Method for reducing pilling

Abstract

A method of preventing or at least reducing the pilling of nonwovens of unsplit and/or at least partially split microfibers and/or microfilaments of synthetic polymers containing at least one polyester component and at least one polyamide component and, if necessary, at least one polyurethane component. The method includes treating the nonwoven physically at least once.

Description

[0001] This application claims priority to German Patent Application DE 102 06 840.2, filed Feb. 18, 2002, which is incorporated by reference herein.

BACKGROUND

[0002] The present invention relates to a method of preventing or at least reducing pilling of nonwovens of unsplit and/or at least partially split microfibers and/or microfilaments of synthetic polymers containing at least one polyester component and at least one polyamide component and, possibly, at least one polyurethane component according to which the nonwoven is subjected to at least one physical treatment. The terms “microfibers” and “microfilaments” are used interchangeably and treated synonomously herein.

[0003] Textile materials made of synthetic polymers such as polyamide, polyester or polyurethane, which have been produced by the traditional method of warp and weft weaving or by stitch formation (knitting) are used extensively in a wide variety of areas of application, e.g., in the clothing or automotive industry, because of their many excellent properties.

[0004] Nonwovens produced by bonding microfibers and/or microfilaments of these materials, in particular unsplit or at least partially split microfibers and/or microfilaments can be produced very inexpensively, but they have only limited suitability for a number of applications.

[0005] The reasons for this include the fact that such nonwovens tend to form nubs, i.e., pilling. This results in an unattractive visual appearance of the nonwoven, which makes such nonwovens unsuitable for a number of applications or at least greatly restricts their possible applications.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to discover a method which results in at least a reduced pilling or none at all with a nonwoven made of unsplit and/or at least partially split microfibers and/or microfilaments of synthetic polymers containing at least one polyester component and at least one polyamide component and, possibly, at least one polyurethane component.

[0007] The present invention provides a method of preventing or at least reducing the pilling of nonwovens made of unsplit and/or at least partially split microfibers and/or microfilaments of synthetic polymers and containing at least one polyester component and at least one polyamide component and, optionally, at least one polyurethane component. The method includes treating the nonwoven physically at least once.

DETAILED DESCRIPTION

[0008] A physical treatment of the nonwoven in the sense of the present invention is understood to be any treatment of the nonwoven accomplished with energy input and/or by using a coating agent, where the coating agent does not enter into any chemical interaction with the polymer material of the microfibers and/or microfilaments of the nonwoven but instead enters only into a physical interaction, such as adsorption. Therefore, the term “physical treatment of the nonwoven” in the sense of the present invention is understood to refer to such methods according to which natural, synthetic or semisynthetic substances supplied in a controlled manner during the treatment interact with the synthetic polymers of the microfibers and/or microfilaments because of physical processes, e.g., due to adsorption.

[0009] Furthermore, this invention also includes such methods in which the synthetic polymers of the microfibers and/or microfilaments react with oxygen from the air surrounding the nonwoven, preferably with an input of energy. The physical treatment of the nonwoven may also include at least two such treatments which take place with energy input and/or using a coating agent and may be performed simultaneously or in any chronological sequence.

[0010] The nonwoven to be treated is preferably used in the method according to the present invention in the form of untreated raw goods.

[0011] The nonwoven to be treated is preferably used in the method according to the present invention as a flat fabric of any desired shape. The nonwoven is especially preferably used in the form of sheets or webs, most especially preferably in the form of webs, preferably like continuous webs of sheeting, in the method according to the present invention.

[0012] The nonwoven to be used in the method according to the present invention preferably includes at least one at least one polyester component and at least one polyamide component, where these two plastic components are preferably used in a ratio of 5 to 95 wt % of at least one polyester component and 95 to 5 wt % of at least one polyamide component, especially preferably 15 to 85 wt % of at least one polyester component and 85 to 15 wt % of at least one polyamide component, most especially preferably 30 to 70 wt % of at least one polyester component and 30 to 70 wt % of at least one polyamide component.

[0013] The polyamide component is preferably selected from the group comprising nylon 6, nylon 66 and nylon 11.

[0014] The polyester component is preferably selected from the group including polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polylactic acid, mixtures and copolyesters thereof.

