EP2758580A1 - Nonwoven fabric with a matrix containing elementary filaments - Google Patents

Abstract

The invention relates to a method for producing a nonwoven fabric containing at least one first polymer component, which is distributed in the form of elementary segments in a matrix made of at least one second polymer component, said method comprising the following steps: a) provision of multicomponent fibers comprising a first polymer component and a second polymer component, wherein - the first polymer component is arranged in a first zone and the second polymer component in a second zone over the cross-section of the multicomponent fibers, wherein - the two polymer components extend in the longitudinal 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 elementary segments; b) connection of the multicomponent fibers in sheet form by application of pressure and temperature in such a manner that elementary segments made from the first polymer component are distributed in a matrix made from the second polymer component. The method according to the invention makes it possible to produce nonwoven fabrics with a high rigidity, smoothness, a dense structure and low porosity.

Description

 Nonwoven fabric with a matrix containing elementary filaments

description

Technical area

The present invention relates to the field of textile products and their

Applications.

The invention relates to a process for producing a nonwoven fabric containing at least one first polymer component which is distributed in the form of elementary segments in a matrix of at least one second polymer component. The

The invention further relates to a nonwoven fabric produced by the process according to the invention, and the use of this nonwoven fabric for producing a nonwoven fabric

Composite.

With the present invention, in particular, the conventional field of application of nonwovens is to be extended by imparting physical, in particular mechanical, properties and properties which are similar to those of paper or films, the advantageous characteristics and properties of nonwovens

CONFIRMATION COPY stay out of endless segments. In particular, nonwovens with a low porosity and air permeability should be provided.

State of the art

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

In melt spinning, a polymeric substance is heated in an extruder and forced through a spinneret by spinning pumps. The polymer leaves the

Nozzle plate as a thread (continuous filament) in molten form, is cooled by an air stream and stretched from the melt. The air stream conveys the endless filaments onto a conveyor belt, which is designed as a sieve. By a

Suction under the screen belt, the threads can be fixed to form a fiber fabric. The solidification of the Fasergeleges can by heated rollers

(Calender), by a vapor stream 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 from only one domain used (see Tyvek®).

From WO 2006/107695 A2 a method for producing a nonwoven fabric is known, in the bicomponent fibers having an outer and an inner Fiber component, produced by a spinning process. The outer fiber component wraps around the inner fiber component and has a higher elongation at break and a lower melting temperature than the inner

Fiber component on. The bicomponent fibers are positioned on a conveyor belt and solidified to a nonwoven fabric under the action of heat. The nonwovens are used to make tents, awnings, parachutes and packaging materials.

From WO 2005 / 059219A1 a multicomponent nonwoven fabric is known, which has a nonwoven fabric bonded over its entire area with at least 50% by weight.

multi-component melt-spun fibers selected from the group consisting of multicomponent staple fibers, multicomponent filaments and

Combinations thereof, wherein the multicomponent fibers have a cross-section and a length and a first polymer component and a second

Polymer component, wherein the first and second polymer components are arranged in virtually constantly positioned, separate zones across the cross section of the multicomponent fibers and is practically continuous in

Length direction of the multi-component fibers extend, the second

Polymer component has a melting point which is lower by at least 10 ° C than the melting point of the first polymer component, and wherein at least a portion of the outer peripheral surface of the multicomponent fibers, the second

Having polymer component. Core-sheath fibers or side-by-side fibers are used as multicomponent fibers. The nonwoven fabric described has a

comparatively large porosity and is therefore unsuitable for applications in which a dense structure is required.

From US 4039711 a thin nonwoven laminate is known which comprises a batt of entangled synthetic polymer filaments interposed between webs of thermoplastic staple fibers. In this laminate, substantially all of the filaments are bonded to the thermoplastic fibers of the web. When Binder fibers are preferably used polyester filaments. The nonwoven fabric is only partially solidified and therefore has a comparatively large porosity.

WO 03/021024 describes a method for bonding a nonwoven web, comprising the following steps:

Forming a nonwoven web of thermoplastic fibers or filaments comprising a polymer which melts below 140 ° C;

 contacting the nonwoven web with a profiled embossing roll, wherein the embossing textured roll has an outer surface with a plurality of raised calendering surfaces each separated by interposed depressions, wherein the raised calendering surfaces are coated with a fluoropolymer and

 Transferring energy to the nonwoven web so that the fibers or filaments melt and form point bonds where the web is raised with the web

 Calender surfaces comes into contact. Due to the profiling of the embossing roller, only partial area solidification takes place in the described method, and the nonwoven web has a comparatively large porosity.

From EP 2151270 A1 a nonwoven fabric for a bag filter is known, which is produced by thermocompression of thermoplastic endless elements.

