Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06C—FINISHING, DRESSING, TENTERING OR STRETCHING TEXTILE FABRICS
  • D06C7/00—Heating or cooling textile fabrics
  • D06C7/02—Setting
• • 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
  • D03D15/50—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 properties of the yarns or threads
  • D03D15/56—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 properties of the yarns or threads elastic
• • 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
  • D04B1/18—Other fabrics or articles characterised primarily by the use of particular thread materials elastic threads
• • 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
  • D10B2211/00—Protein-based fibres, e.g. animal fibres
  • D10B2211/01—Natural animal fibres, e.g. keratin fibres
  • D10B2211/02—Wool
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/30—Woven fabric [i.e., woven strand or strip material]
  • Y10T442/3008—Woven fabric has an elastic quality

Definitions

• the present invention relates to machine washable wool stretch fabrics having good dimensional stability.
• the fabrics also have improved heat-setting properties, hi one aspect, the invention relates to stretch fabrics comprising wool fibers together with elastic fibers where the elastic fibers comprise crosslinked, heat-resistant elastic fibers, and where such fabric does not need heat setting, but the finishing fabric can deliver very good dimensional stability after many washes.
• Fabrics made at least in part from wool fibers are well known in the art. It is also known that these fabrics may shrink or otherwise become distorted during wet processing of the fabric or as a result of consumer use and care. Wool is composed of an outer layer of overlapping scales surrounding an internal core composed of numerous long thin spindle shaped cells, largely composed of keratin. The outer layer is generally only one scale in thickness, except at the overlapping portion where one scale ends and another commences. The scales all generally point outwards along the fiber, towards the tip. It is believed that this structure leads to shrinkage during normal wet washing, as the profile of the fibers favors movement in the direction of the root end of the fiber. This behavior can be compared to a ratchet mechanism in that the relative movement is unidirectional.
• the various chemical treatments currently used are generally done on the wool top, and include various chlorine treatments, potassium permanganate treatments in conjunction with hypochlorite (see GB 569,730), sodium sulfate treatments (sometimes referred to as the International Wool Secretariat Process), oxidase or peroxidase treatments (see US 5,980,579) and permonosulfuric acid treatments. It has also been suggested that permonosulfuric acid treatments can be on a finished garment made from a wool fabric in order to control dimensional stability.
• Garment/fabric dimensional stability dimensional stability following washing of less than ⁇ 3 percent (washing can be done according to modified ISW Tm 31: 5 cycles of ISO 6330 5A wash, wet measurement) dimensional stability following steam pressing according to ISO 3005 of less than ⁇
• Heat-setting is a common way of reducing or eliminating the dimensional instability.
• the heat-setting process typically involves passing the fabric through a heating zone for a time and at a temperature that resets the synthetic fiber's morphology memory to the dimensions of the fabric at the time when the heat-setting process was applied.
• the time and temperature needed for the heat treatment depend on factors such as the fabric construction, the weight of the fabric, other fibers present in the fabric, the type of synthetic fiber, and the previous heat history of the synthetic fiber.
• the issue of dimensional instability is especially pronounced for stretch woven fabrics, particularly knitted stretch fabrics.
• typical heat-setting conditions are from 180 0 C to 210°C for 15 to 90 seconds. These relatively harsh conditions may negatively affect the tenacity of companion fibers and lead to fabric color alteration. Furthermore, the heat-setting step is typically an additional step which adds expense to the fabric production process.
• the finished wool/spandex fabrics are reported to have very poor consistency in fabric width as indicated by varying widths between different rolls of fabric or variation of width within the same roll of fabric. The heat setting process will cause the finishing fabric stretch level to be inconsistent.
• the present invention is accordingly directed to wool fabrics which incorporate stretch or elastic fibers, which fabrics retain their dimensional stability, preferably without the need for traditional heat setting steps.
• the present disclosure is also directed to a method of producing wool stretch fabrics having good dimensional stability wherein the method is characterized by a chemical treatment to remove wool scales and further characterized by the absence of any step in the production process which is performed at a temperature of 160°C or above.
• the stretch fabrics may also include other fibers including cellulosic, more preferably synthetic ones, including polyolefin such as polyethylene and/or polypropylene, polyester, polyamide, and segmented polyurethane fibers.
• the finished stretch fabrics preferably have a dimensional stability of less than ⁇ 5 percent, more preferably less then ⁇ 3 percent, still more preferably within ⁇ 2.0 percent and most preferably within ⁇ 1.5 percent.
