Paper Technology International 2024 - Journal - Page 128
PAPERTECHNOLOGYINTERNATIONAL
and their role
BBarrierin coatings
the paperization of packaging
Oliver Waddington, Head of Business Development - WB Barrier Coatings at Siegwerk
INTRODUCTION:
A growing environmental consumer awareness and rising regulatory requirements for the design of packaging continue to drive
the demand for more sustainable packaging alternatives designed for circularity. As a result, brand owners and packaging designers are
increasingly looking for ways to “paperize” their packaging by using renewable and recyclable 昀椀ber-based materials instead of plastic.
Mega trend “Paperization”
The primary purpose of packaging is to protect, preserve,
and promote the packed goods - a job plastic packaging does very
well in many application areas. But plastic packaging also comes
with major challenges as it’s often not recycled, or even worse,
ends up in the environment and the oceans. The reason for this is
the outdated economic “take-make-use-dispose” principle, which is
responsible for roughly 90 percent of plastic packaging being thrown
away after a single use. We are currently in a transformation phase
moving towards a circular economic model that enables circularity
of packaging by using recyclable and renewable materials so that
resources can be used as long as possible and packaging “waste”
has an economic value and does not end up in nature. Regulatory
requirements for the recyclability of packaging are becoming
increasingly strict worldwide, making it more urgent than ever to
rethink the future design of packaging now.
In this context, 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. Afterall, paper already has a very
well-established recycling stream in many places around the world.
So, wherever the required packaging functionality can be achieved
by switching from plastic to paper or paperboard packaging, we
can already leverage a proven material recovery stream. However,
to unlock the full recycling potential, “paperized” packaging
solutions need to support the recycling process with repulpability
and properties ensuring compliance to existing recycling streams
- otherwise paperization misses its target. Examples of successful
transition from plastic to 昀椀ber-based packaging alternatives are
appearing the market, and in the media, what feels like everyday.
From pouches for dry food like cereal and pasta, to sugar
confectionary and chocolate; to containers for foodservice and foodto-go; trays for fresh fruits and vegetables; to non-food applications
like tissue and hygiene paper packaging.
Barrier and functional coatings as enabler
As most paper and paperboard grades are inherently
porous and hydrophilic, they often have little to no barrier properties
compared to multi- or mono-layered plastic-based packaging, which
clearly limits their performance potential and thereby the suitable
application range for packaging. To achieve the required functional
properties, such as barrier, for suitable pack performance such
as shelf-life; metallized substrates, polyethylene (PE) or other
polyole昀椀nic co-extruded or laminated barrier layers have been
commonly used to coat paper and 昀椀ber-based materials - often with
negative consequences for the recyclability of the 昀椀nal packaging
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Figure 1: Siegwerk’s innovative barrier coatings enable the
transition from plastic-based to 昀椀ber-based packaging.
structure. A safe and sustainable way to get around the performance
limitations of paper and 昀椀ber-based materials is to use water-based
functional coatings as they can create the required barriers between
the 昀椀lling good and the packaging whilst also ensuring recyclability.
In other words, barrier coatings can equip renewable
and 昀椀ber-based materials like paper and board with functional
properties to achieve suitable shelf-life and packaging performance
to replace or reduce the use of plastic. Therefore, barrier coatings
play an essential role in widening the packaging paperization
scope, enabling the use of paper and paperboard for a wider range
of packaging applications and thus support the development of
recyclable and circular packaging solutions in a well-established and
proven recycling stream.
When talking about barrier performances for paper
packaging it is not only about protection against the outside, but
also protection against the inside. Protecting the 昀椀lling good from
the outside includes, for example; barriers against water and water
vapor, oxygen and other gases, as well as aroma, oil, grease, and
UV light. In turn, for the protection of the packaging material from
