Testing and recommending commercial chemicals for controlling back staining in reactive printing washing and wash down effects of Denim ( Enzyme Wash, Stone Wash, Moon Wash)..

SUBJ-12:

Testing and recommending commercial chemicals for controlling back staining in reactive printing washing and wash down effects of Denim ( Enzyme Wash, Stone Wash, Moon Wash)..

Chemicals:

Dye( Tuquoise was taken for experiment as it is famous for a lot of back staining), Stock paste (Containing Urea, Bicarbonate, Mild oxidizing agent ), Hydrogen per oxide 35%, Soda ash, Routing soap for reactive washing(generally acrylic acids).

Purpose:

Back staining is quite a famous issue among printers as it stains white area and minimizes contrast effect and eventually compromising the added value. This is not only the issure for reactive printers but also for Denim industry, Who are busy in dyeing warp yarn of denim and leaving white weft and weaving style ending up with eye catching effect of jean. Now days, Different washes are very famous for carrying out different effects like Stone Wash, Enzyme wash and Moon Wash. When these washes are done dye is released from the warp yarn into liquor (containing some enzyme, acetic acid for maintaining appropriate Ph) these dyes bounce back towards fabric and stick to weft yarn so, again less contrast between warp and weft. New tint of  blue from weft also fade down the actual Denim concept.  So, what can be added to over washing recipe to control this issue.

With out H2O2...   With H2O2...  

Recipe:

Stock paste:

Mild. Oxidizing agent             10  g/Kg

Urea                                        100g/Kg

Sodium Bicarbonate               25g/Kg

Alginate Thickener                  25g/Kg

Water                                      Balance

Total                                       1 Kg

Dye Glass:

Reactive  Dye (Turquoise)      50  g/Kg

Stock paste                              Balance

Total                                       1 Kg

Process:

Print and dry at 110-120°C for 1Min.

Cure at 200C for 1 Min

Washing:

§     Cold rinse

§     Soap at 60^oC With:

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

                         0.8% Hydrogen per Oxide (35%)

                         0.5% Soda Ash (Sodium Carbonate)

§     Hot Rinse

§     Cold Rinse

Note:

Working of Hydrogen per oxide as an anti back staining is very simple, When fabric is in bath for washing its Ph should be slightly alkaline (0.5% soda ash will do it for us). So, this helps the peroxide to strat liberating nascent oxygen there by helping in anti back staining activity.

Some other oxidizing agents can also be tried in addition to Hydrogen peroxide like,

Potassium permanganate

Sodium Hypochlorite

Resist salt (Mild Oxidizing Agents)