Preferably, a core-sheath fiber is used as the thermoplastic polyester. The thermocompression only leads to a partial bonding of the thermoplastic fibers, since otherwise the necessary for the use of the nonwoven fabric air permeability can not be achieved

DESCRIPTION OF THE INVENTION The object of the invention was a process for producing a nonwoven fabric with paper or foil-like features, in particular with a high flexural rigidity and low static friction. The nonwoven fabric should also have a dense structure, low porosity and air permeability.

This object is achieved according to the invention by a process for producing a nonwoven fabric comprising 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, comprising the following process steps:

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

The invention is in particular achieved by a method for producing a nonwoven fabric comprising at least one first polymer component which is distributed in the form of elementary segments in a matrix of at least one second polymer component, comprising the following method steps:

a) providing multi-component 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 is disposed in a second zones over the cross section of the multi-component fibers, wherein Both polymer components in the length direction of

 Multicomponent fibers extend, 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 elementary segments; b) laminar joining of the multicomponent fibers by applying pressure and temperature such that elemental segments of the first polymer component are distributed in a matrix of the second polymer component.

The inventive method is characterized in that special

Multicomponent fibers are connected to each other by applying pressure and temperature surface, so that elemental segments of the first

Polymer component (first polymer) in a matrix of the second

Polymer component (second polymer) are distributed. By the method according to the invention, the surface of the nonwoven fabric can be bonded over the entire surface. According to the invention, "full-surface bonding" means that the surface of the nonwoven fabric is bonded to at least 90%, preferably to at least 95% and in particular to almost 100%, the term "bonded" meaning that the surface in the essential pores is free. The term "separable" is understood according to the invention that the elementary segments can be separated under the influence of pressure and temperature in spatially separated elementary segments.

According to the invention, a nonwoven fabric with a high flexural rigidity, a low static friction and a dense structure with low porosity can be obtained. Thus, the air permeability of the nonwoven according to DIN EN ISO 9273 at 5 cm ² / 100Pa less than 120 l / m ² sec, preferably less than 110 l / m2 sec, more preferably less than 100 l / m ² sec, more preferably less than 90 l / m ² sec and especially less than 80 l / m ² sec.

Without wishing to be bound by any mechanism, it is believed that the use of the special multicomponent fibers with a first zone, the first

Polymer component in the form of at least two separable elementary segments, the formation of the dense structure allows. So can the

Elemental segments under the influence of pressure and temperature separated into spatially separated elementary segments and compressed into a compacted packing with low porosity and low air passage. A low porosity is with respect to various applications of the nonwoven fabric in particular as

Packaging and / or insulation material advantageous. In addition, it also facilitates further processing such as laminating, laminating, printing etc.

In addition, the nonwoven fabric of the present invention can have high strength and waterproofness with low weight. This allows for easy

Processing and handling.

Practical experiments have revealed that nonwovens having particularly low drapability are obtained when the pressure is set to values of 40 N / mm to 150 N / mm, preferably 45 to 140 N / mm, more preferably 50 to 100 N / mm, more preferably 55 to 90 N / mm, more preferably 60 to 90 N / mm, especially 70 to 90 N / mm.

The nonwoven fabric produced by the process 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 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 method according to the invention makes it possible to use energy-intensive mechanical solidification technologies, e.g. Hydroentanglement, to dispense. The nonwoven fabrics produced by the process according to the invention are characterized by isotropic mechanical properties, such as an isotropic ratio of maximum tensile force or tensile force in machine direction to transverse direction. 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 / transverse direction ratio of the maximum tensile force and / or tearing force within the meaning of the invention, it is understood that the

Machine direction / transverse direction ratio of maximum traction and / or

Tear strength in the range of 0.7 to 1, 6, preferably from 0.8 to 1, 5, in particular from 0.9 to 1, 1.

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. Under

Machine direction is understood to mean the direction under which the fibers are deposited longitudinally on a longitudinally moving conveyor belt. The

Direction transverse thereto or orthogonal thereto is the transverse direction. The nonwoven fabric according to the invention is outstandingly suitable for the production of fiber composite materials, since its surface structure, for example via the choice of

Polymers as well as by plasma or corona treatment of the surface can be easily adapted to the other composite components. This allows a versatile use of composite components (film, foil, extrudate, etc.).

The multicomponent fibers can be prepared in a manner known to those skilled in the art. Suitable methods are in particular melt-blown and

Spunbonding. Particularly preferred according to the invention

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. Beneficial to a in

Transversely deflected positioning of the continuous filaments is that this increases the isotropy of the mechanical properties of the nonwoven fabric.

