Transcript Protein Fibers--Wool

FASH 15 textiles
natural protein fibers—wool
natural protein fibers
are of animal origin
•wool & specialty wools—hair & fur of animals
•silk—secretion of the silk caterpillar
natural protein fibers are luxury fibers today
•originally silk, vicuna, cashmere and camel
•wool production rates decrease while costs
increase
composed of various amino acids—have some
common properties due to similar chemical
composition:
•hygroscopic—absorb moisture and generate heat
wool
wool’s combined properties unequaled by any
manufactured fiber
•ability to be shaped by heat & moisture
•good moisture absorption without feeling wet
•excellent heat retention
•water repellency
•feltability
•flame-retardancy
one of the earliest fibers to be spun into yarns &
woven into fabric—most widely used textile fiber
before the Industrial Revolution
production of wool
in 2007:
•Australia—22.5%
•New Zealand—18.8%
•China—18.8%
•Eastern Europe—10.0%
•U.S.—.8% (ranked 10th)
Merino sheep produce most valuable wool:
•good quality fleeces weigh 15-20 lbs each
•3-5 inches long & very fine
•produces high-quality, long-wearing products
•has soft hand & luster, good drape
production of wool
fine wool in the U.S. is produced by 4 breeds:
•Delaine-Merino
•Rambouillet
•Debouillet
•Targhee
•majority produced in Texas and California
•2 ½ inches long
•often used for products that compete with Merino
production of wool
greatest share of U.S. wool productions is mediumgrade—removed from animals raised for meat
these wools:
•have larger diameter
•have greater variation in length (1 ½ - 6 inches)
•are used for carpeting—coarser fiber has high
resiliency & good abrasion resistance
15 breeds commonly found in U.S. vary
tremendously in appearance & type of wool—most
raised in the west
production of wool
•generally sheared once a year—spring
•fleece is removed in one piece with long, smooth
strokes beginning at legs & belly
http://www.youtube.com/watch?v=7646yA3dBSw
as alternatives to shearing (cut costs)
•chemical feed additive—makes wool brittle; several
weeks later wool can be pulled off
•injection—causes sheep to shed fleece within
week
production of wool
raw wool/grease wool—newly removed—30-70%
of weight is impurities; sand, dirt, grease, dried sweat
(suint)
clean/scoured wool—impurities removed
grease is purified to lanolin & used in creams,
cosmetics, soaps & ointments
grading—evaluating fleece for fineness & length
sorting—single fleece separated into sections of
fibers of different quality
types & kinds of wool
the term wool legally includes fibers from sheep,
angora & cashmere goat, camel, alpaca, llama, &
vicuna
•sheared wool—live sheep
•pulled wool—pelts of meat-type sheep
•recycled wool—worn apparel & cutter’s scraps
•lamb’s wool—animals less than 7 months old
often blended with less expensive fibers:
•reduce cost
•extend use
types & kinds of wool
Federal Trade Commission defines label terms as:
•virgin wool—never been processed
•wool—new wool or wool fibers reclaimed from knit
scraps, broken thread and noils (short fibers removed in making
worsted yarns)
•recycled wool—scraps of new woven or felted
fabrics that are shredded back (garnetted) to the
fibrous state & reused
terms on a label do not refer to quality of fiber, but to
past use
types & kinds of wool
quality is based on:
•fiber fineness
•length
•scale structure
•color
•cleanliness
•freedom from damage caused by environment or
processing
physical structure of wool—length
•merino wool—1 ½ - 5 inches
•long, fine wool fibers—average 2 ½ inches
•worsted—compact yarn made from longer
fibers with greater uniformity that have been
combed
•shorter fibers—average 1 ½ inches
•woolens—softer, more loosely twisted yarn
made from shorter, less uniform & less parallel
fibers
diameter varies from 10-50 micrometers
complex structure with cuticle, cortex & medulla
physical structure of wool—medulla & cortex
medulla is a microscopic, honeycomb-like core
containing air spaces—increase insulating power
appears as dark area when seen through
microscope—usually absent in fine wools
physical structure of wool—medulla & cortex
cortex is the main part of the fiber—made up of
long, flattened, tapered cells with nucleus near
center
cortical cells on two
sides of wool fiber react
differently to moisture
& temp—thus unique,
3D crimp
physical structure of wool—cuticle
the cuticle consists of:
epicuticle—thin, nonprotein
membrane that covers scales;
provides water repellency
scales—a dense, nonfibrous
layer that contributes to wool’s
abrasion resistance and felting
properties; can irritate the skin
physical structure of wool—cuticle
felting is unique & important to wool—based on
structure of the fiber
combine agitation, friction & pressure with heat &
moisture—adjacent wool fibers’ scale edges
interlock
prevents fiber from returning to original position
results in shrinkage, or felting, of fabric
participation activity:
felting wool
…take a piece of wool fabric
…wet the wool with soapy water (detergent speeds
wetting)
…work the wool with your hands—rolling it back &
forth or around
…after several minutes, examine the result and
answer the following questions:
•is it felted?
•can you separate the individual fibers?
