METALS: LIGHTWEIGHTING
Seeing the light
In a comprehensive joint study, Henkel
and RLE International have examined and
validated the potential of high-performance
structural foam for lightweighting in automotive
body and closure parts. The study has revealed
that bre reinforced polymer components with
structural foam ribbing and reinforcements
can save more than 40 kg of weight per car
compared to conventional all-metal designs.
Body components, especially closures,
have always been the focus of lightweighting in
automotive engineering, since they form some
of the biggest parts of vehicles. Even one tenth
of a millimetre in thickness can mean several
kilos in overall weight, with subsequent e ects
on fuel or electrical power consumption as
well as carbon emissions. In most modern cars,
however, the engineering limit on thickness and
steel grades are de nitely a challenge so further
thickness reductions can create problems in
meeting the required mechanical strength and
crash protection.
“In a radical new
Henkel and RLE International have demonstrated the sheer
lightweighting potential in hybrid automotive body parts.
approach, we investigated the possibilities of
overcoming these constraints by replacing
traditional all-metal designs with hybrid bre
and structural foam reinforced polymer
solutions,” says David Caro, head of global
engineering, OEM design, automotive &
transportation at Henkel. “The results of our
study have con rmed that we can achieve
signi cant further weight reductions without
compromising the safety in typical crash
scenarios by optimising the sti ness of bre
reinforced plastic frames or carriers with
selective foam ribbing and reinforcements, with
competitive costs.”
The hybrid parts feature a solid frame or
carrier moulded in higher percentage bre
reinforced polymers (FRP) and selective
reinforcements using Henkel’s Teroson EP
structural foam, a commercially available epoxybased
material that delivers high strength and
sti ness at extremely low weight. The foam is
injected into the carrier at prede ned sections,
expands in the e-coat oven and creates a sti
connection between the hybrid component and
adjacent parts in the body-in-white.
Non-cured, it is resistant to normal
automotive washing and phosphating solutions
as well as to electro-dip coating. Curing then
takes place within 15 minutes or less, depending
on the speci c foam grade.
The comprehensive project included all
major body and closure parts of an SUV vehicle,
from the bumpers, fenders, pillars and doors
to the rocker panel, side panels and
tailgate. “The nal designs
Autumn 2019 www.materialsforengineering.co.uk 31
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