Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
  • D01F2/06—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from viscose
  • D01F2/08—Composition of the spinning solution or the bath
  • D01F2/12—Addition of delustering agents to the spinning solution
  • D01F2/14—Addition of pigments
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/06—Wet spinning methods
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
  • D01F1/02—Addition of substances to the spinning solution or to the melt
  • D01F1/04—Pigments
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D1/00—Woven fabrics designed to make specified articles
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D15/00—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used
  • D03D15/20—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used characterised by the material of the fibres or filaments constituting the yarns or threads
  • D03D15/208—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used characterised by the material of the fibres or filaments constituting the yarns or threads cellulose-based
  • D03D15/225—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used characterised by the material of the fibres or filaments constituting the yarns or threads cellulose-based artificial, e.g. viscose
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D15/00—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used
  • D03D15/40—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used characterised by the structure of the yarns or threads
  • D03D15/47—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used characterised by the structure of the yarns or threads multicomponent, e.g. blended yarns or threads
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04B—KNITTING
  • D04B1/00—Weft knitting processes for the production of fabrics or articles not dependent on the use of particular machines; Fabrics or articles defined by such processes
  • D04B1/14—Other fabrics or articles characterised primarily by the use of particular thread materials
  • D04B1/16—Other fabrics or articles characterised primarily by the use of particular thread materials synthetic threads
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04B—KNITTING
  • D04B1/00—Weft knitting processes for the production of fabrics or articles not dependent on the use of particular machines; Fabrics or articles defined by such processes
  • D04B1/22—Weft knitting processes for the production of fabrics or articles not dependent on the use of particular machines; Fabrics or articles defined by such processes specially adapted for knitting goods of particular configuration
  • D04B1/24—Weft knitting processes for the production of fabrics or articles not dependent on the use of particular machines; Fabrics or articles defined by such processes specially adapted for knitting goods of particular configuration wearing apparel
  • D04B1/246—Upper torso garments, e.g. sweaters, shirts, leotards
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2201/00—Cellulose-based fibres, e.g. vegetable fibres
  • D10B2201/20—Cellulose-derived artificial fibres
  • D10B2201/22—Cellulose-derived artificial fibres made from cellulose solutions
  • D10B2201/24—Viscose
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2401/00—Physical properties
  • D10B2401/06—Load-responsive characteristics
  • D10B2401/063—Load-responsive characteristics high strength
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2501/00—Wearing apparel

Definitions

• This invention relates to cellulosic fibers, containing incorporated indigo pigments in the oxidized form, wherein the fibers are made according to a modal process, show a tenacity (conditioned) measured according to BISFA of at least 29cN/tex and a wet modulus measured according to BISFA of at least 5cN/tex/% at 5% elongation. Furthermore the invention relates to the manufacture and the use of such fibers in fabrics and garments (footwear, etc).
• Natural or manmade cellulosic fibres and articles made from them such as yarns or fabrics can be dyed using a number of dye classes.
• the most common dye types used are reactive, where the dyes chemically react with the hydroxyl groups on the cellulose molecules which make up the fibre. This creates a covalent linkage which gives this type of dye high fastness properties.
• Reactive dyes are the most common because they give a high degree of fastness and a full shade range.
• cellulosic fibres can be coloured with other dye types such as direct, vat or sulphur dyes.
• indigo CI Vat Blue 1
• Indigo is used to colour yarns that subsequently are used to produce indigo denim fabrics.
• Spun warp yarns are first prepared into beams and then dyed with indigo (CI Vat Blue 1) prior to weaving the fabric.
• Preparation of yarn is normally simple scouring to remove any impurities but can include such chemical treatments such as caustic soda treatments.
• Indigo can be applied by a number of methods but application to yarn via Rope or Slasher applications account for the vast majority.
• Indigo dye is insoluble in water so is first converted into the soluble, so called “leuco” form using an alkaline reduction system using sodium hydroxide and sodium dithionite.
• This leuco indigo has low substantivity for cellulose, hence only pale depths are obtainable by exhaust dyeing procedures.
• Indigo is therefore applied in a series of dips, with intermediate squeezing and atmospheric oxidation. By repeating the process, dye is applied to the substrate layer by layer to give deep dyeings with relatively low rubbing fastness.
• the cellulosic warp yarns are extended along the range in the form of a rope.
• Yarn groups are typically 300-400 ends called ropes or cables.
• slasher dyeing the warp yarns are extended flatly and separately and arranged parallel to each other. Indigo can also be dyed batchwise or in a fabric form, usually continuously. Batchwise dyeing of hanks of yarn can be carried out in becks with repeated short dips, followed by squeezing and atmospheric oxidation, although these applications are far less common.
