recent trends in textile wet processing
TRANSCRIPT
Recent Techniques In Textile
Wet Processing
Aravin Prince .P., M.Tech (Textiles)
Lecturer/ Apparel Technology
S.S.M.I.T.T, Komarapalayam
+91-9790080302
What is Textile Processing..?
It has four basic process
Preparatory
Dyeing
Printing
Finishing
Testing
Preparation
The ultimate goal of any preparation process is to
produce fabric that is clean and rid of all impurities
that interfere with dyeing and finishing.
Fabric preparation is the first of the wet processing
steps
Desizing
To remove the sizing material from the textile
material (yarn/ fabric/ garment)
Scouring
To remove natural impurities from natural
fibers.
To remove added impurities from man made
fibers
Bleaching
To remove natural coloring matter from fiber
structure
Mostly used hydrogen peroxide; we can use
this to all type of fibers
What Is “Dyeing”…..?
The pleasure derived from imparting colour
to clothing has existed since the time of the
earliest civilisations;
A world of fashion without colour is
impossible to imagine. Coloration processes
produce the most visible results of all the
finishing operations carried out during the
preparation of textile goods
What Is Printing….?
Textile printing is the most versatile and
important of the methods used for introducing
colour and design to textile fabrics.
Considered analytically it is a process of
bringing together a design idea, one or more
colorants, and a textile substrate (usually a
fabric), using a technique for applying the
colorants with some precision.
What is finishing…..?
This facilitates production of attractive
ready-to-sell textiles intended to fulfil
requirements for specific use.
This includes all processes which help to
maintain the value or increase the value of
the textile material.
Textile finishing therefore makes textile raw
material usable by creating properties with a
useful effect.
Recent
Techniques……?
Ultrasonic Assisted WetProcessing
Digital printing Technology
Nano Technology
Bio-Technology
Plasma Technology
Ultrasonic Assisted WetProcessing
Ultrasound energy is sound waves with
frequencies above 20,000 oscillations per
second, which is above the upper limit of
human hearing.
The ultrasonic waves can be generated by
variety of ways. Mostly it is produced by
piezo-electric and magnatostrictivetransducers
Mechanisms:
Increasing swelling of fiber in water.
Reducing glass transition (Tg) temperature
of the fiber.
Reduce the size of the dye particles. It helps
to enhance the transport of the dye to the
fiber.
Applications It degraded starch followed by ultrasonic desizing could
lead to considerably energy saving as compared to conventional starch sizing and desizing.
The scouring of wool in neutral and very light alkaline bath reduces the fiber damage and enhance rate of processing.
It is more beneficial to the application of water insoluble dyes to the hydrophobic fibers.
Among the textile fibers, polyester is structurally compact fiber with a high level of crystallinity and without recognized dye sites.
Ultrasonic waves accelerate the rate of diffusion of the disperse dye inside the polyester fiber.
Benefits
Energy savings by dyeing at lower temperatures and
reduced processing times.
Environmental improvements by reduced
consumption of auxiliary chemicals.
Increased color yields.
Enzymatic treatments supplemented with ultrasonic
energy resulted in shorter processing times, less
consumption of expensive enzymes, less fiber
damage, and better uniformity treatment to the
fabric.
Digital Printing
Digital printing, the most advanced technology in
textile printing is an emerging new technique.
Digital printing in simple terms is the process of
creating prints generated and designed from a
computer, as opposed to analog printing, which
requires printing screens.
Among the various approaches for digital printing
including electro photography, ink jet has gained a
very significant place in the field of innovative
printing techniques.
Mechanism Printing Machine
Nano Technology
Nano Technology…… The concept of Nano tech was first developed in
1930,that time it is called as bottom science.
The term Nano arise from 1970‟s only.
The term „Nano‟ comes from a Greek word „Nanos‟
which means „Dwarf‟.
Dwarf means abnormally small.
1nm = 10-9m
It is about 75000 to 100000 times smaller than the
diameter of the human hair.
This technology that can work at the molecular level,
atom by atom to create large structures with
improved molecules organization by controlling
shape and size at the Nano scale.
