Scouring Process in Textile | How to Scouring Textile Fabric | AlkalineEnzyme Scouring of Cotton Textiles

Yarns and fabrics may be dirty, contain natural waxes or oils, or have been treated with size or lubricants used in spinning, weaving or knitting. These can all interfere with dyeing, often leading to non-level results. Scouring is a large topic, and the process used depends on the fibre type and its condition. “True” scouring of greige cellulosic fabrics is typically done, after desizing, at the boil or at higher temperature in pressure vessels, with as much as 10 grams sodium hydroxide per litre of water, plus surfactants, and the process may last for several hours. Commercial scouring of wool may use solvents, similar to dry cleaning, as part of the process. White fabrics sold at retail have normally be scoured at the mill; “natural” fabrics usually have not (some “natural” fabrics have been scoured but not bleached).

Art dyeing literature often refers to what amounts to laundering as scouring. This is inadequate for greige fabrics, but often quite acceptable for “white goods”. A long machine wash with the hottest water possible, about a gram of soda ash per litre of water (about a teaspoon per gallon) and some (preferably optical brightener free) detergent, followed by two rinses is usually acceptable. Sodium hexametaphosphate may be helpful if the water is hard. Woven white cottons often contain starch that will not be removed by such a limited process.

Alkaline Enzyme Scouring of Cotton Textiles
The invention relates to a process for treatment of cellulosic material, as for example, knitted or woven cotton fabric, comprising the steps of preparing an aqueous enzyme solution comprising pectinase, treating the cellulosic material with an effective amount of the aqueous enzyme solution under alkaline scouring conditions; e.g., pH of 9 or above and a temperature of 50° C. or above, in a low calcium or calcium-free environment, yielding a modification of the cellulosic material such that exhibits an enhanced respond to a subsequent chemical treatment.

Traditionally, cotton scouring has required the use of harsh alkaline chemicals (caustic), extreme temperatures and large volumes of water. Expenses include not only the cost of the caustic and energy, but also the cost of treating waste water to remove residual caustic and by-products.

Today, textile producers have a new, effective alternative to chemical scouring with the advent of the Cottonase™ enzyme. This novel enzyme not only cleans better than chemical scouring, but also greatly reduces the need for extensive waste water treatment and energy consumption. The Cottonase™ enzyme is a versatile, economically viable and environmentally friendly alternative to chemical scouring in cotton preparation.

How to Scouring Textile Fabric:

1. Simply wash your fabric, this includes PFD fabric, in the washing machine in hot water with Soda Ash. Do not add any fabric softeners to the wash. If you must dry your fabric do so without any fabric softener sheets
2. Using an large enamel or stainless steel pot, fill the pot at least half full and place one ounce of soda ash into the pot per pound of cotton or linen fabric/fiber.
3. Place fabric into water, swish it around using a stainless steel spoon.
4. Bring water to a boil!!!
5. Adjust heat to a low boil/hard simmer and allow to boil for two hours. stir the fabric every 15 minutes or so t make sure that the fabric is being adequately scoured
6. After two hours remove from heat source, allow fabric to cool down until the fabric is at room temperature. 
7. Remove the fabric from the water and rinse.

List of Top Textile Universities/Colleges in Pakistan | TextileEngineering Courses in Pakistan | Textile Engineering Colleges inPakistan | Textile Colleges in Pakistan | Apparel Colleges in Pakistan| Garment Colleges in Pakistan | Fashion Colleges in Pakistan

Textile sector was one of the sectors of Pakistani economy, which were in a comparatively better shape than others. Even then it was not enough to produce the number of jobs that could reduce the rampant unemployment rate in the absence of basic infrastructure facilities and a sound industrial base in the country. Textile education in Pakistan is the most attractive for student. To create technical manpower in this sector, Pakistan government open textile engineering course. As well as many private university open this degree. A list of top textile engineering colleges, universities are given below.

Textile students in Pakistan

List of Top Textile Universities/Colleges in Pakistan

National Textile University Faisalabad
Telephone: +92-41-9230081-82
Fax: +92-41-9230098
Email: info@ntu.edu.pk
Web: http://www.ntu.edu.pk


Textile Institute of Pakistan
[ TIP ] Karachi, Sindh, Pakistan
address: EZ/1/P-8, Eastern Zone, Bin QasimKarachi, SindhPakistan
telephone: +92 (21) 34549734
telefax: +92 (21) 34533525
website URL: http://www.tip.edu.pk/
e-mail address: info@tip.edu.pk
staff: public relations: imran iqbal
subjects include: Apparel Manufacturing,Fashion Design
Textile Design,Textile Management,Textile Science.