• the most common denim is derived from coloured warp while the weft thread is left white.
• the warp faced twill weaving one side of the textile is dominated by the blue warp threads and the other side is dominated by the white weft threads.
• the indigo dyeing process in which the core of the warp threads remains white, creates denim's signature fading characteristics.
• vat dyes and sulphur dyes can also be used to colour yarns or fabrics.
• the dyestuffs used to colour cellulosic fibres and articles made from them cannot normally be used to colour fibres (e.g. viscose, modal) during the fibre spinning process.
• the introduction of reactive dyes into the dope used to produce lyocell fibres have been found to adversely affect the stability of the process and is not acceptable for process safety reasons.
• Indigo-dyed denim has some properties which are disadvantageous to some extent and to some requirements (while they are indeed highly welcome to others): Fastness to rubbing and washing is quite poor as the dyestuff is only at the outer surface of the cotton fibers. Denim articles show wash-down effect by losing indigo after washing and laundry treatments (bleaching, oxidizing, etc).
• Denim laundries use various methods to give a variety of effects such as bleached, worn-down and faded look onto the denim fabrics.
• bleaching chemicals such as hydrogen peroxide, hypochlorite and permanganate have been used mainly.
• Recent sustainable options for denim laundry are laser and ozone treatments. Laser light sublimates dye from the fabric surface to give faded and used look as well as to mark certain design patterns. Ozone gas is used to bleach the denim garments via its high oxidation potential.
• Another very big disadvantage is the dyeing process for common denim products: The dyeing with the indigo is performed on the yarn. This process is not only very expensive but potentially heavily polluting the environment, in particular the waste water of the dyehouses.
• Viscose Indigo has a relatively low mechanical strength, in particular in the wet state. Therefore Viscose Indigo fibers are usually blended with significant quantities of polyester fibers. Garments made using such blend yarns show some significant disadvantages: Due to the high content of synthetic fibers the wear comfort is reduced in comparison to garments consisting of 100% cellulosic fibers. Furthermore there may be a need to dye the polyester fiber component as well; however this fiber type needs a different type of dyestuff which is unsuitable for cellulose.
• the fibers according to the invention fulfill the requirements for a modal fiber according to BISFA (see BISFA Terminology, 2009 editi on), which includes that these mechanical properties depend on the titer of the fibers.
• BISFA BISFA Terminology, 2009 editi on
• a fiber of 1.3 dtex according to the invention will show a tenacity (conditioned) of at least 31.4 cN/tex and a wet modulus (wet) of at least 4.39 cN/tex/% at 5% elongation.
• a fiber of 1.5dtex according to the invention will show a tenacity (conditioned) of at least 30.61 cN/tex and a wet modulus (wet) of at least 4.8 cN/tex/% at 5% elongation.
• the indigo pigment contains a very low content of aniline of less than 50ppm, preferably less than 25ppm and even more preferably less than 20ppm.
• the fibers according to the invention contain between 0.5 and 4.0 % (w/w) of the indigo pigment, especially preferred between 1.8 and 3.0 % (w/w), related to the total weight of bone dry fiber.
• Lower indigo pigment content would not provide for sufficiently deep color of the fibers and higher indigo pigment contents would reduce the mechanical strength of the fiber.
• An indigo pigment with very low aniline content in the oxidized form was incorporated during spinning in the form of a pigment masterbatch dispersion, in an amount suitable to obtain an final concentration in the fiber of between 0.5 and 4.0 % (w/w) of the indigo pigment, especially preferred between 1.8 and 3.0 % (w/w), related to the total weight of bone dry fiber.
• the coagulated threads were drawn off from the spinning bath at a speed between 15 and 60m/min.
• the coagulated, drawn threads were further washed thoroughly and cut into staple fibers, having a titer of 1.3dtex and a length of 38mm.
• these fibers are hereinafter referred to as "Modal Indigo".
• the indigo pigment is incorporated inside the whole cross-section of the fiber.
• a microphoto of the cross-section of the fiber shows pigments distributed over the whole area for the cross-section, while conventionally dyed cellulosic fibers show indigo pigments only on the outer surface of the fibers.
• the bleeding rate of the indigo pigment in the fibers according to the invention is significantly lower than the bleeding rate of the indigo pigment in Viscose Indigo.
• Another aspect of the invention is the use of the fiber according to the invention as described above for the manufacture of a fabric (knits, wovens, seamless, etc) with denim appearance, given by laundry effects such as laser and ozone.
• this colored fiber is used in the warp while ecru (i.e. undyed) fibers are used in the weft of the woven fabric to imitate the conventional denim fabrics.
