or islands-in-sea fibers are used as the multicomponent fibers, then the sheath or the sea is preferably formed from the second, matrix-producing polymer. Preferred polymers for the matrix are Copolyester, polypropylene, polyamide, polyethylene, linear low-pressure polyethylene having an α-olefin monomer content greater than 10 wt .-%, ethylene copolymer with at least one vinyl monomer or ethylene copolymer with unsaturated aliphatic carboxylic acids.

The nonwoven fabric is characterized in that the nonwoven fabric is a film-like molten polymer matrix. This contains unmelted elementary segments, which may be circular-segment-shaped or cake-piece-shaped, multilobal or circular in cross-section.

Elementary segments of a circular segmental cross-section show an approximately 1.75 times larger surface area than an elementary segment with a circular cross-section. Due to the larger surface area, a larger adhesion surface is formed.

The weight ratio of the first polymer to the second polymer in the nonwoven fabric can vary within wide limits, as long as it is ensured that the first polymer in the nonwoven fabric is in the form of elementary filaments which are distributed in a matrix of the second polymer. Preferably, the weight ratio of first polymer to second polymer in the nonwoven fabric is 50%: 50%, preferably 70% to 30%, more preferably 60% to 40%.

Preferably, the proportion of the matrix in the nonwoven fabric from 1 wt .-% to 60 wt .-%, preferably from 5 wt .-% to 50 wt .-%, in particular from 10 wt .-% to 40 wt .-%. In these matrix fractions, a nonwoven fabric having a particularly good flexural strength can be obtained.

Preferably, the nonwoven fabric is treated with impregnating agents, in particular flame retardants or hydrophilizing and hydrophobing reagents. In a particularly advantageous embodiment, the nonwoven fabric is sprayed or impregnated with an aqueous flame retardant.

The nonwoven fabric is eminently suitable for the production of composites because its surface structure is e.g. The choice of polymers and plasma or corona treatment of the surface can be easily matched to the other composite components. The very dense surface structure also allows the application of adhesive components such. the application of thermoplastic polymers, preferably polyethylene, copolyester or polyamide, for example in the form of solid adhesive powder via appropriate devices. By heating, the nonwoven fabric can be heat-set at least at the surface via the adhesive components, resulting in stabilization of the nonwoven fabric. The treatment can be carried out on one or both sides, preferably on one side, and preferably takes place after impregnation with binders. The solid adhesive powder can be fixed by heat in the same processing step. In an advantageous embodiment, the nonwoven fabric, which is initially flame-retarded, is provided with powder-based polyethylene-based adhesive and heat-set (for example Schaetti Fix® adhesives from Schaetti AG, Zurich or others).

Another object of the invention is the use of a composite material comprising at least a first layer containing the nonwoven fabric described above, and a second layer which may be formed as a spacer layer and preferably a fiber composite, in particular a scrim, a nonwoven fabric, a film and / or a film, as a soundproofing material.

According to a preferred embodiment of the invention, the second layer is formed as a fiber composite with a thickness (uncompressed) of 0.5 to 5, preferably from 0.8 to 3, in particular from 1 to 2 cm. The respective layers of the nonwoven fabric may be bonded together in various ways depending on the materials used. Practical experiments have shown that particularly strong composites are obtained when the first and second layers are cohesively bonded together by means of a binder.

The thickness and composition of the fiber composite may vary widely depending on the particular application of the composite. Preferably, the fiber composite contains textile fiber waste, such as preferably cellulose fibers, hemp, flax, cotton, bast, sisal, kenaf and / or plastics, preferably polyolefins, in particular polyethylene and / or polypropylene and / or their copolymers or metals. In addition, the fiber waste preferably comprises a binder or a low-melting binder fiber for stabilization and fixation.

The composite material according to the invention can be joined by coating the nonwoven fabric with the fiber composite by laminating and / or laminating the nonwoven fabric, if appropriate using a binder and / or pressure and / or temperature. Also conceivable is the extrusion of a film-forming polymer melt or the application of a thermoplastic material in powder form with subsequent thermal fixation.

