Knitting Fair introduced the history and
origin of Blue Denim Jeans in the last article. Now let’s learn what is denim
fabric made of.
What is denim fabric made of?
Cotton
Denim is a material made from 100% cotton.
This is a cotton thread that is used to make a particular weave. It has warped
threads in which a weft thread is placed under. This forms the traditional
diagonal ribbing on the surface of the material.
What is bull denim?
Cotton Bull Denim is perfect for slipcovers,
upholstery, draperies, pillow covers, headboards and much more. Bull Denim
fabric is often referred to as “tough as nails” due to the strong 3×1 twill
construction. Although the fabric is extremely durable it is also amazingly
soft!
Why are jeans blue?
Blue was the chosen color for denim because
of the chemical properties of blue dye. Most dyes will permeate fabric in hot
temperatures, making the color stick. The natural indigo dye used in the first
jeans, on the other hand, would stick only to the outside of the threads,
according to Slate.
Definition of Denim fabrics
A coarse, twilled cotton fabric, often blue,
traditionally used for overalls and work clothes and now used for jeans and
casual wear.
Denim Pants or another garment made of this
fabric.
A similar but finer fabric used in draperies
and upholstery.
Denim Characteristics
Cotton Thread and Twill Weave
Denim is made from cotton, which is spun and
free of any debris
Blue Color
A distinguishing feature of denim is its blue
color
Durability: Denim is very strong and does not
snag or tear easily. It is also breathable, can be ironed at a high temperature
and creases easily. Suitable for long wear, it is quite stiff when new, but
softens with repeated washings.
Raw materials used for blue denim fabrics: To
produce good quality denim, the conditions have to be optimal regarding the
quality of all the raw materials and yarn used. For raw cotton and the carded
OE (rotor) or ring-spun yarns made from it, the quality criteria are as
follows:
Minimum staple length: 2.7 cm.
The proportion of short fibers (less than 12
mm long): under 40%.
Micronaire value: 4.0 to 4.5.
The Uster values for strength and elongation,
for the evenness CV and imperfections, must conform at least to the 25% plot.
The usual count range of denim warp yarns is
50 to 90 tex and weft yarns is 75 to 120 tex; finer yarns as fine as 25 tex in
twill or plain weave are often used in denim shirts.
Twist factor: 4.5 to 5.0 for warp yarns, 4.2
for weft yarns.
Low yarn hairiness.
Yarn strength and uniformity.
True blue denim Fabrics are made out of 100
percent cotton warp and weft yarns. Fabrics are also made of Elastic core-spun
yarns which are used as a weft yarn for textile fabrics and has gained great importance
in the last decade due to the fact that stretch and recovery, comfort fits and
flexibility properties.
The dual core-spun yarns are composed of
cotton/ filament that contributes durability and polyurethane-based elastane
that provides stretchability to the fabrics. Hereby, both filament and elastane
characteristics have a great influence on denim performance at the same time.
The main purpose of using this type of yarns is to achieve the effect of
filament fineness and elastane draft on denim fabric performance such as
braking force, breaking elongation, tear force, vertical elastic recovery,
moisture management that is wicking rate and water absorption properties.
Meanwhile, filament core-spun yarns with
different filament fineness and 100% cotton yarn are also used as the weft of
the denim. It is found that that filament fineness and elastane draft had a
statistically significant effect on all inspected performances of denim fabrics
except water absorption.
Polyester blends are also manufactured and
are available, however, the overwhelming majority of jeans sold are 100 percent
cotton. The most common dye used is synthetic indigo.
What dye is used for denim?
Indigo
The primary use for indigo is as a dye for
cotton yarn, which is mainly for the production of denim cloth for blue jeans.
Why do jeans fade?
As an example, blue jeans fade where the
fabric is physically rubbed. Most other natural dyes fade equally in sunlight,
and minimally when rubbed. Indigo does not form a chemical bond with the fabric,
like other dyes. The reduced state is also necessary because indigo cannot
dissolve in water, it is insoluble.
Unique Structure of Indigo dye
Indigo, or wood indigo, is a unique dye. The
extraction process reflects the different molecular characteristics of indigo,
as compared to other natural dyes. As an example, blue jeans fade where the
fabric is physically rubbed. Most other natural dyes fade equally in sunlight,
and minimally when rubbed.
Indigo does not form a chemical bond with the
fabric, like other dyes. Instead, it forms a physical bond, bonding molecularly
to the fabric when reduced. The reduced state is also necessary because indigo
cannot dissolve in water, it is insoluble.
When the indigo molecules bond to the fabric and it is re-vetted, the
indigo forms layers – like bricks. This makes indigo very impervious to
sunlight, but indigo will fade with rubbing.
Source:
Ashok Hakoo
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Higher quality yarn improves the weaving
process. Introduction of very small non-film forming resin particles in
conventional size formulations modify and provide improved fiber cohesion in
the warp yarn bundle. This transient effect provides a more compact and
improved yarn substrate to host conventional warp size polymers on the yarn
surface. Evaluation of this technology in producing mills has provided positive
results in all factors associated in the weaving process.
