cid 127 Goal Produce appealing level fast will stay on the fabric color on product with good performance and minimal environmental impact CHAPTER 8 TEXTILE DYING Color Important apparel and interior product characteristic History and Background All dye used to come from natural sources plant insect minerals In 1856 the first synthetic dye was discovered Complex area difficult to get color on fabric in uniform appearance level that will not fade or bleed A colorant describes the dyes or pigments that add color to textiles Coloration is the process of adding color Level describes a textile with same hue value and intensity in all areas Colorfast ness dyes and prints that do not fade or change color or move onto other textiles Dyes and Pigments Two ways of imparting colors Dyes aqueous dyeing Binding dyestuffs and other agents to a textile a chemical reaction occurs Pigments microscopic insoluble colored particles held on the surface of a fabric by a binding agent Conventional or Aqueous Dyeing Dyeing dyestuffs react and combine within a water solution Depth of shade darkness or lightness of color Substrate a ratio cid 127 Weight of fiber Quality of dye Classes of Dyes Affinity dye capable of combining with a particular fiber Dye classes dyes grouped by colorfastness characteristics and those applied with similar techniques Dye Classifications important class Direct Dyes Substantive good on cellulosic fibers brighter colors made of large planar molecules moderate wet fastness most commercially Acid anionic good on wool silk nylon some rayon acrylic and polyester bright colors poor wet fastness may have poor light fastness Fiber Reactive used to dye natural fibers bright pure colors good to excellent fastness Vat cottons a solubility cycle dye difficult to process dull colors good fastness incomplete color range limited color palette used for bottom weight heavy goods Disperse synthetics good fastness may fume fade after fabrication Pigments insoluble in water and do not combine with the textile fiber Natural Dyes minor dye class Best on protein fibers nylon and cellulosics cid 127 More renewable and sustainable From plant animal and mineral sources Used for apparel and interiors limited colors and availability Plant sources Indigo blue Madder Logwood Marigold etc Animal sources Cochineal Murex Cuttlefish urine cid 127 Mineral sources Clay mud stones minerals etc Also most mordants Color Formulations and Matching Shades Lab dip sample swatch of finished dyeing Standard future orders must conform to Dye lot new batch Computer Shade Matching and Computer Controlled Dyeing Color management systems aids in maintaining high color standard and lot to lot shade consistency Spectrophotometer instrument measures percent of reflected light in visible spectrum cid 127 Metamerism Two colors match under one light condition but look different in another light Color matching booth box type device used to test for metamerism Bezold effect when two or more colors merge into one new color i e small scale print or yarn dyed fabric viewed from a distance Think Impressionist painting cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 Solution dyeing Mass pigmentation colored spun or dope dyed add colored pigments to spinning solution color integral spart of fiber cid 127 When dyeing is Done fiber stock top yarn piece or garment Table 8 2 cid 127 Optical color mixing Stages of Dyeing Pre fiber stage synthetics only Best for fibers that are difficult to dye cid 127 Olefins Black polyester Acrylics Sunbrella cid 127 Gel Dyeing color incorporated before fiber coagulates Stock or fiber dyeing Dye is added to loose staple fibers Dyed before yarn processing cid 127 Good dye penetration Tweeds Yarn Stage Dye in yarn stage before fabrications Skein Dyeing immersing skeins loosely wound hanks into dye vats Almost always limited to stripes plaids or structural design fabrics Top Dyeing dyeing fiber before it is spun into yarn to produce heather colors mottled or heather effect cid 127 More expensive than piece dyeing solid colors usually piece or product dyes not yarn or fiber dyes Ex gingham chambray knit structural designs cid 127 More likely to see stripe parallel to warp yarns in woven fabric easier to dress loom or parallel to course in knit fabric Piece Dying dying cloth after it has been woven or knitted Continuous dyeing process fabric travels through dyeing process without stopping Jig Dyeing fabric is passed through a stationary dye bath not totally immersed in the dye bath Pad Dyeing fabric passes through dye bath and then through rollers where dye solution is squeezed into it Beam Dyeing fabric is loosely wound onto perforated cylinder then dye bath is forced through the stationary fabric layers cid 127 Garment Dyeing dyeing of completed garments Color is added after the product is cut and sewn Selling feature in spring and summer Found in socks hosiery T shirts jackets pants towels etc Special Dyeing Effects Table 8 3 Problems is leveling difference in components poor penetration dimensional changes requires well prepared greige goods Cross Dyeing fabric of two fiber types having different dye affinities is dyed in a single bath of different dye classes Produces multicolor effect Union Dyeing two classes of dye in same color to produce one color Do this to produce a Tone On Tone Effect one dye bath to produce different tones in fabric by using fibers with different affinities Resist Dye color prevented from entering fabric in specific areas when piece or yarn dyed Untreated areas absorb dye treated areas do not cid 127 Goal to create a pattern or motif 3 types 1 Batik used hot wax on fabric tool used called a tjanting piece dyed wax removed price related to quality and colors 2 Tie dye AKA Shibori yarn or fabric if wrapped to prevent dye penetration during piece dyeing thread removed after dyeing 3 Ikat yarn tied to prevent dye penetration dyed woven Dyeing in only warp direction single ikat Dyeing both warp and weft double ikat CHAPTER 9 PRINTING Textile Printing Printing dyeing in a localized patterned area Adds color to the surface of specific areas of textiles Producing a face and back the