DAMASK:
A firm, glossy, Jacquard-patterned fabric that may be made from
linen, cotton, rayon, silk, or a
combination of these with various manufactured fibers. Similar to brocade, but
flatter and reversible,
damask is used for napkins, tablecloths, draperies, and upholstery.
DAMPENING
(IN TIRE CORD): The relative ability to absorb energy and
deaden oscillation after excitation.
DECATING
MARK: A crease mark or impression extending fillingwise across the
fabric near the beginning or
end of the piece.
DECATIZING:
A finishing process in which fabric, wound tightly on a
perforated roller, either has hot water
circulated through it (wet decatizing), or has steam blown through it (dry decatizing). The
process is aimed chiefly at improving the hand and removing wrinkles.
DECITEX:
One tenth of a tex.
DECORTICATING:
A mechanical process for separating the woody matter from the
bast fiber of such plants as
ramie and hemp.
DEEP-DYEING
VARIANTS: Polymers that have been chemically modified
to increase their dyeability. Fibers
and fabrics made therefrom can be dyed to very heavy depth.
DEFECTS:
A general term that refers to some flaw in a textile product
that detracts from either performance or
appearance properties.
DEFORMATION:
A change in the shape of a specimen, e.g., an increase in length
produced as
the result of the
application of a tensile load or force. Deformation may be immediate or
delayed,
and the latter may
be recoverable or nonrecoverable.
DEGRADATION:
The loss of desirable physical properties by a textile material
as a result of
some process or
physical/chemical phenomenon.
DEGREE
OF ESTERIFICATION: The extent to which the acid groups of
terephthalic and/or
other acids have
reacted with diols to form ester groups in polyester polymer production.
DEGREE
OF POLYMERIZATION: Refers to the number of monomer units in an
average
polymer. It can be
controlled during processing and affects the properties of the end product.
DEGUMMING:
The removal of gum from silk by boiling in a mildly alkaline
solution. Usually
accomplished on the
knit or woven fabric.
DELAYED
DEFORMATION: Deformation that is time-dependent and is
exhibited by material
subjected to a
continuing load; creep. Delayed deformation may be recoverable following
removal of the
applied load.
DELUSTERING:
Subduing or dulling the natural luster of a textile material by
chemical or
physical means. The
term often refers to the use of titanium dioxide or other white pigments as
delustrants in
textile materials.
DELUSTRANT:
A substance that can be used to dull the luster of a
manufactured fiber. Often a
pigment such as
titanium dioxide.
DENIER:
A weight-per-unit-length measure of any linear material.
Officially, it is the number
of unit weights of
0.05 grams per 450-meter length. This is numerically equal to the weight in
grams of 9,000
meters of the material. Denier is a direct numbering system in which the lower
numbers represent
the finer sizes and the higher numbers the coarser sizes. In the U.S., the
denier
system is used for
numbering filament yarns (except glass), manufactured fiber staple (but not
spun yarns), and
tow. In most countries outside the U.S., the denier system has been replaced by
the tex system. The
following denier terms are in use:
Denier
per Filament (dpf): The denier of an individual continuous
filament or an individual
staple fiber if it
were continuous. In filament yarns, it is the yarn denier divided by the number
of
filaments.
Yard
Denier: The denier of a filament yarn. It is the product of the denier
per filament and the
number of filaments
in the yarn.
Total
Denier: The denier of a tow before it is crimped. It is the product of
the denier per
filament and the
number of filaments in the tow. The total denier after crimping (called crimped
total denier) is
higher because of the resultant increase in weight per unit length.
DENIER
VARIATION: Usually variation in diameter, or other
cross-sectional dimension, along
the length of a
filament or bundle of filaments. It is caused by malfunction or lack of process
control in fiber
manufacturing and degrades resulting fabric appearance or performance.
DENIM:
A firm 2 x 1 or 3 x 1 twill-weave fabric, often having a whitish
tinge, obtained by using
white filling yarns
with colored warp yarns. Heavier weight denims, usually blue or brown, are
used for dungarees,
work clothes, and men’s and women’s sportswear. Lighter weight denims
with softer finish
are made in a variety of colors and patterns and are used for sportswear and
draperies.
