Polyfunctional reactive dyes by Huntsman:- Part 1

AVITERA™SE

Revolutionary Textile Dyeing Products Save Water

The next time you slip on a polo shirt from Lacoste™ or Marks & Spencer, you can take comfort in knowing the process used to dye the fabric is contributing to the sustainability of one of our most precious resources–water.

The mills that these two clothing brands buy fabric from are using revolutionary product AVITERA™ SE, created by Huntsman to significantly reduce water and energy consumption, as well as carbon dioxide(CO2) emissions during the dyeing and washing-off process.

Why it matters

By 2030, the world demand for fresh water will increase by 40 percent. Textile dyeing and finishing processes consume vast amounts of water – in the very parts of the world where it is most scarce. As environmental awareness grows, so does demand for textiles produced in more sustainable ways – yet at low cost.

Up to 26 gallons (100 liters) of water is needed to dye just two pounds (one kilogram) of cotton fabric. With AVITERA™ SE, water usage is reduced to just three to five gallons (15 to 20 liters) per two pounds of material. With the new dyeing technology, one quart (1.3 liters) of fresh water per person per day could potentially be saved in the major Asian textile processing countries such as China, India and Bangladesh.

How it works

Cellulose fibers, such as cotton, viscose or linen, are the most widely used textile fibers. Depending on the year and crop yields, about 30 millions tons of cotton are produced annually. By far the largest part of cellulose fibers is cotton. Pure cotton is mostly dyed using reactive dyes.

The dyeing process takes place in three distinct phases:

• Adsorption and Diffusion
  The reactive dye is adsorbed onto the cellulose surface and then diffuses into the fiber matrix.
• Fixation
  If conditions are favorable (high temperature and/or high pH), the reactive dye reacts with active sites in the cellulose during this phase (fixation), resulting in a strong covalent bond.
• Washing Off
  To obtain the required fastness properties, all these forms of unfixed, adsorbed dye molecules must be washed off the fiber.

Industrial practice has shown that with AVITERA SE, nearly 90 percent of the dye applied to cotton during dyeing is fixed, as opposed to 60 to 80 percent with conventional reactive dyes. This ensures higher yield.

Fabrics can be dyed and washed off at different temperatures and different quantities of water. Hot dyeing systems require a temperature of 176°F (80°C) to make the bond between dyestuff and fabric permanent. These systems also require boiling water and several rinsing baths to completely remove unfixed dyestuffs.

Conventional warm dyeing systems already offer the benefit of creating the necessary bonds at a lower temperature—140°F (60°C)—but still require a lot of water and high temperature for an appropriate wash-off.

AVITERA SE dyes help significantly reduce water and energy consumption and CO2 emissions since dyeing and the washing-off process never exceeds 60°C.With only five percent or less unfixed dye needing to be removed, instead of the usual 15 to 30 percent, the number of rinsing baths to obtain the required fastness properties is greatly reduced.

To ensure that AVITERA SE dyes achieve the targeted resource and cost savings, they must be correctly applied. Huntsman Textile Effects works closely with textile mills to adapt their production processes and guarantee excellence in operation, strict cost control and a sustainable system. Helping brands and retailers to coordinate with mills and communicate with consumers improves cooperation throughout the textile value chain, resulting in greater environmental awareness and more sustainable textile processing.

Polyfunctional reactive dyes by Huntsman

A revolutionary new tri-reactive dye range named Avitera SE was showcased at the ITMA 2011. It is Huntsman’s one of the new innovations towards greening the textile processes. It is said to save upto 50% in power and energy.

It is more of a system than a product to ensure the cellulose fiber dyeing more economical with least amount of resource usage. , as well as reduces carbon dioxide(CO2) emissions during the dyeing and washing-off process. It is most productive for dyeing pure cotton as it is a reactive dye-class.

Industrial practice has shown that with AVITERA SE, nearly 90 percent of the dye applied to cotton during dyeing is fixed, as opposed to 60 to 80 percent with conventional reactive dyes. This ensures higher yield.
Fabrics can be dyed and washed off at different temperatures and different quantities of water. Hot dyeing systems require a temperature of 176°F (80°C) to make the bond between dyestuff and fabric permanent. These systems also require boiling water and several rinsing baths to completely remove unfixed dyestuffs.
Conventional warm dyeing systems already offer the benefit of creating the necessary bonds at a lower temperature—140°F (60°C)—but still require a lot of water and high temperature for an appropriate wash-off.
AVITERA SE dyes help significantly reduce water and energy consumption and CO2 emissions since dyeing and the washing-off process never exceeds 60°C.With only five percent or less unfixed dye needing to be removed, instead of the usual 15 to 30 percent, the number of rinsing baths to obtain the required fastness properties is greatly reduced.

 Huntsman Textile Effects works closely with textile mills to adapt their production processes and guarantee excellence in operation, strict cost control and a sustainable system. Helping brands and retailers to coordinate with mills and communicate with consumers improves cooperation throughout the textile value chain, resulting in greater environmental awareness and more sustainable textile processing. 

