exam 1 Flashcards
calculation for tenacity
grams/denier
or
measure of force/
unit of weight
calculation for stress
breakpoint force (g)/
denier
calculation for strain
elongation (cm)/
original length
x100
=%
calculation for Initial Modulus
a Stress/
a Strain
calculation for Modulus of Elasticity (MOE)
y2-y1/
x2-x1
side by side bicomponent fiber
like split ice cream
helical crimp
adds bulk
which adds stretch
cover core biocomponent fiber
caramel apple
changes surface characteristics
Matrix-fibril type biocomponent fiber
multiple cores
-changes optic qualities (luster, reflectance, dye uptake)
-increases molecular weight which increases strength
cysteine linkages
-in protein
-amino/acid
-basic/acidic reactions
-positive/negative charge reactions
-polarity attracts water
protein molecule
-cystine linkages
-bottle shape chain
-open space allows area for reactions, water absorption, and collapse
- ability to shrink
-poor stability
cellulose molecule
-chicken wire chain structure
-6 OH groups (6n) for absorption
-poor resiliency
-can’t bounce back well
c
II
o
amide linkage
-effects absorbency and
heat stability
-ideal is 4 carbon per amide for optimal absorbency.
COOH3
acetate
-crystalline structure
-substitutes OH for LOWER absorption
-heavier molecule=higher heat stability
crystallinity
compact structure
-higher heat stability
-strong but brittle
amorphous
openly spaced
-low absorbency
-less heat resistant
aromatic ring
-stronger
-heat/flame resistant
n
degree of polymerization
-number of molecules per repeat structure
-higher n=more absorbent and heat resistant
dimensional stability
physical changes when heat or moister are applied
specific gravity/density
weight of material in denier
denier
weight of fiber per 9000 meters
fiber theory
fibers are made up of polymers via a process of linking molecules (monomers) together called polymerization
types of fiber identification
-burn test
-staining test
-chemical solubility
-density gradient
-light microscopy
-polarizing microscopy
-electron microscopy
-infrared microscopy
modification ratio
outer diameter (x)/
Inner diameter(y)
-larger ratio = soiling, crushing, matting
melt spinning
polymer is heated and solidified into any shape through the spinneret
wet spinning
a polymer and a solvent are mixed into a solution and spinneret extrudes into a bath that neutralizes the solvent
dry spinning
a polymer and a solvent are mixed into a solution and spinneret extrudes into the air where the solvent evaporates from the core.
E/V
ratio of solvent evaporation in dry spinning
E= evaporation rate from surface
V= diffusion rate of solvent from center of filament
E<V= round crossection
E>V=irregular
E«<V= collapse center
acrylic vs modacrylic
acrylic has :
-Higher tenacity
-lower density
-higher regain
acetate vs. triacetate
acetate has:
-double the regain (absorbency)
-lower softening temp
-more intense care (dry clean)
-5% more elongation
-worse resiliency
-worse elastic recovery
DS
degree of substitution
absorbency
moistier regain
effects:
-comfort (good for hydrophilic)
-static build up (good for hydrophilic)
-dimensional stability in water (good for hydrophilic)
-wrinkle recovery (poor for hydrophilic)
abrasion resistance
ability to resist wear from abrasion
-nylon has great abrasion resistance
-lyocell and acetate have poor
elasticity
ability to elongate and recover
-spandex has high elasticity as an elastomeric
flexibility
capability of a fiber to bend without breaking.
-flexible fibers have good drape (ie. acetate)
-generally thinner
-rigid fabric holds shape
Hand
the way fabric feels
-effected by fiber surface
-either crimped or straight
pilling
broken ends of a fiber tangling together on the surface
- common for hydrophobic fibers with static
-strong fibers hold on to pill
-rough fiber surface snags (wool)
resiliency
capability of fabric to bounce back after being distorted
-good resiliency does not wrinkle
thicker/ rounder fibers have better resiliency than thin/flat ones
-polyester is very resilient
-cotton has very poor resiliency
strength
fibers capability to withstand stress
strong fabrics include:
- glass, nylon, polyester
weak fabrics include:
-acetate
acrylic
thermoplasticity
ability to handle heat exposure
favorable qualities of cotton
-good strength
-good abrasion resistance
-wicking
-stronger when wet
-no static
-no pilling
unfavorable properties of cotton
-poor elasticity
-poor resiliency (wrinkles)
-damaged by acid
-mildew/silverfish
-poor luster
end uses of cotton
wide range in:
-apparel
-industrial
-home furnishings
favorable properties of flax
-excellent strength
-stronger when wet
-more absorbent than cotton
-good luster
-good hand
-high iron temp
unfavorable properties of flax
-only fair resistance to abrasion (less than cotton)