DENSITY:
The mass per unit volume (usually expressed as grams per cubic
centimeter).
DENT:
On a loom, the space between the wires of a reed.
DEREGISTERING
(CRIMP): Process of disordering or disaligning the
crimp in a tow band to
produce bulk.
DESULFURIZING:
An aftertreatment to remove sulfur from newly spun viscose rayon
by
passing the yarn
through a sodium sulfide solution.
DETERGENT:
A synthetic cleaning agent containing surfactants that do not
precipitate in hard
water and have the
ability to emulsify oil and suspend dirt.
DEVELOPING:
A stage in dyeing or printing in which leuco compounds, dyes, or
dye
intermediates are
converted to the final, stable state or shade.
DEWPOINT:
The temperature at which a gas begins to condense as a liquid at
a given pressure.
Thus in air, it is
the temperature at which the air becomes saturated when cooled with no further
addition of
moisture or change in pressure.
DIAL:
In a circular-knitting machine, a circular steel plate with
radially arranged slots for
needles. A knitting machine equipped with both a dial and a cylinder
(q.v.) can produce double-knit fabrics.
DIAMINE:
A compound with two amino groups. Hexamethylenediamine,
one of the intermediates in the manufacture of nylon 66 salt, is
an example of this chemical type.
DIELECTRIC
BREAKDOWN VOLTAGE: In an electrical insulating material, the
voltage at
which electrical
breakdown occurs, i.e., the voltage at which current will flow and/or the
material
melts.
DIELECTRIC
CONSTANT: Measure of the ability of a dielectric
material to store electrical
potential energy
under the influence of an electric field, measured by the ratio of the
capacitance
of a condenser with
the material as the dielectric to its capacitance with a vacuum as the
dielectric.
DIELECTRIC
STRENGTH: The average voltage gradient at which
electrical failure or
breakdown occurs.
Expressed in volts per mil.
DIFFERENTIAL
THERMAL ANALYSIS: A method of determining the temperature at
which
thermal events
occur in a material undergoing continuous heating.
DIFFUSION:
1. A more or less gradual movement of molecules or ions through a
solution or
fiber as a result
of the existence of a concentration gradient or repulsive or attractive forces.
2.
The random movement
of gas molecules.
DIMENSIONAL
RESTORABILITY: The ability of a fabric to be returned to
its original
dimensions after
laundering or dry cleaning, expressed in percent. For example, 2% dimensional
restorability means
that although a fabric may shrink more than this in washing, it can be restored
to within 2% of its
original dimensions by ordinary home pressing methods.
DIMENSIONAL
STABILITY: The ability of textile material to maintain
or return to its original geometric
configuration.
DIMETHYL
TEREPHTHALATE: [p-C6H4(COOCH3)2]
An intermediate used in the production of
polyethylene terephthalate, the polymer from which polyester fibers and resins
are made.
DIMITY:
A sheer, thin, spun cloth that sometimes has cords or stripes
woven in. It is used for
aprons, pinafores,
and many types of dress goods.
DIP:
1. Immersion of a textile material in some processing liquid. The
term is usually used in
connection with a
padding or slashing process. 2. The rubber
compound with which tire cords
and other in-rubber
textiles are treated to give improved adhesion to rubber.
DIP
PENETRATION: The degree of saturation through a tire
cord after impregnation with an adhesive.
DIP
PICKUP: The amount of adhesive applied to a tire cord by dipping,
expressed as a
percentage of the
weight of the cord before dipping.
DIP
TREATING: The process of passing fiber, cord, or
fabric through an adhesive bath,
followed by drying
and heat-treating of the adhesive-coated fiber to obtain better adhesion.
DIRECT
ESTERIFICATION: In the production of polyethylene
terephthalate, the process in
which ethylene
glycol is reacted with terephthalic acid to form bis-â-hydroxyethyl
terephthalate
monomer with the
generation of water as a by-product.
DIRECTIONALLY
ORIENTED FABRICS: Rigid fabric constructions containing
inlaid warp
or fill yarns held
in place by a warp-knit structure. Used in geotextiles, coated fabrics,
composites, etc.