Application of Nano Technology
in processing
Nano dyeing
Nano finishingHydrophobic finish
Self cleaning effect
UV-protection
Anti-Microbial
Anti-Pollen
Odour fights finish
Flame retardant
This nano finish originally named as “Nano care”& marketed by “Nano Tex”
Hydrophobic surface can be produced mainly in 2 ways
1. By creating rough structure on a hydrophobic surface
2.By modifying a rough surface using materials with low surface energy
Flurocarbon finishes constitute an important class of hydrophobic finish
Hydrophobic Finish
U-V Finish
Rayleigh‟s scattering theory predicts that in order to
scatter UV radiation between 200 and 400 nm, the
optimum particle size will be between 20 and 40 nm.
A thin layer of titanium dioxide is formed on the
surface of the treated cotton fabric which provides
excellent UV-protection; the effect can be maintained
after 50 home launderings.
Treated cotton Un treated cotton
Anti Microbial Finish It is a well known fact that the growth of bacteria and
microorganisms in food or water is prevented when stored in silver vessels due to antimicrobial properties
Silver ions have broad spectrum of anti microbial activities
The method of producing durable silver containing antimicrobial finish is to encapsulate a silver compound or nano particle with a fiber reactive polymer like poly (styrene co-maleic anhydride)
Instead of perfume , we may use thermo sensitive pigment, thermal storage materials or pharmaceutical preparation in the inner core
The treated yarns showed effective antimicrobial activity against various bacteria, fungi
Silver nano particle
Anti-Pollen Finish
Miyuki keori co of Japan is marketing anti-pollen fabrics
The smoothness of the finish on the surface and the anti-static effect does not let pollen or dust to come
close
This finish is given by the polymer which have anti-static or electro conductive composition
Eg. Fluroalkyl –( meth acrylate polymers.)
It is used in coats blouses, gloves,& etc
Odour Fight Finish
A Taiwanese nanotech firm Greenshield has created underwear using nanotechnology that fights odour
This underwear fiber release undetectable negative ions &infrared rays that destroy odour -causing bacteria
The negative ions inhibits the reproduction of bacteria
Far infrared rays causing all the individual atoms being vibrated at a higher frequency which speeds up the metabolism & the elimination of wastes
Tourmaline –a natural mineral emits negative ions
when low level radiation comes in contact with
oxygen, co2 & water molecules in the air-promotes
electrolytic dissociation
This nano finish can eliminate
99.99% of bacteria,
90% of odour,
75 % sticky moisture
Flame- Retardant Finish
Nyacol nano technologies, has been the worldleading supplier of colloidal Antimony pentoxidewhich is used for flame retardant finish on textiles
It contain colloidal antimony pentoxide withhalogenated flame retardants . The ratio of halogento antimony 5:1 to 2:1
10 parts of nycol in 1550 parts of aqueousdispersion, with pH7 and add 40 parts of H2O andsufficient ammonia add for bring out pH9,mix thiswith 50 parts of rubber latex and spray to the Non-woven material
Characteristics of
Nano finished Textile materials
Their protective layer is difficult to detect with the
naked eye.
Saving time and laundering.
This technology embraces environmental friendly
properties.
The crease resistant feature keeps clothing neat.
Nano processed products are toxic free
Garments are good looking and more durable than
ordinary material
Manufacturing cost is low, adding value to the
products.
BIO TECHNOLOGY
Bio Technology
Bio-technology is not a single technology, rather it
is a group of technologies.
It shares two main characteristics-working with
living cells and their molecules and having a wide
range of applications that can improve our lives.
Bio-technology is the one “using organisms or their
products for commercial purposes”.
Enzymes
Enzymes come from a Greek word “Enzymos” which means „in the cell‟ or „from the cell‟.
Enzymes are proteins, composed of amino acids, which are produced by all living organisms. These are responsible for number of reactions and biological activities.
Enzymes not only work efficiently and rapidly also biodegradable.
Enzymatic Desizing Desizing using enzymes is the most effective and
widely used method for the removal of Starch.
Starch liquefying enzymes are directly used in required quantity under controlled condition of pH and temperature.
Amylase enzyme from Malt extract were first used to degrade starch-based sizes for cheap and effective desizing.
Two categories of amylase
i. α-amylase
ii. β-amylase
The α-amylase attacks the starch randomly and
form Dextrins. It is very rapid in action and
produce simple water soluble sugars.
