DYEING OF ELASTIC FIBRES ( DYEING OF SPANDEX,LYCRA,POLY-EURATHANES)

DYEING OF ELASTIC FIBRES ( DYEING OF SPANDEX,LYCRA,POLY-EURATHANES)

• 1.
  Presentations @IIT-D BY VIVEK YADAV 9457631264
• 2.
  A Presentation On DyeingOf Elastane Submitted By Vivek Yadav Submitted To Dr. B.S. Butola
• 3.
  Brief History  Spandexderived from the term expands  Spandex is preferred name in North America , elsewhere it is referred as elastane  Development started during World War II.  F. Bayer, earned a German patent for his synthesis in 1952.  Du Pont as brand name Lycra started full scale manufacture in 1962.
• 4.
  Basics about ElastaneFibre It is a synthetic polymer made up of a long-chain polyglycol combined with a short di-isocyanate, and contains at least 85% polyurethane. Two Segments (long, amorphous segments and short, rigid segments).
• 5.
  Basic Properties overview •Physical Properties of Spandex Fiber: • Cross section- non-circular cross- sectional shapes. • Density: 1.15 to 1.32 g/cc, • Moisture regain 0.8 - 1.2% • Tg -20°C • Breaking tenacity: 0.6-0.9 grams/denier. • Elongation- 300%-400% • Luster: dull luster.
• 6.
  Pretreatment; Bleaching ? •Can be bleach by hydrogen peroxide in a best way . • Not hypochlorite bleaching because they degrade polyurethane. • Cellulose/polyurethane fibre blend can be bleached using hydrogen peroxide where as synthetic/PU fibre blend needs no bleaching agent. where the fabric is treated only with soda ash and other auxiliaries. Why not Hypochlorite bleaching It may cause yellowish color
• 7.
  Free radical degradationof Elastane due to NaOCl bleaching Reference-Chlorine Degradation of Polyether-Based Polyurethane SANDEEP KHATUA, YOU-LO HSIEH Fiber and Polymer Science, University of California at Davis, Davis, California 95616
• 8.
  PU dyeing ? Dyeingdifficult ? • Complicated distribution of soft & hard segment. • Lack of dye reacting sites That’s why elastane has been divided in two groups • Simple elastane( trapping in hard segment of the polymer chain ,needs after treatments) • Dye-able elastane- Development of dyeing sites ( U.S. patent number US 7,838,617 B2 )
• 9.
  Dye able Elastane ThePoly-Urethane-urea is prepared using a combination of 4,4'-MDI (4,4'-Methylene- diphenyl di-isocyanate) and 2,4-MDI, and an amount of chain extenders and chain terminators. Chain terminators-Include secondary amines, for example diethylamine (DEA) Result- Resulting polymer chain having NH- group which will behave like wool , nylon and silk ( dyeing sites) and can be dyed with the help of acid , reactive , metal complex dyes. Fabrics made up of dyeable elastane will cause better over all fastness Reference-DYEABLE SPANDEX, United States Patent, Patent No.: US 7,838,617 B2, Date of Patent: *Nov. 23, 2010
• 10.
  Dyeing Of Polyurethanes •Mostly it is only 2-5% of the total fabric. • Due to high cost of dye-able Elastane they go to obscure it with different fabric structure, high shade dyeing dominant fibre ( polyamide , cotton , PET etc) Dyes may use -Acid Dyes , 1-2metal Complex , Chrome Dyes ,Desperse Dyes , ( heavy shade needs after treatment with tannic acid to improve the fastness properties.) Dyeing Recipe Acetic acid – for pH balance in acidic range Dye- Pre- Metalized Acid Dyes Temperature - ~90 °C Holding time – depends on shade and dye affinity 0 50 100 0 50 100 150 Temp. 90° C Time ( minutes) 2°C/minute 60°C
• 11.
  Blend dyeing ;Elastane with cellulosic Material What if cellulose is dominant ? Process ? Dyed with separate dyes , acid and reactive Polyurethane is first dyed with disperse/acid/metal complex dyes followed by reactive dyeing. Medium and heavy shades- Acid or Metal complex dyes Needs after treatment with tannic acid to improve light fastness property of dyed material. Recipe for dyeing – As usual dyeing recipe for separate acid and reactive dyes , but low pH reactive dyes requires
• 12.
