DE19983828T5 - Multi-component fine fiber webs and laminates thereof - Google Patents

Abstract

Nonwoven laminate that includes:
a first layer having a first side and a second side, said first layer comprising a nonwoven web of multicomponent fibers with a first polymeric component and a second polymeric component in separate zones across the cross-section of the fibers, which is substantially continuous along the Length of the fibers extend, said multicomponent fibers having an average fiber diameter of less than about 7 microns;
a second layer near the first side of said first layer, said second layer comprising a nonwoven web of endless fibers with an average fiber diameter greater than about 10 microns;
a third layer near the second side of said first layer, said third layer comprising a nonwoven web of endless fibers with an average fiber diameter greater than about 10 µm; and
the layers mentioned are connected to one another in such a way that they ...

Description

Territory of invention

The present invention relates on meltblown fiber webs and in particular on multicomponent meltblown fiber webs and laminates thereof.

background the invention

Multicomponent-spunbond fibers are fibers made from at least two polymer streams, which, however, are spun together to form a single fiber. The individual components that make up the multicomponent fiber are usually different polymers and they are in separate Zones or regions arranged continuously along the length of fibers extend. The configuration of these fibers can vary and usually are the individual components of the fiber in a side-by-side arrangement, in a shell / core arrangement, in a cake or wedge arrangement, in an island-in-sea arrangement or arranged in another configuration. Multicomponent fibers and Methods for their production are generally known and for example generally described in U.S. Patent 5,344,297 (Hills); by doing U.S. Patent 5,336,552 (Strack et al.) And U.S. Patent 5,382,400 (Pike et al.).

Generally, the procedures include for the production of spunbond fiber nonwoven webs, the extrusion of one melted thermoplastic polymer through a spinneret Quenching the filaments and then pulling out the quenched Filaments with a high speed air flow with formation arbitrarily arranged fibers on a collecting surface. For example, methods for Manufacture thereof in U.S. Patent No. 4,692,618 (Dorschner et al.), in the U.S. Patent No. 4,340,563 (Appel et al.) And in U.S. Patent No. 3,802,817 (Matsuki et al.). However, meltblown fabrics include one Class of melt-formed nonwoven fabrics that are different from the spunbond fiber webs. Meltblown fiber webs are used in the generally made by extruding a molten thermoplastic Material through a variety of fine, usually circular nozzle capillaries in the form of melted threads or filaments into high speed converging air streams make the filaments of the melted thermoplastic material thinner while reducing their diameter. After that, the meltblown fibers on a collection surface deposited to form a web of randomly distributed meltblown fibers. Meltblown fiber process are described, for example, in U.S. Patent 3,849,241 (Butin et al.); in U.S. Patent No. 5,160,746 (Dodge et al.); in U.S. Patent No. 4,526,733 (Lau); and described in others. Meltblown fibers can be endless (continuous) or finite (discontinuous) and they are generally thinner than about 10 microns in the average diameter. There are also meltblown fibers generally sticky when on a collecting surface or be deposited on another tissue.

Multicomponent meltblown fibers are earlier been made. For example, multi-component meltblown fibers were produced for the Forming a thermally deformable face mask, such as in U.S. Patent 4,795,668 (Krueger et al.). In corresponding Way is in the European Patent application No. 91 305 974.4 (publication No. 0 466 381 A1) a conjugate meltblown fiber web described for thermal Deformation to the shape of a filter cartridge is suitable. In addition, in U.S. Patent No. 5,935,883 (Pike) split, multi-component meltblown fibers and laminates thereof described for use in filter applications, Wipes, Personal care products and for other uses are suitable.

However, there is a need for multi-component meltblown fiber webs those for the production of nonwoven webs and laminates thereof different structures and / or improved physical Properties, for example in terms of softness, firmness, Uniformity, Peel strength and / or controlled barrier properties, used can be. Moreover there is a need for effective and economical processes for their manufacture.

Short Summary the invention

The above-mentioned needs are met and the problems identified by the person skilled in the art are eliminated with the nonwoven webs according to the invention which contain fine multicomponent fibers which have a first polymeric component and a second polymeric component which are arranged in separate zones within the fiber cross section and are located in the extend substantially continuously along the length of the fibers. The extruded multicomponent fibers which are randomly interwoven in the web have an average fiber diameter of less than 7 μm and comprise a first olefin-polymer component and a second amorphous olefin-polymer component. In one aspect, the first polymeric component comprises a crystalline propylene polymer and the second polymeric component comprises an amorphous propylene polymer. In addition, the nonwoven web can have a water pressure of more than 50 mbar and a Frazier air permeability of more than 2.7 m ³ / min / 0.09 m ² (100 ft ³ / min / ft ² ).

• (i) eine erste Nonwoven-Bahn aus Multikomponentenfasern, die eine erste polymere Komponente und eine zweite polymere Komponente in getrennten Zonen über den Querschnitt der Fasern aufweisen, die sich im wesentlichen kontinuierlich entlang der Länge der Fasern erstrecken, wobei die genannten Multikomponentenfasern einen durchschnittlichen Faserdurchmesser von weniger als etwa 7 μm haben;
• (ii) eine zweite Nonwoven-Bahn aus kontinuierlichen (endlosen) Fasern mit einem durchschnittlichen Faserdurchmesser von mehr als etwa 10 μm; und
• (iii) eine dritte Nonwoven-Bahn aus kontinuierlichen (endlosen) Fasern mit einem durchschnittlichen Faserdurchmesser von mehr als etwa 10 μm; wobei die erste Schicht zwischen der zweiten und der dritten Schicht angeordnet ist und wobei außerdem das Mehrschichten-Laminat einen Wasserstaudruck von mindestens 50 mbar, eine Frazier-Luftdurchlässigkeit von mehr als 1,89 m³/min/0,09 m² (70 ft³/min/ft²) und eine Becherzerknüllungsenergie von weniger als etwa 2150 g.mm aufweist.

In another aspect, the present invention relates to nonwoven web laminates comprising

• (i) a first nonwoven web of multicomponent fibers having a first polymeric component and a second polymeric component in separate zones across the cross-section of the fibers that extend substantially continuously along the length of the fibers, said multicomponent fibers having an average fiber diameter less than about 7 microns;
• (ii) a second nonwoven web of continuous (continuous) fibers with an average fiber diameter greater than about 10 microns; and
• (iii) a third nonwoven web of continuous (continuous) fibers with an average fiber diameter greater than about 10 microns; the first layer being sandwiched between the second and third layers and the multilayer laminate also having a water pressure of at least 50 mbar, a Frazier air permeability greater than 1.89 m ³ / min / 0.09 m ² (70 ft ³ / min / ft ² ) and has a cup crush energy of less than about 2150 g.mm.

The first layer expediently comprises a meltblown fiber web and the second and third layers include spunbond fiber layers. According to another aspect, the multi-layer laminate as well comprise a fourth layer, for example a one-component meltblown fiber web, which is adjacent to the first layer and also between the second and third Layer is arranged.

Short description of the drawings

The 1 FIG. 3 is a partially broken away view of a multi-layer nonwoven laminate containing a multi-component meltblown fiber web.

The 2 FIG. 3 is a partially broken away view of a multi-layer nonwoven laminate containing a multi-component meltblown fiber web.

The 3 FIG. 14 illustrates a cross-sectional view of a meltblowing die suitable for making multi-component meltblown fabrics.

The 4A Figure 3 is a schematic drawing illustrating the cross-section of a multicomponent fiber suitable for use in the present invention with polymer components A and B in a side-by-side arrangement.

The 4B is a schematic drawing illustrating the cross-section of a multicomponent fiber suitable for use in the present invention, with polymer components A and B in an eccentric sheath / core arrangement.

The 5 shows a schematic representation of an enlarged perspective view of a nozzle which is suitable for the practice of the invention.

The 6 shows a schematic representation of a cross-sectional view of the meltblowing nozzle, which is in the direction of arrows 102-102 in FIG 5 shows.

The 7 shows a schematic representation of a process plant which is suitable for the production of multicomponent meltblown web laminates; and

the 8th is a cross-sectional view of a multi-component meltblown fiber laminate according to the invention.

