Patent Application
20170130378
Priority is claimed to European Patent Application No. EP 15 193 633.3, filed on Nov. 9, 2015, the entire disclosure of which is hereby incorporated by reference herein.
The invention relates to the use of a nonwoven fabric made of continuous filaments to prevent the escape of down from a textile product filled with down, the continuous filaments having a titer of less than 0.15 dtex. The invention also relates to textile products filled with down and to methods for producing said products.
Down, also called down feathers, are feathers with a short quill and soft feather branches. Down is used in textile products, such as bedding, jackets or sleeping bags, as a filler for thermal insulation. The down is contained and enclosed here in covers made of flat textile fabrics. Textile products filled with down have to be “down-proof” in the provided use. This means that the down does not penetrate or even escape from the covers. As down feather quills are pointed and hard, the covers have to have a high degree of strength. Dense and strong woven fabrics are particularly suitable as covers. Woven fabrics consist of weft and warp threads woven into one another. Down quills, which are indeed pointed but are generally significantly larger than woven fabric threads and woven fabric meshes, cannot penetrate woven fabrics because the fibers cannot be adequately displaced in relation to one another. The down-proofness of woven fabrics can be tested by a standardized method according to DIN 12132-1.
In contrast to woven fabrics, textile nonwoven fabrics are not suitable as covers for filling with down. Even thick textile nonwoven fabrics are relatively easily penetrated by down. Because the fibers of conventional nonwoven fabrics are disordered and can therefore be displaced in relation to one another, down quills can easily penetrate them. The down-proofness of nonwoven fabrics can be achieved if they are thermally or chemically bonded over the surface. The fibers are then bound to one another in a similar way to in a woven fabric and can no longer be freely displaced in relation to one another. A surface bonding of this type is, however, unacceptable in textile applications, as it leads to disadvantageous properties, such as a low degree of softness and elasticity, low porosity and low air and moisture permeability linked therewith. Therefore, woven fabrics are generally used in the prior art for down fillings. Because it was assumed in the prior art that conventional nonwoven fabrics are unsuitable for filling with down, there is also no standardized method for nonwoven fabrics for measuring the down-proofness, which corresponds to DIN 12132-1 for woven fabrics.
However, it would be desirable to also make nonwoven fabrics usable for such applications because nonwoven fabrics specifically have many advantageous properties that distinguish them compared to woven fabrics, such as a high degree of softness, elasticity, stability, porosity, a high degree of air and moisture permeability, but also good availability and processability.
It is therefore proposed in the prior art to use nonwoven fabrics for storing down as a component of laminates. Thus, for example, JP2008/303480A proposes to use a composite material of a woven fabric with a nonwoven fabric. JP2006/291421A also discloses down-proof laminates containing thermally-bonded nonwoven fabrics. However, it is disadvantageous here that components are contained which are not specifically ideal nonwoven fabrics. Laminates are additionally relatively expensive to produce, also because the components have to be glued or otherwise rigidly connected to one another.
German utility model DE 203 10 279 U1 describes bedding covers made of microfiber nonwoven fabrics with good air permeability which offer protection against allergens and mites. The covers have characteristic advantageous mechanical properties for nonwoven fabrics, for example with regard to washability and stability. In the specification laid open to public inspection, it is moreover maintained that the microfiber nonwoven is down-proof. However no proof is provided for this. The microfiber nonwoven according to the embodiment of DE 203 10 279 U1 is a genuine nonwoven which was neither thermally bonded over the surface nor reinforced by other layers in a laminate. Therefore the fibers are displaceable in relation to one another in non-bonded regions and it is not credible to a person skilled in the art that a conventional nonwoven of this type is down-proof. It is rather to be assumed that this is simply claimed in DE 203 10 279 U1 because good impermeability in relation to allergens and mites was found and because down feathers have an approximately similar size. However, conclusions about the impermeability in relation to down can in no way be drawn from the impermeability in relation to allergens or mites. While allergens or mites are simply particles, down has a unique hard, pointed structure with barbs and easily bores through nonwoven fabrics.
The Applicant of the present invention has therefore tested whether the claim of DE 203 10 279 U1 is correct that such fine microfiber nonwoven fabrics are down-proof. DE 203 10 279 U1 has an “embodiment” in which, however, no information is given on the origin or the production of the nonwoven. The general information with regard to the composition of the microfiber nonwoven is also relatively superficial. The microfiber nonwoven fabric described therein corresponds, however, substantially to a product commercially available from Freudenberg, DE under the trade name Evolon 100, which was commercially available in 2003. The product with the trade name Evolon is produced from multi-component fibers of 16 microfibers per filament in a cake-shaped arrangement (PIE 16). As the single fibers are produced from cake-shaped segments, they have an angular cross-sectional profile, which is approximately similar to a triangle. The nonwoven fabrics are bonded by water jet treatment, the multi-component fibers being split into single filaments made of polyethylene terephthalate (PET) and a polyamide (PA). The fiber strength of the multi-component fibers is about 2.4 dtex and that of the single fibers after splitting is about 0.2 dtex and 0.1 dtex. Therefore, the nonwoven fabric Evolon 100 would even be finer than that described in DE 203 10 279 U1 with regard to the polyamide fiber component. However, it is to be assumed that a microfiber nonwoven fabric Evolon 100 from the Freudenberg company was described and investigated in the embodiment of DE 203 10 279 U1. In favor of this is that the information in the utility model substantially coincides with the Evolon 100 nonwoven fabric, that the product Evolon 100 was commercially available in 2003, and that no comparable product from other providers was commercially available in 2003. There is also no indication in the utility model that the Applicant of the utility model produced the product himself.
