ultrasound technology for chemical-mechanical textile finishing
Long-lasting antimicrobial textile finishing reduces infections
and environmental impact
The modular solution for the sonochemical, antimicrobial
finishing of all kinds of textiles can be seamlessly integrated
into existing plants and lines. Following consultation, the test
facility at Brückner's technology center will be available for
product testing from the second quarter of 2021.
In light of the coronavirus pandemic
and the increasing number of hospital infections around the
world involving multidrug-resistant pathogens, antimicrobial
textiles are coming back into focus. An innovative,
ultrasound-based finishing technology developed by Sonovia,
Brückner Textile Technologies, and Weber Ultrasonics now offers
some crucial advantages: because the impregnation meets
industrial requirements for wash resistance, it remains
effective for a long period of time – even against coronaviruses.
Furthermore, the new "sono-finishing" process minimizes the
environmental impact associated with conventional textile
Antimicrobial textiles are nothing new. But because the
majority of impregnations that protect against bacteria,
viruses, and fungi use chemical binding agents that only deliver
limited wash resistance, the protective effect only lasts a
certain amount of time. Additionally, the chemicals and
substances used can be harmful to the environment.
This may not only impact the environment; it can also result
in pollutant residues on finished products. "To ensure
antimicrobial textiles like those used in clothing for medical
workers, hospital linen/laundry, and oronasal masks
significantly reduce the risk of infection, the impregnation
must be able to withstand frequent laundering at the high
temperatures required in the medical sector.
They cannot lose efficacy over the course of their normal
useful life," says Liat Goldhammer, chief technical officer at
Sonovia Ltd., setting out a key requirement. Furthermore,
textile finishing must meet today's high economic and ecological
The ultrasonic equipment was specially designed for this
purpose and enables the zinc-oxide nanoparticles in the
active agent formulation to be firmly and sustainably
embedded in the surface of all kinds of textiles, with
lasting effect. Image source: Weber Ultrasonics AG.
Sonochemical process offers solution
for all types of textiles
In 2017, the company began industrializing a patented sono-finishing
process. The one-step, sonochemical finishing process is
suitable for all types of textiles – whether they're made from
natural fibers like cotton, linen, and silk, synthetic
materials, or a blend of both. The procedure uses zinc-oxide
nanoparticles as an active medium and is based on the physical
phenomenon of acoustic cavitation: when exposed to ultrasound,
small bubbles continuously form in the solution mixed with the
nanoparticles, which then expand and collapse within split
This creates high-energy microstreaming patterns, which move
at around 500 meters per second. These carry the particles with
them and embed them firmly in the textiles. "This is a
distinctive feature of our technology versus conventional
textile finishing processes that use chemical binding agents,"
explains Liat Goldhammer. "With sono-finishing technology, the
particles are mechanically embedded, so the antimicrobial
properties remain in place for a long time." What's more, no
polluting binding agents are required in the process, and the
use of chemicals can be reduced by up to 50 percent.
The formation of cavitation bubbles via ultrasound is crucial
to ensure the reliable application of the antimicrobial
zinc-oxide particles. Standard ultrasonic systems cannot be used
The new technology's proven, lasting protective effects,
in addition to the user-friendly and sustainable process,
make it an optimal solution for finishing clothing for
medical and care workers and many mor applications. Image
Strong partners for
To transfer the technology from the university laboratory to
large-scale industrial production, Sonovia partnered with
Brückner Textile Technologies, a manufacturer of textile
finishing systems and process technology developer, as well as
Weber Ultrasonics, an international manufacturer of ultrasound
technology components – both world leaders in their respective
industries. "Both companies were impressed by the technology's
potential and entered into partnerships with us. This cannot be
taken for granted with such established firms – after all,
collaboration with a startup always comes with certain risks,"
comments Liat Goldhammer.
While the R&D department at Weber Ultrasonics came up with a
made-to-measure ultrasonic concept, Brückner developed and built
a corresponding application unit that can also be integrated
into a wider, continuous finishing process. The first system
prototype for the sonochemical process has been in use at
Brückner's technology center since early 2019.
The antimicrobial finishing is over 99 percent effective
against the SARS-CoV-2 virus. The fabric is used to
manufacture oronasal masks.
Technological, environmental, and
In addition to ensuring maximum process reliability, key
aspects included meeting the modern textile industry's high
standards in terms of productivity, reliability, sustainability,
ease of maintenance, and cost effectiveness.
Compared to conventional textile equipment, the new procedure
not only offers the benefits of more long-lasting antimicrobial
properties and being more environmentally friendly; it also
allows for cost savings. "Although development is not yet
complete, initial, conservative calculations suggest potential
savings of around 10 percent from the reduction of chemicals
used," comments Liat Goldhammer.
The new application unit, which is similar to a padding
mangle, can easily be integrated into existing plants and lines.
It can be used for finishing both woven and knitted fabrics, as
well as nonwovens and carpeting.
Proven wash resistance and efficacy – even against
coronaviruses to prove the lasting and reliable antimicrobial
efficacy of sonochemical textile finishing, Sonovia conducted
testing together with renowned international textile research
and certification institutes. The tests confirmed that the
finished fabrics still retained their full antimicrobial
properties after multiple wash cycles at high temperatures.
Image source: Weber Ultrasonics.
Sonovia now manufactures and sells antimicrobial oronasal
masks made out of textiles that use this technology. Tests
carried out in summer 2020 revealed more than 99 percent
efficacy against SARS-CoV-2. Additionally, the mask filters 95
percent of 3 microns particles, the particle size which has been
identified by the WHO as relevant to the spread of COVID-19.
The new technology's proven, lasting protective effects, in
addition to the user-friendly and sustainable process, make it
an optimal solution for finishing clothing for medical and care
workers and laundry/linen in hospitals, senior homes, and
hotels, as well as many other areas where hygiene and infection
control are critical. The fashion and sportswear industries, as
well as the automotive sector and railroad car fitters are also
interested in sonochemically finished textiles. Relevant tests
are set to be carried out at Brückner Textile Technologies'
technology center starting in the second quarter of 2021.