Resist Printing

SUBJ-17:

Resist Printing

Chemicals:

Dye (1. MCT Range Dye for ground print, 2. VS Range Dye for Over print), Urea, Sodium Bicarbonate, Sodium Sulfite, Alginate Thickener.

Purpose:

Resist printing is a special effect like Discharge printing. As name suggests resist mean TO STOP. Background of fabric in this technique is colored with a dye having MCT (Mono chloro Triazine) Chemistry. Dyes having this chemistry is more stable to reducing agents like Sodium sulfite which is main player in resist printing. So, Ground printing paste has dye, thickener, mild oxidizing agent, Sodium sulfite. While Over print(Full Bloch) dyes are chosen from VS (Vinyl Sulfone) Range. These dyes are unstable to reducing agents like Sodium sulfite

Consequntly a Ground printed portion (usually design/pattern)have sulfite and will eat up all Over color (Full Bloch) on that region. So, over print will only survive those regions which don’t have ground printed. Through this mechanism we can achieve versatile designs and patterns.

Difference Between Discharge and Resist Printing:

Sometime People may confuse Discharge and Resist Printing. Both are two different methods and have versatile useage in textile industry. Results are amazing and adimreable with very low economy (No extra screens, No high class machinery, No special chemicals).

Discharge:

Ground color is eaten up/Destroyed chemically with Sodium formaldehyde sulfoxylate normally called Rangolit C.

Resist:

Over color is eaten up/Destroyed chemically through Soium Sulfite.

Discharge:

Usually discharge is white because Rangolit C is not stable with dyes. So, both RangolitC and dye can not be used simultaneously

Resist:

Resist is most of the time colorful because Dyes with MCT Chemistry are stable with sulfite.

Discharge:

If one wants to have color discharge has to use pigment and binder rather than dye because dyes are not stable with Rangolit C. Where as pigments are stable to Rangolit C.

Resist:

No need to go for pigment and binder in case of Resist as dyes are stable with functional chemical.

Ground Recipe (Design Screen):

Dye (MCT)                             30 g/Kg

Urea                                        100g/Kg

Sodium Bicarbonate               25g/Kg

Sodium Sulfite                       40g/Kg

Alginate Thickener (3%)         Balance

Total                                       1 Kg

Process:

Print, Dry at 120C for 1 Min.

Over Print Recipe (Open Screen/No blocked region):

Dye (VS)                                 30 g/Kg

Urea                                        100g/Kg

Sodium Bicarbonate               25g/Kg

Alginate Thickener (3%)         Balance

Total                                       1 Kg

Process:

Print, Dry at 120C for 1 Min.

Fixation through Saturated Steam at 102C for 8Min.

Washing:

§     Cold rinse

§     Soap at 60^oC With:

                        1-2 ml/l of Soap (General chemical for reactive washing e.g. acrylic acids)

§     Hot Rinse

§     Cold Rinse

Remarks:

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