Avitera SE effects:
 By 2030, the world demand for fresh water will increase by 40 percent. Textile dyeing and finishing processes consume vast amounts of water – in the very parts of the world where it is most scarce. As environmental awareness grows, so does demand for textiles produced in more sustainable ways – yet at low cost.

Up to 26 gallons (100 liters) of water is needed to dye just two pounds (one kilogram) of cotton fabric. With AVITERA™ SE, water usage is reduced to just three to five gallons (15 to 20 liters) per two pounds of material. With the new dyeing technology, one quart (1.3 liters) of fresh water per person per day could potentially be saved in the major Asian textile processing countries such as China, India and Bangladesh. All ready the premier buyers of the world like Lacoste or Marks & Spencer are preferring fabrics from those mills which have adopted the Avitera SE in order to ensure sustainability to their customers. Alps industries, which is the largest home textile exporter from India also has adopted these advanced huntsman dyes and great cost reduction and now they also contributing more towards sustainability as the Managing Director of the company, Ssndeep Agarwal says : “The Avitera SE and Eriopon LT system are revolutionary innovations designed to meet new standards of environmental sustainability and Alps Industries will use this clean technology to take a step in environmental savings.” Bextex from Bangladesh has also signed a deal to use huntsman dyes and chems last year.

Huntsman textile effect made an audit with Masco textiles in Bangladesh which shows the positive effect of their products last year. It proves that their product is certainly helping to reduce resource usage significantly.

Resources	Before Audit	March 2010	Coming Soon
Water	96000 m3	66000 m3	36000 m3
Electricity	2.1 KW	1.5 KW	0.5 KW
CO2	428 t	300 t	163 t

Huntsman is a global manufacturer and marketer of differentiated chemicals.They manufacture products for a variety of global industries, including chemicals, plastics, automotive, aviation, textiles, footwear, paints and coatings, construction, technology, agriculture, health care, detergent, personal care, furniture, appliances and packaging. Huntsman textile effect; which is a integrated part of Huntsman creates, markets and manufactures a broad range of chemical and dye products that enhance the performance properties and colors of finished textiles and materials. It has a long global reach serving over 10,000 customers located in 80 countries. It provides innovative value adding effects and processing solutions to its customers such as brilliant colors with high fastness, easy care, durable protection against oil, water and fire as well as a complete range of pretreatment and dyeing auxiliaries. Their aim is to build a sustainable textile world by innovating sustainable processes and chemicals for the textile industry. They have state of the art research bases and 3000 research personnels in different countries and their tremendous efforts have changed the game with revolutionary products like AVITERA dyes. They acquire 11 primary manufacturing facilities located in eight countries (Switzerland, Germany, France, USA, Mexico, China, Thailand and Indonesia).

Defects in Dyeing with Reactive Dyes

Defect: Colors are not fast to washing, Abrasion;Staining in the fabric when transporting from place to the other, water marks on the fabric 

Remedy : Wash the fabric with soap and soda ash at right temperature. Adding sequestering agent will yield good results. Treating with Ammonia will also give good results.

Defects in the fabric due to Printing- Need to take out full color

Remedy: Treat the dyed fabric with Sodium Hydrosuphite with 5-10 gm Sodium Hydrosulphite at 75 deg C for 30-45 minutes. Add 5-7 gms Caustic Soda for even removal of colors. The color becomes light yellow or brown after removal. Wash it thoroughly with soap.

The color can also be removed by solution of Sodium Hypochlorite. Treat the fabric with a sodium hypochlorite solution ( 3-5 gms Chlorine) for 20-30 minutes. Keep the pH between 9-10. The fabric is treated with Acetic acid after removal of color to remove chlorine and to neutralise the fabric.

The fabric can be redyed after removal of color

Defect: Bleeding in colors during washing, abrasion

Remedy: Boil the fabric with caustic, Treat the fabric with Hydrogen Peroxide ( 5-10 gpl, 60-70 deg C) to make the color fast.


Defect: The fabric has been dyed in darker shade, uneven dyeing

Remedy: To take out color from the fabric treat it with caustic for 45-60 min at 70 deg C. Thereafter treat the fabric with 10-20 gpl Acetic Acid for 40-60 min at 80-85 deg C.

Defect: Uneven dyeing, marks of water, marks of colors

Remedy: Wash the fabric in soap and redye in a darker shade

Defect : The fabric has become stiff and rough after dyeing

Remedy: Finish after adding right softner

Defect: Color staining of fabric, uneven dyeing

Remedy: Redye the fabric in darker shade.

Defect: Color staining in fabrics of darker shade, uneven undyeing

Remedy: Dye the fabric in Sulphur black

Caution: Please treat a small length fabric to check the effectiveness and any harmful effects before commencing a full treatment.

Warp Knitting

It is a commonly known fact that fabrics are constructed through two major techniques- weaving and knitting apart from other minor techniques. In these processes, two distinct sets of yarns called the warp and the weft are interlaced with each other to form a fabric. 'Warp' is the set of yarns that are laid out first on a loom or frame and 'Weft' is the yarn that is woven under and over the warp yarns that are already stretched onto the loom. Thus warp is the continuous row of yarns and the wefts are the yarns that are woven in from side to side. If we go by these definitions, it is clear that textile warping is the processing of creating the base yarn that runs top to bottom on woven cloth.