• this colored fiber can be used in the weft while warp yarn can contain conventional indigo-dyed cellulose fiber.
• indigo-colored modal fiber is on the skin side by bringing the softness, i.e.comfort, of the modal fiber. Wash-down of the warp side would behave differently than using an ecru (i.e. undyed) fiber causing darker shades on the warp side.
• this fabric is a textile fabric with denim appearance that contains between 40 and 100% (w/w) of the fibers according to the invention as described above.
• the fabric shows a rub fastness according to ISO 105-X12:2016 of between 4.0 and 5.0.
• a typically yarn-dyed denim shows a rub fastness of about 3.0.
• the fabric is a woven fabric.
• this fabric contains in the warp between 80 and 100% (w/w), preferably between 95 and 100% (w/w), of the fibers according to the invention. This will result in the typical denim appearance, especially in twill weaving where one side of the textile is dominated by the blue warp threads and the other side is dominated by the white weft threads.
• This fabric may show a shrinkage at washing according to ISO 6330 and shrinkage test according to ONORM ISO 3759 of lower than 5.0%.
• this fabric in another preferred embodiment of the invention is a knit fabric.
• this fabric shows a shrinkage at washing according to ISO 6330 and shrinkage test according to ONORM ISO 3759 of lower than 12.0%.
• Yet another aspect of the invention is a method for manufacturing a fiber according to the invention as described above that includes the steps:
• the pigments used in the process of the invention can be made e.g. according to WO 2004/024826 A2 .
• Common modal spinning conditions as described e.g. in Patent AT287905B or WO 2011/026159 A1 may be applied.
• the indigo pigment is added to the Modal spinning solution in the form of a masterbatch, with an indigo pigment content of e.g. 20% (w/w) in the masterbatch suspension.
• an indigo pigment content e.g. 20% (w/w) in the masterbatch suspension.
• E.g. to obtain 0.5 to 4.0% (w/w) indigo pigment in the final fiber, 2.7 to 20.0% ((w/w), related to the dissolved cellulose) of masterbatch suspension has to be added to the Modal spinning solution, if using a masterbatch containing 20% (w/w) indigo pigment.
• the fibers according to the invention further have a much lower bleeding rate than other spun-dyed modal fibers.
• the bleeding rate of Modal Indigo is also lower than that of Viscose Indigo while the mechanical textile properties are on the much higher level of modal fibers, compared to viscose fibers.
• indigo pigments in the oxidized form keep their typical blue color very stable if they are incorporated in the cellulosic man-made fiber according to the invention, although the dye is very sensitive against oxidation if it is applied on e.g. cotton by conventional denim indigo dyeing.
• hypochlorite bleaching treatments e.g. 2g/l soda, 3g/l sodium hypochlorite; 30min at 30°C, warm and cold rinse, dechlorination with 0.8g/l H 2 O 2 - 30 min at 40°C, warm and cold rinse
• strong peroxide bleaching treatments e.g. 4g/l peroxide, 4g/l NaOH, 90°C for 30min, followed by neutralization (1g/l acetic acid)
• Enhancing the hypochlorite concentration (4g/l sodium hypochlorite, 40°C, 10min, followed by neutralization (3g/l sodium thiosulphate, 30°C, 10min)) could provide a slight effect. However, this treatment is not recommended considering the high amount of chemical used to obtain very small effect on the product.
• Preferred uses of the fibers according to the invention are:
• Modal Indigo shows a much better performance than Viscose Indigo owing to its lower shrinkage and higher strength.
• the low bleeding tendency of the fibers according to the invention may be an advantage.
• Example 1 Manufacture of an indigo-containing spun-dyed modal fiber:
• the incorporated cellulose fiber was made as follows by a process in analogy to the FR pigment incorporated cellulose fiber process as disclosed in AT 287905 B : A viscose with a content of 6% cellulose, 7% NaOH, 39% (in relation to cellulose) carbon disulphide and 3% (in relation to cellulose) of a modification agent was made. It showed a spinning gamma value of 57 and a spinning viscosity of 80 ballfall seconds. 2.3% (w/w), related to the cellulose content of the spinning solution, of indigo pigment with very low aniline content in the oxidized form was incorporated during spinning in the form of a pigment masterbatch, containing 20% (w/w) of pigment.
• the coagulated threads were drawn off from the spinning bath at a speed between 45 m/min.
• the coagulated, drawn threads were further washed thoroughly and cutted into staple fibers, having a titer of 1.58 dtex and a length of 38 mm.
• the tenacity (conditioned) was 32.1 cN/tex and the wet modulus (wet) was 5.5 cN/tex/% at 5% elongation.
