CTE 1401 Study Guide Exam 2 Spring 2013 Chapter 6 Regenerated cellulosic Why are manufactured cellulosic fibers called regenerated They are cellulose or protein produced from natural substances containing cellulose or protein in an unusable form Treated with chemicals to produce a solution that can be regenerated or reformed as a fiber Why are the properties of the manufactured fibers similar to the Natural cellulosic fibers Rayon is composed of cellulose like cotton How have the properties of rayon improved with new research and development A Japanese researcher modified the viscose process to develop a fiber with a physical structure more like that of cotton High wet modulus came about which means like cotton they have greater resistance to deformation when wet What are some of the end uses of rayon Most common type of rayon Apparel interior fabrics Non woven applications Often blended with other fibers to improve performance cotton balls disposable dust cloths disposable diapers High Wet Modulus HWM rayon newer version Has greater strength stretches less Used for cords in tires and some apparel What was the first thermoplastic fiber Acetate What is the difference between the properties of acetate and rayon Acetate is dry spun it dissolves in acetone and properties are desirable aesthetics but low strength and abrasion resistance Rayon properties are good drape and aesthetics low strength and low wrinkle resistance What are some of the end uses of acetate Household and apparel textiles Looks nice feels nice is inexpensive Special occasions costumes graduation robes Suit linings Cigarette filters Why was lyocell approved as a new generic fiber even though it has similar properties to rayon The FTC states Where the fiber is composed of cellulose precipitated from and organic solution in which no substitution of the hydroxyl groups takes place and no chemical intermediates are formed 7 11 Manufactured Fibers What is the best website for finding information about manufactured fibers What is a manufactured fiber Produced commercially through regeneration from natural materials or synthesized from chemicals What was the first synthetic fiber Nylon How does the production of manufactured synthetic fibers differ from regenerated fibers Regenerated fibers are made form natural polymer materials that cannot be used for textiles in their original form but that can be regenerated into usable fibers by chemical treatment and processing Synthetic fibers are made from materials that are created synthetically in a chemical process What are the steps to produce a manufactured fiber Develop the solution dope Extrude through a spinneret Coagulate or solidify the fiber Draw the fiber How do the three ways of creating manufactured fibers differ from each other dry spinning wet spinning and melt spinning Which one uses the fewest chemicals Dry spinning is when natural materials dissolved in chemical extruded into warm air Melt spinning is when chemicals combined to create substance usually as a flake or bead Wet spinning is when natural materials dissolved in chemicals extruded in to chemical bath The one that uses the fewest chemicals is melt spinning What is drawing fiber What does it accomplish Drawing is when the filaments are stretched to modify the molecular arrangements within the fiber Drawing makes the filament both narrow and longer From slide Godet wheels draw out fiber to increase polymer orientation more drawing more crystallinity Know the unique properties and end uses for Nylon Physical Appearance Normally round but may be shaped Example trilobal structure helps to hide soil Light weight Mechanical Allows final product to be lightweight but strong Very strong good for soft sided luggage seat belts hosiery Stretches easily good recovery Good resilience wrinkle resistant carpets don t show foot marks Good abrasion resistance Chemical Moderately absorbent dries quickly Poor electrical conductivity lots of static cling Dyes easily picks up colors in laundry Melts easily Better resistance to UV rays than natural fibers Environmental End Uses Nylon more expensive than many other synthetics Carpets Stretch fabrics Swimwear hosiery Sports wear Ropes Air bags Parachutes Fishing lines High strength Aramid Molecular structure makes them very stiff Resistant to high temperatures up to 700 Do not melt just decompose End Uses Expensive used in high end products where light weight strength and heat resistance are a priority Race driver s and fire fighter s clothing Other protective clothing astronauts safety gloves bullet proof vests Reinforcement fibers Tires aircraft canoes tennis racquets fishing rods Polyester Appearance Strength Low stretch Excellent resilience Can be spun with a variety of cross sections which affect appearance and performance Can be made into microfibers Very strong strength not affected by moisture Often blended with cotton to increase wrinkle resistance End Uses Most widely used fiber in the world Apparel Home furnishings Outdoor textiles furniture awnings Pillow and toy stuffing Resistant to moisture and microorganisms Industrial textiles Firehoses belting Acrylics Light weight Properties are similar to wool Relatively weak Good elongation and recovery Modacrylics are flame resistant self extinguish But Low resiliency usually knitted instead of woven to reduce wrinkling Low absorbency and conductivity Gets static End Uses Used as a substitute for wool Sweaters blankets socks Artificial fur Stuffed toys Knitting yarns Wigs Olefin Very lightweight Inexpensive Very non absorbent must be dyed in solution Weaker than nylon or polyester Good wicking properties Low melting point 32 of carpet and rug market End Uses Carpets and Rugs Carpet backing Home furnishings Very stain resistant Active Sportwear Good wicking abilities Geotextiles established Disposables Shopping bags Diaper liners Cleaning cloths Spandex Can stretch up to 5 times its length and recover Lightweight Degrades in sunlight so doesn t have to be removed after plant growth is Less damaged by sunlight body oils chlorine suntan lotions than rubber Uses Always used with other fibers Stretchy yarn Covered spandex core is covered with another yarn Corespun spandex core is covered with a staple fiber Swimwear Apparel Shapewear Used in small amount 2 5 Provides slight stretch and better fit More wrinkle resistance What are elastomeric fibers Material that elongates stretches and returns to its original shape What is