• Bereitstellen von Mehrkomponentenfasern, welche mindestens zwei Polymere mit unterschiedlichen Schmelzpunkten enthalten,
• flächiges Verbinden der Mehrkomponentenfasern mit einer komprimierenden Wärmebehandlung bei einer Temperatur von 100 °C bis 300 °C, sowie einem Druck von 40 N/mm bis 150 N/mm, derart, dass mindestens ein erstes Polymer in Form von Elementarsegmenten in einer Matrix aus mindestens einem zweiten Polymer verteilt wird.

The sound absorbing material according to the invention can be produced by a process comprising the following process steps:

• Providing multicomponent fibers containing at least two polymers having different melting points,
• laminating the multicomponent fibers with a compressing heat treatment at a temperature of 100 ° C to 300 ° C, and a pressure of 40 N / mm to 150 N / mm, such that at least a first polymer in the form of elementary segments in a matrix of at least a second polymer is distributed.

The method is characterized by the fact that multi-component fibers are connected by applying a pressure of at least 40 N / mm, and at a temperature of at least 100 ° C so flat that at least a first Polymer is distributed in the form of elementary segments in a matrix of at least one second polymer. As a result, a nonwoven fabric having a high flexural rigidity, a low stiction and a dense structure at low porosity can be obtained.

Practical experiments have shown that nonwovens with particularly good sound absorption properties can be obtained when PIE fibers, preferably PIE filaments, preferably with 30-50% polyamide content and 70-50% polyester content, preferably at pressures between 50 and 80 N / mm and temperatures between 130 ° C and 180 ° C, in particular by means of a roller combination of a smooth steel roller and a rough steel roller (roughness 40 microns) are solidified.

The multicomponent fibers can be prepared by methods known to those skilled in the art. Particularly preferred according to the invention is the melt spinning technology.

To produce the multicomponent fibers, a polymeric substance can be heated under pressure in an extruder and pressed through a die to form endless filaments. After exiting the extrusion die, the continuous filaments may be drawn and positioned by means of dynamic laydown methods on a conveyor belt, deflecting them transversely to form a fiber layer. An advantage of a transversely deflected positioning of the continuous filaments is that this increases the isotropy of the mechanical properties of the nonwoven fabric.

• die erste Polymerkomponente in einer ersten Zone und die zweite Polymerkomponente in einer zweiten Zonen über den Querschnitt der Mehrkomponentenfasern angeordnet ist, wobei
• sich beide Polymerkomponenten in Längenrichtung der Mehrkomponentenfasern erstrecken, wobei
• die erste Polymerkomponente einen Schmelzpunkt oberhalb des Schmelzpunkts der zweiten Polymerkomponente aufweist und wobei die erste Zone die erste Polymerkomponente in Form von mindestens zwei trennbaren Elementarsegmenten umfasst.

According to a particularly preferred embodiment of the invention are used as multicomponent fibers, fibers comprising a first polymer component and a second polymer component, wherein

• the first polymer component in a first zone and the second polymer component in a second zone across the cross section of Multi-component fibers is arranged, wherein
• Both polymer components extend in the length direction of the multicomponent fibers, wherein
• the first polymer component has a melting point above the melting point of the second polymer component, and wherein the first zone comprises the first polymer component in the form of at least two separable elemental segments.

The sound absorption material produced by the method according to the invention is characterized in that it comprises a polymer matrix. This contains unmelted elementary segments, preferably Elementarendlosfilamente, which may be constructed in cross-section circular segment or cake piece, circular or multilobal.

The method described above makes it possible to use energy-intensive mechanical consolidation technologies, e.g. Hydroentanglement, to dispense. Furthermore, it is characterized by the fact that it is inexpensive and fast.

The temperature and the pressure with which the solidification of the multicomponent fibers takes place can vary within wide limits and is expediently adapted to the respectively used polymer components in the multicomponent fiber. It is essential here that at the selected temperature and pressure, a substantially complete melting of the first polymer but not of the second polymer takes place.

Practical experiments have shown that nonwoven fabrics having a low drapability are obtained when the pressure is set at values of 45 to 140 N / mm, preferably 50 to 100 N / mm, more preferably 55 to 90 N / mm, still more preferably 60 to 90 N / mm, in particular 70 to 90 N / mm.

Appropriately, the surface connection of the multi-component fibers is carried out by Applying at a temperature of 100 to 300 ° C, preferably from 100 to 250 ° C, more preferably from 110 to 200 ° C, in particular from 120 to 180 ° C.