In order to check the claim of down-proofness made in DE 203 10 279 U1, the Applicant of the present invention has tested whether a microfiber nonwoven fabric of the trade name Evolon, which is comparable with a nonwoven fabric from the embodiment of DE 203 10 279 U1, is actually down-proof. It was established here according to expectation that a microfiber nonwoven fabric of this type has no adequate down-proofness. The microfiber nonwoven fabric does not pass the standardized cushion simulation test for down-proofness according to DIN 12132-1 (see embodiment of the present application: test with Evolon 120, coated with >15 g/m2 polyurethane or crosslinked polyacrylic binder on the inside of the down cover; with pure goose down and goose feathers of class I made of 90% down and 10% feathers according to EN12934). The test specification is actually used to investigate woven fabrics, but may be used analogously and without content modification for nonwoven fabrics. A corresponding standard for nonwoven fabrics is unavailable only because there was hitherto no need for this in the prior art, as nonwoven fabrics are basically not down-proof. Thus, the general expert knowledge could be confirmed, according to which nonwoven fabrics of this type are indeed impermeable to allergens, mosquito bites or mites, but not to down.
The Applicant has also microscopically investigated the effect of down quills on a microfiber nonwoven fabric of this type. The result is shown in
The lack of down-proofness of the microfiber nonwoven fabric according to DE 203 10 279 U1 agrees with the general specialist knowledge, according to which non-thermally bonded nonwoven fabrics, even when they consist of very fine fibers, are not down-proof. DE 203 10 279 U1 does not contain a teaching to overcome the known drawbacks of nonwoven fabrics with regard to the lack of down-proofness. Nonwoven fabrics known in the prior art were thus only suitable to store down if they were adequately thermally bonded or combined with other layers in laminates.
WO 01/48293 A1 relates to sleepwear made of a microfilament nonwoven fabric with a mass per unit area of 60 to 200 g/m3 and a particle retention capacity >90% for particles <0.5 μm. During the production of the nonwoven fabric, multi-component continuous filaments are at least 80% split into continuous microfilaments with a titer of 0.1 to 0.8 dtex and bonded.
WO 01/48293 A1 does not relate to the problem of preventing such pointed down penetrating through nonwoven fabrics. The “particles” are very fine nanoparticles, and specifically, house dust mites and their secretions. On the other hand, down is pointed and has lengths in the centimeter range. A good retention capacity for nanoparticles requires a very fine fiber network, but not a particular mechanical stability. It was therefore to be assumed that a very fine fiber fabric made of fibers that can be displaced in relation to one another is specifically not suitable for preventing the penetration of thin, pointed and comparatively large objects, such as by needles, down quills or mosquito bites. It was therefore generally assumed in the prior art that only particularly stable fiber products, such as textile woven fabrics, prevent the penetration of relatively large pointed objects.
In the context of the present invention, it was also experimentally confirmed that even nonwoven fabrics made of multi-component fibers, which, after splitting, have a considerable proportion of single filaments with a titer of about 0.1 dtex, are not readily down-proof (see above statements on DE 203 10 279 U1 and embodiments). Overall, a person skilled in the art would therefore not have assumed that nonwoven fabrics described in WO 01/48293 A1 could be down-proof.
An aspect of the invention provides a method of preventing escape of down from a textile product filled with down, the method comprising: spinning a nonwoven fabric comprising continuous filaments; depositing multi-component fibers to form a nonwoven; splitting the multi-component fibers into continuous filaments with a titer of less than 0.15 dtex; and bonding the nonwoven using mechanical bonding, comprising a fluid jet bonding, to form a nonwoven fabric, wherein the nonwoven fabric is being thermally or chemically bonded over its surface.
The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:
An aspect of the invention is to provide materials for storing down for textile applications, which solve the problems described above. In this case, textile products with good mechanical properties are to be provided to store down. The textile products should, in particular, have a high degree of softness and elasticity, porosity, air and moisture permeability, but at the same time be down-proof. The materials should be relatively easily available and the production method should as far as possible comprise no expensive processing steps, such as lamination or particular post-treatment steps. Overall, the material should both be able to be easily provided by the producer and be acceptable to a high degree to the user.
Surprisingly, an aspect of the invention is achieved by uses, textile products and methods according to the claims.
An aspect of the invention is the use of a nonwoven fabric made of continuous filaments to prevent the escape of down from a textile product filled with down, wherein the nonwoven fabric is obtainable by a spinning method, in which multi-component fibers are deposited to form a nonwoven, whereby the multi-component fibers are split into continuous filaments with a titer of less than 0.15 dtex, and the nonwoven is bonded by means of mechanical bonding, comprising a fluid jet bonding, to form a nonwoven fabric, the nonwoven fabric not being thermally or chemically bonded over the surface.