The temperature at which the solidification of the multicomponent fibers takes place can vary within wide ranges and is expediently adapted to the particular polymer components used in the multicomponent fiber. Essential here is that at selected temperature and pressure a substantially complete

Melting of the first polymer but not of the second polymer takes place.

Advantageously, the surface bonding of the multicomponent fibers is carried out by applying 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 preferred are rollers with a smooth or only slightly roughened surface. Thus, the calendering is preferably with a

Roll pairing carried out, wherein at least one of the rollers of a surface roughness, measured according to DIN 4768 05.90 from 20 to 100 pm, preferably from 20 to 70 pm and in particular from 30 to 50 pm. According to the invention, it is particularly preferable to use a roll pairing in which one of the rolls has a roughness depth, measured to DIN 4768 05.90 of 20 to 100 .mu.m, preferably from 20 to 70 .mu.m and in particular from 30 to 50 .mu.m and the other roll a smooth roll with a Roughness, measured according to DIN 4768 05.90 of less than 20 pm. Particularly expediently, the surface bonding of the multicomponent fibers is carried out by a single-stage consolidation process.

According to the invention, the first polymer component in a first zone and the second polymer component in a second zone over the cross section of

Multicomponent fibers arranged. Both polymer components extend in the length direction of the multicomponent fibers and the first zone comprises the first polymer component in the form of at least two separable elementary segments. Preferably, the first polymer is in the form of 2, 3, 4, 5, 7, 8, 9 or 16 separable elemental segments in the multicomponent fibers. Overall, therefore, preferably 4, 6, 8, 10, 14, 16, 18 or 32 elemental segments, which alternately comprise the first and second polymer components, are present in the multicomponent fibers, wherein the provision of 16 elemental segments is particularly preferred according to the invention. According to a particularly preferred embodiment of the invention, PIE fibers which comprise 4, 6, 8, 10, 14, 16, 18 or 32 elementary segments are used as multicomponent fibers.

As fibers can be a variety of fiber types including

Multi-component staple fibers, multi-component filaments are used. Practical experiments have shown that nonwovens with particularly good

Strength properties and low porosities are obtained when PIE fibers, hollow-PIE fibers, multilobal fibers, or islands-in-sea fibers are used as multicomponent fibers. Under PIE fibers become fibers

Elementarsegementen understood, which are arranged in the form of a cake piece or circular segment in cross section. For multilobal or island-in-sea fibers, the higher melting polymer component is preferably located in the core and the lower melting polymer component is at least partially at the fiber surface. This facilitates the melting of the lower melting polymer component. The fibers may be formed as staple fibers. Preferably, however, they are formed as continuous filaments.

The effect of reflowing the above-mentioned fibers, such as the PIE fiber or cake-like fiber, is to incorporate stable, for example pie-shaped segments, which 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 the above-mentioned fibers, for example, the PIE fibers is that the example cake-shaped segments in

Cross-section have a very small diameter and therefore can enforce the matrix particularly numerous. 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 multilobal fibers, or Islands in Sea fibers, it is preferred that the shells are made of the lower melting polymer. In this way, the cores are in the form of stable, for example, circular segments embedded in the matrix of the sheath polymer. The advantage of using the multilobal fibers, or islands-in-sea fibers, is that due to the

circular cross section of the core segments forms a particularly dense structure, analogous to a spherical packing.

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 at the

Use of two polymers (bicomponent fibers, in particular

Bicomponent filaments) nonwovens having a stable matrix structure can be obtained.

The basis weight of the nonwoven fabric according to the invention can vary within wide limits. The choice of basis weight is made according to the requirements of the fiber composite. The basis weight is usually from 30 g / m ² to 400 g / m ² , preferably from 35 g / m ² to 200 g / m ² , more preferably from 40 g / m ² to 150 g / m ² , in particular from 40 g / m ² to 120 g / m ² .

For some applications of the nonwoven fabric according to the invention, 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 or hydrophobic, without adding chemicals. This is particularly advantageous in kübernah used products, such as clothing, advantage.

Conceivable is the antistatic finish of the surface, as well as its inspiration with care substances. Also conceivable is the subsequent finishing of the nonwoven fabric with hydrophilic, hydrophobic or antistatic spin finishes, as well as their Providence with care substances. It is also possible additives for

Surface modification already in the continuous film production in an extruder to enter. Also in a dyeing no subsequent coloration is necessary because pigments can be introduced already in the continuous film production in an extruder.

Further, the nonwoven fabric may be subjected to chemical type bonding or finishing such as an anti-pilling treatment

Hydrophilization, an antistatic treatment, a treatment to improve the refractoriness and / or change the tactile properties or gloss, a mechanical treatment such as roughening, sanforizing, sanding or a treatment in the tumbler and / or a treatment to change the appearance such as dyeing or printing.