The application of pressure and temperature can be carried out in the manner known to those skilled in the art. For this purpose, rollers, in particular calenders, are expediently used. Particularly suitable are rollers with a smooth or only slightly roughened surface. Preferably, the surface has a surface roughness of 20 to 60 .mu.m, in particular from 30 to 45 .mu.m.

According to a preferred embodiment of the invention, the nonwoven fabric is impregnated with binders. Suitable binders are in particular acrylates and aminoplasts (phenolic resins, melamine resins), styrene-butadiene copolymers, NBR binder systems and / or polyurethanes.

For some applications of the nonwoven fabric it is expedient to increase the surface energy of the nonwoven fabric by corona and / or plasma treatment. The plasma or corona treatment is preferably carried out in such a way that the surface is given a surface energy according to ISO 9000 of more than 38 dyn, preferably 38 to 70 dyn, in particular 40 to 60 dyn. It is advantageous that the surface can be made hydrophilic without adding chemicals.

Conceivable is the antistatic finish of the surface, as well as its inspiration with care substances. Also conceivable and advantageous is the subsequent finishing of the nonwoven fabric with additives selected from the group consisting of: color pigments, permanently acting antistatic agents, flame retardants and / or the hydrophobic properties influencing additives. Particularly preferred is the use of flame retardants. It is also conceivable equipment with hydrophilic or antistatic spin finishes, as well as their Providence with care substances. It is also conceivable additives for surface modification already in the continuous film production in an extruder to enter. Also with a coloring no subsequent coloring is necessary, since pigments already with the Endlosfilamenterzeugung can be introduced into an extruder.

Further, the nonwoven fabric may be subjected to a chemical-type bonding or finishing such as an anti-pilling treatment, a hydrophilization, an antistatic treatment, a refractory-improving treatment and / or a tactile property-changing property, a treatment Mechanical type such as roughening, sanforizing, sanding or a treatment in the tumbler and / or a treatment to change the appearance such as dyeing or printing.

As already explained above, it is possible with the method according to the invention to produce nonwovens with a dense structure and low porosity, which have high strength at low weight. The fiber titres of the multicomponent fibers preferably have independently of one another values of from 1 dtex to 4 dtex, preferably from 1.5 to 3 dtex, more preferably from 2 dtex to 3 dtex.

There are now various possibilities for embodying and developing the teaching of the present invention in an advantageous manner. For this purpose, on the one hand to the subordinate claims, on the other hand to refer to the following explanation of preferred embodiments of the invention with reference to the drawings and the tables.

Brief description of the drawing

Fig. 1

eine Rasterelektronenmikroskopische(REM)-Aufnahme des Faserquerschnitts des im Ausführungsbeispiel 1, Beispiel 8 hergestellten Vliesstoffs (Kern/Mantel-Filamente / PET/PE) bei 500-facher Vergrößerung

Fig. 2

eine Rasterelektronenmikroskopische(REM)-Aufnahme des Faserquerschnitts eines im Ausführungsbeispiel 2 hergestellten Vliesstoffs (PIE-Filamente / PET/PA) bei 1000-facher Vergrößerung

Fig. 3

den Schallabsorptionsgrad (Alpha Kabine) eines erfindungsgemäßen Spinnvlieses, das gemäß Ausführungsbeispiel 1 hergestellt wurde, im Vergleich zu Evolon 100®

Fig. 4

den Schallabsorptionsgrad eines erfindungsgemäßen Spinnvlieses aus PIE-Filamenten (PET/PA) gemäß den Ausführungsbeispielen 2 und 4 im Vergleich zu einem Spinnvlieses aus SC -Filamenten (PET/CoPET)

Fig. 5

die Polymerabhängigkeit des Schallabsorptionsgrades gemessen im Impedanzrohr nach DIN EN ISO 10345-1

Fig. 6

die Gewichtsabhängigkeit des Schallabsorptionsgrades wird gemessen im Impedanzrohr nach DIN EN ISO 10345-1.

