Value Addition Finishes for Textiles

Value Addition Finishes for Textiles
K V Lokesh
Department Of Textiles
D. K. T. E. Society's Textile & Engineering Institute, Ichalkaranji
Email: lokeshkv.dhtech@gmail.com


Abstract
Textiles with desired functional and aesthetic properties have an evergreen demand among the consumers globally. Unless any product is characterized by value addition, it is now impossible to survive in this highly competitive world market. Only innovative products will be sustainable to open up new markets and new horizons for textile industry. Manufacturers should now produce products to satisfy customers that are best in terms of quality and price. Customers today have a wide range of choices and the one who produces the best quality at a better competitive price will survive and prosper. Processing is important to make a usable but finishing gives better characteristics and value addition to it. It makes textile material attractive, comfortable and finishing can incorporate desirable properties. This paper represents a general overview of all value adding functional finish on textile material.

Key Words: Finishing, Mechanical, Thermo, Chemical, Special, etc..

1. Introduction
Once again after a gap of two decades, the Indian Textile Industry appears to be on the horizon. With the advent of rapid globalisation and liberalization, the Value Added Product has now become the Buzzword! Unless any product is characterized by value addition it is just impossible for it to stand in this highly competitive market. With the coming into effect of the WTO, from 1st Jan 2005, stiff and fierce competition in the world Trade Market is just inevitable. To counter this challenge, one is left with no other alternative but to produce Value Added Product or hence just perish. This holds well in the textile sector, where the finishing technology holds the key. Gone are the days of conventional & traditional fabrics, which are superfed by high performance fabrics with speciality finishes. Indeed, these are the days of research and development, where value added finishes need to be developed. Reforms in this direction ought to be made to meet the challenges of the future not only in the domestic as well as in the International market. Customers seek value for money and the one who offers the best at a highly competitive price is going to survive and prosper.

2. Classification of Textile Finishing
Finishing of textile fabric is carried out to increase attractiveness and serviceability of the fabric. Different finishing treatments are available to get various effects, which add the value to the basic textile material. Value Adding Textile finishes are classified as four types they are;
  1. Mechanical finishes
  2. Thermo-Mechanical finishes
  3. Chemical finishes
  4. Special finishes
2.1. Mechanical Finishes
Mechanical finishes imparts various properties to the fabric such as softness, peach skin effect, luster, bulkiness. In this respect various machines producing special finishes have been introduced by various manufacturing companies such as biancalani, santex, alliace.

2.1.1. Petra From Bianclani (Italy)/ Airo Finish
This is a continuous, modular, open width finishing machine for all types of woven fabrics; it produces smooth and peach skin type finish, enhancing hand and volume through oscillating action of bars of abrasive stone. The oscillating motion of the abrasive bars at a very high frequency against the surface of the fabric causes micro-fibrillation, techno-polishing and/or discoloring of the fabric without any affecting the strength of the fabric or cutting it. This mechanical finish is a alternate to the enzyme finish but is faster and without fabric strength loss. Different looks such as classic look and casual look can be produced by adjustment of the movements and severity of the bars through varying pressure of contrast cylinders mounted below the bars. This machine consists of re-circulation system for water conservation, the user friendly control panel with computerized touch screen system with manual or automatic modes, which can control the fabric speed , pressure of contrast cylinders, depth of abrasion, re-circulation etc. The various special finishes such as discoloring effect on the denim fabric, smoothing, peach skin effect surface ageing on the cotton, viscose, lyocell, linen fabric can be produced.

2.1.2. Raising
Raising

Soft and Supple handle is one of those efficient tools which had done wonders in elaborating the definitions of value added requirements for fabric. Therefore Raising involves lifting up of fibres to a considerable height so that there may be no disturbance in fabric construction. Machine required for this purpose involves fabric movement over a central drum mounted with series of pile and counter pile rollers having their movement in such a fashion that each fibres in lifted in a controlled manner. This finishing work is used to create different feel & a velvety material surface on fabrics & knitwear by loosening a large number of individual fibres from the fabric & subsequent rising & napping in order to crest a dense raised fabric/surface.

2.1.3. Santasoft from Santex Peach Finish
This machine gives high-grade finish in open width form on woven & knitted. It increases the softness and suppleness of the fabric. The fabric passes through a treatment zone in which the fabric is subjected to intensive ‘tumbling’ action. It produces excellent finishes on the denims, cotton cord, pigment printed fabrics, linen and blends.