Another object of the invention is a nonwoven fabric formed as a base material for coating with films, which is produced by a method according to the invention. According to the invention, the coating with films preferably takes place by lamination and / or lamination of the base material, optionally with the use of 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.

Another object of the invention is a nonwoven fabric formed as a base material for impregnation with binders, which is produced by a process according to the invention and the impregnated nonwoven itself. Suitable binders are in particular acrylates and aminoplasts (phenolic resins, melamine resins), styrene-butadiene copolymers, NBR binder systems and / or polyurethanes.

The nonwoven fabric according to the invention is characterized by a high flexural rigidity with low static friction. The nonwoven fabric of the invention is further distinguished by excellent strength properties. Thus, the tear propagation force in machine and / or transverse direction 10 N to 60 N, preferably 20 N to 50 N, in particular 30 N to 40 N. The maximum tensile force in the machine and / or transverse direction can be 70 to 400 N / 50 mm, preferably 100 to 350 N / 50 mm, in particular 150 to 300 N / 50 mm.

For the characterization of special, general nonwoven fabric characteristics

deviating properties, in particular the bending stiffness according to DIN 53350, as well as the static friction coefficient according to ASTM D-4918-97 (2002) are to be used.

Practical tests have shown that the nonwoven fabric according to the invention has a high flexural rigidity with simultaneously high surface smoothness, i. low

Friction coefficient shows. Thus, the nonwoven fabric according to the invention can be a

Bending stiffness of 0.5 N / mm ² to 10 N / mm ² , measured according to DIN 53350 at a bending angle of 10%. Preferably, the nonwoven fabric according to the invention has a bending stiffness of 0.5 N / mm ² to 8 N / mm ² at a bending angle of 10%, more preferably from 1 N / mm ² to 6 N / mm ² , in particular 1 N / mm ² up to 4 N / mm ² . The flexural stiffness information refers to a measurement in the longitudinal or transverse direction. Furthermore, the nonwoven fabric according to the invention may have a bending stiffness of 1 N / mm ² to 20 N / mm ² , measured according to DIN 53350 at a bending angle of 40%.

Preferably, the nonwoven fabric according to the invention has a bending stiffness of 3 N / mm ² to 12 N / mm ² at a bending angle of 40%, more preferably from 4 N / mm ² to 12 N / mm ² , in particular from 5 N / mm ² to 10 N / mm ² on. The flexural stiffness information refers to a measurement in the longitudinal or transverse direction.

The nonwoven fabric according to the present invention may have a coefficient of static friction measured according to ASTM D-4918-97 (2002), tan α of 0.05 to 0.50, preferably 0.10 to 0.40, especially 0.10 to 0.30 , By using a

Roller pairing, in which the rollers have a different roughness, the nonwoven fabric can be designed so that one side of another

Has static friction coefficients as the other side. This embodiment is advantageous because it improves the Aufrollbarkeit of the nonwoven fabric. A special Advantageous coefficient of static friction can be achieved if polyethylene and / or polyamide is used to form the polymer matrix.

Structurally, the nonwoven fabric according to the invention is characterized in that it comprises at least two polymers, wherein the melting point of at least one first polymer component above the melting point of at least one second

Polymer component is where the first polymer component in the form of

Elementary segments exists, which in a matrix from the second

Polymer component are distributed.

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 with a

Temperature difference of 15 ° C to 450 ° C, more preferably from 15 ° C to 200 ° C, even more preferably from 20 ° C to 150 ° C, in particular from 70 ° C to 150 ° C used.

According to a preferred embodiment of the invention, the melting point of the first polymer component is between 230-290 ° C, preferably between 250-280 ° C. The melting point of the second polymer component is preferably 200-260 ° C, more preferably 220-240 ° C.

As polymers, a wide variety of materials can be used.

Preferred combinations for multicomponent fibers include above all

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 contain polypropylene, polyethylene, polyamide, syndiotatkisches

Polystyrene, polyester, and / or mixtures of these polymers, preferably polyethylene terephthalate.

According to a further preferred embodiment of the invention, the first polymer component is selected from the group consisting of: polyester, preferably

Polyethylene terephthalate selected and / or the second polymer component from the group consisting of: polypropylene, polyethylene, polyamide and / or polyester, preferably polyethylene terephthalate.

If islands-in-sea fibers are used as multicomponent fibers, the sea is preferably formed from the second, matrix-producing polymer. Preferred polymers are polyethylene, linear low-pressure polyethylene with an a- 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 produced by the process according to the invention is characterized in that a film-like molten polymer matrix is present in the nonwoven fabric. 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 segment-shaped cross-section show an approximately 1.75 times larger surface area than an elementary segment with a round cross-section.

