When the Society of Plastics Engineers gives a Hall of Fame award for global acceptance of thermoplastic olefins for use on bumper fascia, it prompts me to respond.
Forty-six years ago I got an assignment to develop a replacement for the chrome bumper. I was employed at the Inland Division of General Motors, and the assignment was prompted by Warren Fitzgerald at the design staff, who wanted to continue the body lines of the vehicle onto a body-color bumper. No one ever suggested it was to be a cheap substitute. In fact, our CEO Ed Cole was the conscience for the project. As we approached success with the first application, on the 1968 Pontiac GTO with the Endura bumper, he personally had demonstrations scheduled for him in front of the design staff building. The Endura bumper was a virtual battering ram made of 40-pound-per-cubic-foot cast microcellular urethane, molded into a painted mold — for adhesion and a non-porous surface — onto a steel beam. He wasn't comfortable with putting it directly against the fender, though.
By 1973 the Endura bumper had evolved to an unsupported fascia, injection molded with thermoplastic urethane, introduced on the front of the 1973 Pontiac Grand Am and the 1973 Corvette. John DeLorean championed the project and Ed Cole was still exerting his influence. TPU has about three times the tensile strength and elongation as TPO. You could tow the vehicle pulling the fascia.
I have experienced pulling a TPO fascia from the back of a VW Jetta after backing my bumper hitch under the rear fascia. I don't think I have to belabor here the fact that bumper fascia are a joke with the public. I heard Clark Howard on his radio talk show refer to “fake bumpers.” The material we mold them out of has given them that reputation. The material has poor physical characteristics for the application — not particularly resilient, and the paint doesn't stick all that well on impact. We could never have gotten on a production vehicle with TPO. We had rejected better candidates and we looked at many, including EPDM rubber.
GM started losing its soul and its conscience for the customer in 1974 with the departure of Cole and DeLorean, and engineering's strong influence on the proactive evolution of the product. GM went from being proactive to reactive. The bumper project moved from Inland Division to Guide Lamp Division in 1974, and TPU was replaced with reaction injection urethane (one of the rejects). The compromise was started.
I'm afraid our industry has met the same fate as my bumper project. After all, our customers know “cheap plastic” — and a car company that is not the leader anymore — when they see it.