In the drawing show

Fig. 1

a scanning electron micrograph (SEM) of the fiber cross section of the nonwoven fabric produced in Example 1, Example 8 (core / sheath filaments / PET / PE) at 500-fold magnification

Fig. 2

a scanning electron micrograph (SEM) image of the Fiber cross section of a nonwoven fabric produced in Example 2 (PIE filaments / PET / PA) at 1000 times magnification

Fig. 3

the degree of sound absorption (alpha cabin) of a spunbonded nonwoven according to the invention, which was prepared according to Embodiment 1, compared to Evolon 100®

Fig. 4

the degree of sound absorption of a spunbonded nonwoven of PIE filaments (PET / PA) according to the invention in accordance with embodiments 2 and 4 in comparison to a spunbonded nonwoven fabric of SC filaments (PET / CoPET)

Fig. 5

the polymer dependence of the sound absorption coefficient measured in the impedance tube according to DIN EN ISO 10345-1

Fig. 6

the weight dependence of the sound absorption coefficient is measured in the impedance tube according to DIN EN ISO 10345-1.

Embodiment of the invention

In the following the invention will be explained in more detail with reference to the following embodiments.

Embodiment 1 Production of a Spunbonded Nonwoven from PIE Filaments (PET / PA)

To produce the PIE filaments, polyethylene terephthalate and polyamide are coextruded in a known manner with a perforation throughput of 0.76 g / L min and aerodynamically stretched to form 16 PIE filaments. The proportion of polyamide is between 30 and 50 wt .-%. The endless filaments are placed on top of it

Conveyor belt stored dynamically. Dynamic deposition is understood to mean that the orientation of the filaments to be deposited in the transverse direction can be influenced in a targeted manner. This is followed by solidification of the continuous filaments by a rough steel roller under pressure and heat. The steel roller has temperatures between 130 ° C and 180 ° C at a line pressure between 50 N / mm and 80 N / mm (roughness of 40 microns) on. By subjecting the endless filaments to pressure and temperature, the polyamide is fused and the polyethylene terephthalate is distributed in the form of cross-section cake-like elementary filaments in a matrix of the polyamide. In this case, a spunbonded fabric having a basis weight of 105 g / m ^{2 is} obtained. The result is a spunbonded fabric with dense structure and low porosity at characteristic mechanical values (HZK, WRK, MD: CD ratio). The parameters of the experiment are shown in Table 1. Table 1: Working Example 1, 105 g / m <sup> 2 </ sup> PET / PA nonwoven fabric, PIE filaments, mech. Properties. Kalandetemp. calender pressure PA-share Weight thickness LD 20cm ^2/50 Pa LD Tomb Tensile MD Stretching MD Grab Tensile CD Stretching CD Trap Tear MD Trap Tear CD EN29073 angel. DINEN ISO9073-2 DIN ISO9237 ASTM D5034 ASTM D5034 ASTM D5034 ASTM D5034 ASTM D5733 ASTM D5733 ° C Nmm % g / m ² mm l / m ² sec rayls N50mm % N50mm % N N 130 50 30 103.9 0.2 89 562 224.9 43.7 174.2 41.3 186 163.9 130 80 30 104.7 0.22 81 617 252.5 47.8 205 50.1 185.4 170.3 180 * 80 30 106.6 0.14 27 1852 3192 46.4 272.2 48.5 90.7 90.6 180 * 50 30 106.7 0.15 31 1613 321.8 46.1 206.3 52.3 86.7 84.7 180 * 50 50 104.4 0.15 31 1613 273.8 41.6 226.5 44.7 69.2 63.7 180 * 80 50 106.3 0.15 25 2000 295.9 40.9 221.1 40.4 54.2 55.6 130 80 50 105.7 0.17 46 1087 244.6 43.6 180 39.9 174.9 155.7 130 50 50 106 0.2 65 769 233.2 44.3 179.1 42.6 87 90

Embodiment 2: Production of a spunbonded nonwoven made of core / sheath filaments (PET / Co-PET)