Description of the invention

The nonwoven webs according to the invention include arbitrarily interwoven webs made of fine multi-component fibers. The term "multi-component" refers to Fibers formed from at least two polymer streams and thus extruded that they form a uniform fiber. A specific one Type of multicomponent fiber is a bicomponent fiber that simply includes fibers with two different components. The individual components of a multicomponent fiber are in separate Areas arranged in the fiber cross section that are substantially continuous along the length extend the fiber. The nonwoven webs can be formed in such a way that the fibers are still sticky when they are deposited, and therefore be autogenously connected to each other at the fiber contact points. The integrity if necessary, the web can be improved by additional ones Binding levels, for example by an additional thermal, ultrasonic and / or adhesive binding. As a specific example, the fine multi-component fiber web on a variety of thermal Point bindings over the tissues are distributed, punctiform be thermally bonded.

The cross-sectional configuration of the multicomponent fibers can vary as desired. For example, the individual components of the fiber can be arranged in a side-by-side arrangement, in a sheath / core arrangement, in a striped or other desired configuration. The multicomponent fibers comprise at least two different cross-sectional components and they can comprise three or more components. As indicated above, the individual polymeric components together form the fiber cross section. For example, the 4A a specific embodiment of a bicomponent fiber with a side-by-side configuration in which the two Components are arranged adjacent to each other and each component occupies at least part of the circumference or the outer surface of the fiber. As another example, the 4B eccentric sheath / core configurations that can be used in connection with the invention. In eccentric shells / core fibers, one component completely surrounds or surrounds the other, but is arranged asymmetrically in the fiber. For bicomponent fibers, the respective polymer components can be present in volume ratios of approximately 90/10 to approximately 10/90 and are expediently in the range between approximately 75/25 and approximately 25/75. Ratios of about 50/50 are often particularly desirable, but the ratios used can vary as desired. In addition, the multicomponent fibers can also have various other fiber shapes than those of solid round fibers, for example hollow or flat (eg rib-shaped) fibers.

The multi-component meltblown fiber webs can also ruffled or non-crimped Contain fibers. The ripple can be created for multicomponent fibers by selecting polymeric components that have different load or elastic Have recovery properties and / or crystallization rates. Such multicomponent fibers can be crimped fibers with a helical shape ripple form, with a polymer essentially continuous on the The inside of the helix is arranged.

The multicomponent meltblown fiber web expediently has a basis weight between approximately 5 g / m ² and approximately 300 g / m ² and particularly advantageously between approximately 10 g / m ² and approximately 64 g / m ² . When used in a laminate structure, the meltblown fiber sheet conveniently has a basis weight between about 5 g / m ² and about 34 g / m ² . The respective basis weight varies with the specific use of the bicomponent meltblown fiber web and / or the corresponding laminate. For example, infection control products or medical tissue expediently comprise a multi-component meltblown fiber layer with a basis weight between approximately 12 g / m ² and approximately 25 g / m ² . In addition, the multicomponent meltblown fibers have a fiber diameter of less than approximately 10 μm and expediently they have a diameter between approximately 0.5 μm and approximately 7 μm and particularly expediently they have a fiber diameter between approximately 2 and approximately 5 μm.

The multicomponent meltblown fiber webs of the present invention can have excellent drapability and softness and, for example, multicomponent meltblown webs with a basis weight of about 34 g / m ² or less can have a cup crush energy value of less than about 150 g.mm and more conveniently less than about 100 g.mm. In addition, tissue softness can be achieved without the need for additional mechanical and / or chemical softening treatments. In addition, the multi-component meltblown fiber web can additionally have an excellent volume, an excellent air permeability and / or tensile strength. In one aspect, the multi-component meltblown fabrics of the present invention may include durable fabrics that have peak load values (%) of 40% or more and even greater than 50% in the machine direction. The multicomponent meltblown fibers can also result in a fabric with a large specific surface area that has a good filtration effect, while still achieving good air permeability. For example, multi-component meltblown fiber webs of 20 g / m ² (from 38 cm ² fabric) can have air permeability values of about 1.35 m ³ (50 ft ³ ) per min (CFM) or more, and even air permeability values of about 2, 7 m ³ / min or more (100 CFM). In addition, the multi-component meltblown fibers can have assisted water pressure values of more than about 50 mbar.

The polymeric components of the multi-component meltblown fibers can can be selected from thermoplastic polymers that are suitable for the Production of meltblown fiber webs, for example from polyolefins, Polybutylenes, polyamides, polyesters, polyurethanes, acrylates (e.g. Ethylene vinyl acetates, ethylene methyl acrylates and the like.), EPDM rubbers, Acrylic acids, Polyamide-polyether block copolymers, block copolymers of the general Formula A-B, A-B-A or A-B-B-A such as copoly (styrene / ethylene butylene); Styrene-polyethylene-propylene) -styrene, styrene-poly (ethylene-butylene) styrene as well as other polymers for use in meltblown processes are suitable. Mixtures and / or copolymers are also suitable above polymers for use in one or more components of the meltblown fiber. Moreover can highly amorphous polymers and / or sticky resins, which are usually used as adhesives, also as one or more Components of the multi-component fiber are used. For examples belong, without the invention being restricted to amorphous poly-α-olefins, such as ethylene / propylene copolymers, e.g. the REXTAC family of amorphous Poly-α-olefins from Huntsman Corp. and VESTOPLAST polymers from Creanova AKG.

For example, desirable combinations of polymers may include polyolefin / polyamide; Polyolefin / polyester; Polyolefin / polyolefin and the like. Examples of suitable polymer component combinations include, but are not limited to, polypropylene / polyethylene (for example conventional polypropylene / li near low density polyethylene, conventional polypropylene / polyethylene elastomer, polypropylene elastomer / polyethylene elastomer, polyethylene / ethylene / propylene copolymers and the like); Polypropylene / polypropylene (e.g. conventional polypropylene / amorphous polypropylene, inelastic polypropylene / elastic polypropylene, polypropylene / ethylene-propylene copolymers and the like); Polyethylene / nylon (e.g. polyethylene / nylon 6, polyethylene / nylon 6,6 and the like); Polyethylene / polyester (e.g. polyethylene / polyethylene terephthalate and the like). According to one aspect of the invention, the polymers which are the respective components of the multicomponent meltblown fiber can have a melting point which is different by at least 10 ° C and more expediently they can have a melting point which is different by at least about 20 ° C is. By selecting polymers with different melting points, it is possible to improve the bonding of the laminate structures without significantly deteriorating the fiber structure of the meltblown fiber web. This can be advantageous in terms of maintaining the desired level of porosity, the desired barrier properties and / or the pressure drop along the tissue thickness.

As a specific example, the Multicomponent meltblown fibers comprise a first component, which contains a first propylene polymer and a second component, which contains a second propylene polymer, the second propylene polymer has a narrow molecular weight distribution and a polydispersity number, which is lower than that of the first polypropylene polymer. The first propylene polymer can be, for example, conventional polypropylene and the second propylene polymer may be a polymer which catalyzed at a single site, or by a metallocene was catalyzed. The term "conventional polypropylene" used here means those by traditional catalysts such as Ziegler-Natta catalysts getting produced. Conventional polypropylene polymers essentially include crystalline polymers, e.g. those with traditional Ziegler-Natta catalysts are produced, and they usually have a polydispersity number, the bigger than is about 2.5. For example, conventional polypropylene available in the stores Exxon Chemical Company, Houston, Texas, under the Trade names ESCORENE. To exemplary polymers with a narrow Molecular weight distribution and a low polydispersity (compared with conventional polypropylene polymers) include those which are supported by “metallocene catalysts”, “single-site catalysts”, “catalysts forced geometry "and / or other comparable catalysts were catalyzed. Examples for such Catalysts and polyolefin polymers made therewith are those as described in U.S. Patent No. 5,451,450 (Elderly et al.); by doing U.S. Patent No. 5,204,429 (Kaminsky et al.); in U.S. Patent No. 5,539,124 (Etherton et al.); in U.S. Patent No. 5,118,768 (Job et al.); in U.S. Patent Nos. 5,278,272 and 5,272,236 (both Lai et al.); in U.S. Patent No. 5,554,775 (Krishnamurti et al.) and in U.S. Patent No. 5,539,124 (Etherton et al.); are described the entire content of which is expressly referred to here. Commercial usual Polymers made with such catalysts are available from Dow Chemical Company under the trade name ENGAGE, from DuPont-Dow under the trade name ENGAGE and from Exxon Chemical Company under the trade name ACHIEVE. As can use a specific example the multicomponent fibers comprise a first component made of one Propylene polymer with a polydispersity number of about 3 or higher and a second polymer component from a propylene polymer with a polydispersity less than about 2.5.

