Showing posts with label singeing. Show all posts
Showing posts with label singeing. Show all posts

Friday, April 9, 2010

Polyester Microfibers:- Dyeing and Wet Processing

Microfiber
A synthetic fiber that is extremely soft, lightweight, breathable, durable and ultrafine. In fact, microfibers are two times finer than silk and one hundred times finer than a human hair. Microfiber is currently manufactured from acrylic, nylon, polyester and rayon.Ultra-microfibers on the market are even finer – some having thickness of just 1/200th the thickness of human hair!
Microfibres refer to staple fibres, or individual filaments within yarns, which have fineness less than 1 decitex ( 1 grams per 10,000 meters) and For any fiber to be classified as microfibre yarn, the weight per 10,000 metres of yarn (dtex) is divided by the number of filaments (f), the result must be below 1.
All about microfibers
Properties of Polyester Microfibers




  1. Lightweight and flexible

  2. Good stability and shape retention

  3. Anti-wrinkle property

  4. Have a wicking ability that permits perspiration

  5. Comfortable to wear as they are more spongy

  6. Doesn't water stain - superior water repellency is available

  7. Woven or knitted into a very high quality fabric construction

  8. Formerly commenced as a polyester microfiber, today you can find nylon, rayon and acrylic microfibers too.

  9. Strong and durable, water repellent and wind resistant -so tightly woven, that the fabric can't be penetrated by wind, rain or cold

  10. Lightweight, resilient or resist wrinkling, have a comfortable array, preserve shape and resist pilling

  11. The positively charged microfibers draw dust; the tiny fibers are capable to enter the microscopic surface voids most materials

  12. Washable, dries quickly and also washable in at the water temperatures up to 200 degrees and their characteristics will remain intact.

  13. Electrostatic effect - Hair, lint and other dust particles are attracted and grabbed by the microfibers without lifting dust.

  14. The density of the material allowable it to grip six to eight times its weight in water hence high absorbing power capacity

  15. The attraction capability of the microfibers is so sound, even absorbs bacteria and germs - hence can be use as germ or bacteria free purpose

  16. The fabric consists of millions of small tiny conduits that carry oil and grease too.

  17. Benefits of microfibers

  18. Comfortable - very soft, texture like silk, lightweight

  19. Due to its fineness and superior fiber surface area making deep, rich and bright colors achievable

  20. Less "sweaty" in warm weather than usual synthetics

  21. Quickly cleanable - clean just with water

  22. Highly intense and shrink-resistant

  23. Presents insulation and breathability

  24. Change without help - to establish lovely drape

  25. Very fine - finer than the most precise silk

  26. More reusable for cleaning alternative - compared to other mops more efficient and long life
Dyeing of polyester Microfibers
Due to their fineness, the total surface area of microfibre yarn or fabric is far greater than ordinary fibres. Threfore
1.Due to its special structure ,micro fibers has much larger quantity of size ,oil agents and wax on warp yarns.
2.Since microfibres have very small interstitces, with consequent difficulties of size accessibility and duffusibility, desizing becomes quite difficult and costly.
3.Microfibres have greater absorption area resulting in a dyeing rate four times higher than that of normal, which can cause unlevelness in dyeing.
4.They also require more dyestuff than standard fibres to obtain the same depth of shade.
5.Larger external surface means an increase in number of threads exposed to light which, on destruction of dye, is expressed as lower light fastness rating.
6. Wash fastness and color fastness to rubbing is also poor.
7.Staple microfibres offer difficulty in carding.

The problems in wet processing of microfibers can be overcome by

1.Better knowledge about the size applied and optimum parameters during desizing operation.


To achieve satisfactory dyeing effects ,desizing and refining process must be done before dyeing and after desizing and refining , there should be no impurities left such as electrolyte, antistatic finishing agent , spin finishes and blot.


2.Pre-setting


Suitable pre setting conditions ( time ,temperature and tension) helps not only in stable dimensional stability ,softness but also better dyeing results.