[0015] Such copolyesters can be synthesized either by partial replacement of the acid component and/or by partial replacement of the diol component, as described, for example, by Büttner, “Basisch modifizierte Polyesterfasem” [Base-modified polyester fibers] in Die Angewandte Makromolekulare Chemie [Applied Macromolecular Chemistry], 40/41, 1974, pages 57-70 (no. 593) or G. G. Kulkarni, Colourage, Aug. 21, 1986, pages 30-33. The corresponding literature descriptions are herewith included as reference and are considered part of the disclosure.

[0016] It may also be preferable for the nonwoven to have as the polyester component a polyester based on lactic acid, as described in European Patent 1 091 028. The corresponding description is herewith included as a reference and is considered part of the disclosure.

[0017] The titer of the split microfibers and/or microfilaments of the nonwoven used is preferably ≦1 dtex, especially preferably 0.1 to 0.25 dtex. The titer of the unsplit microfibers and/or microfilaments in the composite is preferably ≧1 dtex, especially preferably 2.0 to 3.2 dtex.

[0018] The nonwoven used in the method according to the present invention is preferably a staple fiber nonwoven or a spunbonded nonwoven, especially preferably a spunbonded nonwoven, which has preferably been processed to form flat structures such as webs, especially preferably similar to fabric webs.

[0019] The corresponding nonwovens can be produced by the conventional methods which are known to those skilled in the art, as described, for example, by Dr. Helmut Jörder, “Textilien auf Vliesbasis (Nonwovens)” [Textiles Based on Nonwovens], avr technical book, P. Kepler Verlag KG, Heusenstamm 1977, pages 13 to 20. The corresponding spunbonded nonwovens may preferably be manufactured according to methods such as those described in European Patent 0 814 188. The corresponding descriptions are herewith included as reference and are considered part of the disclosure.

[0020] For use in the method according to the present invention, preferably nonwovens having a weight per unit area of 15 to 350 g/m2, especially preferably from 60 to 200 g/m2 are used.

[0021] The method according to the present invention for physical treatment of the nonwoven may be performed as a continuous, semicontinuous or discontinuous process, but the continuous process is usually preferred.

[0022] In a preferred embodiment of the method according to the present invention, the nonwoven to be treated is treated thermally.

[0023] Thermal treatment of the nonwoven used may be performed preferably by singeing. Singeing may be performed by conventional methods which are known to those skilled in the art, where the optimum parameter settings, such as temperature, speed, flame intensity, or the distance of the nonwoven from the flame may be determined by preliminary experiments by those skilled in the art. Suitable devices for singeing are available from the company Osthoff Senge GmbH & Co. KG, Wuppertal, Germany, for example.

[0024] In singeing, the nonwoven preferably used according to this invention as a flat sheeting, i.e., preferably as continuous web, is guided at a rate of 60 to 80 meters per minute within the upper quarter of flames reduced to minimal intensity.

[0025] Through this controlled singeing, it is surprisingly possible to reduce pilling without impairing the advantageous properties of the nonwoven, such as its moisture vapor transmission.

[0026] The thermal treatment of the nonwoven used is preferably performed with the help of hot, dry air. It is advantageous here to treat the web of nonwoven to be treated with hot, dry air on a device which is adjustable in length and/or width, preferably on a tenter frame.

[0027] The treatment with hot, dry air is preferably performed in an enclosed apparatus into which the hot air is preferably injected using nozzles. The web of nonwoven to be treated may also preferably be guided horizontally over rollers which are heatable if necessary, and the supply of hot air may be such that one or both, preferably both surfaces of the web of nonwoven to be treated are exposed to the oncoming flow of hot air. The rollers are preferably heated to maintain the temperature in the closed system.

[0028] Both the temperature of the dry hot air as well as the duration of the treatment may be varied as a function of various parameters, such as the ratio of the plastic components or the degree of splitting of the fibers and/or filaments. The temperature of the hot, dry air used for treatment of the nonwoven preferably amounts to 160° to 220° C., especially preferably 180° to 210° C. The duration of the hot air treatment is preferably ≧15 seconds, especially preferably 0.5 to 2 minutes, this treatment duration being set after reaching the desired temperature.

