GREEN UNIVERSITY OF BANGLADESH
Department of Textile Engineering
Lab Report No-10
Course Code : TEX 302
Course Title : Wet Processing II
Lab Name: Study on polyester fabric printing with disperse dye.
Submitted To : Submitted By :
Name : Md.
Name : Robeul
Mahbubur
Islam
Rahman
ID # :173003012
Designation : Senior
Lecturer Department
Department : Textile
Experiment No: 10
Experiment Name: Study on polyester fabric printing with disperse dye.
Introduction:
Dyes are coloured, unsaturated organic chemical compounds capable of giving
colour to a substrate (a textile), i.e. colouring or dyeing it.
The term “disperse dye” have been applied to the organic colouring substances
which are free from ionizing groups, are of low water solubility and are suitable
for dyeing hydrophobic fibres. Disperse dyes have substantivity for one or more
hydrophobic fibres e.g. cellulose acetate, nylon, polyester, acrylic and other
synthetic fibres.
Objectives
1. To know about polyester fabric printing.
2. To know about the disperse dyes.
3. To know about the printing process with disperse dye.
Recipe:
Disperse dyes = 30 gm/kg
Dispersing agent = 5 gm/kg
Acetic acid = 2 gm/kg
Thickener = 40 gm/kg
Cross-Linking agent = 20 gm/kg
Uria = 20 gm/kg
Water = rest
Calculation:
Total 100 gm printing paste
Disperse dyes = (100/30) gm/kg = 3.33 gm/kg
Dispersing agent = (100/5) gm/kg = 20 gm/kg
Acetic acid = (100/2) = 50 gm/kg
Thickener = (100/40) = 2.5 gm/kg
Cross-linking agent = (100/20) = 5 gm/kg
Uria = (100/20) = 5 gm/kg
Water = {100-(3.33+20+50+2.5+5+5)}
= (100-85.83)
= 14.17 gm/kg
Properties of Disperse Dyes:
Disperse dyes are nonionic dyes. So they are free from ionizing group.
They are ready made dyes and are insoluble in water or have very low
water solubility.
They are organic colouring substances which are suitable for dyeing
hydrophobic fibres.
Disperse dyes are used for dyeing man made cellulose ester and synthetic
fibres specially acetate and polyester fibres and sometimes nylon and
acrylic fibres.
Carrier or dispersing agents are required for dyeing with disperse dyes.
Disperse dyes have fair to good light fastness with rating about 4-5.
Printing process of fabric
The negative charge on the surface of hydrophobic fibres like polyester can not be
reduced by any means, so non-ionic dyes like disperse dyes are used which are
not influenced by that surface charge.
Process Sequence:
Preparation of fabric.
Preparation of print paste.
Application of print paste on the surface of the fabric.
Dry the fabric at room temperature.
Steaming at 90deg C
After Treatment.
Working Procedure:
1. Collection of pre-treated sample.
2. Preparation of print paste
*) Dye + acetic acid + Dispersing agent + Boiled water = Paste
*) Paste + Thickener = Print Paste
3. Apply the print paste on the fabric surface according to method and style.
4. Dry the sample at room temperature.
5. Steaming at 110deg C.
6. Soap Wash
After treatment:
The printed fabric is steamed in the steamer 10 min at 105 – 110 0C to penetrate
the dye in the fabric and fix it.
Pre caution:
1. We have to maintain the viscosity of print paste.
2. We have to apply even pressure on squeezer for even printing.
Conclusion:
From this experiment we can get a clear idea about printing of polyester fabric
with Disperse dyes. From others dye this type of dye is different. During this
experiment we have to face some problems that are to be considerable. Overall,
the knowledge of this dye helps us to dye Manmade fibre especially Polyester
properly and helps us in our practical life.