Balochistan University of Information Technology
Quetta, Balochistan, Pakistan
address: Takatu Campus, Chaman Road Baleli QuettaQuetta, BalochistanPakistan
website URL: http://www.buitms.edu.pk/
subjects include:Textile Engineering


Hajvery University
Lahore, Punjab, Pakistan
address: 43-52 Industrial Area, Gulberg-IIILahore, PunjabPakistan
telephone: +92 (42) 111 777 007
telefax: +92 (42) 575 5564
website URL: http://www.hajveryuniversity.com/
e-mail address: admission@hajveryuniversity.com
subjects include:Fashion Design
Textile Design,Textile Engineering


National College of Arts [ NCA ]
Lahore, Punjab, Pakistan
address: 4, Shahrah-e-Quaid-e-Azam54000 LahorePakistan
telephone: +92 (42) 9210599
telefax: +92 (42) 9210500
website URL: http://nca.edu.pk/
e-mail address: info@nca.edu.pk
staff: admin director: Sajida Haider Vandal
chief librarian: Sajida Haider Vandal
public relations: Adnan Mirza
subjects include:Fabric & Textile: Mian Salauddin


Pakistan Knitwear Training Institute
Lahore, Punjab, Pakistan
address: 150 Ali Block Garden TownLahore, PunjabPakistan
telephone: +92 (42) 5880823
telefax: +92 (42) 5869386
website URL: http://www.pkti.edu.pk/
e-mail address: info@pkti.edu.pk
staff: Principal: Riaz Hamid Supra
Vice Principal: Ali Saeed Asghar
public relations: Ali Asghar
subjects include: Fashion & Apparel.


University of Engineering & Technology - Lahore
Lahore, Punjab, Pakistan
address: 54890 LahorePakistan
telephone: +92 (42) 339 270
website URL: http://webs.com.pk/uet/
subjects include:Fabric & Textile.


V.M. Ghani Rangoonwala Community Centre
Karachi, Sindh, Pakistan
address: Dhooraji Colony, Sindh74800 KarachiPakistan
telephone: +92 (21) 493 8025
telefax: +92 (21) 493 0534
staff: admin director: Riffat Alvi
acad director: Saeed A. B. Mirza
admissions officer: Firdous Meboob
chief librarian: Mr. Sultan
public relations: Razi Zubairi
subjects include: Textile Design.


Beaconhouse National University
[ BNU ] Lahore, Punjab, Pakistan
address: 3C Zafar Ali Road54400 LahorePakistan
telephone: +92 (42) 571 8264
telefax: +92 (42) 576 0254
website URL: http://www.bnu.edu.pk/
e-mail address: info@bnu.edu.pk
staff: Dean: Gulzar Haider
public relations: Jasim Azhar
subjects include:Jewelry Design
Texile Design.


Indus Institute of Higher Education
[ ITTM ] Karachi, Sindh, Pakistan
address: ST-2D Gulshan-e-Iqbal Block 17Adjacent National StadiumKarachi, SindhPakistan
telephone: +92 (21) 4801433 35
website URL: http://www.iihe.edu.pk/
e-mail address: ZubairKhan546@hotmail.com
staff: public relations: Muhammad Zubair
subjects include: Fabric & Textile


Pakistan institute of Fashion Design
[ PIFD ] Lahore, Punjab, Pakistan
address: 51-J / lll, Johar TownLahore, PunjabPakistan
telephone: +92 (42) 5315420 30
telefax: +92 (42) 5315420 30
website URL: http://www.pifd.edu.pk/
e-mail address: info@pifd.edu.pk
staff: public relations: Fawad Noori
subjects include: Fabric & Textile,Fashion Design,Fashion Marketing.


Textile University of Faisalabad
[ TUF ] Faisalabad (Lyallpur), Punjab, Pakistan
address: Amin Campus West Canal RoadFaisalabad (Lyallpur), PunjabPakistan
telephone: +92 (41) 875 0971
Fax: +92 (41) 875 0970
Website URL: http://www.tuf.edu.pk/
e-mail address: ahmadking266@gmail.com
staff: public relations: Ahmad Muhammad
subjects include: engineeringTextile.