[0029] The thermal treatment of the nonwoven used is also preferably performed with the help of steam, preferably superheated steam. The steam treatment is preferably performed in an enclosed apparatus into which the steam is injected, preferably with the help of nozzles. The supply of steam is preferably such that the steam flows toward nonwoven fabric to be treated, preferably as a continuous web, from both above and below. In this embodiment of the method according to the present invention, it is also possible to treat the nonwoven to be treated on a device having an adjustable length and/or width, preferably on a tenter frame. However, the web of nonwoven is preferably guided over several rollers, which are called deflecting rollers, and in this way passed through the steam with each of its surfaces. These rollers are preferably heated to maintain the temperature in the closed system.

[0030] Both the temperature of the steam and the duration of the treatment may be varied as a function of various parameters such as the ratio of the plastic components or the degree of splitting of the fibers and/or filaments.

[0031] The temperature of the steam used for the thermal treatment of the nonwoven according to this invention is preferably no more than 160° C., especially preferably no more than 130° C. The dwell time of the nonwoven in the steam is preferably 20 seconds to 5 minutes, especially preferably 25 seconds to 4 minutes and most especially preferably 30 seconds to 3 minutes.

[0032] In another preferred embodiment of the method according to the present invention, the physical treatment of the nonwoven used according to this invention is by mechanical treatment.

[0033] The mechanical treatment of the nonwoven fabric used may preferably be performed by calendering with the help of conventional calenders which are known to those skilled in the art, such as those available from the company Eduard Küsters Maschinenfabrik [Machine Factory] GmbH & Co. KG, Krefeld, Germany.

[0034] Smoothing calenders, in particular two-roller calenders, are preferably used in this mechanical treatment of the nonwoven, preferably as a continuous web by the method according to the present invention, preferably at least one roller being heated. Heatable rollers are preferably completely or at least predominantly made of metal, in particular steel, while the material of the rollers that are not heatable is preferably selected from the group including cotton, paper and plastic.

[0035] This treatment of the nonwoven is preferably performed with the help of a two-roller calender in which the top roller is made of metal, preferably steel, and is heated, and the bottom roller is unheated and is made of cotton, paper or plastic.

[0036] The temperature of the heated rollers is preferably 50° to 210° C., preferably 120° to 200° C., especially preferably 150° to 190° C.

[0037] This mechanical treatment of the nonwoven fabric may also preferably be performed with the help of calenders having at least one embossing cylinder suitable for providing patterns on the nonwoven. In addition to reducing pilling, this also makes it possible to finish the nonwoven with the desired appearance, e.g., with the look of leather or woven goods.

[0038] The temperature of the rollers is preferably set at 140° to 240° C., preferably 150° to 230° C., especially preferably 160° to 220° C.

[0039] The optimum choice of a particular parameter, such as the wrap of the rollers, the line pressure, temperature and the speed at which the nonwoven is passed over the rollers may vary, e.g., as a function of the particular nonwoven used, and may be determined with the help of preliminary experiments by those skilled in the art.

[0040] The nonwoven is preferably moved at a rate of 2 to 40 meters per minute, preferably 4 to 35 meters per minute, especially preferably 6 to 30 meters per minute.

[0041] The line pressure between two opposing rollers in calendering by the method according to this invention preferably amounts to no more than 100 N/mm. For treatment with a smoothing calender, the line pressure especially preferably amounts to 10 to 25 N/mm; for the treatment with a calender having embossing rollers, the line pressure is especially preferably 30 to 50 N/mm.

[0042] To improve the excellent properties of this nonwoven, it may be subjected to a wet treatment following calendering, e.g., by treatment in strand form.

[0043] In another preferred embodiment of the method according to this invention, the physical treatment of the nonwoven is performed by providing it permanently with at least one coating agent over all or part of at least one of its surfaces, where the coating agent may also penetrate at least partially into the nonwoven.

[0044] Full-area application of the coating agent may be performed according to conventional methods which are known to those skilled in the art. Full-area coating of the nonwoven with at least one coating agent is preferably performed by spray, foam or slop-pad coating or by printing, preferably by screen printing, especially preferably by rotary screen printing or flat screen printing. If the coating agent is not applied over the full area, but instead is applied only partially to a part of one or both nonwoven surfaces, the coating is preferably performed in the form of grids (patterns), especially preferably in the form of geometric figures, most especially preferably in the form of stripes or spots, which are preferably distributed uniformly over at least one surface of the nonwoven, preferably in the form of a continuous web.

