Final Exam Flashcards
Permanent finishes
Chemical change in fiber structure
Durable finish
Long lasting but deminishes with cleaning
Semi durable finishes
Removed after several cleanings
Temporary finishes
Removed after cleaning
Foam finish
Finishes are applied from a water based solution,solvent, or foam
Types of finishing by foam
-durable press (keeps appearance)
-water repellent
-soil release
-softeners
- mercerization
-fabric stabilizers
Singeing
Uses heat to remove fuzz off fabric
Desizing
After singeing, enters bath of enzymes/acids/solvent/ and detergents
Scouring
-Prepares fabric for dyeing
-removes impurities
gauge
of needles per inch
course
rows of loops in a knit
wale
columns of loops in a knit
Warp knit
Used in lingerie
Diagonal
-each loop has own yarn source
qualities of WARP knit
-limited stretch
-does not run or ravel easily
-slower and more costly
-produces yardage only
-zig zag on back
Qualities of WEFT knits
A
-4 way stretch
-more stretch in width
-may run or ravel
-can create shaped garments
-can create finished edges
-curls at selvage
-shrinks in wash
-fast, easy and cheap to make
Tricot fabric
-warp knit
-flat production
-used in lingerie
-fastest production speed
-mesh
Raschel fabric
-warp knit
-uses compound needles
-can use large number of yarn guide bars for variation
-lace
Differences between tricot and raschel fabric
-heavy yarns, open spaces, lace, surface effects = raschel
-fine yarns, no or simple design, mesh = Tricot
single weft knits
-jersey
-purl
-rib
double jersey knits
-weft knit
-made with two sets of needles
-looks like jersey on one side and ribbed on the other
-looks like two fabrics bound together
-jacquard can be used to make it
purl knits have:
-have more bulk
-reversible
-lower wind resistance
disadvantages of purl knits are:
-slower to make
-more costly
-poor crosswise stretch
-poor shape retention
Rib knit
-made by alternating wales of knit and purl stitches on the facing of fabric
advantages of rib knit
-excellent crosswise stretch
-more bulk than jersey
-good wind resistance
-does not curl
-warmth
-easy care
disadvantages of rib knit
-opacity makes it less ideal for hosiery
-high cost
-increased weight
-slower production than jersey and purl
advantages of jersey knit
-4 way stretch
-good elastic recovery
-fast and cheap to make
disadvantages of jersey knit
-runs and ravels
-curls at selvage
-can shrink when laundered
double weft interlock knit
-two rib knits knitted together to look like jersey on both sides
-two sets of needles
end use of double knits
-pants
-jackets
-suits
advantages of double knits
-resistant to unraveling
-does not curl
-shape retention
-higher strength
-wind resistance
-good elastic recovery
-good wrinkle resistance
flat bed knitting machine
used for warp knitting such as tricot and rachel
circular knitting machine
used for weft knits such as jersey
-can make shaped garments
Milanese knit
-warp knit
-produces angled pattern on surface like twill
compared to tricot it is:
-smoother
-greater elongation
-higher strength
-less design flexibility
differences between warp and weft knits
yarn supply
-warp have each needle supplied with a yarn
-weft have one yarn supplying all needles
knitting proccess
-warp knits complete a course in one motion
-weft knits stitch courses one after another
machinery
-warp knits use an open flat bed
-weft knits use a circular machine
qualities of warp knits compared to weft
-less stretch
-less bulk
-better dimensional stability
-higher strength
-doesn’t unravel as easily
-good draping
-softer hand
-more sheer
-wont shrink in wash
chromophores are
molecular structures that produce visible color
color is enhanced by
-single and double bonds
-auxochrome
-electro-pair donor (when chromophores are also present)
auxochrome
-a modifier to chromophores that intensifies color
-does not produce color by itself
-is an electro pair donor
-Hydroxyl group (-OH)
-Amine group (-NH2)
-Aldehyde group (-CHO)
-Methyl mercaptan group (SCH3)
OR
NH2
NHR
SUBSTITUTED AMINO GROUP
NR2
chromogen
a relatively colorless substances that can be converted into a dye
Dyes
Soluble in water
Organic
Transparent
Require no binder
Have affinity for substrate
Dye applications
Coloring textiles
Films
Paper
staining
pigments
Insoluble in water
Organic and inorganic
Opaque
Usually require a binder
pigment applications
Vehicles
Walls
Plastics
Wood
metals
direct/substantive dyes
-have polar groups, acidic or basic, that combine with the polar groups of fibers
-hot water dye bath
-used on natural materials (both protein and cellulosic)
-salts added to dye bath
-good to excellent light fastness
-poor wet fastness
-used in apparel and drapery
acid dyes
-in salt form
-bright
-used on protein fibers
-acid acquired through nitro groups and sulfonic acid (NO2, Na03S, SO3Na)
mordant (chrome) dyes
-Cr
-metallized
-metal is added to form insoluble colored salt
-similar to acid dyes (used on same materials)
-less bright than acid dyes
-chromium, aluminum, copper and iron used
-good color fastness to dry cleaning
Vat dyes
-soluble in alkaline solution but not water
-used on cellulose
-excellent colorfastness
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C-O-Na
//
disperse dyes (acetate)
-made for acetate but used on other synthetics such acrylic and polyester
-slightly water soluble but easily dispersed through solution
-requires carrier at low temps
-generally good colorfastness
reactive dyes
-permanent
-chemically bonds to fiber
-used for natural and nylon fibers
-reactive group is attached to dye through auxochrome
fiber dyeing
advantages:
-deep penetration
-uniform color
disadvantages:
-fashion change
-color variation
yarn dyeing
-spools of yarn are dyed in pressurized vat
advantages:
-faster and less labor than fiber dying
-fashion change not as fast
-permits multicolored yarn in fabric
-can produce basic designs
disadvantages:
-fashion change
union dying
fabric containing different fiber types dyed one uniform color
cross dyeing
different fiber types are dyed to produce different colors based on which dyes which fibers accept.
