JEC COMPOSITES MAGAZINE - Issue #137 - November/December 2020 - 36

FEATURE honeycomb
sustainability, the thermoplastic core/
thermoplastic skin sandwich material
combination is a more sensible option
than combining different materials
together.
Also, parts like those manufactured
by DPA can give new life to next-generation components, where the thermoplastic ingredients of the sandwich
can be directly re-processed, e.g. for
injection moulding of glass fibre/PP
composite parts. Furthermore, the
thermoplastic honeycomb allows for
one short production of sectional,
foldable parts like the Creta's, and for
shaping esthetical edge closures.
Unlike paper honeycomb that essentially gets squashed upon moulding, which
leads to reduced performance, the cell
walls of the thermoplastic core, when
heated for moulding, are just calibrated
without buckling as they follow the gap
set by the matching moulds.
So what is next?
Our technology has already been commercialised in the Hyundai trunk floor,
which we are delighted about, and we are
looking into other opportunities as well.
We have a number of advanced development projects for various parts.
Furthermore, we have also been working
with a combination of the PP honeycomb
core with natural fibre/PP composite
skins for those products where this makes
sense.
The role of a Tier 1 supplier is not just

Cross-section of the foldable Hyundai Creta trunk
floor with an integrated hinge

to receive the specs for a new part from
the OEM and design it strictly based
on these specifications. In fact, many
specifications are over-designed with
regards to the performance requirements. Very often, the original specs are
set based on the conventional material
solutions that have proven to work.
Consequently, it should be a Tier
supplier's job to stay creative and
open-minded, and where it makes
sense, to question the specs for a new
model, in order to develop a new part
within a dialog with the OEM. Of
course, a big part of this dialog is the
testing and qualification of a product
based on emerging technologies.
Looking to the future, the partnership
between EconCore and DPA will be
progressing fast. Both companies have
already caught the attention of the
OEMs. DPA is on their way to opening
up new applications very soon, as all the
ingredients of a successful technology
for the future are in their hands: cost,
weight and sustainability.
Sustainability for the future
For EconCore, the future lies in sustainability, which they see as becoming increasingly more important for the next
generation of automotive interiors.
Currently, it's about car interiors using
honeycomb core mainly based on polypropylene but the company is looking
at the next iteration. Among other thermoplastic honeycomb material options,
including polycarbonates and polyamides, they have optimised the technology for processing polyester materials,
particularly focusing on recycled PET.
Their R-PET honeycomb development
has been driven by eco-conscious
employees. Collecting the plastic waste
from the oceans and converting it into a
high-performance honeycomb product
is their take on the "let's save the world"
call. R-PET honeycomb core combined
with PET or R-PET composite skin
layers could also be a viable sandwich
solution within automotive interiors of
the next generation.
Like any savvy manufacturer, DPA and

jec composites magazine / N°137 November - December 2020

EconCore adhere to the act-global/
think local philosophy. When it comes
to the automotive industry, no matter
how global the projects are, each region
has its particularities. The pair believe
that making headliners out of thermoplastic honeycomb panels is very
interesting in Europe but may prove to
be more complicated in Brazil.
In Europe, all raw materials are available
and will not bear the weight of import
costs. Europe's volumes contribute a lot
too. The current production process for
automotive headliners is an extensive
chain that begins with the manufacture
of semi-rigid PU blocks. This is followed by curing of the PU, lamination
of the blocks and assembly of the sandwich until reaching the hot moulding
process. In some cases, additional coatings or surface layers may need to be
added separately, and waterjet cutting
may follow to trim edges.
However, with thermoplastic honeycomb technology, the decorative
surface layers are waiting in the mould
during the very short stage of preheating the honeycomb sandwich lay-up.
Once heated, the entire assembly, including the finishing layers, is pressed
and finished in a cold mould. Edge
trimming and inclusion of sections
with cut-outs (e.g. for the integration
of inserts or handles) is done directly
in the same moulding process.
Based on our experiences, the productivity with such a technology can be
twice as good as that of conventional
processes. Moreover, the open structure of the honeycomb cells would
directly bring an additional benefit
that is being searched for in many interior applications - enhanced acoustic
performance.
Obviously, there is a lot to explore, but
what is for certain is that EconCore
and DPA are just at the beginning of a
long and very exciting journey.
More information:
www.econcore.com

http://www.econcore.com

JEC COMPOSITES MAGAZINE - Issue #137 - November/December 2020

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