In the early 1800s, the introduction of the
mechanical loom promised the potential of dramatically improved fabric
production. However, the mechanical loom also introduced a level of abrasion on
warp yarn that prevented this productivity potential. The abrasion problem was
soon attacked by borrowing technology developed by the coatings industry. In
coatings, surface protection was provided by the application of natural oils
which crosslinked to form a permanent topical barrier. The concept provided the
solution, but the woven fabric was not a candidate for a permanent abrasion
barrier. Starch soon emerged as a suitable material to provide a transient
abrasion-resistant barrier to protect warp yarn. This approach soon led to the
development of the necessary machinery to apply an abrasion barrier and the
concept was adopted by the industry.
During the next two centuries, significant
improvements in coatings technology and materials have been adopted to
accommodate continual changes in yarn composition, yarn formation, and loom
technologies. Warp sizes are now
designed to meet the demands of each fabric style on a case-by-case basis. Warp size suppliers and technicians have
performed admirably in bridging continual changing technologies involved in the
journey from fiber to fabric. We now are
more secure in gauging general rules of viscosity, penetration and overall size
add-on levels for optimum weaving performance. Optimization of the sizing
formulation is now paired with the variables from the slasher through the
greige fabric.
Advances in the use of polymer/starch surface
barriers now dominate spun yarn sizing.
Abrasion protection coupled with nearly 2 centuries of experience has
achieved what is now regarded as the optimum in painting warp yarn. Unfortunately, this experience has fostered
an attitude of complacency to the potential for improving weaving performance
utilizing chemicals in the size box.
The use of nanosize resins (oligomers) has
now been evaluated as components in warp size formulations. On a theoretical basis, and the barrier
coatings approach, these materials provide little optimism for improvements in
weaving. Chemically, oligomer resins
have the basic properties of higher molecular weight polymers of the same
chemistry but are much too low in molecular weight for viable film
formation. Minor adhesion and
plasticization of conventional barrier film formers became the primary hope for
this new technology. Initial trials with
nanosize oligomers in conventional size formulations provided promising results
in both adhesion and plasticization of the barrier coating. In addition, incorporation of oligomer resins
provided differences that were not readily explained.
1.Reduction in both warp and filling stops.
2.Fiber and size shed at both the slasher and
looms were dramatically reduced.
3.Increased yardage of hard yarn on the loom
beam.
These results did not neatly fit into the
barrier concept of warp sizing.
Increased yardage on the loom beam logically indicated reduced size
pick-up on warp yarn. However, multiple
desize analysis of hard yarn from trials and normal production were
equivalent. The repetition of these
trials was consistent with the initial results.
Nanosize oligomer resins were clearly providing a mechanism to
complement barrier coating film abrasion resistance.
Microscopic (60X) photos were utilized to
determine any visual differences between standard and trial hard yarns. Yarns
containing oligomer resin in the size formulation exhibit a smoother surface
with less hard fiber disruption from the sheet break. In addition, the examination of 60X photos of
the sized yarn indicates a significant reduction in yarn core diameter. Sized
yarn diameters exhibit near 20% reduction in comparison to normal formulation
hard yarn at the same add-on.
Examination of 1040X magnification
cross-sections of yarn prior to the size box provides an explanation of the
function of nanosize resins within the yarn bundle. Vacant spaces between
fibers in the bundle are micron or greater in diameter and volume. Fibers in spun yarn systems are mildly
anionic, natural or added, which maintain a repulsive force to keep fibers
apart. As the yarn is wet-out by water,
huge numbers of millimicron oligomer resin particles penetrate and adhere to
fiber surfaces. Repulsive forces existing between fibers are overwhelmed and
the fiber surface is modified with nanosize particles. These small resin molecules provide a
like-like mutual attraction and allow fibers to be drawn closer together to
partially reduce vacant spaces within the bundle. Immediate compaction of the yarn bundle
occurs upon wet-out. A smaller yarn
substrate is now available to host the barrier film. The count of the yarn remains constant with a
smaller diameter bundle. An increase in
the density of the yarn is attributed to improved fiber cohesion within the
bundle.
For more news , please pay attention to yarn fair.
Source: JOHN LARK
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Word “denim” comes from fabric “serge de
Nimes” made in France city of Nimes from where it originates. It has been used
in America since the late 18th century, colored blue with indigo dye to make
blue “jeans”, a type of cotton pants.
Easy care fabric for leisurewear covers a
major preparation of the total production of textiles. Not only classic and
basic denim in twill were in demand but also medium and higher qualities in
twill and chambray in demand. They are used for leisurewear, shirts, blouses,
and jackets. The original dark blue indigo- colors have changed and cover all
shades from super blue to black, light blue, light grey to brown. Now knitting fair
will introduces to you.
History of Denim
As early as 1873 denim was produced by
Bavarian Levi Strauss who emigrated to the USA. He manufactured trousers from
heavy cloth. He soon realized that this type of fabric was ideal clothing for
mine workers, farmers, and cowboys.