-poor drape
-poor elasticity
-poor resiliency
-mildew
end uses of flax
-apparel
-tablecloths
-napkins
-bedding
favorable qualities of silk
-excellent drape
-luxurious hand
-hydrophilic
-little static
-no pilling
unfavorable qualities of silk
-fair resiliency
-fair abrasion resistance
-good strength but loss when wet
end uses of silk
-dresses
-ties
-scarfs
-blouses
-luxury bedding
favorable properties of wool
-good resiliency
-good hand
-good drape
-good elasticity
-hydrophilic
-warm
-resistant to acids
unfavorable properties of wool
-fair/good abrasion resistance
-poor luster
-strength loss when wet
-moths
-shrinks
-felting/pilling
-can be itchy
end uses of wool
-overcoats
-suits
-sweaters
-carpets
-luxury upholstery
-felt hats
favorable properties of acrylic
-inexpensive wool replacement
-good drape
-warm but lightweight
-good resiliency
-good elasticity
unfavorable properties of acrylic
-fair strength
-fait abrasion resistance
-hydrophobic
-static issues
-pilling
end uses of acrylic
-sweaters
-blankets
-carpets
-children’s clothing
-outdoor products i.e. tents/awnings/umbrellas
favorable properties of Lyocell
-strongest cellulosic fiber
-less shrinkage
-stronger when wet
-great luster
-good drape
-soft hand
unfavorable properties of lyocell
-fibers can splinter
-pilling
-not very colorfast
end uses of lyocell
-dress slacks
-blouses
-pajamas
-shirts
-dresses
favorable properties of Nylon
-excellent strength
-excellent abrasion resistance
-very good elasticity
-very good resiliency
-good drape
unfavorable properties of Nylon
-hydrophobic
-static
-pilling
end uses of nylon
-apparel: swimsuits, lingerie, pantyhose’s, jackets
-home furnishing: bedding, carpeting, upholster, luggage
-industrial: rope, parachutes.
favorable properties of Olefin
-good strength
-good abrasion resistance
-excellent resiliency
-repels stains (most hydrophobic)
-can have excellent moisture wicking when thin or blended with other fibers
unfavorable properties of Olefin
-too hydrophobic for most clothing
-static
-pilling
-very low heat resistance
end uses of olefin
-running/cycling clothing
-wetsuits
favorable properties of PLA
-excellent resiliency
-good wicking
-outstanding crimp retention
-good thermal insulaiton
-breathable
-high UV protection
-excellent hand
-excellent drape
end uses of PLA
-pillow stuffing (from crimp retention)
-fibrofill for mattresses/comforters
-activewear
-apparel
-outdoor textiles
favorable properties of polyester
-very good strength
-very good abrasion resistance
-excellent resiliency
-good elasticity
unfavorable properties of polyester
-completely hydrophobic
-absorbs oil
-hard to remove stains
-static
-pilling
end uses of polyester
-apparel
-interior textiles
-industrial
-carpets
-sails
-fiberfill
-sewing thread
favorable properties of Rayon
-fair/good strength
-fair/good abrasion resistance
-hydrophilic
-no static
-no pilling
unfavorable properties of Rayon
-looses a lot of strength when wet
-poor elasticity
-poor resiliency
-shrinks in the wash
favorable properties of spandex
-excellent stretch as an elastomeric
-good recovery
-excellent strength
-no pilling
-no static
-good durability
unfavorable properties of spandex
-poor strength (makes up for it with stretch)
-hydrophobic
-low heat resistance
end uses of spandex
-denim
-undergarments
-swimwear
-athletic apparel
favorable properties of Aramid
-high strength
-good abrasion resistance
-does not melt
-high heat resistance (700F)
-stretch resistance
-very tough (bulletproof)
end uses of aramid
-heat-protective clothing
-cables
-tires
-bulletproof vests
-also known as Kevlar/Nomex
favorable properties of PBI
-excellent flame resistance
-does not melt or burn
-high moisture regain
-remains intact
-low smoke
end uses of PBI
-firefighter uniform
-racecar uniform
-space suit
-hazmat suit
favorable properties of saran
-good strength
-good abrasion resistance
-self-extinguishing
unfavorable properties of saran
-very dangerous chemicals (vynal chloride)
-stiff
-low safe iron temp
-poor hand (slippery)
-no moisture regain
end uses of saran
-upholstery
-outdoor furniture
-filters
-doll hair
most abrasion resistant fibers
-nylon
-olefin
-polyester
-flax
least abrasion resistant fibers
-wool
-rayon
-acetate
most resilient fibers
-polyester
-wool
-nylon
-modacrylic
least resilient fibers
-acetate
-cotton
-rayon
-flax
most absorbent fabrics
wool
flax
lyocell
silk
least absorbent fabrics
acrylic
spandex
polyester
olefin
glass
most elastic fabrics
spandex
olefin
nylon
acrylic
least elastic fabrics
lyocell
cotton
glass
flax
strongest fabrics (dry)
glass
flax
nylon
polyester
olefin
weakest fabrics (dry)
silk
acrylic
wool
spandex
strongest fabrics (wet)
cotton
flax
glass
olefin
weakest fabrics (wet)
acrylic
wool
acetate
rayon