In another aspect, the multi-component fine fibers may include a first olefin polymer component and a second olefin polymer component, the second polymer having a lower density than the first olefin polymer. In addition, the first component may comprise a substantially crystalline polypropylene and the second component may comprise an amorphous polypropylene, ie a polypropylene polymer with a lower degree of crystallinity. The first component expediently has a crystallinity, determined by the heat of fusion (ΔH _f ), which is at least about 25 J / g higher than that of the second component, and particularly expediently it has a crystallinity which is at least about 40 J / g g is higher than that of the second component. As a specific example, the first component can comprise conventional polypropylene and the second component can comprise an amorphous polypropylene. In one aspect, the relative degree of crystallinity and / or polymer density can be controlled by the degree of branching and / or the relative percentage of isotactic, syndiotactic and atactic regions within the polymer. As indicated above, conventional polyolefins generally comprise essentially crystalline polymers and generally have a crystallinity of more than 70 J / g and particularly suitably a crystallinity of about 90 J / g or more. In one aspect, the amorphous propylene polymers suitably have a crystallinity of about 65 J / g or less. The degree of crystallinity or the heat of fusion (ΔH _f ) can be determined by means of DSC in accordance with ASTM D-3417.

Exemplary propylene-based amorphous polymers which are believed to be suitable for use in the present invention are described in U.S. Patent No. 5,948,720 (Sun et al.); in the U.S. Pa tent No. 5,723,546 (Sustic et al.); in European Patent No. 0 475 307B1 and in European Patent No. 0 475 306B1, the entire contents of which are expressly incorporated herein by reference. As further specific examples, the amorphous polymers based on ethylene and / or propylene expediently have densities between about 0.87 g / cm ³ and 0.89 g / cm ³ . However, various amorphous polypropylene homopolymers, amorphous propylene / ethylene copolymers, amorphous propylene / butylene copolymers and other amorphous propylene copolymers which are considered to be suitable for the invention are known. In this regard, stereoblock polymers are considered to be well suited for practicing the invention. The term "stereoblock polymer" refers to polymeric materials with controlled regional tacticity or stereo sequencing to achieve the desired polymer crystallinity. By controlling the stereo regularity during the polymerization, it is possible to achieve atactic-isotactic stereo blocks. Methods for making polyolefin stereoblock polymers are well known and are described in the following articles: G. Coates and R. Waymouth, "Oscillating Stereocontrol: A Strategy for the Synthesis of Thermoplastic Elastomeric Polypropylene" in "Science" 267, 217-219 (January 1995); K. Wagener, "Oscillating Catalysts: A New Twist for Plastics" in "Science" 267, 191 (January 1995). Stereoblock polymers and methods of making them are also described in U.S. Patent No. 5,549,080 (Waymoth et al.) And U.S. Patent No. 5,208,304 (Waymouth). As indicated above, by controlling the crystallinity of α-olefins, it is possible to produce polymers that have novel tensile modulus and / or elongation properties. Suitable commercially available polymers include, for example, those available from Huntsman Corporation under the trade name REXFLEX FLEXIBLE POLYOLEFINS.

In one embodiment, the first and second components each comprise different olefin elastomers. If both polymer components comprise elastomers, the resulting multicomponent meltblown fibers can have good stretching and recovery properties. As another example, the first component may comprise an inelastic polyolefin and the second component may comprise a polyolefin elastomer. For example, the inelastic polyolefin polymer can comprise conventional polypropylene and the polyolefin elastomer can comprise a stereoblock and / or amorphous polyolefin as stated above. Other resilient polyolefins that are considered suitable for use in combination with an inelastic polyolefin component include, but are not limited to, polyolefin elastomers supported by a "single center catalyst", "metallocene catalyst" or catalyzed a "constrained geometry catalyst". In this regard, specific examples of polymer combinations considered suitable for the present invention include conventional polypropylene with a polyethylene elastomer having a density below 0.89 g / cm ³ and more suitably having a density between about 0.86 g / cm ³ and about 0.87 g / cm ³ . Polyethylene elastomers can be made using metallocene or restricted geometry catalysts, and are generally described, for example, in U.S. Patent No. 5,322,728 (Davey et al.) And U.S. Patent No. 5,472,775 ( Obijeski et al.). In addition, a first component may comprise a linear low density polyethylene (which has a density of about 0.91 g / cm ³ to about 0.93 g / cm ³ ) and the second component may comprise a polyethylene elastomer. Furthermore, the first component can comprise a stereoblock polypropylene and the second component can comprise a polyethylene elastomer.

The multicomponent fibers can also include a first component, the propylene, for example conventional Comprises polypropylene and a second component comprising a propylene / ethylene copolymer, for example, a random copolymer of propylene and ethylene a lower proportion of ethylene. An exemplary propylene-ethylene random copolymer is commercially available Union Carbide Corp. under the designation 6D43, the contains about 3% ethylene. To further propylene / ethylene copolymers which are for the use according to the invention considered suitable include olefin multi-stage reactor products, in which an amorphous ethylene / propylene random copolymer in a predominantly semi-crystalline continuous matrix of a lot of propylene monomer / little ethylene monomer molecularly dispersed is. examples for such polymers are described in European Patent No. 400 333 B1 and in U.S. Patent No. 5,482,772 (Strack et al.) their entire content is expressly here Reference is made. Such polymers are commercially available from from Himont, Inc. under the trade name CATALLOY Polymers.

In another aspect, the first component may include a low melt flow rate (MFR) polyolefin and a second component may include an olefin polymer with a high melt flow rate. As a specific example, a bicomponent fiber can comprise a polyethylene, for example linear low density polyethylene, and the second component can comprise a polypropylene with an MFR of more than 800 g / 10 min at 230 ° C. As another example, the first component can be a polypropylene with a low melt flow rate that has an MFR of less than 800 g / 10 min at 230 ° C and the second component may comprise a high melt flow rate polypropylene having an MRF greater than 800 g / 10 min at 230 ° C. Polymers with a high melt flow rate and methods of making them are well known. For example, polymers with a high melt flow rate are described in U.S. Patent No. 5,213,881 (Timmons et al.), The entire contents of which are expressly incorporated herein by reference. The melt flow rate (MFR) can be determined before the polymer is melt processed, according to ASTM D 1238-90b, and the specific test conditions (ie, temperature) for each polymer may vary as described in the above test. The test conditions for polypropylene are 230 / 2.16 and for polyethylene they are 190 / 2.16.

In addition, the multi-component fibers comprise a first component comprising a first polyolefin, and a second component comprising a polyolefin blend. The polyolefin blend can be the same polyolefin or in part a different polyolefin than that contained in the first component. Besides, can the first polyolefin may be a different polymer blend include. As an example, the first component can be a conventional one Comprise polypropylene and the second component can be a mixture from a conventional polypropylene and an amorphous polypropylene include. As another example, the first component can be polypropylene and the second component may be a mixture of an identical one or similar Polypropylene and a propylene / butylene random copolymer. The propylene / butylene copolymer within a component expediently comprises about 0.5 to about 50% by weight the polymer mixture. An exemplary propylene / butylene random copolymer is a polymer available under the trade name DS4D05 available is from Union Carbide and contains about 14% butylene. As another example may include the first component polypropylene and the second component can be a blend of polyethylene and a propylene / butylene copolymer include. Moreover the first component can be a propylene / ethylene random copolymer and the second component may be a blend of polypropylene and a propylene / butylene random copolymer. Furthermore, the the first component comprise conventional polypropylene and the second Component can be a blend of a random copolymer of propylene and Include ethylene and a propylene / butylene random copolymer. The Identification of specific polyolefin-polymer blends mentioned above does not mean that the invention is limited to such combinations of polymers and / or mixtures thereof as for the present invention be considered suitable.

