Study Guide Test 3 Chapter 21 What is the difference between batch and continuous processing Batch processing is meant for smaller amounts of fabric and textiles water and chemicals are mixed in single large vats it is compared with using a washer and dryer In 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 Why is cotton fabric singed It burns off the extra surface fuzz and makes the fabric softer What fiber may be carbonized Why Wool to remove any plant fiber that may be in the wool Why are fabrics bleached before dyeing To obtain and uniform white color What is silk gum and why should it be removed Silk gum is another term for sericin the silk protein and it is removed so the fabric is softer whiter and smells nicer Chapter 22 What three things are required for color to be perceived Light source an object and an observer What are the some of the problems with colors fading etc fading bleeding color moves to another object usually in water migrating color moves from one part of a garment to another by capillary action frosting loss of color due to abrasion and crocking transfer of color from one material to another by rubbing What is the difference between dyes and pigments Dyes are absorbed and pigments only add color on the surface but are not absorbed Pigments are 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 Fiber dyeing Color can be permanent if solution dyed Most thorough and level final color Can do color effect such as tweed More expensive to produce Loss percentage is higher than other stages of dyeing More risky for manufacturer than other stages of dyeing and If fashion changes color can t easily be changed Yarn dyeing next most expensive but less risky They usually look the same on front and back Piece dyeing less expensive that fiber or yarn dying If the fabric is just one fiber content the piece can be dyed easily Product dyeing all parts must be compatible with dye type Can be done quickly without a large storage of inventory Least expensive process What is the difference between union dyeing and cross dyeing They d are both used on mixed blend fibers Union dying requires more than one class of dye used to dye all fibers in blend the same color Cross dying uses one class of dye so different fibers are dyed different colors Know that different fibers cellulose protein synthetic take different dye types Why is it necessary to keep fabric moving in the dye bath to make sure all parts of the garment are dyed equally Vocabulary Metamerism two colors match under one light source but not under another Level as applied to coloration a color that is uniform and looks the same throughout the product Mordant s substance that assists in dye bonding Color matching process of developing formula for reproducing color Color fastness the ability of a textile material to retain its color during use and care Chapter 23 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 apply color directly Resist prevent color from penetrating fabric Discharge removes color Heat transfer What is blotch printing How is it different from overprinting How can you tell which was done by looking at the back of the piece of fabric Blotch is both a colored background and design motifs are printed onto the fabric Overprinting is where the application of a design on a fabric that has already been dyed pigment is not absorbed by the fibers but remain on the surface With overprinting the background color shows on back but not the design What is warp printing How does it differ from true ikat tie dyed yarn Warp yarns are printed before they are woven into the fabric Tie dyed yarn is a resist method of dying and would be seen on back and front How is screen printing done How is it different from roller 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 use engraved rollers more expensive but can give finer detail 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 Must be used on fabric with fiber blends Special chemical is printed on which destroys one of the fibers and leaves a semitransparent area How is the puckered effect of plisse made It is made by imprinting chemicals that cause the fabric to shrink in imprinted areas What is flock printing Design in printed on in adhesive flocking is applied to adhesive Chapter 24 What is the difference between aesthetic and functional finishes Aesthetic finishes affect the appearance texture or dimensional stability of the textile functional finishes affect the performance of the textile How are finishes classified based on how long they remain in or on the fabric Durable finishes are permanent semi durable and non durables are temporary What types of fibers can be heat set permanently Thermoplastics How can a durable finish be applied to a natural fiber Resin treatments Are there any types of finishes that can be applied at home by the consumer Starch finishes fabric softeners What is a calender A mechanical finish where the fabric is passed between a series of two or more rollers A Schreiner calender One calendar rolls embossed with 250 fine diagonal lines per inch flattens yarns A friction calender An embossing calender The process of pressing a pattern onto fabrics It is permanent only when applied to thermoplastics semi durable when applied to fabrics with a resin treatment and temporary on other fabrics How is fabric polished glazed or cired A fabric is glazed polished or cired by saturating it with a starch or resin dried slightly and then fed into a machine with a rapidly moving heated roller What is moir Describes the watered or clouded appearance of ribbed fabrics applied by rollers How can embossing be made permanent By using thermoplastic fabrics What is brushing and napping Brushing is made from staple fibers