The use according to an aspect the invention takes place with a textile product filled with down. The textile product has a cover enclosing a hollow space, in which the down is contained and closed off from the surroundings. The nonwoven fabric forms the cover of the textile product or a part thereof. Nonwoven fabrics according to the definition of DIN 61 210 (Part 2, 1988) are textile fabrics made of loosely deposited fibers that are connected to one another by friction, cohesion or adhesion. The nonwoven fabric as a cover and barrier prevents the down from escaping from the textile product.
The nonwoven fabric consists of continuous filaments. The term “filaments” designates fibers, which, in contrast to staple fibers, are produced by a continuous method and thus deposited directly to form a nonwoven.
In the context of this application, the term “down” designates down feathers of birds, which are suitable for textile fillings. A definition of down is given in DIN 12934. Down is in particular feathers with a short quill and long feather branches arranged in a jet shape. Down also regularly has less hooks than other feathers. Because of its high degree of elasticity and dimensional stability in conjunction with heat-insulating properties, down is used for a large number of textile applications.
The use according to the invention takes place to prevent the escape of down from a textile product filled with down. In textile products of this type, the down filling is contained in a cover separating it from the surroundings. The term “escape” designates each movement of the down, in which the cover is penetrated. In this case, the down may penetrate the cover only partially or completely. Thus, the term “escape” comprises feather quills of down drilling through the cover only with a part of the tip and remaining stuck therein, or they may completely penetrate the cover and leave the textile product.
The down-proofness is preferably determined according to the simulated cushion stress test of DIN EN 12132-1, part 1, in which the nonwoven fabric is used instead of a woven fabric. The nonwoven fabric preferably passes the test according to DIN EN 12132-1, which means that no more than 20 particles escape in every tested direction (longitudinally and transversely), in other words stick in the textile material or have penetrated this material. An average value of a plurality of single measurements is preferably assessed here, for example 5, 10 or 20 single measurements. In particular, no more than 15 particles escape in the test, in particular no more than 12 particles.
In a preferred embodiment, the nonwoven fabric contacts the down filling directly. This means that no further layer is present between the nonwoven fabric and the down. The down touches the nonwoven fabric and would penetrate it if the down-proofness was inadequate. In this case, the nonwoven fabric is preferably used as a textile cover, in which the down is contained. This means that the nonwoven fabric forms the cover per se. It is thus not a component of a laminate with other further layers. If, in other words, the textile product is, for example, an item of bedding, the nonwoven fabric would enclose the down. According to the invention, it was found that, surprisingly, a nonwoven fabric per se made of fibers with a titer <0.15 dtex, without the need for a thermal bonding or a lamination with further layers, in particular woven fabric layers or stronger nonwoven layers, can prevent the escape of down.
Multi-component fibers are filaments of at least two different parallel continuous filaments, which have a phase limit and are connected to one another such that they can be split. The multi-component fibers are split into continuous filaments with a titer of less than 0.15 dtex. Thus, the continuous filaments have a titer <0.15 dtex. This means that the nonwoven fabric as a filament component substantially or exclusively has filaments with a corresponding titer. Nonwoven fabrics of this type may have smaller local regions, in which multi-component fibers have not been split or have been split only incompletely. With an adequate mechanical split, in particular by means of water jet treatment, nonwoven fabrics can, however, be obtained, which virtually exclusively consist of single filaments. Preferably, at least 80%, in particular at least 90%, at least 95%, at least 98% or about 100% of filaments are present, based on the total volume of the fibers. The proportion may be determined microscopically by investigation of randomly selected sections of a nonwoven fabric.
In a preferred embodiment, the splitting takes place into continuous filaments with a titer of less than 0.14 dtex, still more preferably less than 0.12 dtex or less than 0.11 dtex. The titer is preferably greater than 0.01 dtex or greater than 0.025 dtex. In particular, the titer of all the continuous filaments is preferably between 0.01 dtex and 0.15 dtex, preferably between 0.02 dtex and 0.12 dtex or between 0.03 dtex and 0.11 dtex. In particular, the average titer of the continuous filaments is between 0.01 dtex and 0.15 dtex, preferably between 0.025 dtex and 0.125 dtex, in particular between 0.03 dtex and 0.11 dtex.
In a preferred embodiment, the nonwoven fabric contains, as a continuous filament component, a filament mixture, in particular of two or three different filament types. For example, it is preferred for there to be two or more continuous filament types of different titers. Multi-component fibers containing continuous filaments of different degrees of fineness made of various polymers are preferably used. In a preferred embodiment, the nonwoven fabric contains at least two components and continuous filaments here, which have a titer of less than 0.075 dtex, preferably less than 0.065 dtex. The titer of a first fiber component is preferably between 0.80 dtex and 0.15 dtex, preferably between 0.80 dtex and 0.125 dtex, and the titer of a second fiber component is preferably between 0.01 dtex and 0.075 dtex, preferably between 0.02 dtex and 0.065 dtex. The difference in the titers of the two components preferably differs in each case by at least 0.02 dtex. In particular by an addition of this type of a second, particularly fine fiber component, an advantageous combination of down-proofness and stability can be achieved. The proportion of fibers with the lower titer is preferably at least 5 vol. % or at least 10 vol. %, in particular at least 20 vol. %. The number of fiber strands of the first and second fiber component is preferably the same. If the titer of the first fibers is twice as high as that of the second fibers, volume ratios of about 2:1 are obtained, in other words approximately 70:30.