DISC TEST: An in-rubber test
used to predict the fatigue resistance of tire cords and other
industrial yarns.
DISPERSANT:
A dispersing agent, often of a surface active chemical, that
promotes formation
of a dispersion or
maintains a state of dispersion by preventing settling or aggregation.
DISPERSION:
1. A system consisting of finely divided particles and the medium
in which they
are distributed. 2.
Separation of light into colors by diffraction or refraction. 3.
A qualitative
estimation of the
separation and uniform distribution of fibers in the liquid during the production
of a wet-formed
nonwoven fabric.
DISTRIBUTION
LENGTH: In fibers, a graphic or tabular presentation of the proportion
or
percentage (by
number or by weight) of fibers having different lengths.
DIVIDED
THREADLINE EXTRUSION: Spinning of two separate threadlines from
one
spinneret.
DOBBY:
1. A mechanical attachment on a loom. A dobby controls the
harnesses to permit the
weaving of
geometric figures. 2. A loom equipped
with a dobby. 3. A fabric woven on
a dobby
loom.
DOCTOR
BLADE: A metal knife that cleans or scrapes the excess dye from engraved
printing rollers, leaving dye paste only in the valleys of engraved areas.
Also used to describe other blades that are used to
apply materials
evenly to rollers or fabrics.
DOCTOR
STREAK: A defect in printed fabrics consisting of a wavy white or colored
streak in the warp direction. It is caused by a damaged or improperly set
doctor blade on the printing machine.
DOESKIN
FINISH: A soft low nap that is brushed in one direction. Cloth with this
type of finish is used on
billiard tables and in men’s wear.
DOFF:
A set of full bobbins produced by one machine (a roving frame, a
spinning frame, or a
manufactured
filament-yarn extrusion machine).
DOFFER:
1. The last or delivery cylinder of the card from which the sheet
of fibers is removed
by the doffer comb.
2. An operator who removes full bobbins,
spools, containers, or other
packages from a
machine and replaces them with empty ones.
DOFFER
COMB: A reciprocating comb, the teeth of which oscillate close to the
card clothing
of the doffer to
strip the web of fibers from the card.
DOFFER
LOADING: Fibers imbedded so deeply into the doffer
wire clothing that the doffer
comb cannot
dislodge them to form a traveling web.
DOFFING:
The operation of removing full packages, bobbins, spools, roving
cans, caps, etc.,
from a machine and
replacing them with empty ones.
DONEGAL:
A tweed fabric with colorful slubs woven in, donegal is used for
suits and coats.
DOTTED
SWISS: A sheer cotton or cotton blend fabric with small dot motif,
dotted swiss is
used for dress
goods, curtains, baby clothes, etc.
DOUBLE
BACK: A secondary backing glued to the back of carpet, usually to
increase
dimensional
stability.
DOUBLE-CLOTH
CONSTRUCTION: Two fabrics are woven in the loom at the
same time,
one fabric on top
of the other, with binder threads holding the two fabrics together. The weave
on
the two fabrics can
be different.
DOUBLE
END: Two ends woven as one in a fabric. A double end may be
intentional for fabric
styling, or
accidental, in which case a fabric defect results.
DOUBLE-KNIT
FABRIC: A fabric produced on a circular-knitting
machine equipped
with two sets of latch needles situated at right angles
to each other (dial
and cylinder).
DOUBLE
WEAVE: A fabric woven with two systems of warp or filling threads so
combined
that only one is
visible on either side. Cutting the yarns that hold the two cloths together
yields
two separate
cutpile fabrics.
DOUBLING:
1. A process for combining several strands of sliver, roving, or
yarn in yarn
manufacturing. 2.
The process of twisting together two or more singles or plied yarns, i.e.,
plying. 3.
A British term for twisting. 4. The term doubling
is sometimes used in a sense
opposite to
singling. This is unintentional plying. 5.
A yarn, considerably heavier that normal,
produced by a
broken end becoming attached to and twisting into another end.
DOUPPIONI:
A rough or irregular yarn made of silk reeled from double or
triple cocoons.
Fabrics of
douppioni have an irregular appearance with long, thin slubs. Douppioni-like
yarns are
now being spun from
polyester and/or rayon staple.