To produce the Kerrn / sheath filaments, polyethylene terephthalate and a low melting co-polyester are coextruded in a known manner at a hole throughput of 0.8 g / L min and aerodynamically stretched to form core / sheath filaments. The proportion of co-polyethylene terephthalate is 20 wt .-%. The Endless filaments are then dynamically deposited on a conveyor belt. Dynamic deposition is understood to mean that the orientation of the filaments to be deposited in the transverse direction can be influenced in a targeted manner. This is followed by solidification of the continuous filaments by a rough steel roller under pressure and heat. The steel roller has a temperature of 130 ° C at a line pressure of 80 N / mm (roughness of 40 microns) on. By applying the continuous filaments with pressure and temperature, the polyethylene terephthalate is distributed in the form of elementary filaments in a matrix of co-polyethylene terephthalate. Subsequently, a post-treatment in a hot-air oven at a temperature of 160 ° C.
Here, a spunbonded fabric having a basis weight of 100 g / m ^{2 is} obtained. This results in a nonwoven fabric with dense structure and low porosity at characteristic mechanical values (HZK, WRK, MD: CD ratio). The parameters of the embodiment are shown in Table 2 Table 2: Embodiment 2, 105 g / m <sup> 2 </ sup> PET / CoPET nonwoven fabric, SC filaments, mech. Properties. bonding component bonding component Weight thickness LD 5cm ² / 50Pa Tensile MD Stretching MD Tensile CD Stretching CD Tear MD Tear CD EN 29073 angel. DIN EN ISO 9073-2 DIN EN ISO 9237 EN 29073 T3 EN 29073 T3 EN 29073 T3 EN 29073 T3 internal internal % g / m ² mm l / m ² sec N / 50mm % N / 50mm % N N copolyester 20 105 0.19 112 304 47 292 45 152 148

Embodiment 3 Production of a Spunbonded Nonwoven from PIE Filaments (PET / Polyolefin)

To produce the PIE filaments, polyethylene terephthalate and polyethylene or polypropylene are coextruded in a known manner with a perforation throughput of 0.65 g / L min and aerodynamically stretched. The endless filaments are then dynamically deposited on a conveyor belt. Dynamic deposition is understood to mean that the orientation of the filaments to be deposited in the transverse direction can be influenced in a targeted manner. This is followed by solidification of the continuous filaments by a rough steel roller under pressure and heat. The steel roller has temperatures between 125 ° C and 132 ° C. By applying the continuous filaments with pressure and Temperature, the polyolefin is fused and the polyethylene terephthalate distributed in the form of cross-section cake-like elementary filaments in a matrix of polyolefin. This spunbonded nonwovens are obtained with a basis weight of 100 - 105 g / m ² . The spunbonded nonwovens have a dense structure, as well as a low porosity, with characteristic mechanical values (maximum tensile force (HZK), tear propagation force (WRK), machine direction (MD): transverse direction (CD) ratio).
The parameters of the embodiment are shown in Table 3. Example 3, 100-105 g / m <sup> 2 </ sup> PET / polyolefin nonwoven fabrics, PIE filaments, mech. Properties. bonding component bonding component Weight thickness LD 20cm ^2/50 Pa LD Tomb Tensile MD Stretching MD Grab Tensile CD Stretching CD Trap Tear MD Trap Tear CD EN 29073 angel. DINEN ISO9073-2 DIN EN ISO 9237 ASTM D5034 ASTM D5034 ASTM D5034 ASTM D5034 ASTM D5733 ASTM D5733 % g / m ² mm l / m ² sec rayls N / 50mm % N50mm % N N polyethylene 40 100 0.19 69 725 299 % 69 280 72 152 148 polypropylene 38 105 17 46 1087 324 57 375 101 185.4 91

Embodiment 4 Production of a Spunbonded Nonwoven from PIE Filaments (PET / PA)

To produce the PIE filaments, polyethylene terephthalate and polyamide are coextruded in a known manner with a perforation throughput of 0.76 g / L min and aerodynamically stretched to form 16 PIE filaments. The proportion of polyamide is 30% by weight. The endless filaments are then dynamically deposited on a conveyor belt. Dynamic deposition is understood to mean that the orientation of the filaments to be deposited in the transverse direction can be influenced in a targeted manner. This is followed by solidification of the continuous filaments by a rough steel roller under pressure and heat. The steel roller has temperatures of 130 ° C at a line pressure of 50 N / mm (roughness of 40 microns) on.
By subjecting the endless filaments to pressure and temperature, the polyamide is fused and the polyethylene terephthalate in the form of in cross-section cake-piece elementary filaments distributed in a matrix of the polyamide. This spunbonded nonwovens are obtained with a basis weight of 40 - 105 g / m ² .