It was surprisingly found that relatively thin and light nonwoven fabrics with a relatively low mass per unit area also withstand the down. This was unexpected because the down quills are relatively hard and pointed and in conventional uses exert relatively strong forces on the nonwoven fabric, for example if they are pressed into a cushion cover. Without being bound to one theory, it is assumed that the down in a closely interlaced nonwoven fabric, from reaching a threshold value of the fiber fineness, is no longer in a position to displace the individual filaments in relation to one another and to penetrate the nonwoven fabric. When this threshold value is reached, a thin nonwoven fabric is also sufficient for bringing about the down-proofness. On the other hand, a relatively dense nonwoven fabric is also unsuitable above the threshold value to prevent the escape of down. Without being bound to one theory, it is assumed that the down-proofness is not only achieved by the fine fibers, but also by the particular production method with mechanical splitting up of multi-component fibers, by means of which a particularly dense and homogeneous mixing and interlacing of the filaments is achieved.
In a preferred embodiment, the nonwoven fabric has a mass per unit area of 70 g/m2 to 200 g/m2. In a preferred embodiment, the nonwoven fabric has a mass per unit area of 90 g/m2 to 180 g/m2, in particular of 100 g/m2 to 160 g/m2 or of 110 g/m2 to 150 g/m2. The mass per unit area is preferably at least 70 g/m2 or at least 90 g/m2, particularly preferably at least 110 g/m2, in order to ensure a high mechanical stability and down-proofness. The mass per unit area is preferably no greater than 200 g/m2, no greater than 160 g/m2 or, in particular, no greater than 160 g/m2, in order to achieve an adequate porosity, linked with air and moisture permeability.
A nonwoven fabric with two fiber components, preferably made of split bi-component fibers is particularly preferred, the titer of a first fiber component being between 0.08 dtex and 0.15 dtex and the titer of a second fiber component being between 0.01 dtex and 0.075 dtex, the proportion of fibers with the lower titer being at least 10 vol. %, in conjunction with a mass per unit area of 70 g/m2 to 200 g/m2, in particular of 90 g/m2 to 180 g/m2.
The nonwoven fabric is obtainable by a spinning method, in which multi-component fibers are deposited to form a nonwoven, whereby the multi-component fibers are split into the continuous filaments and the nonwoven is mechanically bonded to form a nonwoven fabric. Using production methods of this type, a particular inner structure of the product is achieved. The continuous filaments have irregular cross sections caused by the splitting process. The single filaments are interlaced with one another particularly closely.
The multi-component fibers were preferably produced by melt spinning. In melt spinning, thermoplastic polymers are melted and spun to form fibers. This method allows particularly simple and reliable production of nonwoven fabrics made of multi-component fibers.
The multi-component fibers preferably have two, three or more different continuous filaments. The multi-component fibers are particularly preferably bi-component fibers.
When splitting multi-component fibers, single filaments are generally obtained, which have cross sections with corners or edges. This is advantageous as the single filaments are more poorly movable in relation to one another. It is assumed that the down-proofness is thereby improved.
In a preferred embodiment, the multi-component fibers, in particularly the bi-component fibers, have a cake-shaped (orange, “PIE”, pie) structure. The structure preferably has 24, 32, 48 or 64 segments. During splitting, the multi-component fiber disintegrates into a corresponding number of individual continuous filaments (single filaments). The segments preferably contain alternating polymers here. Also suitable are hollow pie structures, which may also have a hollow space running axially asymmetrically. Pie structures, in particular hollow pie structures, are advantageous because they can be split particularly easily. The single filaments moreover have an irregular cross section, which increases the inner strength of the nonwoven fabric. The term “cake” or “pie”, in the case of such very fine, split fibers, actually describes the design of the spinning nozzle, but only approximately describes the actual cross section of the filaments. Multi-component fibers are particularly preferably in a cake shape of at least 32 segments, and in particular precisely 32 segments, no other fiber component being added. Structures of this type are obtainable in the prior art and can be processed uniformly and easily. The mass per unit area here is preferably at least 110 g/m2.
The fiber-forming polymers of the multi-component fibers are preferably thermoplastic polymers. The multi-component fibers preferably have components selected from polyesters, polyamides, polyolefins and/or polyurethanes. Bi-component fibers with a polyester component and a polyamide component are particularly preferred.
In order to obtain easy splitability, it is advantageous if the multi-component fibers contain continuous filaments of at least two thermoplastic polymers (in different components). The multi-component fibers preferably comprise here at least two incompatible polymers. Incompatible polymers are to be taken to mean polymers of the type which in combination produce pairings that do not adhere or adhere only to a limited extent or poorly. A multi-component fiber of this type has good splitability into elementary filaments and allows an advantageous ratio of strength to weight per unit area. Preferably used as incompatible polymer pairs are polyolefins, polyesters, polyamides and/or polyurethanes in a combination so that pairings are produced that do not adhere or adhere only to a limited extent or poorly.
Polymer pairs with at least one polyamide or with at least one polyester, in particular polyethylene terephthalate, are preferably used because of their limited adhesion. Polymer pairs with at least one polyolefin are preferably used because of their poor adhesion.
