2. manufactured regenerated fibers
produced from naturally occurring polymers
these polymers do not occur naturally as fibers—
processing is needed
starting material is cellulose & protein—majority
used in apparel, interiors and technical products are
cellulosic:
• rayon
• lyocell
• acetate
3. cellulosic regenerated fibers—rayon
the first—many regeneration processes were
developed
commercial production of viscose rayon began in
1910 in the US—sold a ‘artificial silk’ until rayon
was adopted in 1924
produced as a filament until discovered that scraps
could be used as staple fibers…now filament tow
•Cupra rayon—cuprammonium
•Viscose rayon—regular rayon (weaker than HWM)
•High-wet-modulus (HWM) rayon—aka HP (high
performance), polynosic, or modal
4. cellulosic regenerated fibers—rayon
production:
wet spinning most common method
• purified cellulose is chemically converted to
a viscose solution
• forced through spinnerets into a bath
• returned to solid 100% cellulose filaments
HWM process maximizes chain length & fibril
structure
5. cellulosic regenerated fibers—rayon
physical structure:
regular viscose characterized by striations
(lengthwise lines)
cross section—serrated or indented circular shape
(HWM & cupra are more circular)
serrated shape is an advantage in dyeing—
increases fiber’s surface area
•filament—40-5000 denier
•staple & tow—1.5-15 denier
•micro rayon fibers also available
6. cellulosic regenerated fibers—rayon
properties—aesthetics:
made to resemble cotton, linen, wool & silk
can be engineered with
characteristics similar to other fibers
in a blend
has an attractive, soft, fluid drape
sizing may be added to increase
body and hand
Cupra has more silklike hand & luster, can be found
in smaller deniers
7. cellulosic regenerated fibers—rayon
properties—durability:
regular rayon is a weak fiber—loses about 50% of
strength when wet
will stretch slightly before breaking—lowest elastic
recovery of any fiber, will not return to shape
weakness comes from amorphous areas
HWM is more crystalline & oriented so relatively
strong
cupra not as strong as HWM, stronger than viscose
8. cellulosic regenerated fibers—rayon
environmental concerns/sustainability:
•significant processing is involved to produce useable
fiber
•clear cutting may be an issue
•processing wood pulp uses large quantities of acid &
other chemical (water & air pollutioni)
•cupra rayon no longer produced in US—could not
meet minimum air & water quality reqs
•more susatinable alternatives include lyocell & rayon
from managed forests
•biodegradable—current landfill practices?
9. cellulosic regenerated fibers—rayon
uses:
mostly used in woven fabrics—especially apparel
and interior drapery & upholstery
also used in nonwoven fabrics for absorbency
•technical wipes
•medical supplies—bandages, diapers, sanitary
napkins & tampons
Cuprammonium rayon used in dialysis machines to
filter waster products from blood
10. cellulosic regenerated fibers—rayon
types & kinds:
only way to determine specific type of rayon is by
the trade name
•HWM
•solution-dyed
•modified cross-section
•intermediate- & high- tenacity
•optically brightened
•high absorbency
•hollow
•microfibers
•Visil—contains silica, flame-retardant
11. cellulosic regenerated fibers—lyocell
created in part (1990s) due to environmental
concern of rayon production
production:
wet-spun: polymer dissolved in liquid and spun in a
weak bath of amine oxide—low toxicity, low skin
irritation; solvent recovered, purified & recycled
physical structure:
more rounded cross section
& smoother longitudinal
appearance than rayon
12. cellulosic regenerated fibers—lyocell properties
aesthetics:
•luster, length & diameter can be changed depending
upon end use
•processed to produce a range of surface effects
•offers unusual combinations of strength, opacity,
absorbency
durability:
•performs more like cotton than rayon
•strongest of cellulosic fibers
•unique combination of soft hand & good durability,
produces comfortable, long-lasting textiles for apparel
& interiors
13. cellulosic regenerated fibers—lyocell properties
comfort:
•soft, smooth fiber with few static problems
•ideal for apparel that contacts skin
•thermal retention is poor
appearance retention:
•resiliency is moderate—wrinkles but not as severely
as rayon
•shrinks, but not progressively
•may have problems with fuzziness or piling
care
•either gently machine-washable or dry cleaned
•sensitive to acids; resistant to mild alkalis
•sensitive to mildew & some insects
14. cellulosic regenerated fibers—lyocell
environmental concerns/sustainability:
•produced from wood pulp—managed forests/fast-
growing eucalyptus trees
•recovers & reprocesses 99.5% of solvent bath
•chemicals significantly less hazardous to
environment than those used for viscose rayon
•biodegradable—not recycled
•makes extensive use of water, dyes & finishing
chemicals
•dry cleaning solvents present additional
environmental hazards