• Elongation at break was 15.5%. All mechanical properties were measured according to the methods as described in the BISFA booklet " Testing methods viscose, modal, lyocell and acetate staple fibers and tows", 2004 editi on. For the purpose of the examples in this patent these fibers are hereinafter referred to as "Modal Indigo”.
• Example 2 Properties of fabrics containing the fibers according to the invention and their properties
• Shrinkage was measured according to ONORM ISO 3759:2011 after washing of the samples according to ISO 6330:2012.
• the tested woven fabric was the denim fabric of Example 2.a. with Modal Indigo and a denim fabric made in the same way, but containing Viscose Indigo instead of Modal Indigo.
• the tested knitted fabric was the fabric of Example 2.c. with Modal Indigo and a knitted fabric made in the same way, but containing Viscose Indigo instead of Modal Indigo.
• Table 3 shows that the fabrics containing the Modal Indigo fibers according to the invention show significantly lower shrinkage than comparable fabrics made using Viscose Indigo.
• Table 3 Shrinkage [%] Viscose Indigo Modal Indigo Woven fabric 7.0 4.5 Knit fabric 17.5 11.5
• Example 3 Yarn tenacity after denim bleaching processes, compared to Viscose Indigo
• Modal Indigo fibers according to the invention were compared to commercially available Viscose Indigo fibers (obtained from Lenzing Aktiengesellschaft, Lenzing/Austria). Yarns were spun using a Quickspin machine, i.e. by a rotor spinning process. The yarn tenacities were measured before and after treatment with permanganate in aqueous solution according to the following conditons: Pottasium permanganate concentration 4g/l, 40°C, 10min, followed by neutralization with 2g/l disodium metabisulphite at 40°C for 10min.).
• Table 4 shows that while Viscose Indigo after Permanganate bleaching was so degraded that the yarn strength and yarn elongation were unmeasurable (the yarn teared when clamping), Modal Indigo even after Permanganate bleaching shows satisfying mechanical properties.
• a Labomat device with 500mL-tubes operating at a rotation velocity of 20rpm was used. 200ml de-ionized water were measured in a graduated cylinder and heated in the Labomat device to 85°C. 5g fiber were added. The Labomat temperature was raised to 98°C as quickly as possible. The samples were treated at 98°C for five minutes, then cooled down to 70°C as fast as possible. The liquor was transferred into a 100ml beaker and cooled down to room temperature (i.e. 20°C) while the fibers were removed manually.
• Viscose Indigo was obtained according to Example 1.
• Viscose Indigo, Viscose Black (spun dyed) and Modal Black (spun dyed) were obtained as commercially available products from Lenzing Aktiengesellschaft, Lenzing/Austria. All fibers used were staple fibers with a titer of between 1,3 and 1,7 dtex and a cut length of between 38 and 39mm.
• Table 5 Abs [480nm] Turbidity [NTU] Viscose Black 0,0363 10,2 Viscose Indigo 0,0495 22,4 Modal Black 0,1168 29,9 Modal Indigo 0,0158 5,82
• Example 5 Sustainability assessment based on a theoretical model
• Methods A, B and C To assess the sustainability of the invention, it was compared to three conventional denim dyeing methods.
• the three conventional methods compared are hereinafter referred to as Methods A, B and C.
• the method according to the invention has a distinctive savings in water, chemicals, electricity, heat and wastewater (see Table 6: Savings achieved with indigo spun-dyed modal according to the invention compared to methods A, B and C). Heat energy needed to dry the conventionally dyed yarns are not needed for Modal Indigo fibers. Table 6 Savings by the invention compared to Method A Method B Method C Water 99.5 % 99.5 % 99.1 % Chemicals 87.4 % 81 % 83.7 % Electricity 99.96 % 99.96 % 99.96 % Wastewater 99.5 % 99.5 % 99.1 % Heat 100% 100% 100% 100% 100% 100%

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
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• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Coloring (AREA)
• Woven Fabrics (AREA)
• Knitting Of Fabric (AREA)
• Artificial Filaments (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

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• 2020
  • 2020-05-04 EP EP20172742.7A patent/EP3754053A1/fr not_active Withdrawn
• 2021
  • 2021-04-29 KR KR1020227042171A patent/KR20230005349A/ko active Search and Examination
  • 2021-04-29 JP JP2022567426A patent/JP2023524791A/ja active Pending
  • 2021-04-29 EP EP21722460.9A patent/EP4146851A1/fr active Pending
  • 2021-04-29 WO PCT/EP2021/061313 patent/WO2021224112A1/fr unknown
  • 2021-04-29 CN CN202180032610.8A patent/CN115427616A/zh active Pending
  • 2021-04-29 US US17/923,413 patent/US20230212791A1/en active Pending

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