[0045] Application of the coating agent in grids may be performed according to conventional methods which are known to those skilled in the art. Application of the coating agent in grids is preferably performed by spraying or screen printing.

[0046] Suitable coating agents include one or more synthetic or semisynthetic polymers based on at least monounsaturated monomers, which may crosslink after application if necessary. Corresponding monomers may be selected in particular from the group including alkyl (meth)acrylates, acrylonitrile, ethylene, propylene, butadiene, chloroprene, styrene, vinyl chloride, vinylidene chloride, vinyl acetate and urea.

[0047] Preferred coating agents are selected from the group including polyalkyl (meth)acrylates, their copolymers or terpolymers, which may crosslink if necessary, copolymers or terpolymers of at least one alkyl (meth)acrylate and/or styrene and/or vinyl acetate, ethylene/vinyl acetate copolymers, vinyl acetate/maleic acid ester copolymers and aliphatic polyurethanes.

[0048] According to this invention mixtures of two or more coating agents may also be used. The synthetic polymers listed above are essentially known to those skilled in the art, e.g., from “Wässrige Polymerdispersionen—Synthese, Eigenschaften, Anwendungen,” [Aqueous polymer dispersions—Synthesis, properties, applications], Wiley VCH Verlag, Weinheim 1999, pages 25-26 and 214 as well as U.S. Pat. No. 4,902,286. The corresponding descriptions are herewith introduced as a reference and are considered part of the disclosure. The copolymers and terpolymers mentioned above may contain the particular monomers in various amounts, as used conventionally.

[0049] The monomers on which the polyalkyl (meth)acrylates, their copolymers or terpolymers are based may preferably be selected from the group including methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, and 2-ethylhexyl methacrylate. In addition, copolymers or terpolymers of at least one of the aforementioned polyalkyl (meth)acrylates with styrene and/or vinyl acetate, or styrene and/or vinyl acetate copolymers are suitable.

[0050] If a polyalkyl acrylate homopolymer is used as the coating agent, it may preferably be a polyethyl acrylate, poly-n-butyl acrylate, or a mixture of these polymers.

[0051] If a polyalkyl (meth)acrylate copolymer is available as a coating agent, it may preferably be selected from the group including n-butyl acrylate/styrene copolymers, 2-ethylhexyl acrylate/methyl methacrylate copolymers and ethyl acrylate/n-butyl acrylate copolymers.

[0052] If a polyalkyl (meth)acrylate terpolymer is used as the coating agent, it may preferably be composed of the monomers ethyl acrylate, n-butyl acrylate and methyl methacrylate.

[0053] Preferred aliphatic polyurethanes are those in which the polyol component is an aliphatic polyether and/or an aliphatic polyester and/or a polycarbonate.

[0054] A number of the polymers mentioned above are available commercially in the form of aqueous dispersions in various concentrations and may also be used in this form for coating the nonwoven. Likewise, corresponding powders, emulsions or solutions are also suitable.

[0055] If the nonwoven, preferably in a flat form, is coated over the full area or in a grid pattern by a printing method, the coating agent is preferably used in the form of a printing paste containing at least one or more thickeners in addition to one or more coating agents. These thickeners may preferably be selected from the group of natural or synthetic thickeners. Natural thickeners may preferably be selected from the group including starch, optionally partially degraded, vegetable gums, carob bean gum, etherified polysaccharides and alginates. Synthetic thickeners may preferably be selected from the group of water-soluble polymers containing carboxyl groups, preferably including (meth)acrylic acid and/or maleic anhydride.

[0056] In addition, coating agents based on natural polymers, in particular based on latex, starch or derivatives thereof may be used for coating the nonwoven by the method according to the present invention.

[0057] The optimum amount of coating agent to be applied may be varied as a function of various parameters, e.g., as a function of the type of application method, the type of coating agent or the composition of the nonwoven.

[0058] For full-area treatment of one surface of the nonwoven, the coating agent is preferably used in an amount of 6 to 16 g/m2, especially preferably 8 to 14 g/m2, each based on the solids content.

[0059] In the case of a grid-pattern coating of the nonwoven, the amount of solids to be used is determined accordingly from the degree of coverage of the coating agent on the nonwoven with respect to full-area coverage of the nonwoven.