15. cellulosic regenerated fibers—lyocell
uses:
•professional business wear
•leotards
•hosiery
•casual wear
•upholstery
•window-treatment fabrics
•filters
•printers’ blankets
•specialty papers
•medical dressings
•used in blends with wool, cotton & other MF
•used in conveyer belts for strength & softness
17. cellulosic regenerated fibers—acetate
originated in Europe as varnish for airplane wings
in 1924 became 2nd
MF to be produced in US
could not be dyed with existing dyes—disperse
dyes created specifically for acetate/triacetate—
certain of these change color when exposed to
atmospheric pollutants
1st
thermoplastic (heat sensitive) fiber—melt under
hot iron—consumers unaccustomed to this
18. cellulosic regenerated fibers—acetate
production:
•purified cellulose from wood pulp or cotton linters
•mixed with glacial acetic acid; acetic anhydride & a
catalyst
•aged 20 hours—partial hydrolysis occurs
•precipitated as acid-resin flakes
•flakes dissolved in acetone
•solution is filtered
•spinning solution extruded in column of warm air;
solvent recovered
•filaments stretched and wound onto beams, cones or
bobbins ready for use
20. cellulosic regenerated fibers—acetate
physical structure:
•available as staple or filament—filament more silk-
like
•lobular or flower petal shaped cross section—
varied according to use; flat filaments give glitter
21. cellulosic regenerated fibers—acetate properties:
aesthetics:
widely used in satins, brocades & taffetas—luster,
body, & drape more important than durability or
ease of care
durability:
•weak fiber—loses some strength when wet
•has no other compensating factors
•poor resistance to abrasion—may be blended with
nylon to increase strength
22. cellulosic regenerated fibers—acetate properties:
comfort:
•smooth & slick—great for linings
•subject to static buildup
•extremely soft with no allergenic potential
•poor thermal retention
appearance retention:
•not very resilient—wrinkle during use
•wrinkles from washing extremely difficult to
remove
•weaker when wet—shrinks with high heat
•areas of stress do not recover well
23. cellulosic regenerated fibers—acetate properties:
care:
•dry cleaned unless care label says differently
•resistant to weak acids & alkalis
•can be bleached
•soluble in acetone
•cannot be heat set at high enough temp
•thermoplastic & feels sticky at low ironing
temperature
•better sunlight resistance than silk or nylon
•resistant to moths, mildew & bacteria
24. cellulosic regenerated fibers—acetate
environmental concerns/sustainability:
•produced from cellulose & requires significant
processing—wood pulp concerns
•dry-spun so solvent easier to recover & reuse
•less likely to degrade than rayon
•not recycled
•usually dyed with disperse dyes—require special
chemical carriers
•dry cleaning solvents an issue
25. cellulosic regenerated fibers—acetate
uses:
•lining fabrics—must be carefully selected based on
durability of garment
•drapery—sunlight resistance and assortment of
colors
•formalwear—moire taffeta, satin & brocade
•bedspreads, quilts, home sewing fabrics, ribbons,
cigarette filters, personal hygiene products, fiberfill
& filters
http://www.youtube.com/watch?v=Goq1Yr1HiQE
27. cellulosic regenerated fibers—bamboo
•fiber from woody bamboo grass—China
•promoted as sustainable fiber—crowds out weeds &
few insect pests thus grown with no chemicals
•two types: bast (stems) & regenerated from pulp (like
rayon)—most common
•soft hand, silky texture, durable, good breathability,
wicks well & dyes well
28. cellulosic regenerated fibers—seaweed fiber
•marine plant fiber
•produced using process similar to lyocell—
seaweed added to lyocell spinning solution
•manufacturers claim minerals & vitamins absorbed
through skin of wearer
•soft, breathable, comfortable next to skin
•SeaCell: active & pure—silver as antimicrobial
agent for bras, underwear, sportswear, workwear,
carpets, bedding, towels, craft yarn, nonwovens &
hygiene products
29. other regenerated fibers
•Alginate fibers—short fibers used for wound
dressing; protect while allow healing to occur
•Chitosan—exoskeletons of crustaceans; medical
applications
•Azlon—most often made from soybean waste
from tofu manufacturing; durable, soft hand,
wonderful drape, good colorfastness, excellent
absorbency, good comfort & thermal retention
•Silk Latte & Milkofil—made from casein (protein
in milk); soft hand & take dye well, not as durable
as soy fiber
30. manufactured regenerated fibers
participation activity:
…dig through the box of interior fabric samples—find one
with some content that we have discussed today
…on a sheet of paper, discuss the following topics
according to the fabric sample you have selected:
• How was this fiber generated?
• What are the pros of using this fiber/fabric in an
interior?
• What are the cons of using this fiber/fabric in an
interior?
• What sustainability issues are associated with this
fiber/fabric?
…be sure to attach the fabric sample with your written
discussion