Combinations of polyesters have proven to be particularly preferred, preferably polyethylene terephthalate, polylactic acid and/or polybutylene terephthalate, with polyamides, preferably polyamide 6, polyamide 66, polyamide 46, optionally in combination with one or more further components in addition to those mentioned above, preferably selected from polyolefins. These combinations have excellent splitability. More particularly preferred are combinations of polyethylene terephthalate and polyamide 6 or of polyethylene terephthalate and polyamide 66.
Also preferred are polymer pairs containing at least one polyolefin, in particular in conjunction with at least one polyester or polyamide. Preferred examples here are polyamide 6/polyethylene, polyethylene terephthalate/polyethylene, polypropylene/polyethylene, polyamide 6/polypropylene or polyethylene terephthalate/polypropylene.
In a preferred embodiment, the volume ratio of the first to the second continuous filaments is between 90:10 and 10:90, preferably between 80:20 and 20:80.
The average cross-sectional area of the filaments could be less than 15 μm2 or less than 10 μm2. The cross-sectional area of cut filaments may be determined microscopically. The diameter of the continuous filaments may theoretically be determined from the titers taking into account the densities, information about the fiber diameters being not very significant in the case of angular filaments.
Suitable multi-component fibers for producing continuous filaments by means of splitting are known in the prior art. The production of multi-component fibers of this type is inter alia described in FR 2 749 860 A or DE 10 2014 002 232 A1. To produce spun nonwoven fabrics of this type, a spun nonwoven system with the trade name Reicofil 4 from Reifenhäuser, DE may be used, for example.
The polymers form the fiber-forming component of the fibers. The fibers may moreover contain conventional additives. Additives are regularly added to fiber polymers of this type to modify the processability during production or the properties of the fibers. The use of additives also allows adaptation to customer-specific requirements. Suitable additives may, for example, be selected from the group consisting of dyes, antistatic agents, antimicrobial active ingredients, such as copper, silver or gold, hydrophilic agents or hydrophobic agents. These may, for example, be contained in a quantity of up to 10 wt. %, up to 5 wt. % or up to 2 wt. %, in particular between 150 ppm and 10 wt. %.
The nonwoven fabric was mechanically bonded. The mechanical bonding comprises a fluid jet bonding. In mechanical bonding methods, such as fluid jet bonding, the connection of the fibers is produced by frictional fit or by a combination of frictional fit and form fit. The bonding preferably takes place by the close mixing of the filaments. A nonwoven fabric can thus be obtained with advantageous softness and elasticity in conjunction with good porosity. Surprisingly, an adequate down-proofness is obtained, although the individual fibers are actually displaceable in relation to one another. The multi-component filaments are preferably also split into continuous filaments during the mechanical bonding.
The fluid jet bonding takes place under the effect of pressure and fluids. The bonding takes place here by treatment with pressurized fluids, in particular liquids or gases. The mechanical bonding can take place additionally by further methods, such as pressing, in particular by calendering. The splitting of the multi-component fibers preferably takes place simultaneously during the fluid jet bonding. In this case, the bonding is carried out for long enough and with adequate strength. The multi-component filaments are preferably split into continuous filaments during the fluid jet bonding. A suitable combination with further mechanical bonding methods may also be carried out to split up the multi-component fibers completely or at least as far as possible. A thorough mixing and interlacing of the single filaments is simultaneously achieved.
The bonding comprises a fluid jet bonding. The fluid is preferably a liquid, in particular water. A water jet bonding is therefore particularly preferred. In comparison to other fluids, water is preferred because it does not leave any residues, is easily available and the nonwoven fabrics can be dried well. A deposited nonwoven is subjected to a water jet under high pressure here, whereby the nonwoven is, on the one hand, compressed to form a nonwoven fabric and, on the other hand, multi-component fibers are split into single filaments. It was found that a water jet bonding is particularly suitable to achieve a thorough interlacing of the continuous filaments, whereby good mechanical properties are achieved and the down-proofness is also improved. The mechanical bonding, in particular the water jet bonding, is carried out here in such a way that the microfilaments are not, or not too greatly, impaired. When the water jet bonding of fine filaments of this type is too strong, the mechanical stability and in particular the tear resistance (tear strength) may reduce here. The nonwoven fabric preferably has a tear resistance according to DIN EN 13937-2 of 4 to 12 N, in particular of 5 to 12 N or of 6 to 10 N.
In addition to the fluid jet bonding and in particular water jet bonding, further mechanical bonding steps can be carried out. Thus a bonding can take place, for example, by needling and/or calendering. In a preferred embodiment, a prebonding takes place by means of needling and/or calendering, followed by a water jet bonding. The calendering takes place at an adequately low temperature, so no thermal bonding takes place with adhesion of the fibers.
The nonwoven fabric was not thermally bonded over the surface. This means that it was not continuously, in other words over the entire nonwoven surface, subjected to a heat treatment, in which fibers or a hot-melt adhesive are softened so much that fibers adhere to one another. The thermal bonding of fibers takes place by material bonding, wherein the fibers are connected by adhesion or cohesion. A nonwoven fabric without thermal bonding is advantageous as the softness and elasticity are retained. In thermal bonding, on the other hand, the mechanical properties change significantly and in a manner that is disadvantageous for textile applications. In particular, the nonwoven fabric becomes more rigid, in other words less elastic and soft, and less porous, so the air and moisture permeability decrease.