The β-amylase converts starch into maltose
and it is slower in the rate of action
Bio-scouring
Cotton scouring using alkaline which requires harsh chemicals and high temperature leads to high cost.
Bio-scouring is an effective alternative to chemical scouring. Cottonase T enzyme is widely used for scouring which reduces the need for high energy consumption.
It is versatile, economically viable and eco-friendly to cotton scouring.
Bleach Killing
In bleaching, especially with hydrogen peroxide, the reactive dyes are very much sensitive to residual peroxide.
The residual peroxides are converted into water and Oxygen by using the enzymes which shows better results than traditional method.
Reaction takes place at 30-400 C and pH 5.5-7.5 for 15 min
Enzymes like Peroxidases, Glucose oxidases, etc are used.
Bio-washing This process is removal of surface dyes from
fabrics.
Neutral stable cellulase enzyme is used for bio-washing.
This enzymes replaces the pumice stones .
It is produced from humicola isolans.
It is leading to decolourisation without loss in fabric strength.
This enzyme acts at pH of 6
Bio-polishing
It is a finishing process of cellulosic fabrics and
garments.
This process is improving surface of the material .
This process is also called enzymatic singeing .
Bio-polishing with acid cellulose effectively reduces
fabric fuzz and pilling on denim materials.
NORMAL COTTON FABRIC BIO POLISHED FABRIC
Plasma Technology
Plasma Technology…?
Plasma is often called the "Fourth State of Matter,"
the other three being solid, liquid and gas.
A gas becomes a plasma when the addition of heat or
other energy causes a significant number of atoms to
release some or all of their electrons.
The remaining parts of those atoms are left with a
positive charge, and the detached negative electrons
are free to move about.
Those atoms and the resulting electrically charged
gas are said to be "ionized." When enough atoms are
ionized to significantly affect the electrical
characteristics of the gas, it is a plasma.
Applications
Mechanical Properties
Electrical Properties
Wetting (hydrophilic)
Hydrophobic
Uv-protection
Flame-retardancy
The plasma modification of polymeric materials
used as textiles, membranes, non-woven,
composites, and so on, is able to optimize a lot of
interesting properties.
Mechanical Properties
Material: e.g. cotton, other cellulose-based polymers
Treatment: e.g. oxygen plasma
Crease-resistance
Material: e.g. cotton, wool, silk
Treatment: e.g. dipping in N2-plasma
Fabric Cross Section Possesing Cut Resistance For Cotton
Electrical Properties
Antistatic finish
Material: e.g. rayon
Treatment: e.g. plasma
consisting of chloro-
(chlormethyl)dimethylsila
ne
Antistatic Protection
two layer fabric construction
three layer fabric construction
Hydrophobic & Hydrophilic Finish
Improvement of wetting
Material: e.g. PA, PE, PP, PET PTFE...
Treatment: e.g. O2
Hydrophilic treatment serves also as dirt-repellent and antistatic finish.
Hydrophobic finish
Material: e.g. cotton, cotton/PET,
treatment: e.g. per fluorocarbon-plasma
Water-repellent finished cotton/polyester fabric.
plasma treated.
Oil repellency on plasma treated cotton/polyester fabric.
UV-protection Material: e.g. dyed
cotton/polyester
Treatment: TiO2 plasma
Flame-retardancy Material: e.g. PAN,
Rayon, cotton
Treatment: e.g. phosphorus containing monomers
PLASMA TREATMENT FOR UV PROTECTION
PLASMA TREATMENT FOR FLAME RETARDENCY
Advantages
It increases abrasion resistance of cotton materials
It increases dyeing speed
It gives anti-shrinking
It gives anti-dirty
It gives hydrophilicity to polypropylene bonded fiber fabrics
It gives liquid repellency
Conclusion
Thus the Ultrasonic, Digital Printing , Bio ,Nano &
Plasma technology replaces traditional method with
more advantages such as
Replacing harmful chemicals
Require less effluent treatments
Low cost and less energy consumption
No damages to materials
superior quality of the product
In feature , one can expect to see many more
developments in textiles , based on above
technology‟s
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Oct 06
www.forsight.com/journal/nano
www.nano-tex.com
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www.fiber2fashion.com/articles/technology
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www.bharattextile.com/news
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