Showing posts with label automation. Show all posts
Showing posts with label automation. 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







 

Wednesday, January 27, 2010

Automation in Dye House

Automation is a need for todayAutomation today’’s competitive market where quality, cost and availability is playing major role.
In today today’s scenario quality , quantity and service are the most critical requirements for the servival of textile industry . The cost of production is increasings rapidly but the costs such as  labour cost, raw material cost, power cost, etc. are not in our control. The biggest question for a textile dyer today  is to increase the productivity and reduce the production cost.
The options for increasing productivity and reducing cost of production are
􀂾Reduction in Labour cost
􀂾Reducing Utility cost by power saving
􀂾Value enhancement by Quality improvement
􀂾Increasing output Through state of art machinery
􀂾Improving efficiency and service through managemant systems

All these can be possible only by implementing Automation

What is Automation?
Monitoring and controlling of any process with the help of latest technologies like software, ladder and logic controls, Robotics, ERP system and incorporating central computer is called Automation.
 
WHY AUTOMATION

􀂾Achieve more with less.
􀂾Elimination of human error
􀂾Consistency of product
􀂾Minimize Energy consumption
􀂾Easy diagnosis of fault
􀂾Reduction in Resources(Chemicals ,water , energy etc.)
􀂾Reduce manpower.
􀂾Data collection and consolidation.
􀂾Effective application for Complex tasks
􀂾Trending and Report generation.
􀂾Reduction in Effluent
􀂾Improve Safety and Health.
􀂾Reduce breakdowns.
 Dyehouse Management Manual
The very important area for Automation is the dyeing process, because it involves lot of minute parameters which are very  critical. Even in milligrams variation of recipe can change the shade of  the fabric. All the parameters for dyeing like temperature, pressure,water level, water flow, circulation and time of treatment are  most important.
Automation of the dyeing process can improve the producti productivity by controlling the above parameters very accurately.

Automation in textile dyeing and printing means one or more (or all) of the following steps:
a. Programmable process control (by microprocessors) of the machinery;
b. Dissolving and dispensing of the dyes, pigments and chemicals in a central colour kitchen;
c. Computer-controlled weighing of solid material with automatic stock control and the printing of recipe and process cards;
d. Colour measurement, computerized colour matching;
e. Central computer (network), computerized management system

Criteria for selection of  an Automation System

It is very important to identify the need and the feasibility of the system to be automated.The production cost, the complicity of the machines, the utility requirement of the machines, quality parameters of the products are most important factors to consider while planning for Automation.
Select The System which has

1.Flexibility
2.Ease of Programming.
3.Adaptability to change.
4.Expandability
5.Enhanceability of  function.
6.Ruggedness in system.
7.Service Back up.
Learn More
Different types of  automation systems
Seven Steps to Superior Color Control in the Dyehouse
Need of Automation
The Textile Management System

Thursday, January 14, 2010

Computer Color Matching Systems

CCM Basics
Colour theory :-
Basics of color perception and Measurement
Light and color
Color and light Knowledge
Colour difference,
Measuring color in textiles click here
Color Evaluation
Test Methods for color measurements
The right choice of measuring geometry


Instruments (इंस्ट्रुमेंट्स)
Spectrophotometers and colorimeters
Instruments for measuring light and color Read here
Difference between a colorimeter and Spectrophotometer
Colorimeter
  • Comparatively low price
  • Compact Size
  • Simple operation
  • Better mobility
Spectrophotometers (Features of spectrophotometers)
  • Expensive
  • high precision
  • more versatile
  • accurate color measurement
  • suitable for complex color analysis
  • can measure color strength and metamerism
Instruments for color measurement
Selecting a spectrophotometer
Recipe Formulation
Making Primary data
Improving Upon the Data
Recipe Optimization Criteria
Improving reproducibility of dyeing
Quality control
Shade passing Or color Difference evaluation
Color Tolerances for Consistent Pass/Fail Decisions

  • Disadvantages of Visual Pass/Fail Systems
  • Requirements of a Computerized Pass/Fail Program
  • Numerical Basis of Computer Pass/Fail Data
  • Pass/Fail Tolerances Using CIELAB DL*, Da*, Db*
  • Pass/Fail Tolerances Using CIELAB DL*, DC*, DH*
  • Pass/Fail Tolerances Using CIELAB DE*
  • Pass/Fail Tolerances Using The CMC Formula
  • Implementing CMC Pass/Fail 
Measuring Special colors
Measuring Fluorescent colors Read here Fluorescence and color
When a fluorescent color is measured by the spectrophotometer, the spectral power distribution of the light source, including the ultraviolet regions, must be controlled.

Measuring Mettalic colors
when measuring metallic colors, it is more effective to measure and evaluate them with a spectrophotometer that measures color at multiple angles
Measuring Powder objects

When measuring powder with a spectrophotometer, the measurement value varies depending on the density of the powder and the surface conditions. To avoid errors, special methods are required such as placing a fixed amount of powder into a container of a fixed shape and size and maintaining a fixed surface quality.
If the size of the particles is large, use a spectrophotometer which has a large measurement area, so the measurement surface is averaged and repeatable measurement values can be obtained.
Measuring Transparent objects
The measurement of semi-transparent objects requires special consideration because the light might pass through the material and the measurement may be influenced by what is behind the object. To solve this problem, increase the thickness of the object to prevent the light from being transmitted completely. Another solution is to put an opaque white surface behind the object.
Measuring Objects Containing Patterns
When measuring objects that have patterns or textures, the measurement value varies according to the location if a small area is measured. The largest possible measurement area should be used, or measurements should be taken several times in different locations and then the average measurement value should be calculated.


Color measurement for package dyeing
Whiteness/ yellowness Indices
whiteness index
Yellowness index
Strength evaluation of dyes,
Colorfastness



  Useful Readings to Improve efficiency of Color Matching System
Datacolor Video Tuturials on color matching system
introduction to color technology
Video 1 
Video 2
Video 3



Database Preparation for Successful Computer Color Matching Part 2
Database preparation for computer color matching Click here
Measurement methods for textile fabrics click here
Color Measurement Method and Effect of sample presentation
Understanding Color Management and Software in Textile Printing A presentation
Color Management and RIP Software for Digital Textile Printing Managing Color for Optimal Results

Seven Steps to Superior Color Control in the Dyehouse:By Eric Alho, Product Manager Textile Software
Generic dyeing and color matching Click Here
Improving computer control of batch dyeing operations Click here