According to another aspect, the first component is a first inelastic or elastic polyolefin and the second component may be a non-polyolefin thermoplastic elastomer include. Appropriately can the first component is a first inelastic or elastic polyolefin and the second component may be a mixture of one Polyolefin and a thermoplastic non-olefin elastomer. Exemplary thermoplastic elastomers include elastomers, which are made from block copolymers of the general formula A-B-A ', where A and A 'each thermoplastic polymer end block represent a styrene residue, for example contains a poly (vinylarene) residue, and wherein B is an elastomeric polymer center block, for example from a conjugated diene or a lower alkene polymer. For example, an exemplary elastomer includes (polystyrene / poly (ethylene-butylene) / polystyrene) block copolymers, that of Shell Chemical Company under the trademark KRATON available and suitable polyolefin blends are described in U.S. Patent No. 4,663 220 (Wisneski et al.), The entire contents of which are described here expressly Reference is made. The elastomeric thermoplastic elastomers within the mixtures suitably comprise about 5 to about 95% by weight of the polymer portion of the component and more appropriately include them at least about 50% by weight of the polymer portion of the component.

Multi-component meltblown fibers can be made by extruding two or more polymer streams simultaneously through each opening of the meltblown die. Like in the 3 shown, can be in a meltblown nozzle 50 a distribution plate 52 used to maintain the separation of a first polymer stream from polymer A and a second polymer stream from polymer B until the polymers reach the nozzle capillary 54 to reach. The polymers are expediently fed through separate lines to the meltblown nozzle and are kept separate from one another until immediately before the extrusion. air plates 56 can a channel 58 , adjacent to the nozzle 50 generate the thinning air at the nozzle tip 55 past draws.

The molten polymer is released from the tip of the nozzle 55 extruded and extracted by the primary air flowing through the channels 58 moved in the direction of the associated arrows. Methods and devices for making multicomponent nonwoven webs are also described in U.S. Patent No. 3,425,091 (Ueda et al.); in U.S. Patent No. 3,981,650 (Page) and U.S. Patent No. 5,601,851 (Terakawa et al.).

Conventional meltblowing devices and methods maintain the primary air at a temperature above the melting point of the polymer. Thus, when a conventional meltblowing device is used, the Pri Mar air or the thinning air usually a temperature above the melting point of each of the polymers containing the individual polymeric components. However, as discussed in more detail below, the primary air or the thinning air may optionally be at a temperature above or below the melting point of one or more of the extruded polymers. The multi-component meltblown fibers and the resulting webs can be made using meltblowing techniques, such as those described in U.S. Patent 3,849,241 (Butin et al.); in U.S. Patent No. 5,160,746 (Dodge et al); in U.S. Patent No. 4,526,733 (Lau); in U.S. Patent No. 5,652,048 (Haynes et al.); in U.S. Patent No. 5,366,793 (Fitts et al.) and Naval Research Laboratory Report No. 4364 entitled "Manufacture of Superfine Organic Fibers" by V. Wente, E. Boone and C. Fluharty , the entire content of which is expressly referred to here. In addition, a melt spray device can also be used and / or used to make such multicomponent fibers, and an example of an exemplary melt spray device and method is generally described in U.S. Patent No. 4,949,668 (Heindel et al.) ; in U.S. Patent No. 4,983,109 (Miller et al.) and in U.S. Patent No. 5,728,219 (Allen et al.).

Conventional meltblown systems can be used to make multi-component meltblown fiber webs in accordance with the present invention and in these systems hot air is typically used to keep the fiber in the molten state and to pull the fiber out. However, as indicated above, a variety of combinations of polymeric components can be used in connection with the present invention and in this regard, quenching rates and other properties of these polymers are often advantageous to primarily the extruded multicomponent fibers because of the differences in melting points to be made thinner with "cold" air (to be pulled out) to the desired fiber diameter. The term "cold air" as used herein refers to air below the melting point of at least one of the polymeric components. In another aspect, multicomponent meltblown fibers can be thinned (drawn) primarily with air from a temperature below the melting point of the polymer component with the lowest melting point to the desired diameter. Once the meltblown fibers are thinned to the desired diameter, the process must allow the fiber to be quenched or cooled to solidify. Multi-component meltblown fibers can be made using a direct current hot air / cold air meltblown system in which only enough hot air is required to heat the nozzle tip used. In this regard, as in the 5 and 6 shown the pulling force on the fiber primarily from the cold air currents 104 provided while having just enough heated air from the secondary hot air streams 106 is provided to keep the fiber warm during extension. In this regard, the use of cold air can be immediately adjacent to the nozzle opening 111 cause the nozzle to become clogged as a result of polymer solidification. That is why the primary air 104 and the secondary air 106 Appropriately provided in such a ratio that more primary cold air than secondary hot air is used to provide the pull-out force for the formation of fibers. While the use of hot air can be minimized, a minimal amount of hot air is required to maintain the viscosity of the polymer at a level that is suitable for fiber pull-out. The total air flow (based on the total flow rate in kg (lbs.) Per 2.54 cm (1 inch) per hour) can consist of about 5 to about 80% hot air flow and about 20 to about 95% cold air flow. Conveniently, a hot air flow of about 20 to about 50% can be used, and more conveniently, a primary cold air flow of 70% and a secondary hot air flow of 30% can be used.

The fiber-forming polymer can be one nozzle device by means of various devices (not shown), for example a reservoir for the introduction a certain amount of fiber-forming thermoplastic polymer resins into an extruder driven by a motor, the die device supplied become. The polymers that represent the respective components are useful from each other separated until it reached the draw capillary to reach. A primary Flow of an extracting cold fluid with a temperature below the melting point of the respective polymers which are used to form the Fibers are used, is fed to a drawing nozzle by means of a blower and a secondary Flow of a heating fluid, preferably air, is fed to a drawing nozzle by means of a secondary fan. Generally the meltblown fibers emerge from the discharge opening of a drawing nozzle and are pulled out by the air flow (made thinner) and then open a continuous, moving perforated sieve (porous sieve) or Band collected on a nonwoven web. The fiber formation distance is thus the distance between the top surface of the collecting surface and the level of the discharge opening the nozzle. Moreover can, as is well known, collecting the drawn fibers supported on the belt by a suction box.

An exemplary embodiment for the fiber-forming section of a meltblown drawing nozzle is shown in FIG 5 represented schematically and gen mine by the reference number 100 designated. As shown, the fiber-forming portion of the die assembly comprises 100 a nozzle tip 110 , which is connected to the nozzle body (not shown) in a conventional manner. The nozzle tip 110 is generally in the form of a prism (usually an approximately 60 ° wedge-shaped block) that has a knife edge or opening 111 Are defined. The nozzle tip 110 is also bounded by a pair of opposing side surfaces 112 . 114 , The knife edge at the tip of the nozzle 110 forms the apex of an angle which is expediently in the range of approximately 30 to 60 °.

Like in the 5 shown, limits the nozzle tip 110 a polymer feed passage 130 that in further runs 132 ends that through the nozzle tip 110 are limited, which are usually referred to as capillaries. The capillaries 132 are single passageways with the opening 111 directly connected and generally along the length of the nozzle tip 110 run. A distributor (not shown) can carry polymer streams A and B substantially the entire length of the passageway 130 and the adjacent capillary 132 separate from each other. In the 6 showing an enlarged cross-sectional view of the nozzle tip 110 capillaries 132 generally have a diameter that is less than the diameter of the polymer feed passage 130 , As a rule, the diameters of all capillaries 132 same, so that a fiber with a uniform dimension is formed. The diameter of the capillaries 132 is in the 2 represented by the double arrows "d, d". A typical capillary diameter "d" is 0.037 cm (0.0145 inches). The length of the capillary 132 is in the 2 indicated by the letter "L". The capillaries 132 expediently have a length / diameter ratio of 10/1.

