All-thermoplastic bumpers have been used in Ford passenger cars since mid-1980's. The all-plastic bumper is an injection-molded facebar bonded to an injection-molded backplate forming a box beam. It provides benefits such as light weight, cost effectiveness, and corrosion resistance compared with a metallic counterpart. The bumpers are made of a blend of polycarbonate (PC) and polybutylene terephthalate (PBT). The blend is a biphasic system with partial compatibility of the polymers; with additional impact modifiers it has a very high impact strength even at low temperature. Properties of thermoplastic bumpers made of polycarbonate (PC) and polybutylene terephthalate (PBT) blend were evaluated after several years of service in the field. In this study we measured th Izod impact strength, PC molecular weight, and melt flow rate of bumpers collected from various geographical areas in the U.S. Generally, the system had good impact resistance after more than five years of service in the field, retaining most of the original impact strength. There were small changes in PC average molecular-weights and melt flow rates. The results showed that changes depended on both exposure time and the weather conditions of the environment.
The long-term durability of thermoplastic bumpers
Die Langzeit-Haltbarkeit thermoplastischer Stoßdämpfer
SAE Technical Papers ; 1-4
1993
4 Seiten, 1 Bild, 2 Tabellen, 10 Quellen
Conference paper
English
The Long-Term Durability of Thermoplastic Bumpers
Automotive engineering | 1993
|The Long-Term Durability of Thermoplastic Bumpers
SAE Technical Papers | 1993
|