Page 59 - TEXtalks. September-October 2022

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Residual liquor 1 Rinsing bath 2 Rinsing bath 3 Rinsing bath 4 Rinsing bath 5 Rinsing bath 6 Rinsing bath
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th
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50 °C 98 °C 70 °C 50 °C 30 °C
Sustainable Reactive Dyeing Residual liquor 1 Rinsing bath 2 Rinsing bath 3 Rinsing bath
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that Saves Resources 60 °C 1 g/I COTOBLANC SEL 60 °C

60 °C

Fig. 1: Comparison of the rinsing baths in the reactive dyeing process (top: commodities / bottom: process at 60 °C using BEZAKTIV GO and COTOBLANC SEL).

100
90
80
Temperature in °C 60 The BEZAKTIV ZERO GO dyes can, of course, also processes and fulfill highest ecological demands.
70
50
40
30
the BEZAKTIV GO dyes have received a C2C Material
energy and water. These dyes have good fastness
20 be applied in the “GO” process which saves both Among others, the BEZAKTIV ZERO GO and some of
TM
10 levels (like e.g. the multiple washing fastness Health Certificate .
0 according to ISO 105-C09) and can no longer
0 50 100 150 200 250 300 reductively detach p-chloroaniline from the dyes GO for Digitalisation
Time in minutes textiles at detectable limits. The dyeing example Textile finishers can easily see the actual savings that
Commodities BEZAKTIV GO / GO-Process with 60 °C shows that the BEZAKTIV ZERO GO dyes also lead are facilitated by the BEZAKTIV GO and ZERO GO
to very deep colors and that they are especially well dyes: The CHT Textile Dyes App offered by CHT
Fig. 2: The GO Process stands out for lower temperatures and shorter process times. suited for dark shades. The problem with reductively Switzerland is a simple and smart calculation tool.
cleavable p-chloroaniline of dyed cellulose mainly The comparison with the above shown recipes clearly
°C, the dyeing process with BEZAKTIV GO is textile using a washing process with a low water and occurs with very dark shades and above all with shows that the dye application amount and the
generally shorter, which also increases the energy consumption. black, for which most worldwide manufacturers use a necessary electrolyte concentration are much lower
productivity for the textile finisher. Savings in the black based on the Reactive Black 5. The BEZAKTIV when using BEZAKTIV GO dyes than when using
required salt quantity can be simultaneously Even for dyeings in the cold pad batch process the ZERO Black GO does not contain any Reactive Black conventional, bifunctional reactive dyes. Besides the
achieved. The unnecessary salt and the resulting rather high fixation speed allows for shorter dwelling 5 and has therefore a very good multiple washing calculation programme the CHT Textile Dyes App
Many industrial sectors all over the world show a can be observed. The dye properties themselves are lower electrolyte concentration in the dyebath not times. The good wash-off properties lead to savings fastness according to ISO 105-C09 compared with a additionally offers useful bits of information on the
clear trend to sustainability and a conscientious decisive for a successful use of reactive dyes in such only allow for significant cost savings in the recipe in continuous washing processes, specially with dark conventional reactive black. All additional elements of BEZAKTIV GO and ZERO GO products, ranging from
handling of resources. The textile industry is not processes: They must have a sufficiently high fixation but also for an improved washing off process of shades or black. the ZERO GO range have also good multiple color samples, all of the relevant fastness types and
exempted from this trend. Furthermore, the speed, a very good ease of removal of hydrolysates unfixed shares after the dyeing. The dyeing of washing fastnesses, they allow for dyeing more detailed product profiles up to useful
worldwide consumption of cotton is increasing, which and an excellent solubility. Moreover, reactive dyes medium to dark shades where in classic procedures p-Chloroaniline-free dyeing with BEZAKTIV ZERO GO brilliant shades and they can also be excellently used
can lead to tensions in the area of water availability, are expected to reach high overall fastness levels, quite a big share of unfixed dye must be washed off ZERO refers to the content of undesired arylamines for shading the BEZAKTIV ZERO Black GO or recommendations for use.
land for agriculture and the use of agrochemicals. especially a good stability towards multiple washing reveals the benefits of the “GO” process in particular. (as e.g. p-chloroaniline) which are not detectable in BEZAKTIV ZERO Navy GO. The fastness
and also light fastnesses, which allows a generally With the combination of a very high fixation degree these dyes. improvement in multiple washing is mainly an Since the CHT Group is focused on sustainable
Consequently, circular economy approaches, and an longer use of colored textiles, and to lead to and an excellent ease of removal of hydrolysates, the enhanced stability towards oxidative influences and it chemical products and process solutions, the
improved recycling of used textiles gain in reproducible, levelled dyeing results without causing BEZAKTIV GO range allows for a very efficient rinsing Both dyeing results are free from reductively is gaining in importance as it leads to an improved BEZAKTIV GO products also meet highest
importance. However, the reactive dyeing of problems. Last but not least due to a good color and soaping process between 40 and 60°C. An detachable arylamines and have good multiple durability of the textiles, which is a contribution to standards: All of the currently sold elements are
cellulosic fibres like cotton and its blends is still being build-up they must also be efficiently applicable for additional positive effect is achieved by adding only washing fastnesses and a comparable fastness level. sustainability in textile manufacture. Moreover, the bluesign -approved and suited to meet the
®
effected with water-based processes. In this field, dark shades. low concentrations of the CHT auxiliary COTOBLANC The variant with BEZAKTIV ZERO GO, however, requires elements of the BEZAKTIV ZERO GO dyes have high requirements made by GOTS and Standard 100 by
too, a tendency towards cold pad batch processes SEL in the second soaping bath. As a result, significantly lower dye and salt amounts and additionally fixation degrees, can also be applied in continuous OEKO-TEX.
or exhaust processes with short liquor ratios and Sustainable and economical dyeing excellent wet fastness levels can be achieved on the helps save energy and water - see next page for details.
lower temperatures of the dyeing and rinsing baths Compared with a conventional reactive dyeing at 60
September/October 2022 September/October 2022