Textiles Chapter 4 Notes
Natural Cellulosic Fibers
Natural Cellulosic Fibers
• Classified by portion of the plant from which they are removed.
➢ Seed fibers: cotton, coir (coconut), kapok, milkweed
➢ Bast fibers: flax, hemp, bamboo, jute, ramie, kenaf, hibiscus
➢ Leaf fibers: abaca, pina, sisal, henequen
➢ Other: Spanish moss, cedar bark, rush, sea grass, maize, palm fiber
• Cellulose: Glucose – percentage depends on specific fiber; orientation, and
length varies by fiber.
Properties Common to all Cellulosic Fibers
• Good heat conductor
• Heat resistant
• Low resiliency
• Lacks loft
• Good electrical conductor
• Heavy fibers
• Damaged by mineral acids, resists alkalis
• Resistant to some insects; damaged by other insects, mold and mildew
• Moderate sunlight resistance: it will fade but other fabrics will fade faster
• Cellulosic fiber
• Seed-hair fiber, each fiber is a single cell growing from the seed in the “boll”.
Length fineness depends upon genetic type.
• Cotton is the most important fiber in textile/apparel industries.
• Major “Sunbelt” crop in U.S. due to the warm climate and rain.
➢ America Upland cotton grown in: Texas, California, Georgia, Mississippi,
Arkansas, Louisiana, North Caroline, Arizona, Tennessee, Alabama,
Missouri, South Carolina
➢ Extra Long Staple cotton grown in: California, Texas, Arizona, New Mexico
Varies of Cotton
• American Upland: short and medium staple cotton 7/8 – 1 ¼ inches
• Sea Island: Fine, long staple cotton grown in West Indies. 1 ½ – 2 ½ inches
• Egyptian: extra long staple cotton, can be grown in Egypt.
• Pima: extra long staple domestic cotton grown in the Southwest United
• Supima: trademark of the Supima Association of America, a group of growers
in the southwestern part of the United States. Cross section of Cotton Fiber
• Fiber is round when it is growing, but collapses when it dried.
• There is a hollow center, called the lumen, which carries water to feed the
growing tip of the seed hair.
• When it dries, the fiber becomes more bean shaped.
• Looks similar to a lima bean
• Parts: cuticle, wax-like film
➢ Primary cell wall: outer skin
➢ Secondary cell wall
➢ Lumen: central canal
➢ Convolutions: ribbon-like twists, cohesive
• Fineness: varies with maturity and type
• Color: creamy white, natural brown, green, etc.
Shape of longitudinal cotton fiber
• Looks like a twisted ribbon
• Twist along the length are called “convolutions”
➢ There are 200-300 convulsions per inch along the fiber
➢ Convolutions contribute to cohesive fibers
➢ Cohesiveness is the ability of fibers to adhere to one another when
twisted to form yarn.
• Staple length
• Grad: color of fibers and the absence of dirt, leaf matter, seed particles,
tangles, mote or dead fiber, 39 grades
➢ Mote does not absorb dyes, causes defects in fabric
• Character: other fiber aspects, maturity, smoothness, uniformity, fineness,
• What processing needs to happen to produce a good white fabric for
➢ Picking machinery, bleaching, etc.
Molecular Structure of Cellulose
• 99% glucose, high degree of polymerizati