As for example in the 6 shown is the capillary 132 configured to pass the liquid polymer through the orifice 108 ejects as a liquid polymer stream, which is identified by the letter "P". The liquid polymer stream P emerges from the outlet opening 108 in the nozzle tip 110 and flows in a direction generally parallel to that of the capillaries 132 runs. In the 5 and 6 includes the fiber forming portion of the die assembly 100 first and second inner walls 116 which are generally opposed to one another to form a mirror image. The inner walls 116 are also known as "hot air plates" or "hot plates". As in the 5 and 6 are shown, the hot air plates 116 configured and arranged to be with the nozzle tip 110 cooperate, providing a first and a second secondary hot air flow duct 120 define. The secondary hot air ducts 120 are in relation to the nozzle tip 110 arranged so that the hot air flowing through the channels reaches the nozzle tip 110 envelops.

The secondary hot air ducts 120 are the channels along which a stream of hot air flows during use, so that the nozzle tip 110 can be maintained at a sufficiently high temperature to ensure that the polymer stream P is not prematurely quenched or solidified so that it can be extracted by the cold primary air. In addition, the hot air envelope prevents the cooperating secondary hot air ducts 120 is formed that the polymer at the tip of the nozzle 110 or solidifies and breaks near it. The first and second outer walls 118 are also referred to as "cold air plates" or "cold plates" and they are configured and arranged to match the outer surface of the hot air plates 116 cooperate with the formation of first and second primary cold air ducts 122 between. The route "R" over which the cold air plates 116 extend below the plane through the hot air plate 116 formed may vary, and in another aspect, the cold air plates may be parallel to (R = 0) or slightly above that by the hot air plates 116 formed level can be arranged. The first and second primary cold air ducts 122 are configured to take a substantial amount of the fluid flowing through the channels in a direction substantially parallel to the axis of the capillary 132 to steer. In other words, the direction of the fluid flowing through the first and second cold air channels can be broken down into a component stream that is generally parallel to the polymer stream through the capillary 132 runs.

The first and second primary cold air ducts are configured to communicate with a primary cold fluid source stand. The primary source of cold fluid is used one of each of the first and second primary cold air ducts primary forced fluid flow, preferably to supply air to the cold is opposite the secondary be called Air and opposite the molten polymer, i.e. has a temperature that is lower is considered at least one of the melting points of the meltblown process subjected polymers. Although this temperature at certain Arrangements can vary, they can range from about 25 up to about 150 ° C. The cold primary Air causes the extruded fiber to essentially pull out (made thinner) as well as being deterred.

The specific speeds of the cold air flow and the hot air flow depend on the size of the pull-out force required for the fibers, which varies depending on the respective polymer, the temperatures used and the like. In general, the speeds for the cold air flow and the hot air flow are approximately the same. However, there can be a difference of up to 20% between the speeds are present, the speed of the hot air flow is generally higher than the speed of the cold air flow. However, care should be taken to ensure that turbulence and fiber vibrations do not inhibit fiber formation when varying speeds are used. A more detailed description of the apparatus and methods for making meltblown fiber webs using cold air is described in U.S. Patent Application No. 08/994,373, filed December 19, 1997 (Haynes et al.), On the same entire content is expressly referred to here.

The fine fiber nonwoven webs according to the invention are also particularly well suited for use in multilayer laminates. As in 1 shown comprises a multi-layer nonwoven laminate 10 a multi-component meltblown fiber web 12 on a film-like layer 14 , for example a nonwoven web made of spunbond fibers is laminated on. According to a special aspect and as in 2 the multilayer laminate can be a three-layer laminate 15 include, for example, an intermediate layer of multi-component meltblown fibers 18 between a first spunbond fiber web 16 and a second spunbond fiber web 20 to form a spunbond / meltblown / spunbond (SMS) nonwoven laminate.

The film or the film-like material can be one or more layers of one material, for example a film, a nonwoven web, a gauze, a foam, one Include cloth (woven fabric) and / or other material. Expediently includes the film material is a thermoplastic polymer, for example a polyolefin, a polyamide, a polyester, a polyurethane and Mixtures and copolymers thereof. The film material can be stretchy or be non-stretch fabric and / or may be an elastic or include inelastic tissue. According to a preferred embodiment The invention is the multi-component meltblown fiber web on a film material attached, which comprises one or more nonwoven webs.

Under the expression "nonwoven fabric or -Bahn "is a material to understand that has a structure of individual fibers or threads, that are interwoven, but not on an identifiable one As with a knitted or knitted fabric or a fabric (Woven fabric). Nonwoven fabrics or webs are already after many Processes have been produced, for example using meltblowing processes, Spunbonding, hydroentangling, air-laid and bonded carded-rail processes. Other laminate structures and suitable materials for the production these will be discussed in more detail below discussed.

The film material can be produced in the system or unwound from an unwinding roll and fed to a multi-component meltblown nozzle, in order to thereby form the multi-component fibers directly on the film material. Meltblown fibers are often sticky when deposited and further bonding between the two layers may be unnecessary depending on the intended use or application in the laminate. However, it is often desirable to increase the peel strength of the laminate by additional bonding methods. In this regard, the cohesion between the layers can, if desired, be increased by one or more generally known measures, for example by connecting the layers to one another by thermal, ultrasound and / or adhesive bonding. For example, a slide 14 and a multi-component meltblown fiber web 16 be connected to one another in the form of a pattern, for example by punctiform connection. The term "point connection" used here means a connection of one or more layers of a fabric at numerous small discrete connection points. As a specific example, thermal point bonding generally involves passing one or more layers to be bonded together between heating rolls, for example an engraved or patterned roll and a second roll. The engraved roller is appropriately patterned so that the fabric is not bonded over its entire surface, and the second roller can be either smooth or patterned. As a result, various patterns for engraved rollers have been developed for both functional and aesthetic reasons. Conveniently the multilayer laminates are bonded together in a pattern so that the bonded area is less than 50% of the surface area of the fabric, and more desirably the bonded area should be about 5 to about 30% of the surface area of the fabric. Exemplary binding patterns and / or binding methods suitable for use in the present invention, but to which the invention is not limited, are those as disclosed in U.S. Design Patent No. 356,688 (Uitenbroek et al.) In U.S. Pat. U.S. Patent No. 4,374,888 (Bornslaeger), U.S. Patent No. 3,855,046 (Hansen et al.); in U.S. Patent No. 5,635,134 (Bourne et al.); and in U.S. Patent No. 5,858,515 (Stokes et al.) and PCT application US 94/03412 (publication No. WO 95/09261). Like in the 2 is shown, a multi-layer laminate 15 provided which has excellent peel strength, the outer layers 16 . 20 and the intermediate multi-component meltblown layer 18 at a variety of discrete connection points 13 connected to each other that are. Various methods of making multi-layer cohesive laminates are described in more detail below.

Multi-component meltblown web laminates e.g. an SMS laminate, expediently have excellent draping properties and accordingly low cup crumple values. The SMS laminates according to the invention can have a value for the Becherzerknüllungsenergie of less than 2150 g.mm and particularly desirable a value for the cup crumbling energy less than about 2050 g.mm. These cup crumple energy values can can be achieved without the need for additional perform mechanical and / or chemical softening processes. The meltblown fiber webs according to the invention and / or laminates can but also mechanical and / or chemically softened, e.g. in the U.S. patent No. 5,413,811 (Fitting et al.) And in U.S. Patent No. 5,810,954 (Jacobs et al.). Moreover can the SM and / or SMS laminates have excellent tensile strength and / or peel strength (i.e. excellent durability against delamination). In addition, the multi-component meltblown fiber webs and laminates made therefrom have good barrier properties, for example Water pressure values of more than about 50 mbar and even more than about 80 mbar. Furthermore, the fine multicomponent fiber webs and / or from them Laminates produced BFE (bacterial filtration efficiency) values of more than about 95% and particularly advantageously a BFE value of more than about 98% exhibit.