2.1.4. Phantim
This is supposed to be one of the novel effects which are present in the market to have value addition on to the fabric. In real terms it is practiced only on to the denim this is because one of the un-dyed and consequently results in considerable fading of colour due to extensive abrasion. Machine which is used for this purpose involves diamond powder coated roller which results in the required degree of abrasion sufficient enough to fade the colour. Predetermined or desired design could be procured with the help of pneumatically operated needle shape nodes when in contact with the diamond powder coated roller results in fading of that portion. And movement of nodes as well as rotation of the diamond powder coated roller is controlled with the help of computer which creates the design finish meticulously with great precision & accuracy

2.2. Thermo-Mechanical Finish
This method of giving finishing to the fabric employs application of heat with regular mechanical forces to educe novel finishes. This finishes include the following:

2.2.1. Calendaring
Calendering belongs to thermo-mechanical type of finish. Though this one of the old types of finishing method yet it holds sheer importance in finishing department. Here fabric is passed in an open width form over a series of consecutively roller placed vertically in such a manner that considerable amount of tension is provided to the fabric. Rollers over which fabric is placed is incorporated with steam which results in improving lustre of fabric after calendaring

2.2.2. Crush Finish
This is today’s most accepted form of finish by young generation especially in case of ladies wear like tops, dupattas and shirts. This finish can be obtained by incorporating high twisted yarn during weaving. The finish can also be obtained in cotton blends, where POY (partially oriented yarn) is used along with cotton.

2.2.3. Embossing
This type of finishing is only demanded for designer wear. It could be designed with the help of two rollers out of which one roller being male having non designed part carved & other being female made up of either cotton or paper. During the course of passing fabric pressure which is applied by the male roller over female leads in engraving of the design. Application of design becomes stronger with sufficient amount of heat, which results in exquisite results on the fabric & contributes in enhancing value of the fabric.

2.2.4. Pinching
Machine which is used for pinching involves a die which can be simplified into a steel streaked model to press out stress & is able to change streaks very rapidly.

By running this steel streaked model and altering various functions of the computer, variety types of streaks can be ignored. With the help of these types of machines designer streaks can be performed easily on synthetic fibres clothing apart from that it also used in tailored pattern in scarves, women clothing etc.

2.2.5. Pleating
This type of finish can be applied to procure pleating on to the fabric with the help of knives and rollers various pleating effects could be derived by altering the types of knives and rollers. Apart from types of pleat, sequences, extent of different pleats and length of group and space pleats could be computer designed to get unlimited pleat variation.

Here the finish mainly involves creation of very varied shapes & arrangements of folds on textiles using various machines. The term “pleat” comes from the French, and is used to describe material pressed into narrow folds. Various types of pleating machines fare involved. 
  • Knife, squeezing & group pleating machine for the generation of wide range of patterns (less than 1mm)
  • Crystal pleating machines for the generation of vertical folds. (1-5mm fold height)
  • Accordion pleating machine for upstanding folds. (5-50mm)
2.3. Chemical Finishes

2.3.1. Snocool Finish
When temperature rises, we tend to sweat. This is a natural reaction of our body to maintain the temperature around 97 0f. The sweat when evaporates, takes along with it heat equivalent to heat of evaporation of water, thereby maintaining the temperature of the body. The snocool finish uses the moisture management route. This finish absorbs & dissipates sweat evenly throughout & thus gives a cool feeling effect.

Recipe: Snocool SRB Liquid- 3 to 10gpl, Pad the material at 70 % expression - dry – cure at 180 0c for 30-45 sec.

2.3.2. U/V Protective Finish
Ultra violet light is usually defined as elctromagnetic radiation of wavelength between 4 & 400 nm.athe atmosphere absorbs most of the harmful radiations , however, still part of these radiations reach earth’s surface.u/v absorbers are used to protect the skin from these u/v radiations.

Recipe: Fabshield 50 plus 3.0 –5.0% (owf) applied by exhaust method UPF rating observed for this product is 50 plus to 500 plus.

2.3.3. Micro Encapsulation Finishes
Definition of Microcapsule; in simple terms, Quest defines a capsule as “a miniature container that protects its contents from evaporation, oxidation and contamination until its release is triggered by gentle rubbing or shaking.” During encapsulation, tiny droplets of benefit-laden products such as moisturizers, fragrances, deodorizers, vitamins, or repellents are wrapped with a protective coating to form a capsule.
Micro Encapsulation Finishes
2.3.4. Fragrance Finish
These are microencapsulated formulations of various fragrances like musk, rose, jasmine etc. Which are applied on the fabric with the help of a binder? They impart fragrance when they applied in this fashion.

Recipe: Fragma – 1to5gpl, applied by pad dry cure at 170-180 0 c for 30-35 sec.

2.3.5. Mosquitoes Repellent Finishing
Antimos MGL a mentho-glycol is a natural insect repellent active ingredient, derived from lemon eucalyptus, which is a natural & renewable source. Testing of Antimos mgl with a moderately aggressive cage population of aedes aegypti mosquitoes resulted in no bites up to at least 4 hours. This indicates that the product has unusual repellency.

2.3.6. Bio –Polishing
Bio-Polishing is a treatment in which cotton fabric is treated with Cellulase Enzyme which removes the protruding fibres from the fabric surface by hydrolysis reaction thereby giving soft feel to the fabric surface.

RECIPE: Cellusoft SO- 3to5gpl, at pH 5.5 , Temperature 55 0C,time 60-90 min after Completion of treatment time give hot wash at 85 0C for 10 min.

2.4. Special Finishes

2.4.1. Flocking
These are surface finishing techniques for the comparatively inexpensive production of high quality suede, velvet, velour or imitation fur effects.

