Recent trends in automotive design and aerodynamics increasingly lead to a “oneness” or unified image of the bumper with the body. This leads to requirements that the bumper meet the same high surface quality as the body, be capable of more complex geometry, while at the same time becoming larger.
Currently in Japan, the typical approach is to use PP or PUR as a base material. As for the painting operation, a primer is applied and then the bumper must be painted off-line separately from the body.
The purpose of this development effort was to
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1)
improve color matching,
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2)
improve distinctness of image,
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3)
improve impact performance,
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4)
simplify the process, while at the same time,
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5)
achieving a large cost reduction.
The focus of this program was to develop a PPE (polyphenylene ether) / PA (polyamide) bumper material, paint on-line with the body, and eliminate the primer system.
The first step of this program was to establish the on-line paintability of the PPE/PA bumper system. This was then employed on the current model. Next, the primerless system was established with the goal of achieving cost down in addition to the performance and quality benefits already realized. Lastly, the combined process was validated for the primerless, on-line painting system (no primer, bumper and body painted together).