in automotive assembly introduced at K 2010 in Düsseldorf, Germany last month
reduce component weight and increase functionality.
Two of the
technologies are used in the new lightweight Audi A8, which also features an
aluminum space frame.
A display by
MaterialScience featured LED used in fiber optics for daytime running
lights in the front headlamps of the Audi A8.
components were developed in collaboration with Audi AG and Hella. The ten
plastic lenses used in the headlamp are made from Makrolon LED 2245, which
offers high transmission for long light paths, high thermal resistance and
excellent yellowing stability to LED light.
material meets the high optical requirements for exposed headlamp parts and is
within the narrow color tolerance range. It also enables enhanced design
freedom and a considerable weight reduction," says Martin Döbler, an
expert in optical polycarbonate applications at Bayer MaterialScience. LED
lenses are around 50 percent lighter than their glass counterparts.
polycarbonate headlamps are expected to be particularly attractive to
manufacturers of electric vehicles, who are leading the fight against vehicle
rectangular, slightly curved LED headlamp lenses for the Audi A8 are 4 cm long,
2 cm wide and 1 cm thick. They cannot be produced via standard injection
molding because of the complex shape and thick walls of the optical components.
multi-layer injection molding process offers sophisticated mold temperature
control to provide dimensional stability and fast cycle times for
high-precision LED lenses with walls of greatly varying thickness.
design of the LED lenses shows that, compared with glass, polycarbonates offer
much greater design freedom for precision optical parts," says Klaus
Reinartz, head of the global LED project for general lighting at Bayer
advantages of polycarbonate include its high heat resistance and high break and
shatter resistance, which protects the LED lamps against vandalism.
of polycarbonate in lighting fits into plans by resin producers to find new
markets to replace packaging applications that have been cut back because of
concerns about bisphenol A in the transparent, high-impact plastic.
exhibitors showed a new technology in which hybrid front end structures can be
made with specially reinforced, very rigid plastic sheets in place of aluminum.
At the heart
of the technology are sheets developed by Bond-Laminates
, of Brilon,
Germany, that consist of special fabrics embedded in a defined orientation in a
glass-reinforced polyamide 6 matrix. In different versions of the technology
the sheets can be made with different resins and different fibers: glass,
Kevlar or carbon. The original technology was developed by DuPont and acquired
A front end
for the Audi A8 made with the material was displayed by Lanxess, a German resin
producer that provided specially formulated polyamide 6 for the project.
sheet for the Audi project is preformed and then inserted into an injection
mold with three sheets of aluminum. The sheets are then overmolded with
reinforcements and ribbing with Durethan BKV 30EV. The original prototype
developed by Magna Decoma Exterior Systems GmbH was made solely of aluminum.
lightweight organic sheet is used to create a 1.0 mm thin U section on the
lower beam of the hybrid front end that will be used in the Audi A8. Weight
savings are estimated at 20 percent.
some time, we have been developing concepts designed to harness the potential
of lightweight organic sheets in the series production of structural bodywork
components," says Gottfried Sailer, head of the Front End Systems Development
Center at Magna Decoma in Altbach, Germany.
"Our accumulated findings and experience persuaded Audi AG to replace
the aluminum sheet in its lower beam with an organic sheet."
stringent demands in terms of strength and stiffness proved particularly
challenging. The new structural concept incorporates a double torsion ring that
increases the stiffness of the front end of the vehicle significantly. In the
event of a head-on collision, the resulting forces are distributed across three
load planes and four load paths, maximizing safety.
technology may be going through rapid change. In one version, thin organic
sheet precuts (0.5 to 2.0 mm wall thickness) may be heated for a brief period
in an infrared radiation field to prevent oxidative degradation of the
thermoplastic matrix. The sheet would then be pre-shaped by a robot head en
route from the preheating station to the mold and then shaped by the
insert-placing process in the mold.
demonstration at the Engel booth, flat sheets of four-layer, 40 percent
glass-reinforced polyamide are heated with infrared energy to 280C and then
robotically inserted into a 500-ton injection molding machine. There are nine
partners, including Bond-Laminates, in the Engel project. Engel is working on
the technology for a Mercedes application that was not disclosed.
technology, called "Organomelt", is particularly interested for design
engineers. It shows how structural parts can be made from plastic in one
automated production cell even though the parts have deep-draw sections.
sheet hybrid technology can be used in frame components for panoramic roofs.
