Paper Technology International 2024 - Journal - Page 130
PAPERTECHNOLOGYINTERNATIONAL
Developing functional coatings
Today, we already offer a broad range of single and multifunctional coatings for all kinds of requirements that address the
performance gap of paper and board and facilitate the transition to
circular 昀椀ber-based packaging solutions - from 昀氀exible packaging
through to folding cartons and corrugated boxes. Even though
innovative barrier coatings already enable the switch from
overengineered plastic to 昀椀ber-based packaging in some application
areas, packaging paperization still requires extensive R&D efforts to
develop barrier solutions for all performance levels, also meeting the
highest packaging functionality demands. Since several years, we
at Siegwerk have been focusing our attention on the development of
functional and barrier coatings.
When formulating functional coatings for paper and board
applications the work begins with an extremely accurate selection of
raw materials, which are then modi昀椀ed and integrated with additives
with similar functionalities to traditional silicones, waxes, substrate
wetters, tension modi昀椀ers etc. to enable the creation of the required
effects, such as barrier performance, but without impacting the
recyclability of the coated paper or board. In addition, it is important
to further enhance equipment compatibility to support invested
infrastructure and always keeping in line with the newest recycling
requirements for effective 昀椀ber recovery.
Another challenge is packaging safety, especially for
sensitive 昀椀lling goods such as food. At Siegwerk we bene昀椀t from a
highly skilled team of product safety experts as well as specialized,
independently audited, labs which are capable of conducting,
for example; migration tests. Whether it’s staying away from
昀氀uorinated materials, such as PFAS or PTFE, or using new and
innovative materials which need extra attention to be fully tested
and understood, our team keep us one step ahead of legislation and
ensure our coatings are always developed using safe raw materials.
Depending on the end use application and performance
required, our water-based barrier solutions are based on natural,
renewable, or synthetic raw materials, and are also suitable for
food contact. They can all be supplied ready-to-use which enables
customers to use their existing application equipment such as
coating, printing, and converting machines.
Sustainable innovations
Something which has always been important to us is the
use of renewable and natural raw materials in our coatings. This is
an exciting area with many new and innovative materials available
coming into the market, but it also often represents a signi昀椀cant
technical challenge to achieve suf昀椀cient functional performance,
especially for barrier coatings, and also commercial challenges
such as security of supply and cost. With our UniNATURE Water-Oil
Barrier Coating we have launched last year our 昀椀rst barrier solution
with certi昀椀ed natural content for single-use paper plates. It has
proven to effectively reduce the absorption of water, oil and grease
Figure 5: The switch from plastic-based to 昀椀ber-based materials
- generally called paperization - is one of the biggest trends we
see in the market today.
on platestock boards and is suitable for direct food contact while
maintaining its recyclability through the paper recovery system.
Therefore, our barrier coating offers a sustainable alternative to
replace restricted coatings on single-use paper plates according
to Single Use Plastics Directive (EU 2019/904) and other relevant
legislations.
It is already clear today that it will not be possible to
“paperize” every type of plastic packaging and replace it by 昀椀berbased alternatives approved for the paper recycling stream in the
short term. And where plastic 昀椀lms cannot be replaced, our focus
is on enabling mono-plastic structures. Just last year, for example,
we co-developed a water-based oxygen barrier for 昀椀lm, together
with our partner Henkel, that will enable the development of more
recyclable 昀氀exible 昀椀lm for food packaging. This is just one example
of the innovations we are continuously working on together with
our partners and customers, whether to further optimize barrier
properties, enable mono-material structures, or 昀椀nd other ways to
enable sustainable packaging circularity.
Enabling circularity in packaging is one of our key drivers
at Siegwerk. Not only because of plastic reduction, improvement
of reusability, and ease of recycling are clear demands from the
market, but also because we believe we have a responsibility to
future generations to make every effort to handle all resources with
care. We are enabling this trend not only through the development
of new barrier coatings, but also through extending our portfolio
of sustainable solutions for circular packaging in all areas and
continuously increasing the renewable content in all our products,
wherever possible.
For further information, we have prepared a helpsheet
which can downloaded at www.siegwerk.com/en/inks-coatings/
coatings.html.
About Siegwerk
Siegwerk is an international, market-leading manufacturer of printing inks and coatings for
all kinds of packaging. As a family-owned company in its sixth generation, Siegwerk relies on almost
200 years of expertise and knowledge in printing today. The company knows what it takes to develop
and print successful and responsible packaging solutions: From highly functional and eye-catching to
sustainable and safe designs - it provides printers, converters, and brand owners worldwide with highquality ink and coating solutions customized to their individual needs.
About the author: Oliver is commercial and strategic lead for water-based coatings at Siegwerk.
With over 15 years’ experience in the 昀椀ber-based packaging industry working with functional papers
and boards, he has dealt with many types of coatings and for a wide range of packaging applications.
Oliver Waddington, Siegwerk
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