Due to the larger surface area, a larger adhesion surface is formed.

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 and water impermeability 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.

The weight ratio of the first polymer to the second polymer in the nonwoven fabric can vary within a wide range, provided that it is ensured that the first polymer component is present in the nonwoven fabric in the form of elementary filaments which are distributed in a matrix of the second polymer component. This is preferably

Weight ratio of first polymer to second polymer in the nonwoven 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. Furthermore, the nonwoven fabric preferably comprises at least 50% by weight, more preferably 60-100% by weight of multicomponent fibers, more preferably 70-100% by weight of multicomponent fibers, wherein

Multicomponent fibers are in particular melt spun multicomponent fibers.

Due to its low weight, high strength and water resistance, the nonwoven fabric according to the invention is outstandingly suitable for the production of

Packaging materials, bags, bags, envelopes, in particular

Envelopes, ribbons, banners, reinforcing layers, separating layers and / or

Insulation layers. Particularly advantageous is the nonwoven fabric for the production of

Desiccant bags used to meet with desiccants such as S1O2, CaC, bentonite. Due to the low air permeability of the nonwoven fabric, a high retention capacity for the desiccant can be achieved here.

Likewise outstandingly suitable is the nonwoven fabric according to the invention as a base material for the treatment with impregnating agents, in particular binders, resins and / or polymer dispersions.

Another object of the invention is a composite material comprising at least a first layer containing a nonwoven fabric according to the invention, and at least one second layer, preferably formed as a film.

According to a preferred embodiment of the invention, the second layer is formed as a film having a thickness 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 respective layers of the

Nonwoven fabric according to the invention can be used depending on the used

Materials are connected in different ways.

Practical experiments have shown that particularly strong composites are obtained when the first and second layers are cohesively and / or bonded together by means of a binder. The composition of the film used according to the invention can vary within wide ranges, depending on the particular intended use of the composite material. Preferably, the film contains plastics, preferably polyolefins, in particular polyethylene and / or polypropylene and / or their copolymers or metals. It is also conceivable to use a metallized film.

Depending on the desired gain intensity, the thickness of the first layer may vary. Preferably, the first layer has a thickness of from 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.

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

In the drawing show

Fig. 1 is 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 500x magnification,

Fig. 2 is a scanning electron micrograph (SEM) of a

Fiber cross section of a commercially available nonwoven fabric (PE) at 500x magnification, and a scanning electron micrograph (SEM) image of the

 Fiber cross section of a nonwoven fabric produced in Example 4 (PIE filaments / PET / PA) at 1000 times magnification.

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 core / sheath filament (PET / PE)

For the production of the core / sheath Filamehte polyethylene terephthalate and

Polyethylene in a known manner with a perforated flow rate of 0.65 g / L min coextruded 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 subjecting the continuous filaments to pressure and temperature, the polyethylene is melted and the polyethylene terephthalate is distributed in the form of elementary filaments in a matrix of polyethylene. In this case, a spunbonded fabric having a basis weight of 80 g / m ^{2 is} obtained. The spunbonded fabric has a dense structure and a low porosity with characteristic mechanical values (maximum tensile strength (HZK), tear propagation force (WRK), machine direction

(MD): cross direction (CD) ratio). The parameters of the embodiment are shown in Table 1.

Table 1: Embodiment 1, 80 g / m ² PET / PE nonwoven fabric, core / sheath filaments, mech. Properties.

In Figure 1, the film-like structure of the surface or the material structure of spun core-sheath filaments can be seen. This is partly

 Polyethylene domains reinforced by continuous polyethylene terephthalate filaments.

The air passage can be controlled in the range of 135 to 285 l / m ² sec. During solidification, the round cross section of the polyester core structure remains in the

 Essentially received. In the spunbond are polyethylene domains associated with the

 Core segments are reinforced, before. This is particularly visible in the spunbonded nonwovens with a polyethylene content of 36% by weight in the jacket. By the specific

 Fiber orientation comes to typical isotropic

Machine direction / cross direction ratios as shown in Table 2. Kalandertemp. Calender pressure PE content MD: CD ratio MD: CD ratio

 HZK WRK

 ° C N / mm%

 125 50 14 1, 0 1, 0

 132 50 14 1, 1 0.6

 125 80 14 1, 1 1, 1

 132 80 14 1, 1 0.8

 125 50 36 1, 0 1, 0

 132 50 36 1.1 1, 0

 125 80 36 1, 2 1, 1

Table 2: Example 1, 80 g / m ² PET / PE nonwoven, core / sheath filaments, mech. Properties.