3.Alkali weight reduction


Alkali weight reduction s to treat the fabric with concentrated alkali at high temperature.fber molecule hydrolyse under this condition and lose some weight with change in properties, thus space occurs between crossing points and rubbing resistance relative to slippage among yarns becomes small.Alkali weight reduction makes fabric soft, liveliness, limber and improved absorption.


2.Careful selection of the dyes.


Proper dye selection which are
1.Compatible
2.Having same exhaustion rates
3.Having high wash fastness properties.
4.Good migration and levelling properties
 eliminates problems regarding build-up and fastness properties.
Disperse dyes for polyester microfibers


3.Optimizing the dyebath conditions and dyeing cycle.


Optimised dyeing cycles can be worked out by controlling the temperature to account for the high rate of dyeing and to eliminate the risk of uneven dyeing.Chemicals and dyes to be added at, at least 10-20 deg.C lower temperature than normal polyester fiber dyeing. The additions of dyes must be progressive or devided at least into 4 parts. The heating rate must be slow from 40 deg C to 100 deg C. 10-20 min more holding time required at 130 deg C as compared to normal PES.


4.Proper selection of  Dyeing machinery.


The dyeing machine must have the required automation to fufil the requirements of microfiber dyeing such as microprocessor controlled dosing , proper and accurate heating rate control etc.


5.Proper selection of dyebath additives
such as
Levelling agents :- A strong levelling agent which shall start working at lower temperatures.
Dispersing agents :- Higher quantities of dispersing agents are needed because amount of dyes required are more to produce the desired depth.
Chelating agents:-
Anticreasing agents,Dyebath softners/Lubricants :- Because microfiber textiles are prone to creasing , therefore use off dyebath lubricants is must.
6.Proper aftertreatment of dyed goods.
Soaping :- In order to obtain satisfactory color effect , fabric should be soaped after dyeing .Soaping is the key process to achieve satisfactory dyeing results on polyester especially polyester / nylon microdenier fabric.


Reduction clear :-Good reduction clear process is needed to achieve satisfactory washing , rubbing and light fastness properties.
Washing :-Is required for neutralising and removing alkali after reduction clear treatment.
Softening, anti soil and antistatic treatment :-Because microdenier fiber easily stains and produces static charges, a hydrophilic ,antistatic and antisoil treatment besides softening is highly recommended to ensure fabric softness and comfortability.


Recommended Dyeing Cycle for polyester Microfibers
Dianix PLUS( Dystar) or Longsheng  is a new range of five compatible, level-dyeing dyes for reliable dyeing of medium and heavy shades, especially on microfiber and weight-reduced polyester, whether applied under mild alkaline conditions to control trimer, or under conventional acid conditions.
Dianix E-PLUS" for Pale Shades on Polyester Fabrics
Fashion application of polyester

Application of polyester Microfibres
Microfibers are most commonly found in polyester and nylon. Some rayon and acrylic micros are in production and available to consumers. Micros can be used alone or blended with conventional denier man-made fibers as well as with natural fibers such as cotton, wool, and silk.
In textiles
Microfibers are used in a variety of fabrics, but most commonly in dress and blouse weight garments. Suit jackets and bottom weights are becoming available. Look for micros in lingerie, rainwear, outdoor fleece and wind-resistant sportswear, as well as tents, sleeping bags, track and jogging suits. The strength of microfibers make them particularly adaptable to sueded or sandwashed finishes because of their extensive fiber surface area and the use of strong fibers like polyester and nylon. As a result, many microfibers simulate the appearance of sandwashed silk.

