Effects of metal in water on cotton knitted dyeing

process

Khanittha Charoenlarp, Prathompong Wongsrisang,Phannipa Saeaeng Department of Textile Chemistry Engineering, Rajamangala University of Technology Krungthep

Introduction

Five main sectors of textile industry:

Fiber production Spinning Weaving and knitting - Dyeing printing and finishing Garment production

Textile Wet Processing Industr y

Industry Major Production Process Steps- Desizing- Scouring- Bleaching- Mercerizing- Dyeing- Finishing

Bleaching

A chemica l process that elim

inates unwanted colored matter fro

m fibers, yarns, orcloth.

Dyeing

A process that adds color to textiles and

increases product value

Dyeing method

• -batch wise•continuous

Printing

A process is used to impart a colored

pattern or design t o the cloth.

Finishing

T he final operationis carried out after dyeing/printing.It encompasses

various chemical or mechanical treatme

nts performed on fiber,

yarn, or fabric to imp rove appearance, te

xture, or quality.

Fabrication

Finished cloth is fabricated into a va

riety of apparel: household and

industrial products, bags, sheets, towel

s,blankets, etc.

Major Environmental Concerns in Textile Industry Textile Wet Processing

- High water consumption-

Number of washing steps involved in the production process consume

amount of water (and energy too)

Major Environmental Concerns in

Textile Industry Color and metals in the wastewat

er d ue to a variety of dyestuffs an d auxiliary chemicals used.

The main problem of wastewater treatment in dyein

g industry H ow to get rid of the

contamination of dye s in wastewater whic h is mainly complex s

tructure compound a nd toxic.

The quality of water appropriate to textile wet process

Water quality is important on textile wet process which is an significant factor to define product quality.

Good quality of water for textile wet process is clear, soft water, low suspending solid and metal.

The quality of water appropriate to textile wet process

Natural water is normally contaminated with color, turbidity and metal which various depending on the source water.

Objective

To study type and amount of metal which contaminate in cotton knitted.

To study effect of metal in water on cotton knitted dyeing.

To find the optimal length of metal concentration for Thai textile industry

Experimental methods

Materials The fabric used in this study was

knitted cotton fabric.

The dye used in the experiments, was reactive dye

Sumifix HF Blue 2R granSumifix HF Red G granSumifix Yellow 3R gran

Scouring and bleaching

Dyeing process

Dyeing was done in stainless steel canisters of OSCI color.

The liquor-goods was 20:1. Fabrics were introduced into dyeing

solution at room temperature. Temperature was raised to 75oC and dyeing continued at the 75oC for 90 minutes.

After dyeing, the fabric was rinsed in water and air-dried.

five replications were done for each concentration of metal.

Color Strength Evaluation

Dyed fabrics were evaluated for their color strength using K/S values generated by a Hunterlab ColorQuest XE diffuse/ spectrophotometer.

K/S is a function of color depth and is represented by the equation of Kubelka and Munk

The equation of Kubelka and Munk

R is the reflectance of the dyed fabric

K is the sorption coefficient

S is the scattering coefficient.

KS

(1-R)2

2R=

colorfastness evaluation

Dyed fabrics were tested for colorfastness to washing according to AATCC Test Method 61-2001.

Results

Type and amount of metal which contaminate in cotton knitted. The metal contaminates in Cotton

knitted are Fe, Ca, Mg, and Mn.

The amount of Fe, Ca, Mg, and Mn which contaminate in cotton knitted are 35.68, 34.60, 7.00 and 1.27 mg/l respectively

Effect of Ca2+ on dyeing

Effect of Mg2+ on dyeing

Effect of Fe2+ on dyeing

Effect of Mn2+ on dyeing

Effect of Cu2+ on dyeing

Effect of Ca2+ and Mg2+ on Reactive Dyestuffs

Reduced Solubility,Increased Aggregation Can cause dye spotting Unlevel dyeings Loss of dye from recipe (economy) reduced fastness Staining machinery (and subsequent

fabric batches)

Effect of Fe2+, Mn2+ and Cu2+ on Reactive Dyestuffs

precipitation of dyestuff, which could lead to spotting problems.

change of shade. catalyst the chemical reactive

resulting in the reduction of tensile strength of cloth leading to pin hole effect.

Effect of metal on color fastness

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Ca 7 0.971**

Mg 7 0.976**

Fe 7 0.806**

Mn 7 0.889**

Cu 7 0.978**

Conclusion/summary

The optimum stage for reactive. the amount of Ca and Mg less than 10

mg/l the amount of Fe, Mn and Cu less than

0.1 mg/l.

It can be suggested that if the quality of water is well controlled ; the right shade of color can be yielded in the first time of the dyeing process.

Conclusion/summary

Findings of this study will help industry to improve process in several ways such as higher quality of the product, eliminate reprocess, reduce wastewater.

It is hoped that this study will encourage an awareness of water systematic treatment for Thai textile industry.

Thank you

Rajamangala University of technology krungthep.

Assist.Prof. Dr. Ngamthip Wimolkasem. Mrs. Chiraporn Supthanont. Assist. Prof. Pramote Anantawarapong.