FIG. 2 shows the cross section of commercially available flash spun polyethylene (Du Pont Tyvek®). This shows only fibers of a single polymer in a different size and shape. To compare the surface energies, a commercially available packaging nonwoven made of flash spun polyethylene (Du Pont Tyvek®) was used.

Embodiment 2:

 Production of a nonwoven fabric according to the invention from core sheath

 Continuous filaments (PET / PE)

To produce the core / sheath filaments are polyethylene terephthalate and

Polyethylene in a known manner coextruded with a perforation throughput of 0.65 g / L min and aerodynamically stretched to form core / sheath filaments. The polyethylene content in the extrudate is 36 to 40 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 temperatures between 128 ° C and 132 ° C at a line pressure of 80 N / mm (roughness of 40 μηι) on. By subjecting the continuous filaments to pressure and temperature, the polyethylene terephthalate is in the form of elementary filaments in a matrix

Polyethylene distributed. This spunbonded nonwovens are obtained with a basis weight of 40, 60 and 80 g / m ² . It produces nonwovens with dense structure and lower

 Porosity at characteristic mechanical values (HZK, WRK, MD: CD ratio). The parameters of the experiment are shown in Tables 3 and 4.

Table 3: Example 2, 40, 60 and 80 g / m ² PET / PE nonwovens, core / sheath filaments, mech. Properties.

Table 4: Embodiment 2, 40, 60 and 80 g / m ² PET / PE nonwovens, core / sheath filaments, mech. Properties.

Embodiment 3

 Production of a spunbonded core / sheath filament (PET / Co

To produce the core / sheath filaments are polyethylene terephthalate and a low melting co-polyester in a known manner with a perforated flow rate of 0.74 and 0.8 g / L min coextruded and aerodynamically stretched, wherein

Core / sheath filaments are formed. 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 μηι) on. By subjecting the continuous filaments to pressure and temperature, the polyethylene terephthalate is distributed in the form of elementary filaments in a matrix of co-polyethylene terephthalate. Subsequently, a

After 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

Embodiment are shown in Table 5 and Table 6.

Table 5: Embodiment 4, 100 g / m ² PET / CoPET nonwoven, core / sheath filaments, mech. Properties. Kalandertemp. PLD calender pressure Co-PET content MD: CD-D: CD ratio ratio

 HZK WRK

 • c g / Lmin daN%

 130 0.74 80 20 1.1 1, 1

 130 0.8 80 20 1, 2 1, 0

Table 6: Embodiment 4, 100 g / m ² PET / CoPET nonwoven, core / sheath filaments, mech. Properties.

Exemplary Embodiment 4 Production of a Spunbonded Nonwoven of 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, resulting in 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 with a line pressure between 50 N / mm and 80 N / mm (roughness of 40 pm). By subjecting the continuous filaments to pressure and temperature, the polyamide is fused and the polyethylene terephthalate is distributed in the form of elementary filaments in the form of cross-sectionally circular or 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 7 and Table 8. Kalan-Kalan PA- Thickness LD Grave Elongation Grave Elongation Trap Trap der- derAnwicht 20cm Ten- MD Ten- CD Tear Tear tem p. pressure part ^2/50 sile sile MD CD

 Pa MD CD

 EN DIN EN DIN EN 29073 EN EN 29073 AST ASTM

 2907 ISO EN 2907 T3 2907 T3 M D D

 3 9073-2 ISO 3 T3 3 T3 573 5733 angel 9237 3

^• c N / mm% g / m ² mm l / m * s N / 50% N / 50% NN

 ec mm mm

 130 50 30 103.9 0.2 89 224.9 43.7 174, 41.3 185 163.9

 2

 130 80 30 104.7 0.22 81 252.5 47.8 205 50.1 185, 170.3

 4

180 ^* 80 30 106.6 0.14 27 319.2 46.4 272, 48.5 90.7 90.6

 2

 180 * 50 30 106.7 0.15 31 321.8 46.1 260, 52.3 86.7 84.7

 3

 180 * 50 50 104.4 0.15 31 273.8 41, 6 226, 44.7 69.2 68.7

 5

 180 * 80 50 106.3 0.15 25 295.9 40.9 221, 40.4 54.2 55.6

 1

 130 80 50 105.7 0.17 46 244.6 43.6 180 39.9 174, 155.7

 9

 130 50 50 106 0.2 65 233.2 44.3 179, 42.6 87 90

 1

Table 7: Embodiment 4, 105 g / m ² PET / PA nonwoven fabric, PIE filaments, mech. Properties.

Table 8: Embodiment 4, 105 g / m ² PET / PA nonwoven fabric, PIE filaments, mech. Properties.

