JEC COMPOSITES MAGAZINE - Issue #98 - July/August 2015 - 41

feasible for mass production.
While finalizing this second production
step, Hyundai experts and the partner
companies also combined forces effectively to overcome another challenge when
the adhesion between the composite
insert and the overmoulding resin proved
too weak. They soon adapted the overmoulding resin to deliver the necessary
stability and strength.

Getting the right mixture
While working with different fibres and
composites, a number of variables were
difficult to calculate, e.g. when combining
unidirectional glass and carbon fibre
rovings within the insert. The materials do
not have the same coefficient of thermal
elongation so, when the final insert cools
down, the whole part can twist and deform. Therefore, it was crucial to place the
carbon fibre exactly in the right places and
get the mixture of all materials correct to
avoid any distortion at the end. Hyundai
developed two final versions of the new
insert with different combinations of glass
and carbon fibre rovings to showcase the
potential of the new technology.

Significant weight reduction
The main benefit of the newly developed
process and the resulting front bumper
beam structure, composed of both glass
and carbon fibres, is a 43% (3.6 kg)
weight reduction versus the conventional steel structure. Furthermore, the

additional costs compared to the steel
structure are minimal and, last but not
least, the new structure is fully recyclable:
the thermoplastic materials used for the
composite insert and the overmoulding
can be melted down and reused, which is
not possible with most other solutions on
the market.

Building the first prototype
In order to deliver a prototype, various
meetings of the Hyundai team and
project partners were held and countless
calculations made of how the injection
mould and the pultrusion die should be.
With such new materials and production
processes, there was no experience in
how dimensions might change when the
composite cooled down.
Despite this, the composite insert fitted
straight away when added to the injection
mould, so well that no tooling changes
were made after this prototype stage: a
pleasant surprise, but proof of the huge
effort and professionalism of the Hyundai
team and its highly committed partners. As
a result, the only follow-up work was some
process optimization of the overmoulding
parameters; the dimensions of the pultrusion insert were not modified further.

Mass production feasibility
Part of the mass production challenge was
not just creating the parts and production
process, but the tools to produce the
new structure. So Hyundai and Plastic

About HMETC

Omnium not only created CAD data for
About the Hyundai Motor
Europe Technical Centre
The Hyundai Motor Europe Technical
Centre in Rüsselsheim (Germany) is a
young, dynamic company with its roots
in South Korea. Established in 2003, the
organization has grown constantly since
then; its 250 employees are responsible
for developing and designing future generations of vehicles and technologies for
the whole European market and beyond.

the new front bumper crash beam, but
also simulations for this new structure.
Developing these alone took almost a year
because the final composite material - the
mixture of carbon and glass fibres, and the
resin - simply had not been seen in the
automotive industry before, so no simulation data was available. This meant setting
up extensive mechanical tests under
various conditions to create data, finally
delivering accurate simulation results
ready for mass production application.
But if this aspect had given the development team a temporary headache, it was
more than relieved by realization that the
new materials and processes could cut
short production time.

No compromise on design,
safety and performance

Fig. 5: HMETC award winners President Dr. KIM Moo-Sang, Dr. Richeton, Mr. Ringenbach, Dr. Prescher
(head of Engineering), Dr. Coulton

No98 July - August 2015 /

More information:
www.hmetc.com

Feature Automotive

The resulting front bumper crash beam,
based on the Hyundai i30 front structure,
could now be fitted to the car without any
adaptation to the car structure. Even the
foam elements behind the front bumper
fascia could be re-used with the new parts.
This production compatibility is matched
by the safety of the new part: the front
bumper crash beam fulfils the same specifications as the current steel structure and
passed all relevant crash tests, such as the
low-speed insurance test, the pedestrian
protection test and even the EuroNCAP
50 and 64 km/h crash tests. Furthermore,
the new construction also includes a
towing hook that is fully compliant with
all internal Hyundai load tests as well
(Figure 5). n

jec composites magazine 41

http://www.hmetc.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #98 - July/August 2015