DOWNDRAFT
METIER: A dry-spinning machine in which the airflow within the drying
cabinet is in the
same direction as the yarn path (downward).
DOWNGRADE:
In quality control, the lowering of the grade and/or value of a
product due to
the presence of
defects.
DOWNTWISTER:
A cap, ring, or flyer twisting frame.
DOWNTWISTING:
A process for inserting twist into yarn in which the yarn passes
downward
from the supply
package (a bobbin, cheese, or cone) to the revolving spindle. The package or
packages of yarn to
be twisted are positioned on the creel, and the ends of yarn are led downward
through individual
guides and stop motions to the positively driven feed roll and from there to
the
revolving take-up
package or bobbin, which inserts twist.
DOWTHERM®:
Trademark of Dow Chemical Company for a series of heat transfer
media.
Dowtherm jackets
are used around molten polymer processing lines.
DRAFT:
In weaving, a pattern or plan for drawing-in.
DRAFT RATIO: The
ratio between the weight or length of fiber fed into various machines and
that delivered from
the machines in spun yarn manufacture. It represents the reduction in bulk
and weight of
stock, one of the most important principles in the production of yarn from staple
fibers.
DRAPE: A term to describe
the way a fabric falls while it hangs; the suppleness and ability of a
fabric to form
graceful configurations.
DRAW-BACK:
A crossed end; an end broken during warping that when repaired
was not free or
was tied in with an
adjacent end or ends overlapping the broken end. The end draws or pulls back
when unwound on the
slasher.
DRAW DOWN: The amount by which
manufactured filaments are stretched following
extrusion.
DRAW-FRAME BLENDS: Blends
of fibers made at the draw frame by feeding in ends of
appropriate card
sliver. This method is used when blend uniformity is not a critical factor.
DRAWING:
1. The process of attenuating or increasing the
length per unit weight of laps, slivers,
slubbings, or
rovings. 2. The hot or cold
stretching of continuous filament
yarn or tow to align and arrange
the crystalline
structure of the molecules to achieve improved tensile
properties.
DRAWING-IN:
In weaving, the process of threading warp ends through
the eyes of the heddles and the
dents of the reed.
DRAWN
TOW: A zero-twist bundle of continuous filaments that has been
stretched to achieve
molecular
orientation. (Tows for staple and spun yarn application are usually crimped.)
Drawing Sliver
DRAW
RATIO: The ratio of final to original length per unit weight of yarn,
laps, slivers,
slubbings, rovings,
etc., resulting from drawing.
DRAW-SIZING: A
system linking drawwarping and sizing in a
continuous process.A typical system
includes the following elements: (1)
creel, (2) eyelet board, (3) warp-draw machine,
(4) intermingler, (5)
tension compensator
and break monitor, (6) sizing bath, (7)
dryers, (8) waxing and winding units.
DRAW-TEXTURING:
In the manufacture of thermoplastic fibers, the simultaneous
process of
drawing to increase
molecular orientation and imparting crimp to increase bulk.
DRAW-TWISTING:
The operation of stretching continuous filament yarn to align
and order the
molecular and
crystalline structure in which the yarn is taken up by means of a ring-and-traveler
device that inserts
a small amount of twist (usually ¼ to ½ turn per inch) into the drawn yarn.
DRAW-WARPING:
A process in which a number of threadlines,
usually 800 to 2000 ends of POY feedstock, are oriented under
essentially equal mechanical and thermal conditions
by a stretching stage using variable speed rolls, then
directly wound onto the beam. This process gives
uniform end-to-end properties.
DRAW-WINDING:
The operation of stretching continuous filament yarn to align or
order
molecular and
crystalline structure. The drawn yarn is taken up on a parallel tub or cheese,
resulting in a
zero-twist yarn.
DRILL:
A strong denim-like material with a diagonal 2 x 1 weave running
toward the left
selvage. Drill is
often called khaki when it is dyed that color.
DROPPED
STITCHES: A defect in knit cloth characterized by
recurrent cuts in one or more
wales of a length
of cloth.
DROP
STITCH: 1. An open design made in knitting by
removing some of the needles at set
intervals. 2.