Another promising field of application could be reinforcing functional modules
for doors and hatches with integrated mounts for locks and grips, guides for
electric windows and various fasteners. Kurt Knoll, an Engel project engineer,
says the technology may also be used to make components for white goods.
to hybrid assembles was demonstrated by IKV Aachen, a German research group.
The technology was demonstrated on a molding cell producing sports glasses, but
the process has significant potential for automotive applications that could
benefit from use of a structural housing that is made conductive by a metal
demonstration at K 2010, a low-viscosity metal alloy is shot into a K-Tec 200
S/2F injection molding machine from Ferromatik Milacron GmbH, Malterdingen,
technologies for multi-component injection molding IKV has developed a
three-station index plate mold. Sport glasses are produced in a compact
production cell with only one mold and one machine.
temperature of the cavity inserts in the individual stations of the index plate
mold is controlled with water via separate circuits. To enable processing of
the extremely fast solidifying low-melting metal alloy in the area of an electrically
conductive track, the mold is equipped with a variothermal temperature control system.
production of the glasses, the IKV team used polyamides CX 7323 (lens) and CX 9704
(frame) from Evonik Industries AG, Essen, Germany.
metal alloy has a melt point below 200C and has an electrical conductivity in
the range of 8 x 106 S/m. This makes it particularly suitable for the
production of conductive tracks with a high ampacity, the maximum amount of
current a track or cable can carry before sustaining deterioration.
In another K
2010 development, lighter polypropylene (PP) auto parts are possible with new
synthetic mineral fibers from Milliken Hyperform HPR grades that increase
stiffness, temperature resistance
"We envisage HPR-803 being used mainly in
automotive applications, but are not limiting our project scope," says Adam
Watson, who is in charge of marketing for the Hyperform HPR range. "It enables
the production of polypropylene compounds that have mechanical performance
similar to or better than mineral filled compounds, but at lower weight."
fibers have a high aspect ratio of around 40:1. "We expect PP compounds
containing HPR-803 to replace talc-filled types and possibly other non-PP-based
materials too," says Watson. "Tests have also demonstrated that HPR-803 works
very well in combination with talc, giving processors and end users the
opportunity to convert to the new technology in a step-by-step fashion."
One of the
most novel automotive technologies introduced at K 2010 is called "projectile
injection technology", in which a plastic "bullet" powered by a burst
of inert gas is shot through molten plastic.
German molder, developed the technology to improve uniformity of wall
thicknesses created in the gas injection process.
inner diameter is defined by the projectile," says Fabrizio Chini,
advanced projects manager, Röchling Automotive
. "The process
enables us to inject in the same process step additional features, such as lips
One of the
new applications is integrated bi-material tubular sealing used for a cowling
grille on the Ford C-Max, a seven-seat car built in Europe. The C-Max is being
introduced in the North American market next year.
function of the cowling grille is to carry in air for climate-control in the
car, drain water and to stop the hood from fluttering," says Chini. "Steel
hoods are getting thinner and thinner for pedestrian safety, and as a result
they are beginning to flutter."
TPE Plus PP
process starts by partially or completely filling a mold cavity with plastic.
The bullet-like projectile is then shot through the cavity forcing polymer melt
against the walls. In the Ford cowling grille, polypropylene is first injected
into the cavity. A second cavity opens for injection of thermoplastic
elastomer. The projectile is then fired. The result is a part with a
bulb-shaped hollow seal.
grille made for a new Ford model features an innovative injection process.
the same type of part would be made with an extruded EPDM (ethylene propylene
diene monomer) rubber seal attached to a hard plastic section. Chini says the
PIT process cuts cost by 10 percent compared to the traditional process, which
requires manual assembly of the parts. Expensive foamed EPDM rubber is also
eliminated. The TPE is recyclable while the vulcanized rubber is not.
designed with protruding ribs creates notches in the elastomeric material that
reduce permanent deformation and can precisely control the compression force.
Wall thicknesses in the notched areas are 1 mm compared to 2 mm in other
seal created by the projectile creates pressure between the hood and the
cowling grille to damp hood fluttering. Changing dimensions of the seal allows
tuning of the pressure. "The force can also be tuned without any tool
modification just by changing material hardness or the projectile shape,"
interesting innovation, Röchling engineers developed a chamber that recovers
the melted core pushed out of the mold cavity by the projectile. The melt is
stored in the chamber and pushed back into the cavity in the following
injection cycle. "This avoids regrinding the purged materials," says
the projectile, which is made of polyimide, is not re-used. Polyimide polymers
are expensive, but very strong and resistant to heat.