The nonwoven fabric was not chemically bonded over the surface. This means that the fibers were not connected to one another by a chemical reaction and, in particular, not cross-linked with a binding agent. No covalent bindings between fibers were produced.
In one embodiment, the nonwoven fabric could be thermally and/or chemically bonded only in portions (locally). A local bonding in portions, which are uniformly distributed over the nonwoven surface, could increase the stability. The bonding may, for example, take place in the form of a point pattern. In order to obtain the advantageous typical nonwoven fabric properties, at most a small part of the nonwoven fabric should be bonded, however, for example less than 30%, less than 10% or less than 5% of the total area. The down-proofness is also provided here in the non-bonded regions. The local thermal bonding is not used and is not necessary to achieve the down-proofness. However, according to the invention, it is preferred for the nonwoven fabric to not be thermally or chemically bonded at all. This means that no thermal or chemical bonding took place to improve the stability of the nonwoven material per se in the surface. As a result, the advantageous nonwoven fabric properties are completely retained. The fact that the nonwoven fabric has sealing seams, glued seams or similar regions that are used for processing to form a textile product is, of course, not an obstacle to this.
The nonwoven fabric can be post-treated by conventional methods after bonding, for example by drying and/or shrinking. The nonwoven fabric is then formed into a cover, in which the down is incorporated and enclosed.
In a preferred embodiment, the multi-component fibers have a cake-shaped (orange-shaped) structure and are split into continuous filaments with a titer of less than 0.12 dtex, the mechanical bonding comprising a water jet bonding and the nonwoven fabric having a mass per unit area of 70 g/m2 to 200 g/m2. Bi-component fibers, in particular made of a polyester component and a polyamide component, are preferably used here.
In a preferred embodiment, the nonwoven fabric has an average pore size of 5 μm to 20 μm and/or a maximum pore size of 10 μm to 50 μm, measured with a pore size measuring instrument PSM 165 from TOPAS, DE, according to the information from the producer in conformity with ASTM E 1294-89 and ASTM F 316-03.
The thickness of the nonwoven fabric is preferably between 0.20 mm and 0.60 mm, in particular between 0.25 mm and 0.50 mm, measured according to DIN EN 964-1.
The maximum tensile strength (maximum tensile force) in all directions is preferably at least 150 N/5 cm, measured according to EN 13934-1. The maximum tensile elongation in all directions is preferably at least 20%, preferably at least 30%, measured according to DIN EN 13934-1.
The nonwoven fabric is preferably distinguished by very good water absorption. This is preferably at least 250 ml/m2, in particular more than 350 ml/m2 measured according to DIN 53923 in analogy for nonwoven fabrics.
The down-proofness is preferably also retained during relatively long use and conventional mechanical stress. It was found that the down-proofness is retained when the nonwoven fabric is frequently washed. The nonwoven fabric is preferably also down-proof after 5, 10 or 20 domestic washes according to DIN EN ISO 6330 in the sense of DIN EN 12132-1.
The air permeability according to EN ISO 9237:1995-12A is preferably at least 20 mm/s, preferably at least 30 mm/s, measured with a test area of 20 cm2 and a differential pressure of 200 Pa, preferably with an average of 10 or 50 single measurements.
Particularly preferably, the nonwoven fabric has a mass per unit area of 90 g/m2 to 160 g/m2, an air permeability according to EN ISO 9237:1995-12A of at least 20 mm/s and a tear resistance according to DIN EN 13937-2 of 4 to 12 N. According to the invention, it is advantageous for the down-proofness to be able to be achieved with very fine fibers and relatively low masses per unit area, so adequate air permeability for textile applications is achieved.
The nonwoven fabric preferably has at least 12,000 km/m2 single filaments per unit area, particularly preferably at least 13,500 km/m2 or at least 15,000 km/m2. The number of single filaments per unit area can be calculated from the determined mass per unit area and the fineness of the single filaments (in dtex), it being assumed that the multi-component fibers are completely split open. It was found that by setting such a relatively high filament number per area with very fine fibers, a high down-proofness can be achieved.
Overall, it is particularly preferred to harmonize the following properties of the nonwoven fabric with one another:
The nonwoven fabric preferably contains continuous filaments here having a titer of less than 0.075 dtex or consists of fibers of this type. Particularly preferably, the nonwoven fabric consists here of 32 PIE multi-component fibers or contains fibers of this type.
As stated above, the nonwoven fabric is per se suitable for the use according to the invention. Regardless of this, it is conceivable to reinforce the nonwoven fabric with further textile layers. Thus, the use according to the invention may take place, for example, of a laminate of the nonwoven fabric with at least one further layer, for example one or two further layers. In this case, it is preferred for the nonwoven fabric to directly adjoin the down and thereby form a barrier. The nonwoven fabric could be provided on the outside remote from the down with at least one further layer which gives the laminate further desired properties, such as moisture protection or increased mechanical strength. However, in a laminate of this type as well, the purpose of use, in other words achieving the down-proofness, is achieved by the nonwoven fabric per se, which forms the physical barrier for the down. Additional layers, in particular on the outside, are preferably applied for a different purpose, in other words they do not improve or only insubstantially improve the down-proofness.