According to an embodiment of the invention, which is shown in particular in FIG. 3, the composite filaments in cross-section on a circular segment-shaped configuration of the cross sections of the various elementary segments performing areas. It is a filmlike structure in cross section of the material structure of the

to recognize nonwoven fabric according to the invention. There are polyamide domains reinforced by polyethylene terephthalate filaments. The original round

The fiber cross-section is largely deformed by the influence of heat and pressure and can no longer be determined.

Embodiment 5:

 Corona and plasma treatment of a spunbonded web

The surface energy of the produced spunbonded nonwovens is changed by a corona or plasma treatment. In Table 9, this is described in Example 8 (132 ° C / 80 daN / 36% PE) of Embodiment 1. The page marked with ^* is the side of the process facing the charge side. The corona charging takes place at

Standard conditions (room temperature, 7500 V) and various

Speeds. The plasmatization takes place in a low-pressure atmospheric plasma system of Freudenberg Forschungsdienste KG

Room temperature. The surface energies are measured according to ISO 9000 with Sherman test inks from Schnick D-42579 Heiligenhaus. To compare the surface energies, a commercially available packaging nonwoven made of flash spun polyethylene was used.

Surface energy / [dyn] surface energy / [dyn]

 Page 1 Page 2 * Page 1 * Page 2 Page 1 Page 2 * Page 1 * Page 2

Reference 40-42 40-42 # # 40-42 40-42 # #

PE

 Try unbeh. 38-40 38-40 # # 38-40 38-40 # #

8th

 Try Corona Plasma Corona Plasma

8th

 5 m / min # #> 50> 50 # #> 50> 50

 10 # #> 50> 50 # #> 50> 50 m / min

 25 40-42 44-46> 50> 50 40-42 42-44> 50> 50 m / min dyn dyn dyn dyn

 35 38-40 44-46> 50> 50 38-40 42-44> 50> 50 m / min dyn dyn dyn dyn

 45 measurement 1 measurement 1, 0 days storage time at

 m / min room temperature

Table 9: Example 1, Example 8, 80 g / m ² PET / PE nonwoven fabric, core / sheath filaments, surface energies untreated and corona or

Plasma treatment.

As can be seen from the values of Table 9, the nonwoven fabric according to the invention is outstandingly suitable for treatment with plasma and / or corona treatment. Surprisingly, even very thin nonwoven layers can be treated such that they have a surface energy of 40 to 42 dyn. without destruction of the nonwoven fabric takes place.

Embodiment 6:

 Bending stiffness and static friction coefficient of different materials

For the characterization of special, general nonwoven fabric characteristics

deviating properties, in particular the bending stiffness according to DIN 53350, as well as the static friction coefficient according to ASTM D-4918-97 (2002) are to be used. A comparison of the measured values of selected exemplary embodiments shows a high bending stiffness with high surface smoothness, ie low coefficient of friction. It can be seen that a particularly advantageous

Friction coefficient can be achieved when polyethylene or polyamide is used to form the polymer matrix.

Table 10: Various embodiments, bending stiffness acc. DIN 53350.

Table 11: Various embodiments, transverse stiffness acc. DIN 53350.

Table 12: Various embodiments, static friction coefficient tan a acc. ASTM D-4918-97, page assignment A = smooth roller, B = roughing roller.

Embodiment 7:

 Production of spunbond webs from PIE filaments (PET / PA, PE and PP)

To produce the PIE filaments, polyethylene terephthalate and polyamide, polyethylene or polypropylene as binder component 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 binding component is between 30 and 50 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 temperatures between 130 ° C and 180 ° C at a line pressure between 50 N / mm and 80 N / mm (roughness of 30 - 40 μητι).

By subjecting the continuous filaments with pressure and temperature, the binding polymer is fused and the polyethylene terephthalate in the form of im

Cross-section of circular segment-shaped or cake-piece-like elementary filaments distributed in a matrix of the polyamide. This spunbonded nonwovens can be obtained with different basis weights, which are characterized by high mechanical strength. It also spun webs with dense structure and low

Porosity level, which can be designed by the choice of binding component and solidification. Corresponding parameters are shown in Tables 13 and 14. Exemplary embodiment 7-1 7-2 7-3 blending polymer PA PP PE binder polymer share 50 30 40

