Moolaguides com Intro to Textiles Spring 2012 Exam 1 Study Guide CTE1401 Exam 1 Study Guide Test on 2 17 12 Fri at 9 05am Chapters 1 2 Introduction Textile fibers What 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 acetate What are cellulosic fibers Which is the most commonly used cellulosic fiber derived from a plant source cotton Cellulosic fibers can come from different parts of the plant Name one example of each Seed hair cotton Stem flax linen Leaf agave Where 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 spit What 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 Properties What 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 looks Mechanical how it behaves Chemical how it performs Environmental how it react to environment 1 Moolaguides com Intro to Textiles Spring 2012 Exam 1 Study Guide What 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 absorbed What 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 water OLEO likes oil How 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 Fibers What 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 biodegradable Why 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 strength How do they burn meant to burn in nature so they keep burning when removed from flame 2 Moolaguides com Intro to Textiles Spring 2012 Exam 1 Study Guide How can you recognize cotton fibers under a microscope convoluted shape longitudinally kidney bean shaped cross section How is cotton processed 1 Picking 2 Ginning to remove seeds 3 Carding or combining to align the fibers How is linen processed 1 retting rot by soaking in water rain 2 breaking crushing under moveable wooden arm 3 scotching beat with knife 4 hackling metal combs What part of the plants do these fibers come from cotton come from seed hair of cotton plant linen comes from stem of flax plant What 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 jute What 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 rope Why 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 industry 5 Natural Protein Fibers Although 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 wool What breed of sheep produces the most valuable and finest wool merino What is virgin wool has not yet been used in manufacture What are some other animal fibers that are used for textiles camel alpaca llama vicuna guanaco rabbit angora goat mohair cashmere quivuit yak bison What are the properties that animal hair fibers have in common physical properties covered in scales 3 Moolaguides 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 static How do protein fibers burn Slowly and hard to ignite How can you recognize wool and other animal hairs under a microscope scales What is the only natural filament fiber silk Where does silk come from Larva of domesticates silk worms bombyx mori How 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 dried What is raw silk Sericin glue has not been removed What is tussah silk Wild silk obtained from natural habitats of silkworms What is sericulture The art of raising silk worms What does the cross section of silk look like triangular What is the difference between reeled and spun silk reeled silk comes from reeling the filaments of silk directly from the cocoons spun silk is when reeled silk filaments are spun into yarn immediately after