• Dimensional stability values indicated in this invention refer to the difference between the finished fabric length and widthwise dimensions after vs. before laundering plus tumble drying as defined by AATCC135-1987; preferably by drying method: A - tumble drying. Negative values indicate that the final washed dimensions are shorter than the initial ones which translates to shrinkage.
• the present invention also relates to fabrics which can be characterized by consistent stretching at 9 percent-30 percent according to testing method IWS TM 179.
• the present invention also can be characterized in that the finished fabric color is free from discernable yellowing.
• the machine washable wool stretch fabrics of the present invention comprise at least wool fibers and elastic fibers.
• the wool fibers of the present invention can be any type of wool fiber used in the garment industry. Typically the wool used will be the fiber from the fleece of sheep or lambs but also includes fiber from the hair of Angora or Cashmere goats, camels, alpacas, llamas, vicunas and Angora rabbits, for example.
• the wool can be present in any amount, but 20-99 percent by weight is most preferred.
• the wool fibers in their natural state can be characterized by having scales that tend to ratchet down and to interlock with each other thereby binding the fibers together in a process called felting. Accordingly, the wool fibers for use in the present invention are treated to remove at least a portion of the scales.
• This treatment process is generally known in the art, and any such processes may be used in the present invention. Typical processes include chlorine treatment and permonosulfuric acid treatment. Examples of potential chemical treatments for use in the present invention include those described in US 5,980,579, WO2005/005710, EP 0 687 764, US 5,571,286, US 5,755,827 and WO 9502085, which are each hereby incorporated by reference in their entirety.
• the scale removing treatment can be done at any step in the process to make a garment. For example, in many cases it will be most advantageous to remove the scales as a first step so that felting will not occur during any of the later production processes, but in other situations, it may be beneficial to wait until the final garment has been prepared and then treat the whole garment in order to remove at least a portion of the scales from the wool fibers.
• the treatment may also be done at intermediate steps such as after forming the sliver, the top, the roving, the yarn (including elastic yarns if combined with elastic fiber), or after making the fabric. Typically the treatment is done on the top or on the finished garment.
• the machine washable fabrics and garments of the present invention are stretch or elastic, which for the purposes of this invention, means that they contain an elastic fiber.
• an elastic fiber is one that will recover at least about 50 percent, more preferably at least about 60 percent even more preferably 70 percent of its stretched length after the first pull and after the fourth to 100 percent strain (double the length).
• One suitable way to do this test is based on the one found in the International Bureau for Standardization of Manmade Fibers, BISFA 1998, chapter 7, option A. Under such a test, the fiber is placed between grips set 4 inches apart, the grips are then pulled apart at a rate of about 20 inches per minute to a distance of eight inches and then allowed to immediately recover.
• the elastic textile articles of the present invention have a high percent elastic recovery (that is, a low percent permanent set) after application of a biasing force.
• elastic materials are characterized by a combination of three important properties, that is, (i) a low stress or load at strain; (ii) a low percent stress or load relaxation, and (iii) a low percent permanent set.
• Elastic fibers include certain fibers made from polyolefins such as polyethylene or polypropylene, and segmented polyurethane.
• the elastic fiber for use in the present invention is preferably durable enough to survive the scale removing treatment so that such treatment may be done in the presence of the elastic fiber. It is therefore preferred that the elastic fiber be a cross linked polyolefin fiber, more preferably a cross linked polyethylene fiber, of which cross linked homogeneously branched ethylene polymers are particularly preferred.
• This material is described in US 6,437,014, (which is hereby incorporated by reference in its entirety) and is generically known as lastol. Such fibers are available from The Dow Chemical Company under the trade name DOW XLA fibers.
• the elastic fibers comprise from 2 to 20 percent by weight of the article. Depending on the desired application, it maybe preferred that the article comprise at least 3, 4, 5, 6, 7, 8, 9, or even 10 percent elastic fiber, and similarly, the desired application may dictate having less than 20, 15, 10, 9, 8, 7 ,6 or 5 percent elastic fiber. It maybe desirable for knitted articles to contain relatively more of the elastic fiber than woven articles. It is also possible, although not necessarily preferred, that more than one type of elastic fiber may be used in the articles of the present invention. It is preferred that the elastic fibers not include fiber made from segmented polyurethane, however, as this material is likely to degrade under the relatively harsh chemical treatments used for de-scaling and further promotes dimensional instability in the absence of heat setting at temperatures greater than 160 0 C.
• the elastic fibers for use in the present invention can be of any thickness, although 20-140 denier is most preferred, particularly when the fiber is the preferred cross linked homogeneously branched ethylene polymers. Forty denier and 70 denier lastol fiber are especially preferred due to commercial availability.