The subject of the invention is also a textile product filled with down, in particular selected from bedding, a jacket, padding, mattress or sleeping bag, comprising a textile cover and down contained therein. The cover comprises a nonwoven fabric made of continuous filaments to prevent the escape of down, the nonwoven fabric being obtainable by a spinning method, in which multi-component fibers are deposited to form a nonwoven, whereby the multi-component fibers are split into continuous filaments with a titer of less than 0.15 dtex and the nonwoven is bonded by means of mechanical bonding, comprising a fluid jet bonding, to form a nonwoven fabric, the nonwoven fabric not being thermally or chemically bonded.
The cover is a textile layer, which has a suitable shape to store down therein. The textile cover could substantially consist of the nonwoven fabric. This means that the nonwoven fabric forms at least the part of the textile cover, by means of which the storing of the down and separation from the surroundings takes place. Moreover, the textile cover may be modified for other purposes, for example be equipped with decorative elements or with closure means, such as buttons or zips.
The textile product is preferably an item of bedding, a jacket, padding, a mattress or a sleeping bag. The textile product is particularly preferably an item of bedding. Because of the down-proofness in conjunction with the good mechanical properties, and in particular the high degree of softness and elasticity, the nonwoven fabrics are particularly suitable as body overlays or underlays, such as bedcovers, cushions or mattress overlays.
In a preferred embodiment, the down is goose down. This penetrates textile covers particularly easily because of its hardness and shape. It has been found that the use according to the invention with the special nonwoven fabrics makes it possible to store even goose down in a down-proof manner.
Apart from down, the filling may also contain further conventional fillers, such as feathers or synthetic fillers. Down is often used for textile applications in a mixture with feathers. The proportion of down in the filling is preferably at least 30 wt. % or at least 50 wt. %, in particular at least 70 wt. %.
The subject of the invention is also a method for producing the textile product filled with down, comprising the steps:
(a) providing the textile cover, which comprises the nonwoven fabric made of continuous filaments,
(b) filling the textile cover with the down, and
(c) down-proof closing of the textile cover.
The down-proof closing can, for example, take place by thermal sealing, sewing, adhesion or other conventional methods. As spinnable and therefore thermoplastically processable polymers are used in particular, sealing thermal joining methods such as ultrasound sewing or welding are particularly preferred.
The nonwoven fabrics according to the invention are highly advantageous as they are not only down-proof but also regularly provide a high degree of protection to allergens, such as pollen or house dust, or mosquito bites. The latter is particularly advantageous because woven fabrics in general do not provide any protection against mosquito bites. The nonwoven fabrics that can be used according to the invention thus overall provide extraordinarily high protection against disturbing environmental influences.
The nonwoven fabric according to the invention is distinguished overall by an advantageous combination of properties. The mechanical properties, for example with regard to maximum tensile strength, maximum tensile elongation, isotropy, modulus of elasticity or tear resistance, are excellent and allow further conventional applications in the textile area. Moreover, the nonwoven fabric has advantageous properties especially for typical textile applications, such as absorption, washing shrinkage or pore size. Overall it was surprising that a combination of advantageous properties can be achieved in conjunction with a high degree of down-proofness without thermal or chemical bonding and even with a low mass per unit area. In addition it is advantageous that the nonwoven fabric can be easily produced and no special treatment steps, such as lamination or chemical post treatment, are necessary. The materials to produce it, in particular multi-component fibers and corresponding continuous filaments are also easily accessible and processable.
The nonwoven fabric according to the invention has very good down-proofness, while comparable nonwoven fabrics with slightly thicker fibers have no down-proofness. It was surprising here that the down-proofness does not increase proportionally with respect to the fiber fineness, but that nonwoven fabrics with fibers from a certain fiber thickness are unsuitable for storing down, while fibers with a higher degree of fineness suddenly have a high degree of down-proofness. It was not to be expected that specifically in the case of very fine fibers, the down-proofness would suddenly be achieved. It would rather have been expected that very fine fibers could no longer oppose the hard and pointed down quills with adequate mechanical strength. It is thus made possible by the invention to use only mechanically bonded nonwoven fabrics to store down. The invention thus overall solves the problems described at the outset.
The production of nonwoven fabrics with a bi-component spun nonwoven system of bi-component fibers with a cake-shaped cross section is described by way of example below. Two nonwoven fabrics that can be used according to the invention with 32 single filaments (type “PIE 32”) and masses per unit areas of about 100 g/m2 and 130 g/m2 were produced (examples 2 and 4). For comparison with the prior art of DE 203 10 279 U1, two nonwoven fabrics made of bi-component fibers with 16 single filaments (type “PIE 16”) and masses per unit areas of about 100 g/m2 and 130 g/m2 were produced (examples 1 and 3). The components and production conditions are summarized below.
Nozzles:
Nozzle type: PIE16 or PIE 32, pneumatic stretching
Laying:
On a depositing belt with a pre-adjusted speed, which produces a nonwoven mass per unit area of 100 or 130 g/m2.
Bonding: Prebonding by needling with 35 stitches/cm2 and subsequent calendering with steel rollers smooth/smooth, at 160-170° C. and 65-85 N line pressure.