A defect in knit fabric.
DROP
WIRES: A stop-motion device utilizing metal wires suspended from warp
or creeled
yarns. When a yarn
breaks, the wire drops, activation the switch that stops the machine.
DRY
CLEANING: Removing dirt and stains from fabrics or
garments by processing in organic
solvents
(chlorinated hydrocarbons or mineral spirits).
DRY
FILLING: The application of finishing chemicals to
dry fabric, usually by padding.
DRY
FORMING: The production of fiber webs by methods
that do not use water or other
liquids, i.e.,
air-laying or carding.
DRYING
CYLINDERS: Any of a number of heated revolving
cylinders for drying fabric or
yarn. They are
arranged either vertically or horizontally in sets, with the number varying
according to the
material to be dried. They are often internally heated with steam and
Tefloncoated
to prevent
sticking.
DRY-LAID
NONWOVENS: Nonwoven web made from dry fiber. Usually
refers to fabrics
from carded webs
versus air-laid nonwovens which are formed from random webs.
DUCK:
A compact, firm, heavy, plain weave fabric with a weigh of 6 to
50 ounces per square
yard. Plied yarn
duck has plied yarn in both warp and filling. Flat duck has a warp of two
single
yarns woven as one
and a filling of either single or plied yarn.
DULL:
A term applied to manufactured fibers that have been chemically
or physically modified
to reduce their
normal luster. Matte; opposite of bright; low in luster.
DUMBELLS:
A defect frequently seen in wet-formed nonwoven fabrics; an
unusually long fiber
will become
entangled with groups of regular-length fibers at each end, thus producing a
dumbbell-shaped
clump.
DUNGAREE:
A term describing a coarse denim-type fabric, usually dyed blue,
that is used for
work overalls.
DURABILITY:
A relative term for the resistance of a material to loss of
physical properties or
appearance as a
result of wear or dynamic operation.
DURABLE
PRESS: A term describing a garment that has been treated so that it
retains its
smooth appearance,
shape, and creases or pleats in laundering. In such garments no ironing is
required,
particularly if the garment is tumble-dried. Durable press finishing is
accomplished by
several methods;
two of the most common are the following: (1) A fabric that contains a
thermoplastic fiber
and cotton or rayon may be treated with a special resin that, when cured,
imparts the
permanent shape to the cotton or rayon component of the fabric. The resin-treated
fabric may be
precured (cured in finishing and subsequently pressed in garment form at a
higher
temperature to
achieve the permanent shape) or postcured (not cured until the finished garment
has been sewn and
pressed into shape). In both cases, the thermoplastic fiber in the garment is
set
in the final heat
treatment. This fiber, when heat-set, also contributes to the permanence of the
garment shape, but
the thermoplastic component of the blend is needed for strength since the
cotton or rayon
component is somewhat degraded by the durable-press treatment. (2) Garments
of a fabric
containing a sufficient amount of a thermoplastic fiber, such as polyester,
nylon, or
acrylic, may be
pressed with sufficient pressure and time to achieve a permanent garment shape.
DUST-RESISTANT:
A term applied to a fabric that has been tightly woven so that
it resists dust
penetration.
DWELL
TIME: The time during a process in which a particular substance
remains in one
location (e.g., the
time during which molten polymer remains in a spinning pack.)
DYE
FLECK: 1. An imperfection in fabric caused by
residual undissolved dye. 2. A defect
caused by small
sections of undrawn thermoplastic yarn that dye deeper that the drawn yarn.
DYEING:
A process of coloring fibers, yarns, or fabrics with either
natural or synthetic dyes.
Some of the major
dyeing processes are described below:
Batik:
A resist-dyeing process in which portions of a fabric are coated
with wax; during the
dyeing process,
only the uncovered areas take up dye. The process can be repeated so that
several colors are
used. Batik dyeing is often imitated in machine printing.
Chain
Dyeing: A method of dyeing yarns and fabrics of low tensile strength of
tying them endto-
end and running
them through the dyebath in a continuous process.
Cross
Dyeing: A method of dyeing blend or combination fabrics to two or more
shades by the
use of dyes with
different affinities for the different fibers.
