By: N.C.Pan, S.N. Chattopadhyay, A.K. Roy and K. Patra


Diversification is the only avenue for future of jute. Alldiversified products need attractive design, look and feel. For impartingattractive design and look, printing of the fabric with suitable dyes is one ofthe options.

 

Printing is the localized application of the dyestuffthroughout the entire length of the fabric to get a desired design effect. For printing of jute fabric, reactive dyes may be used for their easy application on to the fabric.

 

Reactive dyes chemically react with the jute fibre and areattached to it by covalent bonds.

 

This printing technology, printing of jute fabric withreactive dyes, is ideal for small scale and cottage industries as good washfast prints are obtained by this process.

 

Moreover, most of the diversified products are produced in small scale and cottage industries.

 

Preparatory processing


Plain weave grey jute fabric was scoured with sodiumhydroxide (2%, owf) and non-ionic detergent (5 g/l) at 90-95C for 60minutes and the material-to-liquor ratio was kept at 1:20. After scouring,the fabric was thoroughly washed with hot water and then in cold water,neutralized with acetic acid (2 ml/l) followed by usual cold washing.


Scoured jute fabric was bleached in a closed vessel for 90minutes at 80-85C and the material-to-liquor ratio was kept at 1:20 withhydrogen peroxide (2 vol.), trisodium phosphate (5 g/l), sodiumhydroxide (1 g/l), sodium silicate (10 g/l) and non-ionicdetergent (2 g/l).

 

The pH of the bath was maintained at 10.

 

After bleaching, the fabric was washed thoroughly in coldwater, neutralized with acetic acid (2 ml/l), washed again in cold water andfinally dried.

 

Printing of jute fabric consists of four steps viz., preparation of stock paste, preparation of print paste, application of print paste onto thefabric and fixation of prints.

 

Stock paste was prepared by using thickener (sodiumalginate, 50 gms/kg), urea (310 gms/kg), sodium bicarbonate (40 gms/kg) andwater (600 gms/kg) with high speed stirring.

 

Stock paste should be free from any coagulating matter.

 

Print paste was prepared by using substitution type reactivedye (Amactive Orange H4R, 40 gms/kg) and stock paste (960 gms/kg) with highspeed stirring.

 

 

Scoured-bleached jute fabric was printed with above print paste by screen printing technique. After printing, the fabric was dried at 80C for 5minutes.

 

The fixation of prints was carried out by thermo fixationmethod at a temperature of 150C for 5 minutes.

 

After thermo fixation, cold washing, soaping, again thoroughcold washing and drying was carried out.

 

Evaluation of prints


λmax value, reflectance, K/S value, wash fastness to colour and wash fastness to staining were determined, as per standard methods available, to evaluate the prints. Sharpness of the prints was evaluated by visual assessment.

 

The results of evaluation of prints are as under:


λmax value - 490 nm, Reflectance 4.85,

K/S value (in terms of dye uptake) -9.31,

wash fastness to colour - 4,

wash fastness to staining - 4.


Outcome of printing


Reactive printed jute fabrics produced deep bright prints with good wash fastness rating. Sharpness of the prints was also achieved by this printing technique.

 

Printing of jute fabric with reactive dye is simple and can easily be adopted by small scale and cottage industries.


About the Authors:


The authors are associated with Chemical & Biochemical Processing Division, National Institute of Research on Jute & Allied Fibre Technology, Indian Council of Agricultural Research, Kolkata, India


National Institute of Research for Jute and Allied Fibres Technology (NIRJAFT), Kolkata is engaged with research on industrial processing aspects of jute and allied fibres.