Glossary for Dyes and Pigments
A |
Aniline-
Represented by the chemical formula of C 6H 7N.
Is also known as aniline oil, Aniline is a very commonly used term in
the synthesis of dyes. In fact the term 'aniline dye' is used as a sort
of synonym for synthetic dyes.
Affinity
- It is referred to as the attraction between two things. While in
dyeing affinity it means the preferential attraction of dye towards
fiber rather than for solution of the dye bath. A dye that has strong
affinity easily leaves the dye solution of dispersion. And attaches
itself to the fiber being dyed.
Acid
Dye- A large and popular class of dyes which are applied to
polyamide fibers from acidic solutions. Essentially synthetic dyes, they
are used for silk, wool and nylon.
Azo-
Azo refers to a chemical compound that contains double nitrogen
atoms with a double bond between them (-N=N-). With more than 2000
organic compounds, azo dyes forms the largest group of dyes. They
display light-fastness, stability, strongness and respond well to mixing.
"Azo" is the term applied for a class of dyes based on the
above chemical structure. Azo dyes may be found among the dye classes of
direct, acid, basic, reactive and disperse.
B |
Basic
Dye- Basic dyes are the dyes that is able to react with acidic
groups on fibers. They are also referred to as cationic dyes.
Bifunctional
Reactive Dye- These are the groups of reactive dyes that typically
has more than one type of reactive group in their molecule structure.
They are special in the way that these reactive dyes are designed for
having the potential to react with the fiber in more than a single way.
Binder-
Typically a material, that is nearly colorless, used to attach a
pigment to fabric binders are like "glue" that holds the
pigment in place. Examples are of Paints that has pigments mixed with
binders.
C |
Cation-
It is a positively charged ion. Numerous chemicals applied in textile
processing are referred to as cationic. That means when the compound
ionizes in a solution, it's actually the positively charged ion that is
"operational".
Cellulose-
A polymer consisting of a large numbers of units, each of the
general formula represented by C 6H 10O 5.
Chromophore-
It is a color-bearing compound, by their special property found in an
organic molecule they make it appear colored.
Colour
Index- A publication jointly brought out by the Society of Dyers and
Colorists of Great Britain and the American Association of Textile
Chemists and Colorists.
Chrome-
Any of some salts of chromium, that is used in tanning and dyeing.
D |
Direct
application- A method usually used to describe a process where a
solution of dye is locally applied to different areas of fabric, like
squirting, painting, spraying, stamping, etc.
Direct
Dye- A class of dye based on application method. Which is
essentially carried out by immersing the fiber in a dye solution without
any requirement of other chemicals for bonding the dye to the fibers.
Disperse
Dye- A dye that is seldom soluble in water. Disperse dyes are found
in the dye bath as a kind of suspension or dispersion of microscopic
particles, with only a minuscule amount in true solution at any given
moment of time.
E |
Exhaust
Dyeing- Exhaust Dyeing is used for denoting the application of a dye
bath of a moderately larger liquor to goods ratio, where the fiber is
immersed for a while. It allows the dye molecules to exit the bath and
get attach to the fibers.
Enzyme-
A type of protein that performs the role of a catalyst in a
biochemical reaction. Enzymes are now popularly used in textile
processing. Examples are Amylase enzymes are applied for desizing, and
cellulase enzymes are used in modification of cellulosic fabrics.
F |
Fixation-
Fixation refers to the formation of a sort of final bond
between the fiber and dye. The bond type formed changes with the type of
dye and the fiber. To cite an examples, reactive dyes generally fixes by
covalent bond, while in the case of acid dyes fixing is done by a
variety of mechanisms like hydrophobic forces and ionic bonding.
FBA-
Fluorescent brightening agent.
G |
Gel
Dyeing- A continuous type of tow-dyeing method where soluble dyes
are used to wet-spun fibers in the gel state (i.e. After the processes
of extrusion and coagulation, but before drying and drawing).
H |
Hardness-
Term used in respect of water, a measure that ascertains the content
of minerals that imparts specific properties.
I |
Illuminating
Dye- A dye that is mixed with discharge paste in printing methods
also referred to as head dyes.
Indigo-
A sort of natural or synthetic vat dye given the designation of
Colour Index Vat Blue 1. Indigo is perhaps one of the oldest colorants
that is used for textiles. Originally extraction was done from plants,
but now it is usually synthetic.