The main processes in flocking are as follows:
  • Application of adhesive: e.g. by squeegees, rollers, screens or spray methods.
  • Flock application
  • Drying: The drying conditions are dependent on the requirements of the particular bonding agent used.
  • Final treatment: removal of excess flocks by bruising with brush rollers together with a mechanical suction unit.
According to the present state-of-the art, the following methods are used for flocking. Mechanical, Pneumatic, Electrostatic, Combination of mechanical / electrostatic, and Combination of pneumatic / electrostatic

2.4.2. Lisa Finish
This is a mechanical Finish, which involves the combination of damping, & Pitch Finishes. This Finish is widely give to suiting’s, shirtings.in this finish the fabric is first moistened by damping machine then passed over the soft nylon bristles lisa rollers and finally it is passed over the emery rollers. The effect which obtained is completely different than the normal peach finish.

2.4.3. Nano Finishes
This technology inculcates the application of nano-sized particles of various chemicals in the finishing process of textiles. For instance, ‘Silver fresh', antibacterial, deodorant material based on incorporation of silver particles.
Fig:-Silver particle penetration image
Fig:-21st-century Fabric processing will face changes brought out by nanotechnology.
This nanotech application of water-and-oil repellent finishing is effective for use in natural fibers such as cotton, linen, wool and silk. Unsurpassed performance in durability and water and oil repellency may be expected with natural fibres. Nano-Pel cotton withstands 50 home launderings, with functionality levels well-maintained for water and oil repellency even after 20 washes.
Water Repellent Finish, Mechanism of Stain Release,
2.4.4. Antimicrobial Finish
Microbes are minute organisms, which con be most dangerous for creating harm to our lifestyle in different ways. So to make the environment healthy, hygienic and fresh, it becomes very important to have the control over growth of the microbes and for these the garments / fabrics should be treated with some specialty chemicals, which can restrict the growth of these microorganisms. Antimicrobial finishing is one of the special types of finishing given to the textiles where the chances of bacterial growth are high and the safety is paramount.

Recipe: Fabshield AEM 5700 0.5 % (For exhaust method)

Fabshield AEM 5700 7.0 gpl (For padding method)

Fabshield AEM 5700 2.0 % solution (For spray method)

2.4.5. Flame Retardant Finish
Flame retardant finishing is not any finish used for textiles, but it is the need of an hour. The finished material is used not only to produce garments but carpets, curtains, etc. which are used in public places like hotels, theatres etc. The effective flame proofing of the materials used in these areas are of paramount importance.

2.4.6. Thermocat Finishing
  • A finishing agent for producing heat retaining effect.
  • This type of finishing when applied to the fabric keeps it warm.
  • Produces heat retaining effect due to infrared radiation owing to its porosity.
  • Especially suitable for 100% cellulose and its blends.
Recipe: Thermocat ACL- 30to100gpl Pad (with 80% pick-up), dry at 80°C and cure at 130°C for 2 min.

2.4.7. Ozone Fading
Ozone can react with aliphatic & aromatic bonds. For this reason it is possible to use ozone gas for anti-felting finish of wool, without treatment becoming economically significant. Polyester is easily damaged by ozone than polyamide, because polyester’s aromatic ring system can be easily oxidised & destroyed by the ozone. This could be termed as ozone fading. The appearance of oxidative bleaching of blue, red & yellow disperse dyes caused by the effect of atmospheric zone which is similar in appearance to gas fading. This effect is most common in acetate, triacetate & polyester dyes. Heat treatment of triacetate & polyester improves fastness to ozone fading. It can be prevented by using anti-(oxidation) ozonate softening agent such as diphenylenediamine (also uses as gas fading inhibitor) & p-octylphenol (which has no gas fading inhibitor), which means that using the method detailed here, ozone fading can be prevented. The slight high cost of employing this finish is more than recovered with the improvement of performance characteristics of the denim garment. Furthermore, anti-ozonate could be a good “marketing” tool too.

2.4.8. Plasma Treatment
Plasma is the least organised collection of electrons and atomic nuclei, i.e. it is a mixture of these 2 components. The gaseous phase on the other hand, is characterized by the formation of atoms, the bonding of atomic nuclei & electrons. Plasma application to fibres: low plasma can be used to chemically change the fibre surface, which is achieved by polymer etching, oligomers are decomposed from the fibre surface in an inert gas plasma according to the following mechanism (on polyester fibres). In longer treatment (1min) and high power input (in watts) the etching is associated with a index and apparently darker colouring.

Conclusion:
Globalisation has opened the doors to competition at the highest level. Every industry must now produce products those are best in terms of quality & price. Customers now have a wide variety of choices in each price range & one who offers the best at a competitive price will survive & prosper. For the Indian Textile Industry, challenges are even greater. Technologically speaking in the textile processing industry there is still a lot to ask for. The thrust areas in textiles, in the coming years will very much center on: Process optimization through improved shorter duration processes i.e. efficient & effective processes, Customized solutions, Value addition, Global competitiveness: high standards of quality at lowest possible cost, and Eco awareness.

References
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