Final bonding and splitting of the bi-component filaments into single filaments by water jet bonding with 4 to 6 alternating passages on the upper side A and lower side B of the nonwoven fabric in the order ABAB(AB) at 220-250 bar, with a nozzle strip hole diameter of 130 μm on a depositing belt of 80 mesh.
Post-Treatment:
The nonwoven fabric is then dried using a cylindrical continuous dryer at 190° C. and partially shrunk in order to ensure as far as possible a washing shrinkage of <3% at the first hot wash.
The production speeds in the method steps after discharge from the nozzles depends on the mass per unit area aimed for.
Using suitable measuring methods, properties of the nonwoven fabrics produced according to examples 1 to 4, which are significant for typical textile applications, were investigated. The tests are based on the following standards in the versions valid on the application date, if not otherwise stated:
The results are summarized in Table 1 below:
The results show that all the four nonwoven fabrics have good textile properties. At the same mass per unit area, the nonwoven fabrics of the type PIE32 that can be used according to the invention (examples 2 and 4), in comparison with the comparative nonwoven fabrics of the type PIE16 (examples 1 and 3), exhibit improved wash resistance, allergen-proofness and mosquito bite resistance.
The down-proofness was tested using the simulated cushion stress test according to DIN EN 12132-1. This standard is used to test the down-proofness of woven fabrics and can be used analogously for nonwoven fabrics. According to part 1, a simulated cushion stress was carried out. The test took place on two cushions, the measurements of which were 120 mm×170 mm. In the case of cushion 1, the longer side runs in the direction 1. In the case of cushion 2, the longer side runs in the direction 2. White, new, pure goose down and feathers of class 1, 90% down/10% feathers, were used as filling material. The test material corresponds to EN 12934—characterization of the composition of fully treated feathers and down. The number of down/feathers or parts penetrated after 2,700 revolutions was determined as the result. According to the definition, a sample is down-proof if it achieves a result in all directions of 20 or less.
For the nonwoven fabric according to example 2 (PIE32, 97 g/m2 mass per unit area), a result of 16 was obtained in direction 1 (one particle stuck in the textile material, 15 particles in the plastics material bag) and a result of 34 was obtained in direction 2 (2 particles stuck in the textile material, 32 particles in the plastics material bag). For the nonwoven material according to example 4 (PIE32, 127 g/m2), a result was obtained in the direction 1 of 9 (2 particles stuck in the textile material, 7 particles in the plastics material bag) and a result in direction 2 of 3 (0 particles stuck in the textile material, 3 particles in the plastics material bag). The results show that the nonwoven fabric according to the invention has excellent down-proofness. The down-proofness of a nonwoven fabric according to the invention with a mass per unit area 100 g/m2 is already high, while the down-proofness at 130 g/m2 corresponds completely to the requirements of bedding.
For comparison, a nonwoven fabric made of a mixture of continuous filaments with a titer of 0.1 dtex and 0.2 dtex was investigated. The nonwoven fabric was produced analogously to example 1 but had a mass per unit area of 120 g/m2 and was additionally equipped with a stabilizing coating of polyurethane (15 g/m2). After a domestic wash, a result in direction 1 of 42 (5 particles stuck in the textile material, 37 particles in the plastics material bag) was obtained in the simulated cushion stress test according to DIN EN 12132-1 and a result was obtained in direction 2 of 35 (3 particles inserted in the textile material, 32 particles in the plastics material bag). The nonwoven fabric therefore has no down-proofness that is suitable for textile applications.
On microscopic investigation, it was shown that the feather quills of the down easily penetrate comparative nonwoven fabrics of this type (
The results show that the comparative nonwoven fabrics are not down-proof, as expected. On the other hand, it was surprising that a slightly finer nonwoven fabric is down-proof.
Nonwoven fabrics made of 32 PIE bi-component fibers or of mixtures with 50% 16PIE and 32 PIE bi-component fibers with different masses per unit area were produced. The down-proofness of the nonwoven fabrics was determined as described in example 6 with the simulated cushion stress test for woven fabrics in analogy with DIN EN 12132-1. It was calculated from the fiber finenesses of the single filaments how many single filaments are present per unit area of nonwoven fabric (1 dtex corresponds to 10 g/km).
The fibers and split filaments have the following properties:
The properties of the nonwoven fabrics and the results are summarized in Table 2 below.
As already stated above with regard to example 6, it is assumed that a sample is down-proof when a result of 20 or less penetrations is achieved in all directions. According to DIN EN 121321, the nonwoven fabrics B, C, F, G and H are therefore down-proof. The nonwoven fabrics also have good air permeabilities and are therefore suitable for textile applications, for example as bedding. The results show that it is advantageous to match the filament fineness and the weight per unit area to one another in such a way that an adequately high number of fibers is present per unit area. It may be advantageous here when using relatively fine filaments to set the weight per unit area such that a desired air permeability is provided.
While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B, and C” should be interpreted as one or more of a group of elements consisting of A, B, and C, and should not be interpreted as requiring at least one of each of the listed elements A, B, and C, regardless of whether A, B, and C are related as categories or otherwise. Moreover, the recitation of “A, B, and/or C” or “at least one of A, B, or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B, and C.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15 193 633.3 | Nov 2015 | EP | regional |