The production of denim has developed into a
major part of the world textile industry. Word “denim” comes from fabric “serge
de Nimes” made in France city of Nimes from where it originates. It has been
used in America since the late 18th century, colored blue with indigo dye to
make blue “jeans”, a type of cotton pants.
Jeans come from “Genes” – a name given by
French to Genoa and the people from Genoa where the cotton trousers were made.
In the 1800s, in the time of the Gold Rush, American gold miners needed clothes
that were strong, lasted longer and did not tear easily.
Levi Strauss, a businessman, and Jacob Davis,
a tailor, supplied miners with denim pants that were made from durable material
and reinforced with rivets at the places where pants tended to tear which
prolonged life of pants. This marked the beginning of the legend of jeans and
brand Levi Strauss is still hugely successful today.
Denim was first used for clothes worn by
workers because of its high durability. Then it became widely popular in the
1930s when Hollywood started making cowboy movies in which actors wore jeans.
With the beginning of World War 2, production of the jeans drops but world meet
denim when American soldiers started wearing them when they were on the leave.
When the war ended, other companies that made
denim started appearing like Wrangler and Lee.
Young people started wearing denim in the
1950s a mean of rebellion. This fashion was also inspired by Hollywood with by
Marlon Brando with his 1953 film “The Wild One” as well James Dean’s movie
“Rebel Without a Cause” from 1955. Some public places like schools and theaters
banned jeans because of what they symbolized.
Denim crossed from counterculture to fashion
in the 1960s and 1970s when manufacturers started to make different styles of
jeans. Fewer jeans were made during World War II, but ‘waist overalls’ were
introduced to the world by US soldiers, who sometimes wore them off duty. By
the 1960s, both men’s and women’s jeans had the zipper down the front. Historic
photographs indicate that in the decades before they became a staple of
fashion, jeans generally fit quite loosely, much like a pair of bib overalls
without the bib. Indeed, until 1960, Levi Strauss called its flagship product
“waist overalls” rather than “jeans”.
After James Dean popularized them in the
movie Rebel Without a Cause, wearing jeans became a symbol of youth rebellion
during the 1950s. During the 1960s the wearing of jeans became more acceptable,
and by the 1970s it had become a general fashion in the United States for
casual wear. However, the acceptance of jean to becoming casual wear is still
relatively low in Japan.
Examples of intentional denim distressing
strictly to make them more fashionable can be seen as early as 1935 in Vogue’s
June issue. Michael Belluomo, editor of Sportswear International Magazine,
Oct/Nov 1987, P. 45, wrote that in 1965, Limbo, a boutique in the New York East
Village, was “the first retailer to wash a new pair of jeans to get a used, worn
effect, and the idea became a hit.” He continued, “[Limbo] hired East Village
artists to embellish the jeans with patches, decals, and other touches, and
sold them for $200.”
In the early 1980s, the denim industry
introduced the stone-washing technique developed by GWG also known as “Great
Western Garment Co.” Donald Freeland of Edmonton, Alberta pioneered the method,
which helped to bring denim to a larger and more versatile market. Acceptance
of jeans continued through the 1980s and 1990s. Originally an esoteric fashion
choice, in the 2010s jeans may be seen being worn by men and women of all ages.
Denim is popular for long-term use and is a fashion fabric for casual wear.
General features of the denim fabric are as follows: Cotton or cotton-polyester
blended, durable and heavy-weight twill-weave. Maybe napped or printed, made
with spandex or other stretch yarns, or otherwise modified for fashion. Dec 13,
2018.
Origin of Denim
Denim is a type of cotton twill textile, in
which the weft passes under two or more warp threads. Warp threads of denim
fabric are dyed in indigo while weft threads remain plain white. Denim was
first used for clothes worn by workers because of its high durability.
With the rope dying system, the core of the
yarn usually remains white. This ensures the fading of the colors after
multiple washing. It should slowly become lighter. Denim is a type of cotton
twill textile, in which the weft passes under two or more warp threads. Warp
threads of denim fabric are dyed in indigo while weft threads remain plain
white. That is why denim is blue on the one side and white on the other. When
used for jeans, denim is turned blue on the outside and because of the way it
is made it fades in a characteristic way.
Original denim was dyed with dye from plant
Indigofera tinctoria. Modern denim is dyed with synthetic indigo. Denim is
often dyed with indigo and dried many times over to get a stronger color that
will not fade quickly. After the denim is made into clothing it as most often
washed to make it softer and to reduce or eliminate shrinkage. Denim that is
not washed is called dry or raw denim.
Denim fades in time and gets a worn outlook
which is often desired as a fashion detail. Some denim is artificially
distressed so a worn-out look can be got even before wearing. Denim that is not
made of pure cotton but also has an elastic component (most often elastane) is
stretch denim. Beside indigo dyeing, denim can be colored with sulfur dyeing
which is used for dyeing of denim in colors other than indigo.
Source:
Ashok Hakoo
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