Scouring Treatments of Cotton, Silk, Wool and Synthetics Materials

Natural fibers contain oils, fats, waxes, minerals, leafy matter and motes as impurities that interfere with dyeing and finishing. Synthetic fibers contain producer spin finishes, coning oils and/or knitting oils, Mill grease used to lubricate processing equipment, mill dirt, temporary fabric markings and the like may contaminate fabrics as they are being produced.

The process of removing these impurities is called Scouring. Even though these impurities are not soluble in water, they can be removed by Extraction, dissolving the impurities in organic solvents, Emulsification, forming stable suspensions of the impurities in water and Saponification, Converting the contaminates into water soluble components.

Scouring is usually carried out by means of continuous or discontinuous systems, with the same machines used for downstream treatments; temperature, processing time, pH, concentration of reagents, depend on the fibre,whiteness required and on the machine used.Incomplete scouring processes usually originate dyeing and printing defects due to different degrees of wettability and to inconsistent affinity for dyes of the material.

Types of Scouring Treatments
1.Scouring By Chemicals Means
2.Bio scouring or scouring with Enzymes

Scouring of Cotton
In the scouring process the cotton cellulose material is treated with a solution containing alkali ( soda ash and caustic soda), an anionic and/or nonionic detergent, a wetting agent, a complexing and sequestering for the removal of metal ions and polyacrylates or polyphosphonates as special surfactant free dispersing agents, at high temperature.

The scouring operation was conventionally done in kier machines and hence the process was called kier boiling , but now a days the scouring is done mostly in the dyeing machines itself as a part of combined or single operation such as scouring and bleaching.

I. Saponification of fats into water soluble soap and water miscible glycerin under alkaline conditions.
II. Hydrolysis of proteins into water soluble degradation products.
III. Dissolution of amino compounds.
IV. Solubilising of pectose and pectins by converting into soluble salts .
V. dissolution and extraction of mineral matter.
VI. Emulsification and solubilisation of natural oils and waxes.
VII. removal and dispersion of dirt particles and kitty by the action of alkali and detergent.

The material after scouring is more absorbent , free from natural impurities and coloring matter.This treatment can be carried out on filaments, yarns and fabrics.

Scouring of Silk
The scouring of pure silk is a degumming process used to remove sericin (silk gum) from fibroin floss. Sericin is the gummy element which keeps together the fibroin floss and gives the silk a hard hand and dull appearance. It is carried out on yarn, on dyed yarn, piece-dyed fabric or on products ready for printing. The treatment, which causes a loss of weight ranging between 24 and 28%, gives the degummed silk a lustrous appearance and a soft hand; the treatment is carried out with soapy solutions or with buffer dissolving agents. It is also possible to use enzymes (protease), which hydrolyses sericin.

Scouring of Wool
On wool, the scouring process removes oils and contaminants accumulated during upstream processing steps and can be carried out on slivers, yarns and fabrics with solutions containing sodium carbonate with soap or ammonia, or anionic and non-ionic surfactants, which carry out a softer washing to avoid any damage to the fibres.

Scouring of Synthetics
The scouring process applied to synthetic fibres removes oils, lubricants and anti-static substances, dust, contaminants and can be carried out on yarns and fabrics (when warp yarns have been bonded, the treatment is called debonding). It is carried out by means of surfactants, detergents and emulsifying agents.

Ordinary Honey Comb | Brighton Honey Comb | End Uses of Honey Comb

The honey comb weaves derive their name from their partial resemblance to the hexagonal honey comb cells of wax in which bees store their honey. These weaves form ridges and hollows which give a cell like appearance to the textures. Both warp and weft threads float somewhat on both sides, which coupled with the rough structure, renders this class of fabric readily absorbent of moisture. The weaves are of two classes, namely,

(i) Ordinary honey comb or honey comb proper
(ii) Brighton honey comb

Ordinary Honey Comb

These weaves are characterized by the following features
(a) Cell like appearance with ridges and hollows
(b) Single line crossing a single line or double line crossing a double diagonal line
(c) More warp and weft floats
(d) Moisture absorbent due to floats
(e) Constructed with pointed drafts
(f) A reversible fabric having similar effect on both sides.

Brighton Honey Comb

These weaves are characterized by the following features :
(a) Non-reversible cloths in which face appears different from back side of the cloth
(b) Constructed on straight drafts only
(c) Repeat size is a multiple of 4
(d) Length of longest float is N/2 – 1, where N is the repeat size
(e) A single diagonal line crosses a double diagonal line
(f) Formation of 4 cells per repeat i.e., two large and two small cells (ordinary honey comb forms only one cell per repeat)
(g) The number of threads in a repeat must be a multiple of 4.

