3-23-10
Natural Fiber Materials
Cloth, Wood, Paper
Chapter 18 Lecture 21
Important Concepts:
1. Natural fibers from plants
a. cloth
2. Wood and wood products
a. Fuel, construction
3. Paper
a. Means of communication
Fibers
Botanical – long narrow tapering cell, dead and hollow at maturity; composed of cellulose and lignin; for
support.
Commercial – long narrow flexible material; maybe from animal, mineral, synthetic, or plant.
Types:
1. Surface fibers – from seeds, leaves, fruits (mostly hairs)
2. Bast (soft) fibers – phloem tissues (mostly fibers) of dicots
3. Hard (leaf) fibers – vascular bundles (xylem, phloem, fibers) leaves of monocots
Fibers must stand up to twining in sipinning process, which holds the fibers together
mechanically
Characteristics:
Look and feel
Strength
Elasticity
Density
Resistance to heat, chemicals, sun, etc.
Historical Perspective
Plant fibers – used throughout human history, initially as strips of bark, stems, or leaves to make
mats, baskets, etc.
Flax has been used for 8000 years, so plant fibers were apparently used in weaving before
animal fibers.
Cellulose
Plant fibers are composed of cellulose - long chain of glucose molecules
Animal fibers are protein (collagen)
Properties
o Withstand high temperatures
o Does not incorporate colors easily
o Resistant to animal pests, but susceptible to fungi and termites
o Less elastic than animal fibers and have higher affinity for water
o Gene = RSW1
*most synthetic fibers are produced from petroleum (nylon, polyester, etc.) – exception is rayon (made
from cellulose, mostly from wood pulp)
Plant fibers that are short, brittle, or slippery cannot be twined woven, plaited, or spun, can be used for
paper, fiberboard, cellophane, and rayon (synthetic “silk” made from cellulose, mostly from wood pulp)
Fiber Extraction
Retting – produces bast fibers
o Plant stems placed in water or wet area to rot
o Thick walled xylem remains and must be removed by scotching
o Fibers are hackled (separated and aligned) by drawing them across a comb
Ginning – seed fibers
o Fibers are removed from seed
Decortications – hard fibers
o Unwanted tissues scrapped away by hand or machine
Cotton: Seed & Fruit Fibers
Most important fiber plant
Easily processed mechanically
Fibers dye well and withstand vigorous washing
Archeological evidence 10,000 years ago in Peru
Tremendous influence on history; especially U.S. history
Top producers: …
Species
o Member of Mallow family; shrubby perennial
o Needs warm climate and lots of water
o Fibers from seed haris (e.g., 20,000 per seed); seeds packaged in a capsule (cotton boll)
o Hairs are 90% cellulose
SEE POWERPOINT