High-Temperature
Dyeing: A dyeing operation in which the aqueous dyebaths are maintained
at temperatures
greater than 100°C by use of pressurized equipment. Used for many
manufactured
fibers.
Ingrain:
Term used to describe yarn or stock that is dyed in two or more
shades prior to knitting
or weaving to
create blended color effects in fabrics.
Jet
Dyeing: High temperature piece dyeing in which the dye liquor is
circulated via a Venturi jet
thus providing the
driving force to move the loop of fabric.
Mass-Colored:
A term to describe a manufactured fiber (yarn, staple, or tow)
that has been colored by the
introduction of pigments or insoluble dyes into the polymer melt or spinning solution prior to
extrusion. Usually, the colors are fast to most destructive agents.
Muff
Dyeing: A form of yarn dyeing in which the cone has been removed.
Pad
Dyeing: A form of dyeing whereby a dye solution is applied by means
of a padder or
mangle.
Piece
Dyeing: The dyeing of fabrics “in the piece,” i.e., in fabric form after weaving or
knitting as opposed to dyeing in the form of yarn or stock.
Pressure
Dyeing: Dyeing by means of forced circulation of dye through packages of fiber,
yarn, or fabric under superatmospheric pressure.
Reserve
Dyeing: 1. A method of dyeing in which one component
of a blend or combination fabric is left
undyed. The objective is accomplished by the use of dyes that have affinity for
the fiber to be colored
but not for the fiber to be reserved. 2. A method of
treating yarn or fabric so that in the
subsequent dyeing operation the treated portion will not be dyed.
Short-Liquor
Dyeing: A term used to describe any yarn or piece dyeing in which the
liquor ration has been
significantly reduced. The technique was designed to save water and energy.
Skein
Dyeing: The dyeing of yarn in the form of skeins, or hanks.
Solvent
Dyeing: A dyeing method based on solubility of a dye in some liquid
other than water, although water may
be present in the dyebath.
Space
Dyeing: A yarn-dyeing process in which each strand is dyed with more
that one color at irregular
intervals. Space dyeing produces an effect of unorganized design in subsequent
fabric form. The two
primary methods are knit-de-knit and warp printing.
Thermal
Fixation: A process for dyeing polyester whereby
the color is diffused into the fiber by
means of dry heat.
Union
Dyeing: A method of dyeing a fabric containing two or more fibers or
yarns to the same
shade so as to
achieve the appearance of a solid colored fabric.
Yarn
Dyeing: The dyeing of yarn before the fabric is woven or knit. Yarn can
be dyed in the
form of skeins,
muff, packages, cheeses, cakes, chain-wraps, and beams.
DYEING
AUXILLARIES: Various substances that can be added to the
dyebath to aid dyeing.
They may necessary
to transfer the dye from the bath to the fiber or they may provide
improvements in
leveling, penetration, etc. Also call dyeing assistants.
DYE
RANGE: A broad term referring to the collection of dye and chemical
baths, drying
equipment, etc., in
a continuous-dyeing line.
DYES:
Substances that add color to textiles. They are incorporated
into the fiber by chemical
reaction,
absorption, or dispersion. Dyes differ in their resistance to sunlight,
perspiration,
washing, gas,
alkalies, and other agents; their affinity for different fibers; their reaction
to
cleaning agents and
methods; and their solubility and method of application. Various classes and
types are listed
below.
Acid Dyes: A class of dyes
used on wool, other animal fibers, and some manufactured fibers.
Acid dyes are
seldom used on cotton or linen since this process requires a mordant. Acid dyes
are widely used on
nylon when high washfastness is required. In some cases, even higher
washfastness can be
obtained by aftertreatment with fixatives.
Aniline
Dyes: Dyes derived chemically from aniline or other coal tar
derivatives.
Anthraquinone
Dyes: Dyes that have anthraquinone as their base and the carbonyl
group
(>C=O) as the
chromophore. Anthraquinone-based dyes are found in most of the synthetic dye
classes.
Azo
Dyes: Dyes characterized by the presence of an azo group (-N=N-) as
the chromophore.
Azo dyes are found
in many of the synthetic dye classes.