• the elastic fiber may also be a conjugate fiber, for example, a sheath/core bicomponent fiber.
• the elastic. fiber may be used bare, or it may first be incorporated into a multifilament, for example, covered yarn, or into staple fibers, for example, corespun yarn, as is generally known in the art.- In a preferred embodiment the elastic fiber is siro spun with the wool to form an elastic wool yarn.
• the textile articles of the present invention may further comprise additional non- elastic natural or synthetic fibers.
• Non-elastic synthetic fibers include those made from materials such as polyester, nylon, polyethylene, polypropylene, and blends thereof.
• Natural fibers include fibers made from cellulosic materials such as cotton, flax, ramie, rayon, viscose and hemp. Natural fibers from other materials can also be used in the textile articles of the present invention, including fibers such as silk or mohair.
• the washable wool stretch fabrics of the present invention can be made by any conventional means.
• the articles of the present invention include fabrics which have been woven (where the elastic fiber or yarn can be in the warp direction, the weft direction or both) or knitted, including warp knitting, (for example, Milanese, Raschel and Tricot , knitting) weft knitting (for example, circular knitting and flat knitting) and garment knitting technologies such as seamless articles.
• warp knitting for example, Milanese, Raschel and Tricot , knitting
• weft knitting for example, circular knitting and flat knitting
• garment knitting technologies such as seamless articles.
• the type of knitting construction is also not intended to be a limiting factor of the present invention.
• Known construction types include plain single jersey, single jerseys containing tuck and miss stitches (such as Lapique, Cross-mis 1x1, Lacoste & Plain pique), double jerseys (such as Plain Rib and Plain Interlock), double jerseys containing tuck and miss stitches (such as Milano Rib, Cardigan, Single Pique & Punto di Roma).
• Wool fabrics and particularly knitted wool fabrics are known to suffer from a lack of dimensional stability over home laundering, for example, excessive stretching or shrinkage.
• Traditional methods for producing knitted fabrics therefore include a heat setting step, particularly when the fabric includes fibers incorporating synthetic polymers. The heat-setting step is done after knitting and can be done either prior or post dyeing.
• the heat setting process generally involves applying a biasing force to hold the fabric at its desired dimensions (typically with the use of tenter frames) and subjecting it to high temperatures, particularly temperatures higher than any temperature that the fiber or article is likely to experience in subsequent processing (for example, dyeing) or use (for example, washing, drying and/or ironing).
• a biasing force typically to hold the fabric at its desired dimensions (typically with the use of tenter frames) and subjecting it to high temperatures, particularly temperatures higher than any temperature that the fiber or article is likely to experience in subsequent processing (for example, dyeing) or use (for example, washing, drying and/or ironing).
• the heat-setting temperatures are such that at least some of the crystallites in the fiber will melt.
• the fabric is then removed from the heat, and the molten portions are allowed to recrystallize, and then the biasing force can be removed.
• the recrystallization causes the fabric to have a "memory" of the dimensions at which the fabric was maintained during the heat-setting process, even after the biasing force
• One aspect of the present invention is therefore directed to a method for making a machine washable wool knitted fabric characterized in that the entire process occurs at a temperature less than about 160°C. Depending on the content of other fibers which make up the fabric, even lower temperatures can be used without sacrificing dimensional stability. Thus, the entire process may occur at a temperature of less than 150°C, 140°C, 125°C, 100°C or even 80°C. hi certain embodiments of this invention, the process can further be characterized by an absence of tentering. Thus, yarns or fibers containing at least some elastic material can be knitted into fabric and the fabric can directly be subjected to the desired finishing treatments without the need for placing the fabric into a tenter frame and exposing it to the high temperatures normally associated with heat-setting.
• finishing treatments include at least one step in which the temperature is higher than 8O 0 C.
• the fabric will be "fixed” in a similar manner to the typical heat setting process, but at a lower temperature and without the need for special apparatus to ensure a biasing force.
• Typical finishing steps are conducted at temperatures of 80°C or greater, which is sufficient for this purpose, and yet such fabrics will not normally be exposed to temperatures this high during normal use and care.
• the present invention is also directed to machine washable wool textile articles having stretch and dimensional stability.
• "textile articles” includes finished fabric as well as products made from the fabric including bed sheets and other linens, and garments.
