Issue 02/2017

Thermoforming / Rigid Packaging
A sticky
situation
Creating hot filled candy molds
from bioplastics
DSC results for thermoformed tray
Making trays for PLA or PHA based candy and chocolate
packaging has been possible for a number of
years, but creating a bioplastic thin-gauge thermoformed
tray that can also act as a mold for hot, sticky caramel
at 130°C is a new breakthrough in biopolymer science.
Solegear Bioplastic Technologies Inc. (Vancouver, British
Columbia, Canada) has developed a new thermoforming
biopolymer that can do just that, allowing chocolatiers and
confectioners to move away from conventional heat-resistant
PP packaging and adopt bioplastic packaging across
their full product range. Solegear’s latest biopolymer contains
80% biobased content and is eligible to be certified
compostable. Testing has shown that packaging trays made
from Solegear’s latest material will consistently retain dimensional
stability up to 130°C, even when being filled with
hot, sticky caramels or chocolates with high fat and sugar
contents – ingredients that usually spell disaster for first
generation bioplastics.
The thermoformed tray was manufactured using conventional
extrusion and thermoforming methods. In addition to the
requirement to retain a high percentage of biobased content
so that the resulting trays could be certified compostable,
the main challenge for development of this biopolymer was
to engineer a formulation that would produce packaging that
could withstand the considerable chemical and mechanical
stresses introduced when hot caramel was poured into the
tray, including heat resistance and dimensional stability up to
130°C. Solegear’s Product Development team, deployed its
expertise in manipulating high-performance biopolymers and
non-hazardous, biobased additives to successfully create this
new innovative formulation. The manufacturing process was
also optimized to achieve a sufficient level of crystallinity of over
45% (see DSC plot) and high impact resistance of more than
75 kg·cm (Gardner drop weight impact resistance, ASTM D5420).
These significant performance requirements posed numerous
technical barriers during the course of production trials before
a suitable high quality packaging was manufactured. Using its
know-how and a design approach focused on the concurrent
testing of multiple variables and criteria, Solegear succeeded in
achieving the desired results in just under one year.
These bioplastic trays not only act as molds for hot and sticky
candies and chocolates at 130°C, but can also form the final
packaging for the product, moving successfully from production,
to transport and to fridge and freezer storage without cracking and
without leaching any elements into the candies and chocolates.
Solegear’s material formulation and the final thermoformed
high heat resistant trays contain no “Chemicals of Concern” that
may potentially be harmful to human health and the environment.
This becomes especially important in the food industry where
safety and security have become a priority concern for consumers
and product manufacturers. Traceability of materials is proving
to be challenging for fossil fuel-based plastics, and can be
more precarious for recycled materials where the source and
composition are rarely well documented.
The first full-scale packaging made from Solegear’s new
material is expected to be on retail shelves in 2017. Solegear is
continuing further product development to meet the needs of
additional food safety and security opportunities.
And for those of us who are nuts about caramels and
chocolates, it can now be a bit more of a guilt-free experience
knowing we’re doing something better for the planet. MT
www.solegear.ca
bioplastics MAGAZINE [02/17] Vol. 12 13