J |
Jet
Dyeing- Used to dye Polyester.
K |
Kilogram-
An unit of mass (weight) in the system of metric. It equals
approximately 2.2 pounds avoirdupois.
L |
Liquor
ratio (also liquor to goods ratio)- The ratio that is used to denote
the weight of the dyebath or any other processing bath to the weight of
goods that is being dyed or processed.
Leveling
Acid Dye- A class of acid dyes, leveling acid dyes offers bright
colors and level very easily.
Lightfastness-
Light Fastness is typically used as measure to ascertain how
resistant a coloring material, such as dye would be fading when exposed
to light.
There are a number of standard textile industry methods that evaluates
how lightfast a dyed fabric is.
Lake-
Lakes are the type of pigments produced as a result of absorbtion of
the dye on the substrate. Most common substrate can be alumina hydrate.
M |
Metal-Complex
Dye- A dye that typically has co-ordinated metal atoms in its
molecule. A very vital point here to note is that unless the term "metal-complex
dye" is applied in direct association with a specific
application class of dye, for example "metal-complex reactive dye"
or "metal-complex disperse dye" its use can be deprecated.
Mordant-
Refers to chemicals that helps in attachment of dyestuff to fibers
by bonding to the fiber as well as to the dye. A mordant must show high
affinity for both dye and fiber, performing its role to attach the
dyestuff to the fiber.
N |
Non-ionic
- A chemical that does not ionize in a solution, while remaining is
in intact molecular form some surfactants are non-ionic.
No-wick
HF- Use lies with Liquid Decorator Colors, for enabling fine line
drawing.
P |
Pigment-
A substance used in the particulate form that is substantially
insoluble in a medium. But pigments can be mechanically dispersed in
that medium to carry out modification in its colour and/or properties of
light-scattering.
pH-
A perfect measure of the concentration of hydronium that is found in
a solution.
R |
Reactive
Dye- A dye that, under proper conditions, can react chemically with
a substrate for forming a covalent dye-substrate linkage.
Retayne-
A type of cationic dye fixing agent. Typically used on cotton
fabrics for improving wet fastness of the direct dyes and to add color
paper pulp.
S |
Sulphur
Dye- A dye, that contains sulphur as an integral part of the
chromophore and as well as in attached polysulphide chains. Sulphur dyes
are not soluble in water, and must get converted to a soluble form
before application.
Sublimation-
The conversion of solid directly into gas, without passing through
the liquid phase. Some disperse dyes can sublime.
Sodium
Hydroxide- Represented by the chemical formula of NaOH; it is a
strong base; also called caustic soda or lye, or just "caustic"
in dyeing terms.
T |
Tannic
Acid- A mixture of compounds derived from natural sources like oak.
Tannic acid treatment, followed by a treatment of tartar emetic, has
been reported to improve the washfastness of dyed nylon or wool.
U |
Union
Dye- A dye that is generally a mixture of two or more different
classes of dye, used to dye blends of fibers.
Ultraviole-
Light that is beyond the portion that is visible of the light
spectrum at the blue end. It is the Ultraviolet light that causes fading
of colors, and makes fluorescent compounds glow.
V |
Vinyl
Sulphone- A type of reactive dye, that is typically used for
cellulosic fibers but with some use for wool also. Vinyl sulphone
reactive dyes are generally intermediate in their reactivity, so they
are used above room temperature, but considerably below the boiling
point of water.
Vat
Dye- Vat dyes are water-insoluble dye, that usually contains keto
groups, which is normally applied to the fiber from an aqueous alkaline
solution of the reduced enol (leuco) form, that subsequently gets
oxidised in the fiber to an insoluble form.
W |
Washfastness-
Washfastness is used to measure resistance of a dye to washing out.
Wetting
Agent- A type of chemical which helps the water to penetrate a
material or to form a film over its surface; usually it is a surfactant.
Wetting agents are generally used in the dyeing process where it helps
the dye solution to penetrate to the individual fibers.
Y |
Yarn
Dyeing- In this process, Yarn gets dyed before being woven into
fabric.
Z |
Zinc
Formaldehyde Sulphoxylate- A Colour Index Reducing Agent 6, used for
application in discharge.
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