FASH 15 textiles

manufactured regenerated fibers

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

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

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

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

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

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

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?

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

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

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

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

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

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

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

cellulosic regenerated fibers—lyocell types & kinds:

because it is relatively new, fewer modification available—more modifications expected

cellulosic regenerated fibers—acetate

originated in Europe as varnish for airplane wingsin 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

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

cellulosic regenerated fibers—acetate production:

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

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

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

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

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

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

cellulosic regenerated fibers—acetate types & kinds:

•solution-dyed•flame-retardant•sunlight resistant•fiberfill•textured filament•modified cross section•antibacterial•thick-and-thin slublike filament

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

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

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

manufactured regenerated fibersparticipation 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