straws, cotton buds and stirrers has
been delayed for six months by DEFRA
until October 2020. This is a temporary
measure, but concurrently must not
threaten progress towards more
sustainable packaging.
MANUFACTURING
CONSIDERATIONS
As a material, plastic is inextricably
linked with energy and resource savings.
Its low weight makes it both cost
effective and flexible to use, adding to
the sustainability score when measuring
environmental, social and governance
(ESG) performance. If anything, this
pandemic has presented retailers, brand
owners and packaging manufacturers
with the opportunity to review, realign
and reinforce the value of their packaging.
From a machinery performance
viewpoint, thinner wall sections bring
changes in processing requirements.
Among them, higher pressures and
speeds, faster cooling times, and
modifications to part-ejection and gating
arrangements. These process changes
need to be factored into the mould,
machinery, and packaging component
design.
Even when using less raw material,
packaging forms the protective layer so
still needs to be engineered to provide
strength. Choosing the best machine
for your packaging application is critical.
Understanding the melt stability and how
the plastic will perform as an end product
should form the basis of all decisions.
To support these efforts, Sumitomo
(SHI) Demag continues to pioneer the
development of packaging machines. The
company’s El-Exis SP range, available
globally, now comprises 10 machines,
with a clamp force range of between
150 and 1,000 tons.
Capable of delivering dry cycle times
of less than two seconds, the latest
generation of EL-Exis SP’s are specifically
designed to withstand the higher
stresses and injection pressures that
are so critical in achieving repeatability,
particularly in thin walling. This range
is aimed squarely at high volume
manufacturers of polymer products,
including caps and closures, thin wall
containers and lids.
With the introduction of a new control
valve regulating the hydraulic pressure
during the loading of the accumulator,
the range consumes up to 15% less
energy that previous generations
of El-Exis machines. These savings
are dependent upon the packaging
application, moulding cycle time and
process parameters.
Additionally, all-electric drives set a
new benchmark for achieving absolute
processing precision, accuracy and
dynamics. These are essential criteria
in the quest to achieve the highest
process consistency, as well as reducing
scrap to a minimum during start-up and
during ongoing production. The fast and
precise response of these direct drives
also enables special processes to be
implemented with pinpoint accuracy,
opening up new possibilities for
packaging moulders.
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