The multicomponent meltblown fiber web can be manufactured individually or in an inline process, such as in U.S. Patent No. 5,271,883 (Timmons et al.) And U.S. Patent No. 4,041,203 (Brock et al.). In it is like in 7 a method for producing a multilayer laminate is described, which comprises a series of nonwoven devices for producing a cohesive multilayer laminate 88 in a continuous inline process. One or more rows of spunbond devices 64 shed spunbond fibers 65 on a continuous perforated (porous) surface 62 from. A vacuum box can be placed below the educational surface 63 be arranged, which supports the formation of the web. Numerous spunbond fiber methods and devices are well known, such as those described in U.S. Patent No. 4,340,563 (Appel et al.), U.S. Patent No. 3,692,618 (Dorschner et al. ), in U.S. Patent No. 3,802,817 (Matsuki et al.), in U.S. Patent Nos. 3,338,992 and 3,341,394 (both Kinney), in U.S. Patent No. 3,502,763 (Hartman ), in U.S. Patent No. 3,542,615 (Dobo et al.) and in U.S. Patent No. 5,382,400 (Pike et al.). The spunbond fibers can be either crimped or uncrimped fibers. In addition, the spunbond fibers themselves can be single-component fibers, multi-constituent fibers, multi-component fibers or other fiber shapes. In a special embodiment of the invention, the spunbond fiber web formed by one or more spunbond devices can be a polyolefin fiber web with a basis weight between about 7 g / m ² and about 170 g / m ² and particularly advantageously between about 12 g / m ² and about 50 g / m ² . In addition, the spunbond fibers can expediently have a fiber diameter of less than approximately 50 μm and particularly advantageously of approximately 10 to approximately 25 μm. In one aspect of the invention, polyolefin spunbond fibers can include polypropylene spunbond fibers. According to a further aspect of the invention, the spunbond fibers can comprise multicomponent fibers. Exemplary multicomponent spunbond fiber nonwoven fabrics include, but are not limited to, those described in U.S. Patent No. 5,382,400 (Pike et al.); in U.S. Patent No. 5,622,772 (Stokes et al.); in U.S. Patent No. 5,695,849 (Shawver et al.); and in U.S. Patent Application No. 08/671,391 (Griesbach et al.), the entire contents of which are incorporated herein by reference. In one aspect, the spunbond fibers may at least partially include a similar and / or identical polymer so that it is one of the components of the multi-component meltblown fabric. In addition, the spunbond fiber may comprise a polymer having the same or a similar melting point as the polymer which is the lower melting component of the multicomponent meltblown fiber web.

The spunbond fibers 65 can on perforated (porous) surfaces 62 are deposited, which migrates in the direction of the associated arrows. The spunbond fiber layer 66 migrates in the formation of the surface 62 below a first line of multi-component meltblown fiber devices 70 over which multi-component meltblown fibers are deposited directly on the spunbond fibers. Below the educational surface 62 next to the meltblown device 72 can be a vacuum box 63 be arranged, which supports the formation of the meltblown fiber web. Polymers A and B can be separated from the reservoirs in pipelines 67 and 68 the meltblown device 70 are fed. If desired, one or more layers of meltblown fiber webs can be formed on top of one another. In the 7 are three consecutive meltblown devices 70 . 74 and 78 shown, each of layers of meltblown fibers 72 . 76 and 80 deposit. However, not every meltblown layer need be a multi-component meltblown layer, nor is it necessary for each layer to comprise the same combination of polymeric components. For example, one or more of the meltblown fiber layers can comprise different polymer combinations. However, each of the meltblown and spunbond fiber webs expediently has at least one essentially similar or identical polymer.

Subsequent to the deposition of meltblown fiber layers 72 . 76 and 80 can spunbond fibers 83 on the formation surface and especially on the top meltblown fiber web 80 are deposited to form a spunbond fiber layer 84 , If desired, one or more additional layers of spunbond or other fibers can be deposited thereon. In addition, the second spunbond layer 84 an identical, similar and / or a different material, based on the underlying spunbond fiber layer 66 , include. For example, one spunbond layer can be selected to give an excellent feel (feel) while the other can be selected to provide improved tensile strength, abrasion resistance, or other desirable properties.

The multiple layers can then be treated to increase the peel strength of the resulting laminate. The layers can be connected to one another by means of one or more devices known per se, for example by connection by thermal, adhesive and / or ultrasound bonding. Like in the 7 shown, the multiple layers through the gap 87 be passed through the first and second rollers 86A and 86B is formed to connect the multilayers of the fabric in a punctiform manner to form a multilayer laminate 88 ,

In connection with the in 7 The system shown can use various other conventional devices that are not shown for clarity. In addition, it is clear to the person skilled in the art that the respective method can be varied in several ways without thereby leaving the spirit and scope of the invention. For example, the individual layers of the laminate can be produced separately, stored on a roll and then unwound from it in order to be further processed as required. In the case of formation outside the plant or in a separate process, it can often be desirable for handling purposes to produce the meltblown layer on a carrier film, for example on a spunbond fiber web with a low basis weight.

As stated above, it is possible to incorporate meltblown fiber layers of different compositions into the laminate structure. For example, a first meltblown layer may comprise a one-component meltblown fiber web and the second meltblown fiber web may comprise a multicomponent fiber web. Thus, as a specific example, the first meltblown fiber web may comprise a one-component meltblown fiber web, as described in U.S. Patent No. 5,188,885 (Timmons et al.), The entire contents of which are expressly incorporated herein by reference and the second layer may comprise a polyethylene / polypropylene bicomponent meltblown fiber web. Such a layered composite meltblown fiber web can expediently be arranged between outer layers of polyolefin spunbond fiber webs. As an example and as in 8th shown comprises a multi-layer laminate 90 first and second outer spunbond layers 90A and 90B , wherein first and second multi-component meltblown fiber layers 92A and 92B are arranged in between. Between the two multi-component meltblown fiber layers 92A and 92B is a one-component meltblown fiber layer 94 arranged. This three-layer structure of the meltblown fiber webs can also be reversed, a one-component meltblown fiber web being arranged between two single-component meltblown fiber webs. According to another aspect, crimped multicomponent spunbond fiber webs can be used in combination with one or more single component meltblown fiber webs to create a filtration gradient. In this regard, the multi-component meltblown fibrous web can have a higher bulk and a larger average pore size than the one-component fibrous web. In this way, filter life can be improved because larger particles can be trapped upstream within the multi-component meltblown fiber web, while finer particles can be trapped downstream within the single-component fiber web.

Regarding the air filtration materials and Of the various medical tissues, it is often beneficial to use an electret from the multi-component meltblown fiber webs and / or the laminates thereof to provide the barrier properties of the tissue to improve. Process for the production of electret objects Polyolefin nonwoven webs are generally known, for example can the webs according to the invention and laminates are subjected to an electret treatment as in U.S. Patent No. 4,215,682 (Kubic et al.), U.S. Patent No. 4 375,718 (Wadswoth et al.) And U.S. Patent No. 5,401,446 (Tsai et al.).

In a further aspect, the multi-component meltblown fiber webs and / or the laminates thereof can be shaped into permanent three-dimensional shapes. The term "three-dimensional shape" as used herein means a fabric having dimensions in the X (length), Y (width) and Z (thickness) directions, each dimension of the molded fabric being greater than the thickness of the fabric bes itself. For example, a flat or sheet-like fabric that has been treated to have a permanent cup-like shape is a three-dimensionally shaped fabric if the permanent curvature of the fabric is such that the shaped article has a Z direction that is larger is than the thickness of the fabric. The three-dimensional shape of the pad can be achieved by one of several methods and, for example, the multi-component meltblown webs or laminates thereof can be brought into the desired shape by molding or thermoforming. The multicomponent meltblown fibrous web or a laminate thereof is expediently thermoformed in such a way that the good feel (feel) and softness are maintained, as described, for example, in US Pat. No. 5,695,376 (Pike et al.), whereby the entire content of the above-mentioned publications is expressly referred to here. The web or the laminate with a three-dimensional shape is expediently reversibly deformable, ie the object has a permanent three-dimensional shape that can be curved (bent) or deformed and which easily returns to its original three-dimensional shape when the deformation force is removed. For example, the multicomponent meltblown fiber webs and / or laminates thereof can comprise the shape of an article, such as a women's insert, a diaper insert, a face mask (protective masks) and the like.

