Page 72 - TEXtalks. May-June 2023

72 73 Create new effects and designs a process develo
More productive and Contactless rotor spray dyeing opens up completely textile indu

new possibilities in fashion design - directly in the
WEKO Group who i
dyeing process. For example, one-sided dyeing or
application syst
overdyeing without penetration. Multicolor dyeing
cost-efficient uses several dyes in one liquor or one after the other powders
Textile, Paper,
(dye baths are without contact and remain
metal, and many
contamination-free). Deliberate creation of vintage,
offer you the la
salt & pepper, slub yarn look, and much more only by
thanks to new varying the spray parameters. Open up new technologies for
than 400 install
possibilities for your customers.
In finishing the
stenter frame li
Small scrap
process technology Due to the larger number of spray points, and work with st
quality result.
homogeneous dyeing is produced without tailing or
side-center variations. Due to the non-contact
ITMA 2023
application, liquor contamination, different
substantivity behavior of the dyes, or even possible
method live at I
hydrolysis do not play a role. In particular, the Experience th
WEKO booth B103
Rota pray separation of certain processes ensures a stable and to having
easily reproducible result.
Who is RotaSpray? Contact: RotaSpr
Member of WEKO Holding
RotaSpray GmbH is a German machinery info@rotaspray.d
manufacturer of rotor spray application systems and www.weko.ne
Today's processes often have the problem that small Today's standard - Pad-Dry-Pad-Steam process for
lots can't be produced cost-efficiently because the fabric
start-up scrap is too high and the preparation The Pad-Dry-Pad-Steam process (PDPS) is
sometimes takes too long. considered the worldwide standard in continuous
dyeing with reactive and vat dyes and is very widely
With the latest German developments of the used in the main textile countries for mass
RotaSpray PS² process, the continuous dyeing production. The PDPS process covers the entire RotaSpray Spraying System
process is rethought and enables sustainable, easily color space in all color depths. In Europe, this
reproducible, and waste-minimized production. process can hardly be used economically anymore problems and high wastewater treatment costs. excellent transfer from laboratory to production.
Especially for reactive, VAT and disperse dyes. due to the ever-decreasing batch sizes. Because this
process is not suitable for small-lot production The new standard - PS² (Pad-Spray-Steam) for fabrics Short steaming time and salt-reduced to salt-free
Due to the non-contact rotor spray application, dyes because of a strong tendency for tailing at the start of Instead of the two-bath application of dye and fixation production
and auxiliaries are applied homogeneously on one or each batch. Also, it is a very energy-intensive bath with energy-intensive intermediate drying To increase reactivity, it is possible to increase the
both sides. The penetration level can be adjusted by process based on intermediate Thermosol (Thermosol), the rotor spray process can be used to alkalinity of the alkali by up to one pH level compared
using the flexible rotor spray parameters and the processing. The high amounts of salt used in the dye apply the respective fixing bath directly after the dye to the standard recommendation. This allows
selection of the correct auxiliaries as required. recipe for reactives lead to additional ecological bath without intermediate steps - because the reduced steaming time by up to -50%. Keep in mind
non-contact application means that the dye remains the overall footprint of a PS² line is much more
stable on the fabric and the fixing chemistry is not compact and investment is far less than in a
contaminated or affected in any way. This helps to conventional PDPS line. A so-called dilution effect
drastically reduce energy costs and CO² emissions. due to padder and wet-on-wet spray application and Reduced migration tendency, better long-term quality the use of water, wastewater, energy auxiliaries, and
an associated loss of fixing yield in deeper shades The lack of intermediate drying additionally reduces time are parallel resulting in a cost-cutting industrial
Small scrap should not become unmentioned here. This loss of the migration tendency of the dyes to the surface of dyeing process with lower CO² emission.
In addition the PS² process is mainly characterized yield in darker shades can be compensated by the fabric and leads to a better full-body dyed quality.
by the minimization of the tailing during the start-up adding only a small amount of Glauber's salt (up to After several household washes, this effect turns out After use, only 8 - 25 l of fluid has to be emptied, but
of the dye set. These are mainly caused by hydrolysis to be very positive. this is not contaminated by the WEKO process and,
and substantivity effects with reactive dyes and are 80 g/l) to the spray liquor. Light to medium shades depending on the type, can possibly be re-used.
almost unavoidable despite optimum dye selection in are dyed salt-free. In general, the leachability of the Sustainable spray dyeing solution
the classic pure padder process. In the PS² process, reactive dyes in the PS² process is greatly improved With the latest developments of RotaSpray and Especially for large dye baths as in the DENIM
tailing can be reduced from up to 200 m in padding by the reduced salt load, thus reducing water WEKO, the entire dyeing process is revolutionized slasher area, the water reprocessing plants can also
down to 2-20 m in rotor spray technology with consumption. and made more sustainable. A strong reduction in be massively relieved.

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