2. manufactured regenerated fibers
produced from naturally occurring polymers
these polymers do not occur naturally as fibersâ
processing is needed
starting material is cellulose & proteinâmajority
used in apparel, interiors and technical products are
cellulosic:
⢠rayon
⢠lyocell
⢠acetate
3. cellulosic regenerated fibersârayon
the firstâmany regeneration processes were
developed
commercial production of viscose rayon began in
1910 in the USâsold a âartificial silkâ until rayon
was adopted in 1924
produced as a filament until discovered that scraps
could be used as staple fibersâŚnow filament tow
â˘Cupra rayonâcuprammonium
â˘Viscose rayonâregular rayon (weaker than HWM)
â˘High-wet-modulus (HWM) rayonâaka HP (high
performance), polynosic, or modal
4. cellulosic regenerated fibersârayon
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 fibersârayon
physical structure:
regular viscose characterized by striations
(lengthwise lines)
cross sectionâserrated or indented circular shape
(HWM & cupra are more circular)
serrated shape is an advantage in dyeingâ
increases fiberâs surface area
â˘filamentâ40-5000 denier
â˘staple & towâ1.5-15 denier
â˘micro rayon fibers also available
6. cellulosic regenerated fibersârayon
propertiesâaesthetics:
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 fibersârayon
propertiesâdurability:
regular rayon is a weak fiberâloses about 50% of
strength when wet
will stretch slightly before breakingâlowest 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 fibersârayon
environmental concerns/sustainability:
â˘significant processing is involved to produce useable
fiber
â˘clear cutting may be an issue
â˘processing wood pulp uses large quantities of acid &
other chemical (water & air pollutioni)
â˘cupra rayon no longer produced in USâcould not
meet minimum air & water quality reqs
â˘more susatinable alternatives include lyocell & rayon
from managed forests
â˘biodegradableâcurrent landfill practices?
9. cellulosic regenerated fibersârayon
uses:
mostly used in woven fabricsâespecially apparel
and interior drapery & upholstery
also used in nonwoven fabrics for absorbency
â˘technical wipes
â˘medical suppliesâbandages, diapers, sanitary
napkins & tampons
Cuprammonium rayon used in dialysis machines to
filter waster products from blood
10. cellulosic regenerated fibersârayon
types & kinds:
only way to determine specific type of rayon is by
the trade name
â˘HWM
â˘solution-dyed
â˘modified cross-section
â˘intermediate- & high- tenacity
â˘optically brightened
â˘high absorbency
â˘hollow
â˘microfibers
â˘Visilâcontains silica, flame-retardant
11. cellulosic regenerated fibersâlyocell
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 oxideâlow toxicity, low skin
irritation; solvent recovered, purified & recycled
physical structure:
more rounded cross section
& smoother longitudinal
appearance than rayon
12. cellulosic regenerated fibersâlyocell properties
aesthetics:
â˘luster, length & diameter can be changed depending
upon end use
â˘processed to produce a range of surface effects
â˘offers unusual combinations of strength, opacity,
absorbency
durability:
â˘performs more like cotton than rayon
â˘strongest of cellulosic fibers
â˘unique combination of soft hand & good durability,
produces comfortable, long-lasting textiles for apparel
& interiors
13. cellulosic regenerated fibersâlyocell properties
comfort:
â˘soft, smooth fiber with few static problems
â˘ideal for apparel that contacts skin
â˘thermal retention is poor
appearance retention:
â˘resiliency is moderateâwrinkles but not as severely
as rayon
â˘shrinks, but not progressively
â˘may have problems with fuzziness or piling
care
â˘either gently machine-washable or dry cleaned
â˘sensitive to acids; resistant to mild alkalis
â˘sensitive to mildew & some insects
14. cellulosic regenerated fibersâlyocell
environmental concerns/sustainability:
â˘produced from wood pulpâmanaged forests/fast-
growing eucalyptus trees
â˘recovers & reprocesses 99.5% of solvent bath
â˘chemicals significantly less hazardous to
environment than those used for viscose rayon
â˘biodegradableânot recycled
â˘makes extensive use of water, dyes & finishing
chemicals
â˘dry cleaning solvents present additional
environmental hazards
15. cellulosic regenerated fibersâlyocell
uses:
â˘professional business wear
â˘leotards
â˘hosiery
â˘casual wear
â˘upholstery
â˘window-treatment fabrics
â˘filters
â˘printersâ blankets
â˘specialty papers
â˘medical dressings
â˘used in blends with wool, cotton & other MF