[0060] Application of one or more coating agents may be performed over a broad temperature range. The application is preferably performed at normal temperature. Depending on the form of application of the coating agent used, e.g., as a powder, dispersion, or solution, it may be advantageous or even necessary to dry and/or condense the coated nonwoven according to conventional methods which are known to those skilled in the art, i.e., to induce crosslinking of the coating agent applied.

[0061] Nonwovens are usually also dyed and/or imprinted to create the desired appearance. The physical treatment of these goods according to this invention is usually performed after dyeing and/or imprinting.

[0062] For coloring the nonwoven before the treatment according to this invention, conventional dyestuffs which are known to those skilled in the art may be used, in particular vat dyestuffs and/or sulfur dyestuffs, including in their dissolved form, i.e., in the form of corresponding leuco vat dyestuffs or water-soluble sulfur dyestuffs, organic or inorganic pigments or disperse dyestuffs, as well as conventional methods of dyeing and/or imprinting familiar to those skilled in the art, e.g., the methods mentioned above for applying the coating agent.

[0063] A dyestuff selected from the group including anthraquinoids, indigoids or leuco vat ester dyestuffs is preferably used as the vat dyestuff, as described, for example, in “Rath—Lehrbuch der Textilchemie” [Rath—Textbook of Textile Chemistry], Springer Verlag, Berlin, Heidelberg, N.Y., 3rd edition, 1972, pages 462-485. The corresponding description from the literature is herewith introduced as a reference and is considered part of the disclosure.

[0064] Preferred disperse dyestuffs and corresponding dyeing methods are described, for example, in German Patent Application 101 25 843.7. The corresponding description is herewith included as a reference and is considered part of the disclosure.

[0065] Preferred organic and inorganic pigments as well as the corresponding dyeing methods are described in German Patent Application 101 29 366.6. The corresponding description is herewith included as a reference and is considered part of the disclosure.

[0066] The physical treatment and, optionally, dyeing of the nonwoven may be followed by conventional finishing steps which are known to those skilled in the art for finishing the goods.

[0067] Nonwovens made of unsplit and/or at least partially split microfibers and/or microfilaments of synthetic polymers treated by the method according to the present invention, containing at least one polyester component and at least one polyamide component and, optionally, at least one polyurethane component are characterized by a reduced tendency to pilling or none at all and thus because of the very attractive appearance of these materials, are suitable in particular for production of expensive, high-quality products, such as clothing, home textiles, upholstery fabrics, bunting, lining materials, preferably those for luggage items, and for production of furnishings for transportation means, preferably the interior furnishings of transportation means. Transportation means in the sense of the present invention include in particular motor vehicles, rail vehicles, water craft and aircraft.

[0068] Therefore, the present invention also includes the use of at least one nonwoven treated according to this invention for production of clothing, home textiles, upholstery fabrics, bunting, lining materials, preferably linings for luggage items, e.g., suitcases or handbags, and for production of furnishings for transportation means, preferably interior furnishings of transportation means.

[0069] The pilling tendency of the nonwovens treated according to this invention is determined according to DIN 53,863. The corresponding description is herewith included as a reference and is considered part of the disclosure.

[0070] The present invention is explained below on the basis of examples. These explanations are only examplary and to not restrict the general scope of the invention.

EXAMPLES

Example 1

Singeing

[0071] A spunbonded nonwoven sheeting bonded by the water jet technique and having a weight per unit area of 115 g/m2, composed of partially (≧85 wt %) split microfilaments having a titer of 0.10 to 0.13 dtex of 30 wt % nylon 66 and 70 wt % polyethylene terephthalate was dyed with a disperse dyestuff in the usual manner.

[0072] Then the nonwoven imprinted in this way was passed over a conventional singeing machine (Osthoff Senge GmbH & Co. KG, Wuppertal) so that the unimprinted surface of the nonwoven was passed within the upper quarter of the flames, reduced to a minimal intensity, at a speed of 80 meters per minute.

[0073] The spunbonded nonwoven thus printed and treated according to this invention was then tested for its pilling tendency according to DN 53,863. The corresponding values are listed in Table 1 below.

Comparative Example 1

[0074] The dyed spunbonded nonwoven used according to Example 1 was then tested for its pilling tendency according to DN 53,863. The corresponding values are listed in Table 1 below.