Basic Dyes: A class of
positive-ion-carrying dyes known for their brilliant hues. Basic dyes are
composed of
large-molecule, water-soluble salts that have a direct affinity for wool and
silk and
can be applied to
cotton with a mordant. The fastness of basic dyes on these fibers is very poor.
Basic dyes are also
used on basic-dyeable acrylics, modacrylics, nylons, and polyesters, on which
they exhibit
reasonably good fastness.
Developed
Dyes: Dyes that are formed by the use of a developer. The substrate is
first dyed in a
neutral solution
with a dye base, usually colorless. The dye is then diazotized with sodium
nitrate
and an acid and
afterwards treated with a solution of B-naphthol,
or a similar substance, which is
the developer.
Direct dyes are developed to produce a different shade or to improve
washfastness
or lightfastness.
Direct
Dyes: A class of dyestuffs that are applied directly to the substrate
in a neutral or alkaline
bath. They produce
full shades on cotton and linen without mordanting and can also be applied to
rayon, silk, and
wool. Direct dyes give bright shades but exhibit poor washfastness. Various
aftertreatments are
used to improve the washfastness of direct dyes, and such dyes are referred to
as “aftertreated
direct colors.”
Disperse
Dyes: A class of slightly water-soluble dyes originally introduced for
dyeing acetate
and usually applied
from fine aqueous suspensions. Disperse dyes are widely used for dyeing
most of the
manufactured fibers.
Fiber-Reactive
Dyes: A type of water-soluble anionic dye having affinity for
cellulose fibers. In
the presence of
alkali, they react with hydroxyl groups in the cellulose and thus are liked
with the
fiber.
Fiber-reactive dyes are relatively new dyes and are used extensively on
cellulosics when
bright shades are
desired.
Gel
Dyeing: Passing a wet-spun fiber that is in the gel state (not yet at
full crystallinity or
orientation)
through a dyebath containing dye with affinity for the fiber. This process
provides
good accessibility
of the dye sites.
Macromolecular
Dyes: A group of inherently colored polymers. They are useful both as
polymers and as
dyes with high color yield. The chromophores fit the recognized CI classes,
i.e.,
azo, anthraquinone,
etc., although not all CI classes are represented. Used for mass dyeing, hair
dyes, writing inks,
etc.
Metallized
Dyes: A class of dyes that have metals in their molecular structure.
They are applied
from an acid bath.
Naphthol
Dyes: A type of azo compound formed on the fiber by first treating the
fiber with a
phenolic compound.
The fiber is then immersed in a second solution containing a diazonuim salt
that reacts with
the phenilic compound to produce a colored azo compound. Since the phenolic
compound is
dissolved in caustic solution, these dyes are mainly used for cellulose fiber,
although
other fibers can be
dyed by modifying the process.
Premetallized
Dyes: Acid dyes that are treated with coordinating metals such as
chromium. This
type of dye has
much better wetfastness than regular acid dye. Premetallized dyes are used on
nylon, silk, and
wool.
Sulfur
Dyes: A class of water-insoluble dyes that are applied in a soluble,
reduced form from a
sodium sulfide
solution and are then reoxidized to the insoluble form on the fiber. Sulfur
dyes are
mainly used on
cotton for economical dark shades of moderate to good fastness to washing and
light. They
generally give very poor fastness to chlorine.
Vat
Dyes: A class of water-insoluble dyes which are applied to the fiber
in a reduced, soluble
form (leuco
compound) and then reoxidized to the original insoluble form. Vat dyes are
among
the most resistant
dyes to both washing and sunlight. They are widely used on cotton, linen
rayon, and other
cellulosic fibers.
DYE
SITES: Functional groups within a fiber that provide sites for chemical
bonding with the
dye molecule. Dye
sites may be either in the polymer chain or in chemical additives included in
the fiber
DYNAMIC ADHESION: The
ability of a cord-to-rubber bond to resist degradation resulting
from flexure.
DYNAPOINT
PROCESS: A continuous computer-controlled process
for manufacturing tufted
carpets with
intricate patterns from undyed yarn. The carpet is dyed as it is tufted and the
colors
and pattern are
clearly visible through the primary backing of the carpet.