The result is spunbonded nonwovens with dense structure and low porosity at characteristic mechanical values (HZK, WRK, MD: CD ratio). The parameters of the experiment are shown in Table 4. Table 4: Embodiment 4, 40 - 105 g / m <sup> 2 </ sup> PET / PA nonwoven fabrics, PIE filaments, mech. Properties. bonding component bonding component Weight thickness LD 20cm ^2/50 Pa LD Tomb Tensile MD Stretching MD Grab Tensile CD Stretching CD Trap Tear MD Trap Tear CD EN29073 argel. DINEN ISO9073-2 DIN ISO9237 ASTM D5034 ASTM D5034 ASTM D5034 ASTM D5034 ASTM D5733 ASTM D5733 % g / m ² mm l / m ² sec rayls N / 50mm % N50mm % N N polyamide 30 105 0.15 50 1000 423 60 381 62 90 90 polyamide 30 80 0.2 736 68 323 46 304 59 93 93 polyamide 30 60 0.15 1122 45 234 42 222 51 63 68 polyamide 30 40 0.09 1660 30 145 37 135 47 29 33

Embodiment 5: Comparison of the sound absorption coefficient of a spunbonded nonwoven made of PIE filaments (PETIPA) with a microfiber spunbonded nonwoven (Evolon®)

200 0,07 0,03 0 0 250 0,05 0,02 0,03 0,05 315 0,02 0,04 0,06 0,04 400 0,09 0,07 0,09 0,09 500 0,1 0,1 0,13 0,07 630 0,12 0,24 0,2 0,19 800 0,34 0,35 0,34 0,36 1000 0,51 0,53 0,53 0,66 1250 0,77 0,73 0,78 0,73 1600 0,79 0,77 0,84 0,77 2000 0,84 0,91 0,96 0,88 2500 0,86 0,88 1 0,82 3150 0,85 0,88 0,87 0,79 4000 0,89 0,89 0,77 0,74 5000 0,87 0,88 0,86 0,8 * Ausführungsbeispiel 1 ; PA Anteil [%]; Kalanderdruck [N/cm]; Kalandertemperatur [°C] In order to determine the degree of sound absorption of selected variants of embodiment 1 in comparison to an Evolon® microfiber spunbond of the same weight, the various materials are subjected to an alpha-cabin test based on ISO 20354: 2003. The corresponding measured values are shown in Table 5. Table 5: Exemplary embodiment 1, sound absorption coefficient (alpha cabin) compared to Evolon 100® Third center frequency Evo100 ^® Example 1 617 rayls Example 1 1087 rayls Example 1 1613 rayls set* 30/80/130 50/80/130 30/50/180 Sound absorption coefficient [Hz]

200 0.07 0.03 0 0 250 0.05 0.02 0.03 0.05 315 0.02 0.04 0.06 0.04 400 0.09 0.07 0.09 0.09 500 0.1 0.1 0.13 0.07 630 0.12 0.24 0.2 0.19 800 0.34 0.35 0.34 0.36 1000 0.51 0.53 0.53 0.66 1250 0.77 0.73 0.78 0.73 1600 0.79 0.77 0.84 0.77 2000 0.84 0.91 0.96 0.88 2500 0.86 0.88 1 0.82 3150 0.85 0.88 0.87 0.79 4000 0.89 0.89 0.77 0.74 5000 0.87 0.88 0.86 0.8 * Embodiment 1; PA share [%]; Calender pressure [N / cm]; Calender temperature [° C]

In FIG. 3 is the sound absorption coefficient (alpha cabin) of a spunbonded nonwoven according to the invention, which was prepared according to Embodiment 1, shown in comparison to Evolon 100®.

Embodiment 6: Comparison of the sound absorption coefficient of a spunbonded nonwoven made of PIE filaments (PETIPA) with a spunbonded nonwoven made of SC filaments (PET / CoPET)

To determine the degree of sound absorption of a selected variant of embodiment 4 (105 gsm PETIPA PIE) in comparison to embodiment 2 (100 gsm PET / CoPET SC), the various materials are subjected to a test in the impedance tube based on DIN EN ISO 10354: 1. The corresponding measured values are in FIG. 4 played. In this figure, the sound absorption coefficient of a spunbonded nonwoven fabric according to the invention made of PIE filaments (PET / PA) according to embodiments 2 and 4 is compared with a spunbonded nonwoven fabric of SC filaments (PET / CoPET). The fiber dependence of the sound absorption coefficient is measured in the impedance tube according to DIN EN ISO 10345-1.