• the articles of the present invention recover promptly to dimensions which are less than 20 percent over its original dimension after being stretched up to (1) 100 percent widthwise and/or (2) 45 percent lengthwise (all at extension rate of 500 mm/min for a specimen 50 mm wide and gauge length 100 mm). More preferably, the article will return to within 15 percent of the original dimensions, and more preferably to within 10 percent. It should be understood that the amount of stretch and recovery will be a function of the weight of the fabric and the fabric construction. It is also contemplated that the articles of the present invention will have stretch in more that one direction, and indeed for many applications this will be preferred. It is not necessary that the articles have the same amount of stretch in each direction to be within the scope of this invention.
• the textile articles of the present invention are dimensionally stable.
• "dimensionally stable” means that the stretch fabrics change less than 5 percent in either direction (growth or shrinking), more preferably less than 3 percent in either direction, and even more preferably less than 2 percent in either direction and most preferably within ⁇ 1.5 percent.
• Shrinkage is generally perceived as being the typical form of dimensional instability and the fabrics of the present invention will have a dimensional stability higher (that is, less negative) than -5 percent in the width and/or the lengthwise direction, preferably higher than -4 percent, more preferably higher than -3 percent and most preferably higher than -2 percent (with 0 percent representing no shrinkage or growth).
• Dimensional stability values are calculated by the difference between the finished fabric's length and widthwise dimensions after vs. before laundering.
• dimensional stability (new dimension - original dimension)/original dimension.
• any finishing processes known in the art may be used. This includes processes such as scouring, mercerizing, dyeing and drying. It is preferred that at least one of the finishing processes be conducted at a temperature which is greater than any to which the end consumer will likely expose the garment, for example, 80 0 C or greater.
• EXAMPLES Example 1 Polyester blend with wool and DOW XLATM fiber 4OD
• Wool fiber is chemically treated with a chlorine treatment on the wool top to remove wool scales. This treated wool fiber is then blended with polyester fiber to produce a yarn which is about 65 percent by weight polyester and 35 percent by weight wool. The blended fiber is then dyed. The dyed fiber is then combined with 40 denier DOW XLATM fiber (available from the Dow Chemical Company) at a draft of 4.3 via siro spinning to produce an elastic yarn.
• DOW XLATM fiber available from the Dow Chemical Company
• the elastic yarn is used in the weft direction to make a fabric with a warp yarn (the warp yarn is dyed polyester/wool fiber prepared as above, without siro spinning with DOW XLATM fiber) count (Nm) 52 two ply and a weft yarn count (Nm) 52 two ply having 24 ends/cm and 22.5 picks/cm.
• the resulting fabric contains about 33 percent by weight wool, 63 percent polyester and 4 percent Dow XLA fiber.
• the resulting fabric has a weight (as determined by ASTM D3776-1996 (2002)) of 240.7 gm/m 2 (240.7 GSM).
• the fabric is finished according to standard processes, and measured.
• the finished fabric exhibits a stretching level of 16 percent as determined according to IWS TM 179.
• the fabric is subjected to IWS test method 31:5 cycles of ISO 6330 5A Wash, wet measurement. The fabric is then re-measured.
• the fabric exhibits weft washing shrinkage (testing method IWS TM 31) of less than 1.9 after 5 washes. As the industry standard for "machine washable" garments is less than 3 percent, this fabric easily meets the industry standard.
• Super 100 Superwash wool fiber is chemically treated fiber which has been treated with a chlorine treatment on wool top to remove wool scales.
• the treated wool is then combined with 40 denier DOW XLATM fiber at a draft of 4.3 via siro spinning to produce the elastic yarn.
• the yarn is used in the weft direction (the warp was 100 percent wool) to make fabrics with a warp yarn count (Nm) 80 two ply and a weft yarn count (Nm) 76 two ply.
• the resulting fabric is about 96 percent wool and about 4 percent DOW XLATM elastic fiber, which may vary depending on the particular weave construction.
• a series of different weave constructions as set forth in Table 1 is prepared and the fabrics are dyed and finished according to standard processes. Each had a width of approximately 150 cm.
• the dimensional stability of these fabrics is tested after 5 cycles of washing according method ISO 6330 5A wash, wet measurement, as in Example 1 (that is, IWS TM31).
• the fabrics are also tested for dimensional stability following steam pressing according to testing method ISO 3005.
• the stretch and unrecoverable extension in the weft direction was determined according to IWS TM 179.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Woven Fabrics (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Knitting Of Fabric (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Inorganic Fibers (AREA)
• Bedding Items (AREA)

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• 2006
  • 2006-03-03 AU AU2006220812A patent/AU2006220812A1/en not_active Abandoned
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  • 2006-03-03 AT AT06736986T patent/ATE452230T1/de not_active IP Right Cessation
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