The laminates according to the invention can be used be for or as a component in clothes, for example in industrial Work clothes, in undergarments, pants, shirts, jackets, gloves, Socks and the like can laminates according to the invention in infection control products, for example surgical gloves and towels, face or protective masks, Headgear, foot and shoe covers, Wound dressings, Bandages, sterilization covers, Wipes, patients linen and the like. Moreover can Laminates according to the invention in one or more different aspects as a component within personal care products, for example articles for the Personal hygiene, for example diapers, training pants, absorbent underpants, Adult incontinence products, feminine hygiene products and the like. be used. As specific, non-limiting examples of this, the Multi-component meltblown fiber webs and / or laminates thereof are used are associated with or in a manner as described in the following references: U.S. Patent No. 4,720,415 (Vander Wielen et al.); U.S. Patent No. 3,949,128 (Ostermeier); U.S. Patent No. 5,620 779 (Levy et al.); U.S. Patent No. 5,714,107 (Levy et al.), U.S. Patent No. 5,759,926 (Pike et al.); U.S. Patent No. 5,721,180 (Pike et al.); U.S. Patent No. 5,817,584 (Singen et al.); U.S. Patent No. 5,639,541 and U.S. Patent No. 5,811,178 (both Adam et al.); U.S. Patent No. 5 385,775 (Wright et al.); U.S. Patent No. 4,853,281 (Win et al.); European Patent Application No. 95 938 730.9 (Publication No. 0789612); European Patent Application No. 95 901 138.8 (publication no. 0729375). As further examples can on the multi-component meltblown fiber nonwoven webs several films are laminated, for example those like they in U.S. Patent No. 5,695,868 (McCormack); in the U.S. patent application No. 08/724,435, (McCormack et al.); filed on February 10, 1998, in the U.S. patent application No. 09/122,326 (Shawver et al.); filed on July 24, 1998, in U.S. Patent No. 4,777,073 (Sheth); and in U.S. Patent No. 4 867 881 (Kinzer) are described. The above list of applications of the multi-component meltblown fiber webs and laminates thereof not exhaustive and there are numerous additional ones Uses for the tissues of the invention.

In addition, various functional additives and Processing aids of one or more components of the multi-component fiber can be added as desired. For example, it is common to use thermal-oxidative Stabilizers, UV stabilizers, wetting agents, nucleating agents, pigments and / or other functional additives add to the fibers. Can also the multi-component meltblown fibers of one or more external Treatments are subjected to desired properties of the tissue to improve and / or lend it to him. For example, it’s common to use nonwoven fabrics with wetting agents, flame retardant agents, antistatic agents, odor control agents and the like. These treatments can be used in conjunction with the multicomponent meltblown fiber webs and laminates according to the invention of which can be applied as desired.

Testing

Frazier Luftddurchlässipkeit

This test determines the air flow rate a sample at a specified size of the surface and a set pressure. The higher the Airflow rate per given surface size and pressure is all the more open is the material so that it allows more fluid to pass through. The air permeability data given here were obtained using an air permeability tester TEXTEST FX 3300.

Hydrohead

A measure of the liquid shut-off properties of a fabric is the water pressure test. The dynamic pressure test determines the water level or the water pressure (in millibars) that the tissue withstands before it allows the liquid to pass through. A fabric with a higher water pressure value gives a better barrier against the ingress of a liquid than a fabric with a lower water pressure. The water pressure data given therein were obtained according to Federal Test Standard 191A, Method 5514, with the exception of the modification given below. Water pressure was determined using a hydrostatic water pressure tester available from Marl Enterprises, Inc., Concord, NC. The sample is exposed to a standardized water pressure that is increased at a constant rate until the first sign of leakage on the surface of the tissue occurs in three separate areas (an edge leak adjacent to the brackets is not taken into account). Materials not applied to a support, such as a thin film or a thin nonwoven, are applied to a support to prevent the sample from tearing prematurely.

drapability

The draping test measures the stiffness of a fabric or its durability against bending. The draping stiffness test determines the bending length of a Fabric using the principle of a cantilever bending of the fabric under its own weight. The length of the bend is a measure of the interaction between the weight of the fabric and the stiffness of the fabric. A 2.54 cm (1 inch) x 20.3 cm (8 inch) fabric strip is included at a speed of 12 cm / min (4.75 inch / min) in one direction parallel to its length dimension shifted so that its front edge protrudes beyond the edge of the horizontal surface. The length of the overhang is determined when the tip of the sample is under its own weight pressed down is going to a point where a line that is the top of the Fabric connects with the edge of the platform, with the horizontal forms an angle of 41.5 °. The longer the overhang the slower the sample was bent, indicating a stiffer Tissue indicates. The draping stiffness is calculated as 0.5 times the bend length. A total of 5 samples of each tissue should be tested. This procedure corresponds to the ASTM standard test D-1388 with the exception the above information. The test device used is a cantilever bending test device, Model 79-10, available from from Testing Machines Inc., 400 Bayview Ave., Amityville, NY 11,701th

tensile strenght

The tensile strength or peak load measures the maximum load (force in grams) before the sample breaks. A 10.16 cm x 15.24 cm (4 inch x 6 inch) sample is placed in a rubber coated clamp or clamp of 2.54 cm x 2.54 cm (1 inch x 1 inch) and one with Rubber-coated 2.54 cm x 5.08 cm (1 inch x 2 inch) large clip or clamp (with the longer dimension oriented perpendicular to the load) so that the machine direction (ie the direction in which the fabric is made) is clamped The sample is placed in the brackets so that there is a 7.62 cm (3 inch) gauge length The test can be performed with an 1130 Instron tensile tester (available from Instron Corporation, Canton , MA) and a crosshead speed of 30.48 cm (12 inches) / min and a 4.54 kg (10 lbs) load cell. The load at break is given in grams. The normalized tensile strength is calculated by dividing the tensile strength by the basis weight (in g / m ² ) and in grams / m ² . The peak stretch is the percentage of stretch at peak load.

Becherzerknüllung

The softness of a nonwoven fabric can be determined using the "cup crumple" test. In the cup crumpling test, tissue stiffness is determined by measuring the peak load or "cup crumpling" required by a 4.5 cm diameter hemispherical foot around a 25 cm x 25 cm piece of tissue that results in an inverted cup with a 6.5 cm in diameter and 6.5 cm in height, while the cup-shaped fabric is surrounded by a cylinder approximately 6.5 cm in diameter to maintain uniform deformation of the cup-shaped fabric. The average of 10 readings is used. The foot and cup are aligned to avoid contact between the cup walls and the foot that could affect readings. The peak load is measured in grams while the foot falls at a speed of 40.6 cm / min. The cup crumple test also gives a value for the total energy required to crumple a sample (the "cup crumble energy"), which is the energy from the start of the test to the peak stress point, ie the area under the curve is represented by the load in grams on one axis and the distance of the hike in mm on the other. The cup crumbling energy is therefore in g. mm specified. Lower cup crumpling values indicate a softer laminate. A suitable device for measuring the loading Sugar crumplings are a Sintech tensile device and a 500 g load cell using TESTWORKS software, all of which are available from Sintech, Inc., Research Triangle Park, NC.

Examples

example 1

The first and second polymers were melted and the respective melted polymer streams were passed separately through the drawing nozzle device until immediately before entering the drawing nozzle capillary. The first polymer comprised a linear low density polyethylene (DOW 6831A LLDPE) and the second polymer comprised conventional polypropylene (Montell PF015). The meltblown fibers were formed using a primary hot air stream at a temperature of about 226 ° C. The resulting bicomponent meltblown fiber had a side-by-side cross-sectional configuration and the first and second components each made up about 50 volume percent of the fiber. A meltblown fabric of 17 g / m ² (0.5 ounce / yd ² ) had a water back pressure on a support of 70 mbar and an air permeability of 1.86 m ³ (69 ft ³ ) per min per 0.09 m ² (ft ² ) on.

