JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016 - 23

natural fibres

Automotive lightweighting
with natural fibre-reinforced solutions

By

What if you could reduce part weight by 5% or more, maintain
mechanical performance, and even use more sustainable materials
in the construction of your vehicles? A new natural fibre-reinforced
thermoplastic formulation now makes it possible.
Marc Mézailles
Global autoMotive industry ManaGer,
renaud Maurer
senior r&d enGineer
Polyone corPoration

Lightweighting priorities:
forward and at least 5%

W

eight reduction is one of the
pillars of automotive original
equipment manufacturers'
(OEMs) efforts to improve their vehicles'
fuel efficiency, as required by global regulations. Not only do lower-weight vehicles
use less fuel, but they also generate fewer
carbon dioxide (CO2) emissions. It is estimated that every kilogram of weight saved
in a car reduces its CO2 emissions by 75 to
100 mg per kilometer travelled.

To avoid both the penalty and any
potential negative impact on their top
and bottom line, automotive OEMs are
actively seeking materials that offer an
optimum performance-to-weight ratio for
each application.

Uphill battle for
most natural fibres
Genetic, growing, seasonality and weather
conditions all influence the performance
of agro-based natural fibres such as hemp,
flax, ramie, jute, kenaf, miscanthus, and
bamboo. In addition, the availability of
these fibres is not global, representing a
limitation for the automotive market.
Wood-derived fibres also are an option.
These typically have been by-products of
the wood industry and have been used
as fillers in several types of polymers for
wood plastics composite (WPC) applications such as fencing and decking. Their

No102 January - February 2016 / jec

Feature Automotive

The penalty for not reducing the average
CO2 emissions is significant. For carmakers marketing their vehicles in Europe,
failure to reach the incremental CO2 limits
imposed by the European Commission
(average emissions per vehicle for the
entire fleet at 130 g/km in 2015, and then
95 g/km in 2021 - equivalent to a fuel
efficiency standard of 4.1 litres/100 km)
would force OEMs to pay a significant
penalty of up to €95 per g CO2 over the
limit for each new car sold.

But where should lightweighting efforts be
focused? On most current passenger cars,
the weight of a vehicle is generally 60% at
the front and 40% at the rear of the car. This
balance, plus a low centre of gravity of the
car, is crucial for proper vehicle dynamics.
Therefore, the most critical areas of focus for
lightweighting are primarily located at the
front of the car - for example in under-thehood applications and front components
such as lighting systems. Instrument panel
carriers and other semi-structural parts also
are of interest as these weigh enough to justify closer examination for reduced weight.
The incumbent material for many of the
applications in the front section of a car
is injection-moulded short E-glass fibrereinforced polypropylene (PP-SGF), which
offers a relatively low density, along with
good mechanical properties, and is readily
available around the world. If not for the
new EU regulations, it is very likely that few
automotive engineers would be seeking
alternatives to the proven PP-SGF.
But these new regulations are forcing a
re-think about even the most established
incumbent materials. In general, though,
automotive OEMs have said that a new
material solution has to offer at least a
5% reduction in density, at comparable
performance, to be seriously considered as a
replacement.

Natural fibres: a viable option?
Perhaps a new reinforcing material should
be considered. Suppliers of thermoplastic
compounds have developed materials
reinforced with many different types of
alternative fibres, and especially natural
fibres. But the use of natural fibre-reinforced thermoplastics (NFR-TP) has
been very limited in applications requiring
superior mechanical performance, and
thus limited in scope on a vehicle.
A new NFR-TP solution has now
been developed that offers automobile
manufacturers and their suppliers the
opportunity to choose natural fibres
and still achieve high-level mechanical
performance.

composites magazine 23
Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016
