Moolaguides com Textiles Exam 3 on April 20 2012 Disclaimer There is no copyright infringement intended through the distribution of this study guide The following material is intended to help students study for a test as if hiring a tutor I genuinely wish you all the best CTE1401 Exam 3 Study Guide 9 05 am Friday April 20th Chapter 21 Textile Wet Processing Outline No Study Guide Provided Goals Understand the difference between batch and continuous processing Learn the steps for preparing fabric for dyeing or finishing Preparation of Fabrics Washing Removes dirt Any processing materials such as oils or sizing starches Bleaching To obtain a uniform white color before dyeing Batch Processing compare with using washer and dryer Used for smaller amounts of fabric 100 to 1000 yards of fabric Textiles water and chemicals are mixed in a single large vats Then rinsed and dried Continuous Processing Different vats are used fabric moves from one to the next on rollers Unfinished fabric is fed in one end finished fabric comes out the other Fabric may be washed bleached dyed dried and have finishes applied Processes 10 to 100 yards per minute Additional Processes Cotton singeing Excess surface fuzz short ends are burned off Produces a smoother fabric Wool carbonization Dilute sulfuric acid is applied then fabric is baked Carbonizes any plant matter which then falls out Process may also be done before spinning the wool yarn Silk degumming Silk is soaked in an alkaline solution to remove sericin silk protein Makes fabric softer and whiter also smells better Note See summary page 400 401 Chapter 22 Color What three things are required for color to be perceived light source object observer What are the some of the problems with colors fading etc Source Kadolph Langford 2002 336 What is the difference between dyes and pigments Dyes substances that add color to materials by being absorbed 1 Moolaguides com Textiles Exam 3 on April 20 2012 Pigments substances that add color to materials on the surface are not absorbed Usually printed What are the different stages at which coloration can be applied to textiles Which are the most and least expensive What are the advantages and disadvantages of each 1 Fiber dyeing Solution dyeing or Fiber stock dyeing MOST expensive PROS Color can be permanent if solution dyed Most thorough and level final color Can do color effect such as tweed CONS More expensive to produce Loss percentage is higher than other stages of dyeing More risky for manufacturer than other stages of dyeing If fashion changes color can t easily be changed 2 Yarn dyeing SECOND MOST expensive CONS Somewhat expensive Some material is wasted PROS Less risky Individual yarns are dyes to give pattern effect like gingham Fabric is the same on front back Special effects with space dying 3 Piece dyeing Cross dyeing or Union dyeing SECOND LEAST expensive PROS fabric is dyed a solid color before being made into a product most common and inexpensive 4 Product dyeing LEAST expensive PROS Least expensive Fast no storage of fabrics etc Good for t shirts towels CONS Yarns must match fabric later Fabric blends need 2 types of dyes CONS Dye can settle in seems and create unleveled appearance All parts must be compatible with dye type 2 Moolaguides com Textiles Exam 3 on April 20 2012 Source Kadolph Langford 2002 336 What is the difference between union dyeing and cross dyeing Union dyeing more than one class of dye used to dye all fibers in blend the same color Cross dyeing One class of dye used so different fibers are dyed different colors Know that different fibers cellulose protein synthetic take different dye types cellulose reactive and direct protein nylon acid dyes acetate polyeter disperse dyes Why is it necessary to keep fabric moving in the dyebath Vocabulary Metamerism two colors match under on light source but not under another Level as applied to coloration A color that is uniform and looks the same throughout the product Mordants substance that assists in dye bonding Color matching process of developing formula for reproducing color using color measurement the process of evaluating color in form of numerical values Color fastness the ability of a textile material to retain its color during use and care Chapter 23 Textile Printing What is printing Applying pigment to specific areas of textiles Can also be used to apply resist bleach adhesive or burn out paste What are the four printing methods we discussed in class How are they different from each other DIRECT PRINTING Creation of a colored design by applying a dye or pigment directly on a textile yarn or fabric 3 Moolaguides com Textiles Exam 3 on April 20 2012 blotch application colored background and design printed on fabric overprinting printing over a piece dyed fabric block old method similar to using a stamp warp warp yarns are printed before they are woven into fabric RESIST PRINTING A substance coats fabric in designated areas and prevents fabric from absorbing dye in those areas batik wax tie dye bound with yarns rubber bands ikat warp yarns are resist dyed selectively before weaving DISCHANGE PRINTING Piece dyed fabrics discharge paste removes color from specified areas Allows for light designs on dark colored fabric What is blotch printing How is it different from overdyeing How can you tell which was done by looking at the back of the piece of fabric blotch undyed fabric printed on front white on back white back blotch overprinting dyed fabric with design printed on front colored fabric on back colored back overprinted What is warp printing How does it differ from true ikat tie dyed yarn warp printing has the warp yarns dyed before they are woven Ikat uses resist dye method not printing How is screen printing done How is it different from roller printing Screen Printing Color is applied to a fabric using a screen Parts of the screen that are not to be dyed are covered with a barrier Roller Printing designs are printed on engraved rollers What is jet printing Ink jets similar to computer controlled paper printers eject small droplets of dye liquid onto textile fabric in predetermined pattern What is devore burn out What type of fabric must it be used on burnout Used on fabric with fiber blends Special chemical is printed on which destroys one of the fibers ex use acid on a cotton polyester blend destroys the cotton How is the puckered effect of plise made Plisse puckered effect created by imprinting chemicals that cause fabric to