Weight (g / sqm) EN 29073 angel. 105 104 100

Thickness (mm) DIN EN ISO 9073-2 0, 15 0, 17 0.19

Air permeability 20cm ² / 50Pa (l / sqm / sec) DIN EN ISO 9273 31 46 69

Tensile strength / md (N) ASTM D 5034 274 324 299

Tensile strength / cd (N) ASTM D 5034 226 375 280

Elongation / md (%) ASTM D 5034 41 57 69

Elongation / cd (%) ASTM D 5034 45 55 72

3% w / w (N) ASTM D 5034 92 36 87

3% M / cd (N) ASTM D 5034 94 50 70

Tear strength / md (N) internal, 75 mm / 300 mm / min 69 101 152

Tear strength / cd (N) internal, 75 mm / 300 mm / min 68 91 148

Table 13: Embodiment 7, PE1 Γ / ΡΑ, PP and PE nonwoven Fe, PIE filaments, mech.

properties

Table 14: Porosity measurements according to ASTM 1294, working examples 7-1 to 7-3.

(Table 15: pore size distribution of the embodiments 7-1 to 7-3 according to ASTM 1294.) -> see Figure 4

Claims

claims 1. A process for producing a nonwoven fabric comprising at least a first  Polymer component, which is distributed in the form of elementary segments in a matrix of at least one second polymer component, comprising the following method steps: c) providing multi-component 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 zones over the cross section of Multi-component fibers is arranged, wherein  Both polymer components in the length direction of  Multicomponent fibers extend, 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 elementary segments; d) laminar joining of the multicomponent fibers by applying pressure and temperature such that elementary segments of the first polymer component are distributed in a matrix of the second polymer component. 2. A process for producing a nonwoven fabric according to claim 1, characterized in that the first polymer is in the form of 2, 3, 4, 5, 7, 8, 9 or 16 separable elemental segments in the multicomponent fibers. 3. A process for producing a nonwoven fabric according to one or more of the preceding claims, characterized in that the melting point of the first polymer component is at least 15 ° C above the melting point of the second polymer component. 4. A process for producing a nonwoven fabric according to one or more of  preceding claims, characterized in that the surface bonding of the multicomponent fibers by applying a  Temperature of 100 ° C to 300 ° C and a pressure of 40 N / mm to 150 N / mm is performed. 5. A process for producing a nonwoven fabric according to one or more of  preceding claims, characterized in that the surface bonding of the multi-component fibers is carried out by a preferably single-stage solidification with a pair of rollers, wherein at least one of the rollers of a surface roughness, measured according to DIN 4768 05.00 of 20-100 pm, preferably 20-70 pm and in particular of 30-50 pm. 6. A process for producing a nonwoven fabric according to one or more of  preceding claims, characterized in that as  Multi-component fibers PIE fibers, hollow PIE fibers, multilobal fibers or side by side fibers are used, which are composed of at least two polymers with different melting points. 7. nonwoven fabric, in particular formed as a base material for coating with films and / or for impregnation with binders, prepared by a method according to one or more of the preceding claims, characterized by a bending stiffness of 0.5 N / mm ² to 10 N / mm ² , measured according to DIN 53350 at a bending angle of 10% and / or a bending stiffness of 2 N / mm ² to 13 N / mm ² , at a bending angle of 40%. 8. A nonwoven fabric according to claim 7 characterized by an air permeability according to DIN EN ISO 9273 at 5 cm2 / 100Pa at a basis weight of 100 g / m2 of less than 120 l / m2 sec, preferably less than 110 l / m2 sec, more preferably less than 100 l / m 2 sec, more preferably less than 90 l / m 2 sec and in particular less than 80 l / m 2 sec 9. Nonwoven fabric according to claim 7 or 8, characterized by a  Machine direction / transverse direction ratio of the maximum tensile force according to EN 29073 T3 of 0.7 to 1.6, preferably 0.8 to 1.5, in particular 0.9 to 1.1. 10. Nonwoven fabric according to one or more of claims 7 to 9, characterized  characterized in that the proportion of the matrix in the nonwoven fabric in the range of 1 wt .-% to 60 wt .-%, preferably from 5 wt .-% to 50 wt .-%, in particular of 10 wt .-% to 40 wt .-% is. 11. Nonwoven fabric according to one or more of claims 7 to 1, characterized  in that elementary segments of a first polymer are present in the nonwoven fabric, which are circular segment-shaped in cross-section or  cake-shaped, circular or multilobal, which are distributed in a matrix of the second polymer component. 12. Use of a nonwoven fabric according to one or more of claims 7 to 11 for producing a composite material. 13. A composite material comprising at least one first layer, which contains a nonwoven fabric according to one or more of claims 7 to 11, and at least one second layer, preferably formed as a film. 14. Composite material according to one or more of the preceding claims, characterized in that the second layer as a film having a thickness of 0.01 mm to 1 mm, preferably from 0.05 mm to 0.5 mm, in particular of 0.1 mm is formed to 0.2 mm.