Moolaguides.com – Intro to Textiles Spring 2012 Exam 1 Study GuideCTE1401 Exam 1 Study GuideTest on 2.17.12, Fri at 9:05amChapters 1, 2. Introduction, Textile fibersWhat is the AATCC?*American Association of Textile Chemists and Colorists, the world’s leading not-for-profit professional association for the textile design, materials, processing, and testing industries.What is the difference between natural and manufactured fibers? Name examples of each.*Natural- seed hair, bast, leaf, silk, wool*Manufactured- viscose rayon, lyocell, acetateWhat are cellulosic fibers? Which is the most commonly used cellulosic fiber?*derived from a plant source*cottonCellulosic fibers can come from different parts of the plant. Name one example of each:Seed hair- cottonStem- flax(linen)Leaf- agaveWhere do natural protein fibers come from? Which natural protein fiber is different from all of the others?*derived from an animal source*hair- wool, cashmere, camel, etc.*silk is the only one that’s not hair, it is worm/spider spitWhat is the difference between an amorphous and crystalline fiber structure? How can this affect the performance of the fiber?*amorphous- chain of polymers has a random arrangement (absorbent,weaker, stretchier, low luster)*crystalline- chain of polymers has an orderly arrangement (not absorbent, strong, not as flexible, more resilient, usually manufactured)3. Fiber PropertiesWhat is luster in a textile?-amount of light reflected by the fiber-natural has subtle luster, manufactured have brighter luster-cross sectional shapes affect luster (flat=high, trilobal=medium, pentalobal=soft)What is the meaning of the four properties we use to describe fiber?Physical- how it looksMechanical- how it behavesChemical- how it performsEnvironmental- how it react to environment1Moolaguides.com – Intro to Textiles Spring 2012 Exam 1 Study GuideWhat is the difference between absorption and adsorption?*aBsorption- ability of a fiber to take water into itself*aDsorption- water is held on surface of fiber rather than being absorbedWhat does hydrophobic mean? Hydropilic? Hygroscopic? Oleophilic?*hydrophobic- fiber does not absorb fiber readily (rain coat)*hydrophilic- fiber readily absorbs water or other liquid (bath towel)*hygroscopic- fiber take up and retains moisture from the air; does not readily release by evaporation (wool absorbs 2/3 weight in water before feeling wet)*oleophilic- has a strong affinity for oil-based substances such as salad oil, grease, etc. (polyester)SCO scoops up the waterOLEO likes oilHow does burning a fiber determine which generic group it belongs to (protein, cellulose, thermoplastic, inorganic)?*melt- polyester*catch fire and keep burning- cotton*catch fire then stop burning- hair*don’t react to heat- *shrink in heat (wool sweater, cotton t-shirt shrink in dryer)How does electrical conductivity of a fiber relate to having problems with static?4. Natural Cellulosic FibersWhat properties do cellulosic fibers have in common?*derived from a plant source*good absorption, slow to dry, subject to mold and mildew, low electrical conductivity, no static cling*stronger when wet*may shrink when washed*does not melt, will scorch and burn, will continue burning when removed from flame*harmed by acids, resistant to alkalis(baking soda)*biodegradableWhy are they stronger when wet?*fills up like a fire hose, making it more stiff*when it fills up with moisture, the inner layers swell and push out against the primary wall, providing strengthHow do they burn?*meant to burn in nature, so they keep burning when removed from flame2Moolaguides.com – Intro to Textiles Spring 2012 Exam 1 Study GuideHow can you recognize cotton fibers under a microscope?*convoluted shape longitudinally*kidney bean shaped cross sectionHow is cotton processed? 1- Picking2- Ginning to remove seeds3- Carding or combining to align the fibers How is linen processed? 1- retting- rot by soaking in water/rain2- breaking- crushing under moveable wooden arm3- scotching- beat with knife4- hackling- metal combsWhat part of the plants do these fibers come from?*cotton come from seed hair of cotton plant*linen comes from stem of flax plantWhat is a bast fiber? What is the most common bast fiber used for clothing?*fibers that come from the stem of a plant*woody core surrounded by fibers, then an outer coat*linen flax, hemp, juteWhat are some other plants used for fiber? What are the major uses for jute?*jute plants grow 6-16 ft. tall*coarser and weaker than linen*used in burlap, erosion cloth, ropeWhy can’t hemp be grown in the United States?*tobacco farmers got it outlawed as the cousin to marijuana because they wanted the land for the tobacco industry5. Natural Protein FibersAlthough it is possible to make regenerated protein fibers (from soy or milk), all commercially used protein fibers are natural.What is the most used animal fiber?*sheep’s woolWhat breed of sheep produces the most valuable and finest wool? *merinoWhat is virgin wool?*has not yet been used in manufactureWhat are some other animal fibers that are used for textiles?*camel, alpaca, llama, vicuna, guanaco, rabbit(angora), goat(mohair/cashmere), quivuit, yak, bisonWhat are the properties that animal hair fibers have in common?*physical properties: --covered in scales3Moolaguides.com – Intro to Textiles Spring 2012 Exam 1 Study Guide--3D crimp--keratin--round cross section--sometime hollow core--color: white, cream, brown, gray, black--staple length from 2” to 10” in a year’s growth--low luster*mechanical properties:--amorphous, weak--weaker when wet--good elongation, elastic recovery--excellent resilience*chemical properties:--hydrophilic--thermal insulation--burns slowly and hard to ignite--low conductivity, but can have staticHow do protein fibers burn? Slowly and hard to igniteHow can you recognize wool and other animal hairs under a microscope? scalesWhat is the only natural filament fiber? silkWhere does silk come from? Larva of domesticates silk worms, bombyx moriHow is it processed? *For cultivated silk, silk worms cover themselves in cocoon of sericin-covered silk strands, then the cocoons are put in hot water to kill the worms and the fiber are reeled and driedWhat is “raw” silk? Sericin (glue) has not been removedWhat is “tussah” silk? Wild silk obtained from natural habitats of silkwormsWhat is sericulture? The art of raising silk wormsWhat does the cross section of silk look like? triangularWhat