Example 2

Treatment with Hot Air

[0075] A spunbonded nonwoven web having a weight per unit area of 100 g/m2, bonded by the water jet technique and composed of partially (≧85 wt %) split microfilaments having a titer of 0.10 to 0.15 dtex and made of 30 wt % nylon 6 and 70 wt % polyethylene terephthalate was needled on a 6-field tenter frame from the company Bruckner (model VNB with a vertical chain and direct gas heating) with an appropriate advance, so that the nonwoven sheeting, which was fed into the tenter frame with a slight waviness, formed a smooth, wrinkle-free surface after the heat treatment in the discharge field of the tenter frame. The temperature presetting was 205° C. for all six fields of the tenter frame. The speed of the nonwoven was regulated within the system with the help of the surface temperature measurement of the nonwoven so that the dwell time at a temperature in the range of 203° C. to 206° C. was a constant 50 seconds.

[0076] The air supply through hole-type nozzles was adjusted so that the top air acted on the nonwoven with 80% of the maximum possible intensity and the bottom air acted on the nonwoven with 60% of the maximum possible intensity.

[0077] Then the spunbonded nonwoven treated in this way was tested according to DN 53,863 to determine its pilling tendency. The corresponding values are listed in Table 1 below.

Comparative Example 2

[0078] The dyed spunbonded nonwoven used according to Example 2 was then tested according to DN 53,863 to determine its pilling tendency. The corresponding values are listed in Table 1 below.

Example 3

Calendering

[0079] A spunbonded nonwoven sheeting having a weight per unit area of 100 g/m2, bonded by the water jet technique and composed of partially (≧85 wt %) split microfilaments having a titer of 0.10 to 0.13 dtex and made of 30 wt % nylon 66 and 70 wt % polyethylene terephthalate was calendered on a 2-roller calender (model 412.50 from Küsters Maschinenbau [Küsters Machine Construction]) equipped with a heatable steel roller and a cotton roller. The nonwoven was calendered without friction at a rate of 5 meters per minute and a line pressure of 30 N/mm, the temperature of the steel roller being 200° C.

[0080] The nonwoven treated according to this invention was dyed by the exhaust dyeing method at pH 4.5 and a bath ratio of 1:30 with 0.7 wt % (based on the weight of the nonwoven) of the disperse dye Foron® Blau [blue] RD-GLF (Clariant, Frankfurt) in the presence of 1.5 mL/L of the leveling agent Eganal PS (Clariant, Frankfurt) and 2 mL/L of the running crease inhibitor Sevosoftal UFB (Textilcolor, Sevelen, Switzerland), 2 mL/L 60 wt % acetic acid and 2 g/L sodium acetate. Dyeing was begun at 20° C., then the bath was heated to 130° C. at 2° C./min and dyeing was performed for 30 minutes at this temperature. Then it was cooled to 70° C. at −1.5° C./min, rinsed with cold water and a reductive scouring was performed with a bath ratio of 1:30 using 6 mL/L 32 wt % sodium hydroxide solution and 2 g/L concentrated hydrosulfite (BASF) for 20 minutes at 80° C. Then the dyed nonwoven was rinsed with cold water and acidified with 1 mL/L 60 wt % acetic acid. The rate of circulation of the goods during the entire dyeing operation was 100 meters per minute. The subsequent drying was performed with low tension on a screen belt dryer from Santex AG, Tobel, Switzerland, model Santashrink, for 40 seconds at a temperature of 130° C.

[0081] The spunbonded nonwoven treated and dyed in this way was then tested according to DIN 53,863 to determine its pilling tendency. The corresponding values are shown in Table 1 below.

Comparative Example 3

[0082] The dyed spunbonded nonwoven used according to Example 3 was then tested according to DIN 53,863 to determine its pilling tendency. The corresponding values are shown in Table 1 below.

