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Water bottles produced by the share brand are made of 100% recyclate
The plastics debate presents the food and beverage industries with serious challenges, but the KHS Group says increased use of recycled PET could provide a solution.
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blow moulder and bottle quality,” says Arne Wiese, product manager for Bottles & Shapes at KHS Corpoplast. KHS works closely with preform manufacturers. They are often the companies which subject washed PET
lastic can be very easily recycled,
flakes or rPET granulate to further
especially PET, as it satisfies the
thermomechanical processing and prepare
legal requirements governing food-
them for injection moulding. KHS is also
grade materials. With other materials,
liaising with various engineering companies
i.e. polypropylene, polyethylene and
on preform manufacture. Data from the
polystyrene, quality loss on application is
injection moulding process can be used to
irreversible, but recycled PET can always be
adapt the stretch blow moulding process.
brought up to the standard of new material.
This makes bottle production faster and
The cost of virgin PET is based on crude oil and benefits from current low market
more efficient and improves the quality of the finished containers.
prices. The charge for recycled PET (rPET)
With recyclate, the colour can vary from
has grown and companies now pay about
batch to batch. Darker material absorbs heat
20% more for rPET than the original
better and lower heating capacity requires
material. Some beverage producers also
less energy. This makes production efficient,
fear that rPET may discolour or that its
although adaptations must be made to the
intrinsic viscosity may drop.
blow moulding programme on the stretch
The European PET Bottle Platform helps to assure high quality standards with
blow moulder. It is essential that effects are quantified.
clear specifications and certifications.
Another challenge is intrinsic viscosity. “The
From a technical standpoint, there is
longer the recyclate is boiled under vacuum,
nothing preventing the global use of high
the longer the polymer chains become. This
percentages of recycled PET. Brand owners
means that the intrinsic viscosity increases
are even opting to use bottles made of
and quality improves. This could result in
100% recyclate.
additional costs, which not everyone is
Brands such as Danone Waters, Pepsi
prepared to invest,” Wiese points out. “We
and Coca-Cola plan to introduce a
have to come up with ways of redistributing
worldwide quota of 50% by 2025. Their
material from uncritical areas, such as the
objective? They would like the consumer
bottle base in the case of still water, to
to interpret the slight greying that can
more critical zones.” Experience shows that
occur when PET bottles are recycled
manufacturers of premium brands – whose
several times as a hallmark of quality for
containers have thicker walls – have less
sustainable packaging.
cause for adjustment than discounters,
The KHS Group has been examining the
where lightweighting options have often
use of recyclate since 2012. KHS’ Bottles
been exhausted. This is where recyclate can
& Shapes service programme focuses on
reach its limits.
the practical application on stretch blow
KHS technology in cooperation with
moulders and filling and packaging lines.
inspection technology manufacturer
“We run tests to qualify recycled PET so
Agr International boasts some
that we can tell our customers in advance
successes. Unit Mold Control is a digital,
which impact the material will have on the
automated control system that regulates the
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Food Review | May 2020
FAST FACT:
What sets bottles apart from other plastic products born in the postWorld War II rise of consumerism is the sheer speed with which the beverage bottle, now ubiquitous around the world, has shifted from convenience to curse. The transition played out in a single generation.“The plastic bottle transformed the beverage industry and it changed our habits in many ways,” says Peter Gleick, co-founder and president emeritus of the Pacific Institute in Oakland, California, and author of Bottled and Sold: The Story Behind Our Obsession with Bottled Water.
blow stations on the InnoPET Blomax individually. It helps to control material distribution; reduces variations in wall thickness by up to 30% and lessens fluctuations in quality during stretch blow moulding. “This is especially relevant when using recycled PET,” explains Frank Haesendonckx, head of technology at KHS Corpoplast. “The quality of material can vary, meaning that the lower the preform weight, the greater the fluctuations in material in the bottle and the more unstable it becomes.” During continuous wall thickness inspection, the new system identifies unwanted material displacement and automatically counteracts this. Unit Mold Control combines weight reduction with bottle stability and is one of the many sustainable and effective answers thrown up by the current packaging debate. •
KHS - www.khs.com
