Give thermosets an even break

By Alfred A. Bulitz, managing director, Gira Giersiepen GmbH, Plastics Div., Radevormwald, Germany

Thermosets represent the older generation of plastics on the market today. Despite many positive properties, they are often relegated to a humble position among the material families.

Unrightfully so! In many modern applications, thermosets prove the better alternative. For example, glass-reinforced thermosets can provide the automotive sector with outstanding qualities at competitive cost. They offer excellent thermo-mechanical properties such as dimensional stability as well as outstanding heat and chemical resistance.

The blame for neglecting thermosets can be laid, to a great extent, at the feet of continual developments and improvements made in thermoplastics. These advances may have displaced thermosets in many applications. But they also have driven thermosets out of the minds of many designers and engineers. In universities and technical institutes, thermosets often are mentioned only as crusty, antiquated polymer products, unworthy of today''s high-tech applications.

In many design departments, engineers don''t even examine the possibilities of applying thermosets simply because of a lack of knowledge about the multiplicity of uses this "old" workhorse can offer. Especially in the automotive sector, thermosets are far too often not even given a fleeting consideration.

But, I am happy to say, changes are occurring. Some processors, including my own operation, have been instrumental in starting what one could call a renaissance in the use of these classic products. Specialty high-temperature-resistant thermosets with improved processability and shorter cycle times are today finding uses in value-added applications. As a result, processors find they can mold flawless, dimensionally stable, highly reproducible parts.

With today''s molding technology, thermosets are processed into highly complex thin-wall parts with tight tolerances. In such applications, thermosets have a distinct advantage over competitive materials such as aluminum, which requires post-production finishing and treatment. Thanks to the latest injection molding technology, many functions can be integrated into a single, high-precision part.

Gira Giersiepen GmbH, as a leading European processor of automatic electro-technical systems for building and construction, has targeted the benefits of thermosets. With 50 years processing experience with its own product line, it has built up a valuable pool of compression and injection molding knowledge of these materials for highly technical and aesthetically appealing goods.

Now, Gira Giersiepen wants to share this processing know-how gained over decades with other companies that want to benefit from the possibilities thermosets offer. In the recently established plastics technology division, we are developing, designing, and processing thermoset parts, systems products, and tools for a wide range of sectors. I''m convinced that modern thermosets offer a great potential. That''s why we chose to apply thermosets, with their outstanding basic properties, to high-tech products and systems. More than ever, thermosets offer an interesting alternative to metals, especially in vehicle design.

I see extremely good chances for thermosets to gain a larger share in this market. Light, load-bearing plastics are penetrating the automotive sector and providing an interesting, workable alternative to metals. Instead of simple parts, vehicle designers are turning to complete, complex integrated plastics systems. As material requirements become more stringent, I see our direct competitors, thermoplastics, reaching their physical limits.

Take glass-reinforced phenolic molding compounds, for example. These can be used for a variety of under-the-hood applications in radiator or brake systems, fuel pipes, and the drive train. Such solutions meet rigorous requirements for heat and chemical resistance, dimensional stability, and resistance to dynamic fatigue when temperature changes are extreme. I also see thermosets as the appropriate materials for motor oil lines and pumps, in exhaust systems, vacuum pumps, compressable parts, and flanges.