In this case, the effect of the PIE fiber geometry, which is advantageous in terms of an increased degree of sound absorption, is shown in direct comparison to a SC spunbonded nonwoven. The density of the two different binder fiber polymers is in the same range (~ 1.1 g / cm ³ ).

Embodiment 7: Comparison of the sound absorption coefficient of spunbonded nonwovens made of PIE filaments with different binding components

To determine the degree of sound absorption of the variants of embodiment 3 (105 gsm PET / polyolefin PIE) in comparison to a selected comparable variant of embodiment 4 (105 gsm PET / PA PIE), the various materials are subjected to a test in the impedance tube based on DIN EN ISO 10354: 1 subjected. The corresponding measured values are in FIG. 5 played.

Here, the advantageous effect of the PIE fiber geometry in combination with polyamide as binding component in terms of an increased degree of sound absorption is shown direct comparison to polyolefin-containing spunbonded fabric, especially in higher frequency ranges.

Embodiment 8: Comparison of the sound absorption coefficient of spunbonded nonwovens made of PIE filaments with different basis weights

To determine the degree of sound absorption of the variants of embodiment 4 (40-105 gsm PET / PA PIE), the various materials are subjected to a test in the impedance tube based on DIN EN ISO 10354: 1. The corresponding measured values are in FIG. 6 played.

Here, the advantageous with regard to an increased degree of sound absorption effect of PIE fiber geometry in combination with polyamide as a binding component in direct comparison with polyolefin-containing spunbonded especially in higher frequency ranges clearly.

Embodiment 9: Heat Dependent Tensile and Deformation Test on PET / PA nonwoven fabrics made from PIE filaments

To determine the tensile properties of the base materials of Example 1 under elevated temperature variants are tested based on ASTM D5034 at a test temperature of 160 ° C to maximum tensile strength and maximum tensile elongation at break. The corresponding results are shown in Table 6. In order to evaluate the deformation properties under heat (thermoformability), fixed specimens of the substrates are deformed in a simple test setup (OTI test) by means of a circular stamp heated to 160 ° C. (ball diameter 9 cm, absolute specimen size 24 cm diameter, freely deformable specimen size 20 cm ). there the path length up to the damage in cm, the force in N at a deformation of 5%, as well as the maximum force to be applied for deformation in N are used as parameters for the evaluation of the material properties. A long path length at 160 ° C with corresponding (lower) force therefore means positive deformation properties under heat (thermoformability). Corresponding measured values are shown in Table 6. Table 6: Heat-dependent tensile and deformation test on base materials of the embodiment 1, test temperature 160 ° C. test conditions Grab Tensile strain Grab Tensile strain Crush test MD MD CD CD PA-share calender pressure Calender temperature ASTM D5034 ASTM D5034 ASTM D5034 ASTM D5034 OTI track OTI M5% OTI max.force Prüftemp. 160 ° C 160 ° C 160 ° C 160 ° C 160 ° C 160 ° C 160 ° C % N / mm ° C N % N % cm N N 30 50 130 155.9 49.4 170.9 49.5 10.26 262.8 1655 30 80 130 158.2 46.6 152 48.5 10.8 248 1853 30 80 180 * 148.1 36.7 145.5 42 11.06 267.5 2016 30 50 180 * 167.9 42.4 153.9 42.7 11.02 279.1 2005 50 50 180 * 138.6 35.2 131.5 39.1 10.44 255.9 1731 50 80 180 * 141.5 33.3 130.9 36.3 10.12 262.3 1629 50 80 130 145.6 40 135.8 41.9 10.66 246.6 1778 50 50 130 147.9 40 156.2 47.2 10.36 249.6 1683

Claims (14)