End Uses
The fabrics constructed from honey comb weaves have more thread floats on both sides and have a rough structure. This renders more absorption of moisture. The weaves are, therefore, suitable for towels and also in various forms for bed covers and quilts.

What is Pigment Dyeing? | Pigment Dyeing Process | Process Flow Diagramfor Pigment Garment Dyeing Process

Pigment Dyeing

Pigment dyeing is not really “dyeing” in it’s truest form because the pigments stick on the fabric with the help of binders.. Pigments are insoluble in water. They exist in the form of finely ground molecules, milled for garment dyeing purposes into a paste. When anionic dispersing agents are added, a slightly negative charge is present, thus the foundation for pigment dyeing is born.

When a positively charged cationic pre-treat is added to the fiber a magnetic bond is formed. The process is complete when a cationic binder is added to “lock” the pigment into place.In pigment dyeing no actual chemical reaction takes place between the dye and the fabric.

The pigment dyeing process is generally a three step process such as:

1.Cationisation of the Fabric 

Or giving electric charge to the fabric by a powerful cationic pretreatment.
Pigment dyeing is an electrical process whereby the goods to be dyed are given an electrical charge opposite that of the pigment. When the pigment is added to the bath, the opposite electrical charges attract each other, much like the north and the south poles of two magnets. Because of the electrical nature of the process.

A typical recipe for cationizing Step
• Cationic Imparting Agent
• Wetter
• Acetic Acid for pH control

The cationic agent is applied with a wetting agent and acetic acid onto the fabric in the batch or commercial dyeing machine. After a period of time, the fabric is rinsed.

2.Pigment Exhaustion on the Fabric
The pigments are first mixed with water and a dispersing agent that imparts an anionic charge to the pigments. This solution is added gradually to the dyeing machine. The temperature of the bath is slowly increased and the machine is held at the dyeing temperature for up to 20 minutes. The fabric is held at an elevated temperature to increase the adsorption of the pigments.

A typical recipe for this step
• Pigment colorants
• Dispersing agent

3.Binder Application

A binder used in the exhaust pigment dyeing procedure for fixing pigment colors.Binders are commonly acrylic polymers with nonionic and cationic nature. It improves crock and wash fastness.After the pigment is exhausted , the binder is fed into the dyeing machine and exhausted onto the fabric over a period of time. Acetic acid is added to the bath, which facilitates binder polymerization, then the fabric is rinsed, the dyeing machine is drained, and the fabric is extracted.

Dyeing Process Flow Diagram

A Process flow diagram for pigment Garment dyeing process

Advantages of Pigment Dyeing

1.Its applicable to a wide range of textiles and wide gamut of colors available. Some brilliant fluorescent pigments are available for special applications and fashion items.
2.The process of pigment dyeing can also be relatively cheap.
3.The process chemicals are less toxic , environmentally friendly and least polluting.
4.The color fades with the repeated use , just like denims.

Limitations of Pigment Dyeing
1.Color fading could be a problem if not desired, and can only be kept intact with further chemical treatments.
2.The abrasion resistance and hand could be unsatisfactory depending upon the pigment, binder and softener used.
3.Dark and deep shades are better produced with other dyestuffs rather than pigments.

List of Best Textile Engineering Universities in Sri Lanka | TextileCourses in Sri Lanka | Textile Engineering Colleges in Sri Lanka |Textile Colleges in Sri Lanka | Apparel Colleges in Sri Lanka | GarmentColleges in Sri Lanka | Fashion Colleges in Sri Lanka

Sri Lanka Institute of Textile and Apparel
Sri Lanka Institute of Textile & Apparel (SLITA) was established on July 01, 2009 under the provisioning Act No.12 of 2009 by merging Clothing Industry Training Institute and Textile Training & Services Centre which had jointly served the Apparel Industry for near 25 years.
URL : http://www.textile-clothing.lk/

University of Moratuwa
Katubedda10400 MoratuwaSri Lanka (Ceylon)
tel: +94 (1) 64 54 41
url:http://www.mrt.ac.lk
admin director: Arthur C. Clarke
chief librarian: S. Rubinasingham
public relations: Rasika Amarasiri
libraries: University of Moratuwa Library
subjects: Fabric & Textile: L. D. Fernando