Beginning of Warp Knitting 
Warp knitting is an important and an ever growing industry. When compared to weaving, this industry can be considered as newer. Nobody knows about who invented weaving and hand knitting but it is known that mechanical knitting, in form of socks producing machine, was invented by Reverend William Lee in 1589. Crane of Nottingham applied warp yarn guides to the knitting frame invented by Lee in around 1775 which initiated warp knitting. Paget, in 1861 and Willium Cotton, in 1864, made certain improvements in the looms. The compound needle was invented by Mattew Townsend in 1849, which contributed in making the textile knitting machine simpler and faster.

Warp Knitting Machines
There are two basic types of warp knitting machines. They are- Tricot knitting machine and Raschel knitting machine. Earlier, the Tricot machines were equipped with bearded needles and Raschel machines were equipped with the compound needles. However, the modern versions of both these types of machines are equipped with compound needles. The distinction between these two machines is, therefore, made by the type of sinkers in them and the roles these sinkers play in loop formation. The sinkers in a Tricot machine control the fabric throughout the knitting cycle. However, in the Raschel machines, sinkers are only used to ensure that the fabric stays down when the needles rise. The type of knitting machine influence the product construction specifications and, therefore, is an important factor in the whole process.

Yarn Preparation 
Yarn preparation in warp knitting combines methods used in weaving and knitting. In some cases, the ends of yarn can be fed directly off cones into the knitting machine but the number of cones needed restricts this working method. The large floor space required for a creel is justified only when it is technologically essential- for example, with Jacquard and curtain machines. In all the other cases, the yarn ends are fed off warp beams. Yarn preparation can be reduced to a simple winding of yarn ends on to the warp beams in a knitting machine since artificial yarn is mainly used along with moderate tensions applied to the knitting yarn. As such, smooth operation can be ensured without sizing the yarn.

The quality of warp beam is crucial for determining the quality of the knitted fabric. Variations in yarn thickness, tension, twist and other factors too might result in a defective fabric. In most of the cases, warping mistakes are not easy rather impossible to correct during the knitting process.

Methods of Warping 
The yarn manufacturers, these days, can supply prepared warps but most of the knitting firms prefer to prepare their own warping equipment and warp beams independently. Mostly, they select the standard types of yarns and warp effect yarns in the plant. There are two basic methods of warping that can be used to prepare the warps for the knitting machines- Indirect Warping and Direct Warping

Indirect Warping: The yarns from the yarn packages are wound onto an intermediate cylinder (mill) in many parallel groups with a specified density, and then they are back wound onto the warp beam.

Direct Warping: The ends of the yarn are wrapped in one operation, from the yarn packages onto the warp beam.

However, there are certain requirements that have to be kept in mind while using both the methods, information about which has been given in the table below.

Requirements for Direct and Indirect Warping
Requirement	Yarn ends density	Direct Warping
Yarn ends per section	R	R
Number of revolutions	R	R
Warp length	R	R
Number of sections	NA	R
Yarn ends per section	NA	o
R - Required; O - Optional; NA - Not Applicable

Warping Defects 
There are certain major warping defects on beam warpers that can be identified as given below.

Lapped Ends :
The broken end of yarn is not tied to the end on the warp beam and overlaps the adjoining yarn. The beam is not properly braked and the signal hook fails to operate.

Bulges : Yarn ends are drawn from the middle and the broken end is not correctly pieced up to the adjoining yarn.

Broken ends on the beam : It occurs due to reasons mentioned in the above point. A group of ends is broken and tied as a bunch or worked-in with overlapping.

Yarn cut at the butts of the warp beam/ slackness of extreme yarns : It occurs when the reed is improperly set with respect to the warp beam flanges or there is a deformation of the warp beam flange.

Excessive or insufficient number of yarn ends : The number of yarn ends of the beam becomes excessive or insufficient due to the incorrect number of bobbins in warping.

Conical winding on the beam : 
It occurs due to incorrect load applied by the pressure roller. 

Slacks & irregular yarn tension :
It happens due to any on of these reasons- improper threading of the yarn into the tension devices, ejection of yarn from under the disc of the yarn tensioning device, or yarn tension devices of poor quality.

Frequent yarn breakages at the beam edges : 
It results due to burrs and nicks on the surface of the warp beam flanges.

Improper length of warping :
It is due to malfunction of the counter, and the brakes of the measuring device & warp beams. 

Coarse Knots : 
It is due to manual tying-up.

Loose yarn winding :
It happens when the pressure roller is lightly pressed against the warp roller.

Fluff, oily ends and yarn of different density : 
It is due to the careless work of the operater, creeler and oiler.

Bulgy winding on the warp beam :
It is due to Irregular laying of yarn ends in the reed, missing a dent and placing two ends in the adjoining yarn.