Assembly simplified
Thermoplastic Grill Opening Reinforcement (GOR)
withstands e-coating process
The first thermoplastic grill opening reinforcement (GOR) to be produced by Ford has recently been unveiled and will make its debut on the redesigned 2003 Lincoln Navigator and Ford Expedition. The project was a partnership between Ford Motor Company and Venture Industries using DuPont Rynite PET Polyester Resin.
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| Front-end assembly showing GOR made with PET Polyester Resin (photo: DuPont) |
The one-piece GOR, which can withstand the heat of the
e-coating process, is said to offer significant weight savings compared to
a thermoset sheet moulding compound (SMC) component, whilst the DuPont material
offers good heat, strength and dimensional stability.
Assembly time reduced
The company claims that the use of the PET Polyester Resin has helped to simplify
the design process, making it less complex, whilst at the same time reducing
assembly time by eliminating the need for labour intensive drilling and trimming
stages which would be required by an SMC GOR. The end result, according to
the company, is a robust, e-coating capable, one-piece thermoplastic GOR that
is a solid foundation for headlights and other front-end components.
Staying focused
Nick Stanziola of Venture Industries commented: “The GOR is crucial for
the fit and alignment of key vehicle front end components. The strength and
resistance to warpage of the resin helps ensure that essential parts, such
as headlights stay properly focused and bumpers line up with the bonnet.”
The crystalline structure is said to deliver high resistance to heat sag which
in turn helps to reduce warpage. This ensures that the GOR returns to its
original shape after the material expands and contracts during e-coat baking.
A cool solution
Such stability is essential to protect long-term component fit, and it also
helps to improve durability by eliminating material degradation. E-coating
demands temperatures of 191C and technicians from DuPont worked closely with
Ford and Venture to help ensure that the GOR remained within tolerance despite
the very high temperatures. Part-production cycle time was also reduced by
the combined expertise of the three companies. A particular problem was the
cooling cycle, and a customised water cooling process was designed for the
mould which eventually saw the cooling time reduced from eight to two minutes.
The way ahead
The success of the GOR programme could open new avenues for high-heat resistant
thermoplastics particularly in demanding body and chassis applications. Ken
Hines of DuPont believes that they are only scratching the surface. “This
application demonstrates that there is still a great deal of unrealised potential
for high-performance thermoplastics in the automotive industry. We are ready
to use our experience to improve total part economics and function.”
www.dupont.com