Example 2

The first and second polymers were melted and the respective melted polymer streams were passed separately through the drawing nozzle device until immediately before entering the drawing nozzle capillary. The first polymer comprised a linear low density polyethylene (DOW 6831A LLDPE) and the second polymer consisted of an amorphous polypropylene homopolymer (Huntsman 121 FPO). The meltblown fiber was formed using cold primary air at a temperature of about 27 ° C. The resulting bicomponent meltblown fiber had a side-by-side cross-sectional configuration and the first and second components each made up about 50 volume percent of the fiber. A meltblown fabric of 17 g / m ² (0.5 ounce / yd ² ) had a water pressure of 52 mbar on a support and a Frazier air permeability of 3.38 m ³ (125 ft ³ ) per min per 0.09 m ² (ft ² ).

Example 3

First and second polymers were melted and the respective melted polymer streams were passed separately through the die assembly until just before entry into the die capillary. The first polymer was a linear low density polyethylene (DOW 6831A LLDPE) and the second polymer was an amorphous polypropylene homopolymer (Huntsman 121 FPO). The meltblown fiber was formed using hot primary air at a temperature of about 226 ° C. The resulting bicomponent meltblown fiber had a side-by-side cross-sectional configuration and the first and second components each made up about 50 volume percent of the fiber. The meltblown fabric of 17 g / m ² (0.5 ounce / yd ² ) had a water back pressure of 51 mbar and an air permeability of 1.48 m ³ (92 ft ³ ) per min per 0.09 m ^{2 on a support} (ft ² ) on.

Example 4

First and second polymers were melted and the respective melted polymer streams were passed separately through the die assembly until just before entry into the die capillary. The first polymer consisted of an amorphous propylene polymer (Huntsman 120 FPO) and the second polymer consisted of crystalline polypropylene (Exxon 3505 polypropylene). The resulting bicomponent meltblown fiber had a side-by-side cross-sectional configuration and the first and second components each made up about 50 volume percent of the fiber. A 20 g / m ² (0.6 ounce / yd ² ) meltblown fabric had a peak load of 0.79 kg (1.74 lbs) and a peak elongation of about 56% in the machine direction and a peak load of 0.47 kg (1.04 lbs) and a peak elongation of about 83% in the cross machine direction.

Example 5

A first and a second polymer were melted and the respective melted polymer streams were passed separately through the die assembly until just before entry into the die capillary. The first polymer was linear low density polyethylene (DOW 6831A LLDPE) and the second polymer was conventional polypropylene (Motnell PF015 polypropylene). The resulting bicomponent meltblown fabric of 17 g / m ^{2 had} a side-by-side cross-sectional configuration and the first and second components each made up about 50% by volume of the fiber. The meltblown fabric was placed directly between two meltblown webs of bicomponent spunbond fibers. The bicomponent spunbond fibers were sheath / core (50/50) fibers made of polyethylene / polypropylene and each had a basis weight of 17 g / m ² . The three layers were thermally bonded to one another using a pattern, the bonds accounting for approximately 18% of the surface area of the fabric. The SMS laminate had a water back pressure of 66 mbar, an air permeability of 1.89 m ³ (70 ft ³ ) per min per 0.09 m ² (ft ² ), a cup crushing energy of 2032 g.mm and an average on a carrier Drapability of 1.74 cm in the cross-machine direction and 3.22 cm in the machine direction.

Summary

The present invention provides Multi-component fine fiber webs and multi-layer laminates made from them to disposal, which have an average fiber diameter of less than about Have 7 μm and a first olefin polymer component and a second, different ones Polymer component, for example an amorphous polyolefin or Polyamide. Multilayer laminates containing the multi-component fiber fine fiber webs, will also be available provided, for example spunbond / meltblown / spunbond laminates or Spunbond / meltblown / meltblown / spunbond laminates. The fine multicomponent fiber webs and the laminates thereof give laminates with an excellent one Softness, excellent peel strength and / or controlled permeability.

Claims (23)

A nonwoven laminate comprising: a first layer having a first side and a second side, said first layer comprising a nonwoven web of multicomponent fibers with a first polymeric component and a second polymeric component in separate zones across the cross section of the fibers, which extend substantially continuously along the length of the fibers, said multicomponent fibers having an average fiber diameter of less than about 7 µm; a second layer near the first side of said first layer, said second layer comprising a nonwoven web of endless fibers with an average fiber diameter greater than about 10 microns; a third layer near the second side of said first layer, said third layer comprising a nonwoven web of endless fibers with an average fiber diameter greater than about 10 µm; and wherein said layers are bonded together to form a multilayer laminate with a water pressure of at least 50 mbar, a Frazier air permeability of more than 1.89 m ³ (70 ft ³ ) per min per 0.09 m ² ( ft ² ) and a cup crumbling energy of less than 2150 g.mm. A nonwoven laminate according to claim 1, wherein said first layer a nonwoven web of autogenously connected Includes fibers. A nonwoven laminate according to claim 1, wherein said first layer comprises a nonwoven web of meltblown fibers. The nonwoven web laminate of claim 3, wherein the said second layer comprises a nonwoven web of spunbond fibers. A nonwoven laminate according to claim 4, wherein said second layer comprises a nonwoven web of spunbond fibers. The nonwoven web laminate of claim 5, wherein the said second layer and said third layer comprise bicomponent spunbond fiber webs. The nonwoven web laminate of claim 6, wherein at least a component in each of the first, second and third mentioned Layers comprises a propylene polymer and also said multilayer laminate a cup crumbling energy less than 2050 g.mm. The nonwoven web laminate of claim 6, wherein at least a component in each of the first, second and third mentioned Layers comprises an ethylene polymer and also said multilayer laminate a cup crumple energy less than 2050 g.mm. A nonwoven web laminate according to claim 5, wherein said laminate has a Frazier air permeability greater than 2.7 m ³ (100 ft ³ ) per minute per 0.09 m ² (ft ² ). The nonwoven web laminate of claim 5, wherein the first polymeric component of said multicomponent meltblown fiber web a propylene polymer having a crystallinity of more than 70 J / g and also the second polymeric component of the meltblown fiber web mentioned is an amorphous Poly-α-olefin with a crystallinity of less than about 65 J / g. The nonwoven web laminate of claim 5, wherein the said second and third spunbond layers are stretchable and Moreover introduced the first polymeric component of the multicomponent meltblown fiber web mentioned comprises elastic polyolefin and said second component the multi-component meltblown fiber web is an elastic polymer includes. The nonwoven web laminate of claim 11, wherein the called second component of the multi-component meltblown fiber web comprises an elastic polyolefin. The nonwoven web laminate of claim 11, wherein the second component of the multi-component meltblown fiber web one Mixture of a polyolefin and a thermoplastic non-olefin elastomer includes. The nonwoven web laminate of claim 11, wherein the second component of the multi-component meltblown fiber web elastic non-olefin thermoplastic elastomer. The nonwoven web laminate of claim 11, wherein the second component of the multi-component meltblown fiber web Block copolymer with a residual styrene end block and an elastomeric middle block includes. The nonwoven web laminate of claim 5, further comprising a fourth layer comprises a nonwoven web of one-component polypropylene meltblown fibers comprises and in the further the fourth layer between the said second layer and said third layer and adjacent is arranged to said first layer. The nonwoven web laminate of claim 16, wherein the first polymeric component comprises a crystalline propylene polymer and the second polymeric component is an amorphous propylene polymer includes. Nonwoven web that includes: a train of arbitrarily with each other intertwined extruded multi-component meltblown fibers, where the multicomponent fibers mentioned have an average fiber diameter less than about 7 μm have and a first olefin polymer component and a second include amorphous olefin polymer component. The nonwoven web laminate of claim 18, wherein the first polymeric component comprises a crystalline propylene polymer and the second polymeric component is an amorphous propylene polymer includes. The nonwoven web of claim 18, wherein the first polymeric component is a propylene polymer with a crystallinity of over 70 J / g includes and also the second polymeric component has an amorphous poly-α-olefin a crystallinity from below about 65 J / g. The nonwoven web of claim 20, wherein the second polymeric component comprises a propylene homopolymer. A nonwoven web according to claim 18, wherein said comprises first component polyethylene and said second component an amorphous poly-α-olefin with a crystallinity below about 65 J / g. The nonwoven web of claim 18, wherein said nonwoven web has a water pressure greater than 50 mbar and a Frazier air permeability greater than 2.7 m ³ (100 ft ³ ) per minute per 0.09 m ² (ft ² ) having.