Issue 02/2019

Thermoforming / Rigid Packaging
Thermoforming with biobased
plastics for greater sustainability
Are biobased and biodegradable plastics also suitable
for thermoforming? The Turkish plastics processor
Göncay Plastik, which manufactures millions of
plastic lids for drinking cups for fast-food chains, answers
the question with a definite “yes”. The company has plenty of
good experience with Bio-Flex ® , a biobased compound from
the portfolio of FKuR that meets the high specifications on
processability and product properties.
The application of plastics in the packaging segment, which
is frequently characterised by extremely large production
runs, is at the centre of discussion more than ever before.
Proven ways to gain greater acceptance include the use of
recycling-friendly monolayer structures and the lowering of
material consumption by reducing the thickness and thus
the weight of the product. A lesser known aspect here is that
biobased thermoplastics are also suitable for one of the most
commonly used production processes in the industry, namely
thermoforming – also known as vacuum forming. The
products combine an aesthetic appearance with functionality
plus a significant increase in sustainability.
Millions of lids for hot and cold drinks
Göncay Plastik reports on the successful use of a
thermoformed product from a biobased thermoplastic
instead of a conventional thermoplastic. The company,
founded in 1988, is headquartered in Istanbul, Turkey, and
delivers to customers in over 50 countries, predominantly
in Europe. One of its biggest-selling products is a range of
thermoformed plastic lids for hot and cold drink cups for
international fast-food chains. With a production capacity
of 6 million lids a day, Göncay Plastik manufactures over 70
different shapes and sizes for virtually all types of plastic
cups and beakers used around the world. In 2018 the
company switched part of this production to the product
Bio-Flex S 7711 from FKuR.
Managing Director Ibrahim Göncay remembers well how it
all started: “We received the assignment from our customers
– belonging to the best-known branded companies in the
world – to maximise the environmental compatibility of our
products by reducing the amount of material used and by
deploying sustainable materials. In order to come up with the
right answers, we turned to Mert Kumru from Kumru Kimya,
the local representative of FKuR. We then received sample
materials for pilot trials and extensive application-related
assistance during the sampling process.”
The result of this cooperation was that Bio-Flex S 7711
proved to be the best-suited material for the production of
the thermoformed lids. Kumru: “Bio-Flex S 7711 combines
the high elasticity that is required for easy pressing of the lid
onto the beaker with the necessary stiffness and rigidity for a
firm and reliable fit despite the low wall thickness. It naturally
also has the required heat resistance and heat deflection
temperature. However, in the end, the real solution to the task
only came about through the combination of these beneficial
material properties with some process modifications that
affected both the extrusion line for the film manufacture and
the thermoforming station.” As Göncay further reported,
production of the lids has been running without a single
customer complaint since it was switched to Bio-Flex.
The right material for every task
Thermoforming is a highly economical process for the
million-fold manufacture of products such as the previously
mentioned beaker lids as well as blister packs and trays. In
all cases, the first step is to heat up a two-dimensional plastic
film or sheet and then, under a vacuum or with compressed
air, press it against the contours of a mould. This results in
the three-dimensional mouldings, predominantly for the
packaging segment, but also for the toy, consumer goods
and automotive industries, as well as many other segments.
Basically, all thermoplastics are suitable for
thermoforming, which means that an appropriate material –
from commodities to high-performance plastics – exists for
every project. FKuR meets the need for biobased types with
certain Bio-Flex PLA blends, with a partially biobased PET
and also with a biobased HDPE.
Flexible, biobased and biodegradable
Bio-Flex products are blends from FKuR’s own
development centre. They are based on PLA (polylactic acid)
and thus consist entirely or partially of natural raw materials.
They are also entirely biodegradable (according to EN 13432).
Through the choice of related additional polymers, all grades
are significantly more flexible than the rather brittle pure
PLA. In addition to the Bio-Flex S 7711 used at Göncay,
Bio-Flex F 6611, F 6711 and F 7510 as well as S 5630 WH
are specifically suitable for thermoforming. Furthermore,
according to EN 10/2011, they are also all suitable for use as
packaging materials for food contact applications.
Bio-Flex S 7711 combines high stiffness and strength
as a prerequisite for particularly thin-walled yet stable
thermoformed parts. It has the highest elongation at break
of this product family, allowing high plasticity and forming
characteristics combined with good resilience properties.
Bio-Flex F 6611 is a certified GMO-free type. It is noted
for its pleasant tactile properties and pearlescent gloss.
Furthermore, it satisfies the criteria of standard EN 13432
and is thus classified as a certified compostable material.
Typical applications include food trays and coffee capsules.
Furthermore, Bio-Flex F 6711, which has similar properties,
is also suitable for applications with acidic foodstuffs such
as fruit.
Bio-Flex F 7510 has a lower density than the F 6611 and
F 6711 grades. Accordingly, its stiffness and strength are
closer to those of pure PLA Typical applications for this grade
include cold drink lids.
12 bioplastics MAGAZINE [02/19] Vol. 14