in-class
assignment for coloration
Textile
Terminology and labeling
Chapters
20, 21 Coloration (dyeing and printing)
ADDING COLOR TO TEXTILE
MATERIALS
In-class assignment on color
1. The two methods of applying color
are printing and dyeing.
2. Solid colors are usually achieved
by piece dyeing.
3. If a material is red, which color
wavelength is not absorbed? red
4. When all light wavelengths are absorbed,
the resulting color is white.
5. Two sources for natural dyes are
roots,
flowers, plants, insects, etc.
6. Dyeing is usually done in a dyebath.
7. Which fiber fades from gases in the
air (fume fading)? acetate
8. The type of coloration that does
not absorb is pigment.
9. The dyeing of fibers before being
made into yarns is stock dyeing.
10. The most expensive stage of dyeing
is solution dyeing.
11. Most stripes are made from which
stage of dyeing? yarn
12. The stage of dyeing that gives a solid color is piece
dyed.
13. A solid color made by mixing dyes for two or more fiber
types is union dyeing.
14. The most economical stage of dyeing is garment dyeing.
15. Dyeing in a localized area to produce a design or pattern
is printing.
16. The three main types of printing are roller, screen,
heat transfer.
Dyes - substances that add color to materials
by being absorbed
Pigments - substances that add color to
materials on the surface; are not absorbed
Dyeing - a colorant is uniformly distributed within or on the surface
of
all fibers throughout a yarn or fabric
Printing - a colorant is applied to localized areas on fabric or
yarn surfaces; includes the print pattern and the process
Stages of dyeing textile materials
1. Fiber dyeing - color is added
in the fiber state
Solution
dyeing is adding color to the manufactured fiber in the solution stage
before it is extruded.
Solution
dyeing is very durable; the color is all way through
Stock dyeing
is adding color to loose fibers by immersing in a dyebath
FIBER DYEING IS AN EXPENSIVE TYPE OF DYEING.
The manufacturer is taking a chance on the fashions remianing the same
throughout the season or longer.
2. Yarn dyeing - color added in the
yarn stage
Yarn dyed products are usually the same on both sides such as with plaids
and stripes.
The yarns may be space-dyed - the yarn is immersed in different colors
along the length of the yarn.
3. Piece dyeing - Most solid color
fabrics are piece-dyed. The fabric is immersed in a dyebath and comes
out a solid
color front and back.
If a fabric
is a blend of fibers that do not take a similar type of dye, dyes are mixed
to create a dye that
will provide
a penetrate all fiber types and give a solid color. This is union
dyeing.
If a fabric
is a blend of fibers that do not take a similar type of dye and the desired
effect is to have a
fabric that
is more than one color, one dye type is used and the fabric is multi-colored.This
is cross dyeing.
PIECE DYEING
IS THE LEAST EXPENSIVE TYPE OF DYEING.
4. Product dyeing - the products (garments,
sheets, curtains, etc.) are immersed in a dyebath after the
product is
completely assembled, including trim, labels, seams, etc. Everything must
be compatible including trims, labels, thread, etc. Being able to
dye at this stage enables a company to be able to reduce inventory.
Colorfastness is the most common consumer complaint
Colorfastness is the ability of a textile material to retain its
color during use and care
Fading - color becomes lighter; cause could be age, light, pollutants,
chlorine, water, etc.
Bleeding - color depositing on another material
Migrating - color moviing from one part of the garment to another
Frosting - color loss due to abrasion
Crocking - transfer of color from one material to another by rubbing
Printing - a colorant is applied to localized areas on fabric or yarn surfaces; includes the print pattern and the process
Direct printing - the printed patter is put
directly onto the fabric
Examples of direct printing
include:
Application - colorant
is printed onto a white fabric
Duplex - a fabric is printed
on both sides; may be the same design or different
Overprint - a motif is printed
over a dyed fabric. The overprint motif does not show on the back
Blotch - both the background and the
motif are printed on the fabric; the back is usually white
Processses of direct
printing
1. Roller printing - usually small
designs; designed is engraved into copper rollers. The dye is held
in the engraved portions and rolled over the fabric. There is a different
roller for each color. Only about 25% of the printed fabric is roller printed.
2. Screen printing - larger designs.
The dye is forced through openings in a screen onto the fabric. A
different screen is used for each color. Today,
most printing is done by the screen printing method. Read about rotary
and flat-bed screening in textbook.
Resist printing
- the colorant is resisted in certain areas of the fabric by a substance
such as a wax, string, etc.
The dye is not deposited where the resist
substance is on the fabric. Examples are batik, tie-dye
Discharge printing - the fabric is dyed a dark solid color and a discharge paste is used to discharge the dye in designated areas.
Heat transfer printing - colorant is applied to a special type of paper. The colorant vaporizes when it is heated and it redeposits on the fabric.
Textile
terminology, textile labeling
Terminology:
Natural fibers - any fibers that
exist as such in the natural state
Common names - the names given to natural
fiber (such as cotton, flax, ramie, sisal, wool,
Silk, hemp
Manufactured fibers - fibers derived
from a process of manufacture from any substance which, at any point in
the
manufacturing process, is not a fiber.
Generic fiber names - names given by
the Federal Trade Commission for fibers of a particular chemical structure
(ex.
polyester, spandex).
In order for a new generic fiber to be named
“the fiber must have a chemical composition
‘radically different’ from other fibers or that chemical composition must
give
it significantly different physical properties;
the fiber must currently be, or soon be, in active commercial use; and
the
granting of the generic name must be of importance
to the consuming public ‘at large’ rather than to a small group of
knowledgeable professionals.”
Trademark names - the names given by
manufacturers for their versions of a particular fiber (ex. Dacron
polyester,
Lycra spandex, Anso nylon) . Trademark
names are always in capital letters.
Textile Labeling is enforced by the Federal Trade Commission.
Textile Fiber Product Identification Act (TFPIA) - effective March 1960
Conditions of TFPIA -
1. All textile products have a label
attaches that lists fibers from which they are made with the exception
of upholstery
stuffing, outer coverings of furniture, mattresses,
linings, interlinings, stiffenings or structural paddings; sewing and
handicraft threads, bandages an surgical dressing.
2. Generic fiber names must be listed
in the order in of percentage of fiber by weight. Fiber quantities of 5%
or less may be listed as "other" unless the fiber serves a specific purpose.
There is a tolerance
of 3% of the listed weight.
3. The name or registered trademark or registered number must appear on the label.
4. The country of origin must be listed
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Wool Products Labeling Act
Same requirements as the Textile Fiber Products
Identification Act AND:
2. Wools other than sheep's wool must
be labeled as such
3. Recycled wool must be identified
.
.
Know generic fibers in chart
on page 30 of your textbook. Be able to match the fiber with the
correct category:
Natural cellulosic
Natural protein
Manufactured cellulosic
Manufactured synthetic
Manufactured inorganic
Know the properties of each of the above categories (see your course notes and notes below).
Be able to match the names of generic fibers, fiber tradenames (such as Kevlar), fabric structures (such as plain, twill, etc) or fabric names (such as gabardine) and textile companies.