  Dyeing of elastane/polyamide blends PROBLEM ? As the dyes used to be hydrophobic in nature , favors polyamides and rush towards it quickly. Causing unleveled dyeing SOLUTION? We use anionic retarders which competes with dyes for dye sites on the fibres cause level dyeing on both the fibres ANIONIC RETARDERS? Sulphonic acids, such as naphthalene sulphonic acid . It consist about 2%. For combined dyeing of elastane and polyamide blends , following is the recipe Dye- Metal complex dyes, Acetic acid- as pH maintainer Anionic retarders- Sulphonic Based Organic Compounds. REFERENCE- U.S PATENT NO. 3653798 0 50 100 0 50 100 150 Temp. Time (minutes) Anionic retarder at 70°C Dyeing ~ 95°C
• 13.
  Dyeing of polyesterelastane blends • Both the polyester and the spandex are hydrophobic fibers and both can take dispersing dyes, • What at low temperature? • PU take up high disperse dyes ( below 100°C) • What at high temperature? • From 100°C, dye began to rush towards PET , by holding it to 130°C , we get even dyeing • Problems ? • Elastane is not suitable for high temperature dyeing as PET requires high temperature dyeing. • Solution ? • Carrier ? • It will lower down the Tg of PET, creates possibilities to dye around 98°C . • It will followed by a reduction clearance process to achieve better washing fastness of the blends, specially from elastane.
• 14.
  Dyeing recipe Disperse dye-as required pH regulator (ammonium acetate) - .1-2 gpl Carrier - .1-1 g.p.l. ( Organic compounds having phenols) MLR ration 1-5 and up to 1-50 pH = ~ 4 to 6 Temperature ~ 100 °C Reduction clearance sodium dithionite – 0.1 to 4 gpl sodium hydroxide- .1 to 3 gpl Soaping agent - .2 to 3gpl Temperature- 70°C Note The dispersing dye is related to a low temperature or moderate temperature dispersing dye. Resultant dyed fabric will provide following fastness value- Grade 4~5 of changed color in soaping; Grade 4~5 color fastness to sunlight; Reference-Polyester -spandex elastic fabric dyeing method Europian patent-EP 2 067 892 A1 dated-10.06.2009
• 15.
  References • Textile Science:An Explanation of Fibre Properties by E.P.G. Gohl & L.D. Vilensky, 2nd edition , page no. 98-105 • DYEABLE SPANDEX, United States Patent, Patent No.: US 7,838,617 B2, Date of Patent: *Nov. 23, 2010 • METHOD FOR DYEING FABRIC COMPRISING ELASTOMERIC FIBER, United States Patent, Patent No.: US 6,613,103 B2, Date of Patent: Sep. 2, 2003. • STUDY OF PROCESSES OF DYEING POLYURETHANE FIBRES BY VARIOUS CLASSES OF DYES, by A. E. Tret’yakova, V. V. Safonov, and A. Yu. Yusina, Fibre Chemistry, Vol. 44, No. 5, January, 2013 (Russian Original No. 5, September-October, 2012) • Processing of polyurethane fibre and its blends, Article in Man-Made Textiles in India · July 2003, byBharat H Patel. • PROCESS FOR THE DYENGS OF BLENDS OF SPANDEX FBERS ANDPOLYAMDE FIBERS, United States Patent, George Leslie Boardman, patent no. 3,653,798, Date-Apr. 4, 1972 • PROCESS FOR DYEING SPANDEX FIBERS, Inventor: Jai P. Sharma, Hickory, N.C., United States Patent, Patent Number: 5,382.264, date-Jan. 17, 1995 • METHOD FOR DYEING FABRIC COMPRISING ELASTOMERC FIBER, Inventors: Robert FImmediato, Patent No.: US 6,613,103 B2, Date of Patent: Sep. 2, 2003 • Chlorine Degradation of Polyether-Based Polyurethane SANDEEP KHATUA, YOU-LO HSIEH Fiber and Polymer Science, University of California at Davis, Davis, California 95616