Other Main products for which microfiber are ideally suited:


  • Microfiber Glass Cloth
  • Duster/Multi-purpose Microfiber Cleaning Cloth
  • Microfiber Scrubber
  • Microfiber Kitchen Cloth
  • Microfiber Optical & CD Cloth
  • Microfiber Mops
  • Microfiber Cleaning Sponge
  • Microfiber Cleaning Cloths – Terry Cloths, Suede Cloths, Waffle-Weave Cloths
Microfiber Makes the Grade
http://www.tex.in/education/nextiles/fib/mic/mic.html
http://ygmfranchise.blogspot.com/2007/07/cleaning-tips-microfiber.html
http://www.microfibergreen.com/is-microfiber-green-product.html
http://www.norwexnow.com/microfiber%20science.html







 

Monday, February 1, 2010

Gas Singeing Machines

Singeing is a finishing method for smoothing surfaces of fabrics by burning and removing fuzz thereon, and visualizing fabric textures. A gas-singeing machine is normally employed.
The gas-singeing machine is typically equipped with four burners, and is capable of singeing one or both surfaces of the fabrics. A water-cooled roller is provided at a location opposite to the burners, thereby enabling singeing to be performed without undermining the strength of even thin fabrics. It is important to set a drain temperature of the water-cooled roller in a range of 50 to 550C. Cautions are required because a dew-point is generated when the water-cooled roller is cooled down too much, and results in increased amount of remaining fuzz or adhered carbon. The fabric feed speed is preferably set at around 100 to 150m/minute.
                                                       







Swastika Gas Singeing Machine
Textile Wet Processes: Preparation of Fibers and Fabrics

Rotary Cylinder Singeing Machines

In this type of singeing machine, the cloth passes over and in contact with a heated rotary cylinder made of copper or cast iron. The rotary cylinder has internal firing and revolves slowly so that constantly a fresh surface of the roller comes in contact with the cloth. The direction of rotation of the cylinder is opposite to the direction of the fabric so that the protruding fibres or nap of the fabric is raised.
This type of machine is particularly suitable for the singeing of velvets and other pile fabrics.
If the singeing of both sides of the fabric is required, then two cylinder are employed, one for each side of the fabric.
Singeing of Knitted Goods
Because knitted fabrics are very sensitive to tension , it is therefore necessary to take special care in singeing. Important control factors in knit singeing are
  • Appropriate Singeing temperature for the particular fiber compositon.
  • Tension control at fabric entry, fabric run and fabric delivery.
  • The machines should have tension controls throughout the fabric passage. 
Gas Singeing Process and machines
Singeing Fundamentals

Plate Singeing Machines

Plate Singeing Machine

In this type of singeing machine, the cloth passes over and in contact with one or two heated curved copper plates. The thickness of the plates ranges from 1 to 2 inches. The heating of the plates is done by a suitable burning arrangement of gas mixed with air. The plates are heated to bright redness and the cloth passes over and in contact with these plates at a speed ranging from 150 to 250 yards per minute.
The passage of the cloth can be arranged in such a manner that one or both sides of the fabric may pass over and in contact with the heated plate(s), in order to accomplish singeing of one or both sides of the fabric in a single passage.
In order to avoid local cooling of a certain part of the plate(s) by constant passage of cloth over it, an automatic traversing mechanism is fitted to the machine. This mechanism brings the cloth into contact with a constantly changing part of the plate(s), not only to avoid local cooling but also local wearing of the plate(s).

 

Tuesday, December 1, 2009

Singeing

Also called gassing,Singeing is a part of pretreatment process of fabric and usually a first step after weaving. Singeing is a process applied to both yarns and fabrics to produce an even surface by burning off projecting fibres, yarn ends, and fuzz. This is accomplished by passing the fibre or yarn over a gas flame or heated copper plates at a speed sufficient to burn away the protruding material without scorching or burning the yarn or fabric.
Singeing is a finishing method for smoothing surfaces of fabrics by burning. A gas-singeing machine is normally employed. The gas-singeing machine is typically equipped with four burners, and is capable of singeing one or both surfaces of the fabrics. A water-cooled roller is provided at a location opposite to the burners, thereby enabling singeing to be performed without undermining the strength of even thin fabrics. It is important to set a drain temperature of the water-cooled roller in a range of 50 to 55 C. Cautions are required because a dew-point is generated when the water-cooled roller is cooled down too much, and results in increased amount of remaining fuzz or adhered carbon. The fabric feed speed is preferably set at around 100 to 150m/minute.
Yarn singeing and singeing machines
Common problems in singeing and solution
Singeing Fundamentals