Example 4

Screen Printing

[0083] Spunbonded nonwoven web with a weight of 100 g/m2, bonded by the water jet technique, composed of partially split microfilaments (≧85 wt %) having a titer of 0.10 to 0.13 dtex and made of 30 wt % nylon 66 and 70 wt % polyethylene terephthalate was screen printed with the coating agent Acronal® DS2373 based on an acrylate/acrylonitrile copolymer (BASF AG, Ludwigshafen, Germany) on a print knock-off table (Thieme model 510, angle opening) for screen printing using flat screen stencils, after the coating agent had first been adjusted to a printable viscosity using an acrylate thickener. The amount of solids of the coating agent applied, based on the weight per unit of area of the nonwoven, was 3.4 g/m2. The coating agent was applied by using a printing stencil with a grid of 100 spots per cm2 and a spot diameter of 0.6 mm (corresponding to a print coverage of 28 area %) and an RKS doctor (model 50/00/6/80, 295 mm, 45° angle). Then the nonwoven treated in this way was dried for 120 seconds at 150° C.

[0084] The spunbonded nonwoven treated in this way was then tested according to DIN 53,863 to determine its pilling tendency. Table 1 below shows the values thus obtained.

Comparative Example 4

[0085] The printed spunbonded nonwoven used according to Example 4 was then tested according to DIN 53,863 to determine its pilling tendency. Table 1 below shows the values thus obtained.

[0086] Testing the Pilling Tendency:

[0087] The pilling tendency was determined according to DIN 53,863 using a Martindale abrasion and pilling tester (model 406, James H. Heal & Co. Ltd., England). The samples of nonwoven used in this test had a diameter of 38 mm. An abrasive cloth SM 25 (code number 701-202, James H. Heal & Co. Ltd., England) was used as the abrasion substrate. The samples of nonwoven were moved against the abrasive with the abrasion movement “Lissajous” under a test pressure of 9 kPa. Samples were classified and evaluated after 125, 500, 1000 and 2000 cycles. The evaluation was performed according to the EMPA (Swiss Materials Testing Institute) photographic standard for woven fabric (SN 198525) which is herewith introduced as a reference and is considered part of the disclosure.

[0088] Table 1 below summarizes the results obtained for the pilling tendency of the nonwovens treated according to Examples 1 through 3 and Comparative Examples 1 through 3. 1 TABLE 1 Evaluation Evaluation Evaluation Evaluation after after after after 125 cycles 500 cycles 1000 cycles 2000 cycles Example 1 4-5 3-4 3 2-3 Comp. Ex. 1 3 2-3 2 2 Example 2 5 5 4-5 4 Comp. Ex. 2 4 4 3 2-3 Example 3 5 5 4-5 3-4 Comp. Ex. 3 3-4 3 2 1-2 Example 4 5 5 5 4-5 Comp. Ex. 4 4 4 3 2-3 5 = no pilling; 1 = very severe pilling

Claims

1. A method of reducing pilling of a nonwoven material made of unsplit and/or at least partially split microfibers of synthetic polymers, the nonwoven material containing at least one polyester component and at least one polyamide component, the method comprising:

providing the nonwoven material; and

physically treating the nonwoven material at least once, thereby reducing pilling of the nonwoven material.

2. The method as recited in claim 1, wherein the nonwoven fabric includes at least one polyurethane component.

3. The method as recited in claim 1, wherein the nonwoven material is used as a flat fabric.

4. The method as recited in claim 1, wherein the physically treating is performed continuously.

5. The method as recited in claim 1, wherein the physically treating includes thermally treating the nonwoven material.

6. The method as recited in claim 5, wherein the thermally treating is performed by singeing.

7. The method as recited in claim 5, wherein the thermally treating is performed using hot, dry air.

8. The method as recited in claim 7, wherein the hot, dry air has a temperature of 160° C. to 220° C.

9. The method as recited in claim 8, wherein the temperature is 180° C. to 210° C.

10. The method as recited in claim 7, wherein the thermally treating is performed for a duration of ≧15 seconds.

11. The method as recited in claim 10, wherein the duration is 0.5 to 2 minutes.

12. The method as recited in claim 5, wherein the thermally treating is performed using steam.

13. The method as recited in claim 12, wherein the steam is superheated steam.

14. The method as recited in claim 12, wherein the thermally treating is performed so that the nonwoven fabric has a dwell time in the steam of 20 seconds to 5 minutes.

15. The method as recited in claim 14, wherein the dwell time is 25 seconds to 4 minutes.

16. The method as recited in claim 14, wherein the dwell time is 30 seconds to 3 minutes.

17. The method as recited in claim 12 wherein the steam has a temperature of no more than 160° C.

18. The method as recited in claim 17, wherein the temperature is no more than 130° C.

19. The method as recited in claim 7, wherein the physically treating is performed on a device, wherein one of a length and a width of the device is adjustable length.