continues dyeing
-open width fabric
-100+ meters
-specific amount of dye used to have even color and a depleted bath by the end
garment dyeing
-more colors/finishes can be offered to small lots
-line colors can be dropped/added mid season
-color decision can be delayed till processing
-multiple finishes on the same style
-reduces inventory requirements
pigment dyeing
-water insoluble
-have to be fixed to cellulose via alum or catatonic fixing agents
-excellent light fastness
- AL2(SO4) aluminum sulfate
resist printing
-tie-dye
-batik (wax blocking)
-ikat (warp yarns dyed)
-stencil
-screen
screen printing
-fabric is pulled over frame and coated in photochemical film
-design area is cleaned off into an open mesh for color to pass through
-rotary or flatbed
discharge
-removal of dye from dyed fabric
-used when print fabric has dark colored background
-colored dye is then applied over the discharged areas
-bleach may weaken fabric where applied
transfer printing
transfers color from paper to fabric
-vapor phase: sublimation ink transfers with heat
-wet transfer: dyes dissolved in water and transferred with heat and pressure.
-melt transfer: dyes mixed with thermoplastics, printed on paper, and transferred onto fabric with heat and pressure
digital printing
-similar to computer printing
-for custom orders and samples
permanent finish
A chemical change in fiber structure, (does not change by use or cleaning)
durable finish
Last a long time, but effectiveness diminishes gradually by each cleaning
Semidurable finish
Removed after several cleaning, can be reapplied at home
temporary finish
Removed or substantially diminished by one cleaning
singeing finish
-uses flames or heat to remove protruding ends of fibers
-then enters desizing bath
desizing finish
-occurs after singeing
-is a bath that uses solvents, enzymes, detergents or acids
scouring/boil-off
-prepares fabric for dyeing/finishing
-or to make fabric white
boil off = cotton, silk, manufactured fibers
scouring = woolen/worsted
solvent scouring
-removes oils that were used for lubricating and softening yarns
-reduce static during knitting
bleaching
-removes impurities that scouring cannot
-important for pastel blue/violet
-aims to create colorless material
reducing bleaches
-hydrogenates unsaturated bonds to mask color
-unstable reaction
-sun and oxygen can reverse it
oxidizing agents
-give a more permanent white
-breaks double bonds to remove color
-not easily reversed
-used more often
tentering
-mechanical straightening of fabric
-fabric is held flat and moved apart while drying
-is part of mercerizing
mercerization
-chemical finish for cellulose fiber
-adds luster but straightening fibers
-improves dyeing
-improves strength
heat setting
-on thermoplastics: produces special shapes or pleats, wrinkle resistance,
-effect of setting depends on:
temp
time
pressure
brushing
-mechanical finish
-removes short/loose fibers
-preliminary to napping or shearing
calendaring
smooths surface under pressure of heated rolls (synthetics) or resin (naturals)
weighting
-for silk fabric after de-gumming
-increases body and firmness
-decreases durability to light/air/sweat
-uses insoluble polymer
embossing
-created with calendaring (heated rollers)
-resin can improve durability
-easier way to create a dimensional design than waving/knitting it in
raised surfaces
-napping/sueding/brushing
-base satin/twill fabric is hidden (strong weaves to withstand brushing)
-surface covered with low twist staple fibers
-wired cylinders or sandpaper create nap
-surface is then sheared for even nap length
morie
-mechanical finish
-mix of gloss and matt surface
-watery/wood grain/iridescent design
-two fabrics are calendared together and taken apart
acid finish
-primarily for denim
-worn/faded appearance
-softens fabric (cellulase)
-tumbles with pumice for waring
-bleach for fading
basic / standard finishes
-antimicrobial
-flame retardant
-static resistance
-wrinkle resistant
-uv resistant
flame retardancy
-decreases rate of oxygen diffusion
-the fumes formed when burning work to deplete oxygen and inhibit combustion
-can be inheriant quality of fabric or added as treatment after
flame retardant chemicals
-borax
-boric acid
-ammonium compound
-solvent vapor leaves salt compounds insoluble
soil release
-hydrophilic surface attracts water to release soiling
-coats fibers so that soil cannot penetrate
stain/soil resistant
-high degree of surface tension allows soil to float on top of fabric
-silicon
-wax