â˘used in conveyer belts for strength & softness
17. cellulosic regenerated fibersâacetate
originated in Europe as varnish for airplane wings
in 1924 became 2nd
MF to be produced in US
could not be dyed with existing dyesâdisperse
dyes created specifically for acetate/triacetateâ
certain of these change color when exposed to
atmospheric pollutants
1st
thermoplastic (heat sensitive) fiberâmelt under
hot ironâconsumers unaccustomed to this
18. cellulosic regenerated fibersâacetate
production:
â˘purified cellulose from wood pulp or cotton linters
â˘mixed with glacial acetic acid; acetic anhydride & a
catalyst
â˘aged 20 hoursâpartial hydrolysis occurs
â˘precipitated as acid-resin flakes
â˘flakes dissolved in acetone
â˘solution is filtered
â˘spinning solution extruded in column of warm air;
solvent recovered
â˘filaments stretched and wound onto beams, cones or
bobbins ready for use
20. cellulosic regenerated fibersâacetate
physical structure:
â˘available as staple or filamentâfilament more silk-
like
â˘lobular or flower petal shaped cross sectionâ
varied according to use; flat filaments give glitter
21. cellulosic regenerated fibersâacetate properties:
aesthetics:
widely used in satins, brocades & taffetasâluster,
body, & drape more important than durability or
ease of care
durability:
â˘weak fiberâloses some strength when wet
â˘has no other compensating factors
â˘poor resistance to abrasionâmay be blended with
nylon to increase strength
22. cellulosic regenerated fibersâacetate properties:
comfort:
â˘smooth & slickâgreat for linings
â˘subject to static buildup
â˘extremely soft with no allergenic potential
â˘poor thermal retention
appearance retention:
â˘not very resilientâwrinkle during use
â˘wrinkles from washing extremely difficult to
remove
â˘weaker when wetâshrinks with high heat
â˘areas of stress do not recover well
23. cellulosic regenerated fibersâacetate properties:
care:
â˘dry cleaned unless care label says differently
â˘resistant to weak acids & alkalis
â˘can be bleached
â˘soluble in acetone
â˘cannot be heat set at high enough temp
â˘thermoplastic & feels sticky at low ironing
temperature
â˘better sunlight resistance than silk or nylon
â˘resistant to moths, mildew & bacteria
24. cellulosic regenerated fibersâacetate
environmental concerns/sustainability:
â˘produced from cellulose & requires significant
processingâwood pulp concerns
â˘dry-spun so solvent easier to recover & reuse
â˘less likely to degrade than rayon
â˘not recycled
â˘usually dyed with disperse dyesârequire special
chemical carriers
â˘dry cleaning solvents an issue
25. cellulosic regenerated fibersâacetate
uses:
â˘lining fabricsâmust be carefully selected based on
durability of garment
â˘draperyâsunlight resistance and assortment of
colors
â˘formalwearâmoire taffeta, satin & brocade
â˘bedspreads, quilts, home sewing fabrics, ribbons,
cigarette filters, personal hygiene products, fiberfill
& filters
http://www.youtube.com/watch?v=Goq1Yr1HiQE
27. cellulosic regenerated fibersâbamboo
â˘fiber from woody bamboo grassâChina
â˘promoted as sustainable fiberâcrowds out weeds &
few insect pests thus grown with no chemicals
â˘two types: bast (stems) & regenerated from pulp (like
rayon)âmost common
â˘soft hand, silky texture, durable, good breathability,
wicks well & dyes well
28. cellulosic regenerated fibersâseaweed fiber
â˘marine plant fiber
â˘produced using process similar to lyocellâ
seaweed added to lyocell spinning solution
â˘manufacturers claim minerals & vitamins absorbed
through skin of wearer
â˘soft, breathable, comfortable next to skin
â˘SeaCell: active & pureâsilver as antimicrobial
agent for bras, underwear, sportswear, workwear,
carpets, bedding, towels, craft yarn, nonwovens &
hygiene products
29. other regenerated fibers
â˘Alginate fibersâshort fibers used for wound
dressing; protect while allow healing to occur
â˘Chitosanâexoskeletons of crustaceans; medical
applications
â˘Azlonâmost often made from soybean waste
from tofu manufacturing; durable, soft hand,
wonderful drape, good colorfastness, excellent
absorbency, good comfort & thermal retention
â˘Silk Latte & Milkofilâmade from casein (protein
in milk); soft hand & take dye well, not as durable
as soy fiber
30. manufactured regenerated fibers
participation activity:
âŚdig through the box of interior fabric samplesâfind one
with some content that we have discussed today
âŚon 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?
âŚbe sure to attach the fabric sample with your written
discussion