20. The method as recited in claim 19, wherein the device is a tenter frame.

21. The method as recited in claim 1, wherein the physically treating includes mechanically treating the nonwoven material.

22. The method as recited in claim 21, wherein the mechanically treating is performed by calendering using at least one pair of rollers.

23. The method as recited in claim 22, wherein the calendering includes rotating the rollers in the same direction.

24. The method as recited in claim 22, wherein the calendering is performed on a smoothing calender.

25. The method as recited in claim 24, wherein the smoothing calender is a two-roller calender.

26. The method as recited in claim 25, wherein at least one roller of the two-roller calender is heated.

27. The method as recited in claim 25, wherein a top roller of the two-roller calender is heated and made of metal and a bottom roller of the two-roller calender is unheated and is made of at least one of cotton, paper and plastic.

28. The method as recited in claim 27, wherein the metal is steel.

29. The method as recited in claim 25, wherein a temperature of the rollers of the two-roller calender is 50° C. to 210° C.

30. The method as recited in claim 29, wherein the temperature is 120° C. to 210° C.

31. The method as recited in claim 29, wherein the temperature is 150° C. to 190° C.

32. The method as recited in claim 22, wherein at least one of the at least one pair of rollers is an embossing roller.

33. The method as recited in claim 32, wherein at least one of the at least one pair of rollers is heated.

34. The method as recited in claim 32, wherein a temperature of the rollers is 140° C. to 240° C.

35. The method as recited in claim 34, wherein the temperature is 150° C. to 230° C.

36. The method as recited in claim 35, wherein the temperature is 160° C. to 220° C.

37. The method as recited in claim 22, wherein the calendering is performed with a line pressure of no more than 100 N/mm.

38. The method as recited in claim 25, wherein a line pressure of the smoothing calender is 10 to 25 N/mm.

39. The method as recited in claim 32, wherein the calendering is performed with a line pressure of 30 to 50 N/mm.

40. The method as recited in claim 22, wherein mechanically treating includes moving the nonwoven material at a rate of 2 to 40 meters per minute.

41. The method as recited in claim 40, wherein the rate is 4 to 35 meters per minute.

42. The method as recited in claim 41, wherein the rate is 6 to 30 meters per minute.

43. The method as recited in claim 1, wherein the physicaly treating includes coating at least a portion of a first surface of the nonwoven material using at least one coating agent.

44. The method as recited in claim 43, wherein the coating is performed by at least one of a spray, foam, and slop-pad coating.

45. The method as recited in claim 43, wherein the coating is performed by imprinting.

46. The method as recited in claim 45, wherein the imprinting includes screen printing.

47. The method as recited in claim 46, wherein the screen printing includes at least one of rotary screen printing and flat screen printing.

48. The method as recited in claim 43, wherein the coating includes applying the coating agent in an amount of 6 to 16 g/m2 based on solids of the coating agent.

49. The method as recited in claim 48, wherein the amount is 8 to 15 g/m2.

50. The method as recited in claim 43, wherein the coating is performed using patterns.

51. The method as recited in claim 50, wherein the pattern includes geometric figures.

52. The method as recited in claim 51, wherein the geometric figures include at least one of stripes and spots.

53. The method as recited in claim 50, wherein the pattern is uniformly distributed over at least the first surface.

54. The method as recited in claim 50, wherein the coating is performed is performed using at least one of spraying and screen printing.

55. The method as recited in claim 1, wherein the nonwoven material is for use in clothing.

56. The method as recited in claim 1, wherein the nonwoven material is for use in a home textile.

57. The method as recited in claim 1, wherein the nonwoven material is for use in an upholstery material.

58. The method as recited in claim 1, wherein the nonwoven material is for use in bunting.

59. The method as recited in claim 1, wherein the nonwoven material is for use in a lining material.

60. The method as recited in claim 1 wherein the lining material includes a lining material for a luggage item.

61. The method as recited in claim 1, wherein the nonwoven material is for use in furnishings for transportation means.

62. The method as recited in claim 61, wherein the furnishings are interior furnishings.