DM120 Lecture 12 Outline of Last Lecture I Nonwovens Outline of Current Lecture II Textile Dyeing A Aqueous dyes III Pigments IV Classes of dyes V Color formulations Current Lecture Dyes and Pigments two ways of imparting color Dyes aqueous dyeing textile treated in aqueous solution and dyestuffs Pigments microscopic insoluble colored particles Conventional aqueous Dyeing Process 1 2 3 4 Cleaning fibers scoured Dye molecules adhere to fiber Penetrate fiber Migrate in the fiber Fiber is completely dyed Pigment Coloring Unlike dyes insoluble in water and do not combine with the textile fiber Can be used for any fibers Loss of color and fading with each succeeding cleaning Dyeing dyestuffs react and combine with in a water solution Depth of shade darkness or lightness of color Substrate fiber yarn fabric garment OWF on weight of fiber Classes of Dyes These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute No one universal dye for all textile fibers Affinity dye capable of combining with a particular fiber Dye classes dyes grouped by color fastness characteristics and by those applied with similar techniques Color formulations and matching shades Lab dip sample swatch of finished dyeing Standard future orders must conform Dye lot new batch Computer shade matching and computer controlled dyeing computer management systems 1 Color and shade matching systems 2 Aids in manufacturing high color standard and lot to lot shade consistency Spectrophotometer instrument measures percent of reflected light in visible spectrum Metamerism Two colors match under one light condition but look different in another light Color flare change in color of fabric because of a change in light source Color matching booth box type device used to test for metamerism What causes metamerism Chemical differences in dye components Different fabric types and different dyers but used to be used as matched items Needs attention and consideration When is dyeing done Stock dyeing dyeing fibers before it is spun into yarn Yarn dyeing dyeing of yarns before they are woven or knitted Skein dyeing immersing skeins loosely wound hanks into dye vats read about types of yarn dyeing in ch 8 of book Piece dyeing dyeing cloth after it is woven or knitted read about jet jig pat and beam in book Continuous dyeing fabric travels through dyeing process without stopping Garment dyeing dyeing completed garments