1. Use of a non-woven fabric comprising at least two polymers, where the melting point of at least one first polymer is above the melting point of at least one second polymer, and where the first polymer takes the form of elemental segments distributed in a matrix made of the second polymer, as acoustic absorption material, where the thickness of the non-woven fabric is from 0.01 mm to 1 mm, preferably from 0.05 mm to 0.5 mm, in particular from 0.1 mm to 0.2 mm, characterized in that the permeability of the non-woven fabric to air is from 20 to 100 l/m²sec, measured in accordance with DIN EN ISO 9237, for a weight per unit area of 100 g/m², 20 cm² and 50 Pa.
2. Use according to Claim 1, characterize in that the airborne acoustic absorption coefficient α(0) of the non-woven fabric, measured in an impedance tube in accordance with DIN EN ISO 10354-1, for a weight per unit area of 100 g/m², is ≥ 0.6 at a frequency of from 1000 Hz to 4000 Hz.
3. Use according to one or more of Claims 1 to 2, characterized in that the proportion of the matrix in the non-woven fabric is in the range from 1% by weight to 60% by weight, preferably from 5% by weight to 50% by weight, in particular from 10% by weight to 40% by weight.
4. Use according to one or more of Claims 1 to 3, characterized in that the difference between the melting points of the first and second polymer is at least 15°C, preferably at least 20°C.
5. Use according to one or more of Claims 1 to 4, characterized in that, distributed in a matrix made of the second polymer in the non-woven fabric there are elemental segments made of a first polymer, their cross section having the shape of a segment of a circle or of a sector of a circle, or having the shape of a circle or having multilobal shape.
6. Use according to one or more of Claims 1 to 5, characterized in that the non-woven fabric has been impregnated with at least one binder selected in particular from acrylates and aminoplastics (phenolic resins, melamine resins), styrenebutadiene copolymers, NBR binder systems and/or polyurethanes, and has been provided with a flame retardant.
7. Use according to one or more of Claims 1 to 6, characterized in that the non-woven fabric has, on at least one side, at least one adhesive component in powder form, preferably made of a thermoplastic polymer, in particular of polyethylene, copolyester or polyamide, and/or has been provided with a flame retardant.
8. Use according to one or more of Claims 1 to 7, characterized in that the weight per unit area of the non-woven fabric is from 30 g/m² to 400 g/m², preferably from 35 g/m² to 200 g/m², more preferably from 40 g/m² to 150 g/m², in particular from 40 g/m² to 120 g/m².
9. Use according to one or more of Claims 1 to 8 for the production of cladding components for the interior region of automobiles, preferably automobile roof linings, mats, door cladding, column cladding, parcel shelves and/or boot lining, or else wheelhousing lining, and/or for sound deadening in vehicles, aircraft and trains, in the construction sector and in small devices, in particular in the acoustic frequency range from 100 to 5000 Hz.
10. Use according to one or more of Claims 1 to 9, characterized in that the acoustic absorption material is produced by a process comprising the following steps:

    - provision of multicomponent fibres which comprise at least two polymers with different melting points,

    - surface bonding of the multicomponent fibres by compressive heat treatment at a temperature of from 100°C to 300°C and at a pressure of from 40 N/mm to 150 N/mm, in such a way that at least one first polymer in the form of elemental segments is distributed in a matrix made of at least one second polymer.
11. Use according to one or more of Claims 1 to 10, characterized in that the multicomponent fibres comprise a first polymer component and a second polymer component, where

    - the arrangement has the first polymer component in a first zone and the second polymer component in a second zone across the cross section of the multicomponent fibres, where

    - both polymer components extend in a longitudinal direction of the multicomponent fibres, where

    - the melting point of the first polymer component is above the melting point of the second polymer component, and where the first zone comprises the first polymer component in the form of at least two separable elemental segments.
12. Use according to Claim 11, characterized in that multicomponent fibres are PIE fibres, hollow-PIE fibres, core/sheath fibres, multilobal fibres or side-by-side fibres, where these are composed of at least two polymers with different melting points.
13. Use according to one of more of Claims 10 to 12, characterized in that the surface bonding of the multicomponent fibres is carried out via exposure to a pressure of from 40 N/mm to 100 N/mm, preferably from 60 N/mm to 80 N/mm, in particular from 50 N/mm to 90 N/mm.
14. Use according to one or more of Claims 10 to 13, characterized in that the surface bonding of the multicomponent fibres is carried out via exposure to a temperature above 100 °C, preferably from 100°C to 300°C, more preferably from 110°C to 200°C, in particular from 120°C to 180°C.

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