Academy of Design (AOD)
We are Sri Lanka’s only fully integrated design school offering you an undergraduate education in Fashion Design, Interior Design, Graphic Design and Jewellery Design.
Courses
B.A. (Hons) Fashion Design
B.A. (Hons) Interior Design
B.A. (Hons) Graphic Design
NC Jewellery Design
Contact:
AOD Colombo (Pvt) Ltd
29, Lauries Road, Colombo 04.
Tel : (0)11-5867772, (0)11-5867773, (0)11-5742480, (0)11-5742490.
Email : info@aod.lk
URL :http://www.aod.lk

Raffles Design Institute
About Raffles Design Institute, Sri Lanka
At Raffles Design Institute, our commitment is to afford our students a high quality education that provides our graduates with well-rounded hands-on learning experience that is relevant to the Sri Lankan and global industry.
Courses:Fashion design,Fashion marketing,jewellery design.
web site Url:http://www.raffles.lk/

Introduction of Mordant Dye | Properties of Mordant Dyes | Mechanism ofMordant Dyeing | Application of Mordant Dyes

A dyestuff that requires the use of a mordant. There are very few synthetic dyestuffs currently in use that require a separate mordant, except for some dyes for wool, where mordant dyes are still quite popular. Since chromium is almost exclusively used as the mordant on wool, chrome dye has become essentially synonymous with mordant dye. Many natural dyes (plant extracts, etc.) require a mordant. The mordant used can significantly influence the hue produced with a particular dyestuff. These are special acid dyes in which certain metal atom can be introduced during dyeing. These are water soluble dyes and affinity for silk, wool and polyamides. Mordant dyes requires a mordant in their application and these dyes upon cobination with the mordant deposit on the fiber in the form of insoluble color. Most commonly dyes have hydroxyl or carboxyl groups and are negatively charged (anionic) in nature.

Properties of Mordant Dyes

1. These dyes are economical dyes and are generally used to produce dark shades such as dark greens , dark blues and blacks.

2. These dyes have good leveling and color fastness properties.

3. The interaction between fiber and dye is established through very strong ionic bonds , which are formed between the anionic groups of the colorant and ammonium cations on the fiber. Chromium or the metal ion acts as bridge between the dye and fiber , which gives rise to a very strong linkage , resulting into excellent fastness properties.

However there are disadvantages of the chrome dyes also such as longer dyeing cycles, difficulties in shading , risk of chemical damage to the fiber and the potential release of chromium in the waste water.

Mechanism of Dyeing
Since these are a special class of acid dyes , which are soluble in water and applied to the fiber from an acidic bath. When a solution of an acid mordant dye is mixed with a solution of potassium dichromate in the presence of sulfuric acid , chromium ion from dichromate forms a complex with the dyes , this complex is insoluble in water ,and hence precipitates on the fiber.

There are three different methods of application of chrome dyes on the fiber,

1. Chrome – Mordant method
2. After chrome method
3. Meta chrome method

Application of Mordant Dyes

Chrome-Mordant Process
In chrome mordant process, the fiber is first treated with potassium dichromate in the neutral bath or in the presence of either sulfuric or formic or oxalic acid. When sufficient amount of chromium is taken up by fiber , it is taken out , squeezed and entered in the dye bath containing acid mordant dye. The dye form an insoluble complex with chrome present on the fiber .

After Chrome Method
In this method the substrate is first treated with the dye , the dye is exhausted by the addition of an acid , and after complete exhaustion the material is taken out squeezed and then run in a solution containing potassium dichromate and an acid. Metal dye complex is formed on the fiber , which is insoluble.

Meta Chrome Process
This is a single bath process , in which the material is treated with in a bath containing acid mordant dye , potassium dichromate and ammonium sulphate.

The dye along with potassium dichromate and ammonium sulphate got absorbed by the fiber and evenly distributed but no complex is formed because the pH is not suitable for the chemical reaction to take place.

In the second step of the meta chrome process, when the dye bath is heated , ammonium sulphate is converts into ammonia and sulphuric acid , which makes the bath strongly acidic and potassium dichromate in the presence of strong acid now react with the dye molecule forming an insoluble complex on the fiber.

A dyeing cycle for dyeing of wool with chrome dyes is shown below

Dyeing cycle of Wool

Here, 

A=Gluber salt+Acetic acid+Leveling agent
B= Dye
C= Potassium Dichromate
D=Acid