•explain what happened.
chemical composition of wool
wool fiber is a cross-linked protein called keratin—
same protein found in horns, hooves & in human
hair and fingernails
keratin consists of carbon, hydrogen, oxygen,
nitrogen & sulfur—combine to form over 17 different
amino acids
flexible molecular chains of wool held together by
natural cross links—cystine linkages—most
important part
if damaged, entire structure destroyed:
alkalis, pressing & steaming, careless washing, exposure to light
properties of wool—aesthetics
wool contributes loft & body to fabrics
has matte appearance—shorter fibers often blended
with longer fibers to modify luster or texture
drape, luster, texture, and hand vary according to:
•yarn structure
•fabric structure
•finish
examine varieties
properties of wool—durability
moderate abrasion resistance stems from scale
structure & excellent flexibility—can be bent back on
themselves 20,000 times without breaking
(cotton—3,000 & flax—75)
•atmospheric moisture helps wool retain flexibility
•crimp & scale make fibers cohesive & clingy—
stronger yarns
•excellent flexibility, elongation & elastic recovery
wool fabrics can be used & enjoyed for many years
properties of wool—comfort
more hygroscopic than any other fiber—13-18%
moisture regain under standard conditions
poor conductor of heat—good insulator
wool fibers recover well from crushing—fabrics
remain porous & trap air
some are allergic to chemical components of wool;
others bothered by harsh edges of coarse wools
lightweight wools very comfortable in spring & fall
properties of wool—appearance retention
resists wrinkling and recovers well from wrinkles
maintains its shape fairly well during normal use
dry-cleaning helps to retain shape & size
when hand-washing be careful to avoid shrinkage or
stretching
properties of wool—care
does not soil readily—removal of soil is relatively
simple
•grease & oil do not spot wool fabrics as easily
•do not need to be cleaned after every use
•layer with washable garments next to skin
gentle use of firm, soft brush removes dust &
returns matted fibers to original position
garments require rest between wearing to recover
very susceptible to damage when wet
properties of wool—care
dry-cleaning recommended
hand-washing procedures:
•avoid agitation
•squeeze gently
•support item so it does not stretch
•air-dry flat
•do not machine or tumble dry—felting will occur
•chlorine bleach damages wool
•very sensitive to alkalis—strong detergents
•attacked by moth larvae & other insects—store so
inaccessible to moths
environmental concerns & sustainability
although a renewable resource, not produced
without environmental impact
•sheep graze so closely—soil erosion
•animal waste disposal
•sheep producers oppose programs to save
wolves & other natural predators
•treatment of sheep
•shearing practices
•health & back problems associated with
shearing hundreds of sheep daily
•intensive use of water, energy & chemicals
used to clean wool fiber, produce fabrics & finish
and dye them
environmental concerns & sustainability
organic wool—
•sheep fed organically grown feed
•graze on land not treated with pesticides
•not dipped in synthetic pesticides
some companies use barcodes to enable
consumers to trace path wool takes from grower to
production—criteria must be met to have barcode
•animal health & welfare
•long-term environmental respect
•fiber quality standards
uses of wool
most important use is adult apparel
•perform well & look great
•fit well—shaped through tailoring
•durable fabrics drape well
•comfortable under variety of conditions
•retain appearance during wear & care
minimal use in interiors—
•standard by which carpet is judged
•upholstery—durability & natural flame resistance
specialty wools
most obtained from goat, rabbit, and camel families
available in smaller quantities & usually more
expensive
vary in quality & require dry cleaning
two categories:
•coarse, long outer hair—interlinings, upholstery &
some coatings
•soft, fine undercoat—luxury coating, sweaters,
shawls, suits, dresses, interior textiles
mohair
•angora goat
•major producers: South Africa, U.S., Turkey
•sheared twice a year—fall & spring
•adult goat yields about 5 lbs of fiber
•fiber length 4-6 inches/8-12 inches
•used in hand-knitting yarns, pile fabrics & suitings
qivuit
•rare, luxurious fiber
•underwool of domesticated musk ox—6 lbs of wool
per year
•can be used just as it comes from animal
•resembles cashmere in hand & texture—much
warmer
•shed naturally
angora
•hair of angora rabbit
•produced in Europe, Chile, China, & U.S.
•harvested up to 4 times/year—plucking or shearing
•fiber yield varies with rabbit, health, breed 8-30 oz.
•two most common breeds—
•English—fine, silky fiber
•French—coarser
camel hair
•obtained from two-humped, Bactrian camel
•major producers: China, Mongolia, Iran,
Afghanistan, Russia, New Zealand, Tibet, Australia
•excellent insulator
•collected as shed or sheared—about 5 lbs/year
•finer fibers valued for apparel
•often blended with sheep’s wool
•used in coats, jackets,
scarves & sweaters
cashmere
•small Cashmere goat
•raised in China, Mongolia, Tibet, Afghanistan, Iran
•main source of income for herders in these
countries
•vary in color from white to gray to brownish gray
•usually combed by hand during molting season
•used for sweaters, coats, suits, jackets,
loungewear & blankets
•fabrics are warm, buttery in hand,
and have beautiful draping
llama & alpaca
•domesticated animals of South
American camel family branch
•fiber 8-12 inches long
•noted for softness, fineness, & luster—
appreciated by fashion designers
•natural colors range from white-light
fawn, light brown, dark brown, gray &
black
•used for apparel, handcrafts & rugs
•more difficult to dye than other wools
•llama is coarser and most often used
for coats, suitings, ponchos & shawls
vicuna & guanaco
•rare wild animals of South American camel family
•were killed for fiber, now sheared similar to sheep
•vicuna is one of softest, finest, rarest and most
expensive of all textile fibers
•short, very lustrous fiber; light cinnamon in color
•threatened species—
poaching continues to be
problem
yak
•produced by large ox found in Tibet & Central Asia
•collected by combing out during spring molt
•fiber is smooth & lustrous
•often used natively in apparel, rope, tent covers
•internationally used to blend with cashmere—
extend use & lower cost
•coarser than cashmere
•dark brown or black