On the occasion of the Fakuma trade fair in Friedrichshafen, Germany, which is taking place from October 18-22 this year, BASF (Ludwigshafen, Germany) is introducing three new crash-optimized specialty polyamide 6 grades at hall B4, booth 4306.

Initially targeted for body applications intended to provide pedestrian protection, these high-strength plastics are also suitable for other crash-relevant components in the vehicle such as steering wheels, structural inserts, and seat components; essentially wherever fast absorption of high amounts of energy is required. Compared to their predecessor from the CR family, they offer further improved impact strength. Commercial quantities of all three grades are available immediately.

The first two grades are designated Ultramid B3ZG7 CR and Ultramid B3ZG3 CR are reinforced with 35 or 15 percent glass fiber, respectively. The third grade is Ultramid B3ZG10 CR, the first impact-modified polyamide 6 from BASF with a loading of 50 percent glass fiber.

For material development and testing purposes, BASF developed a bending and torsion test specimen specifically for the new crash-optimized grades. The test specimen, which can be used for tests at customers, is reminiscent of the Eiffel Tower in Paris and has 45° ribbing. While the classic CR material Ultramid B3WG6 CR can already be distorted by almost 150° in static torsion tests without breaking, the new grades withstand distortion by the enormous angle of up to 240° without being damaged. There is hardly any other material class on the market that can undergo such a load and remain intact.

The topology of the part on which these tests were performed was optimized in view of load-bearing by means of BASF's Ultrasim simulation tool. Using this test specimen, the company can perform single-point and three-point bending tests in addition to the torsion test. At the same time, the characterization of a particular material can be validated on this test specimen for optimization by Ultrasim. 

The three new grades of the Ultramid CR family are specialties in the line of compounded polyamide 6 formulations. They are said to be ideal for rapidly absorbing a great deal of energy in demanding situations. What in the meantime has become an almost classic application is the so-called LBS (lower bumper stiffener), a large Ultramid part that Opel uses as a stiffening element below the front bumper for pedestrian protection, and the requirements for which are becoming more demanding from model to model. "We assist customers who use these high-performance specialties to design their parts with our Ultrasim service pack," explains Andreas Wüst, CAE expert for engineering plastics at BASF.

The three products were developed as a modular system with custom-tailored properties and, depending on requirements, offer the customer a somewhat softer or stiffer version. "This makes it possible to play with geometry, stiffness and toughness, allowing parts to have a stiffer or softer spring action", continues Anka Bernnat from technical marketing. All in all, the three plastics offer an improvement in elasticity of up to 200 % and up to 50 % increased stiffness. Structural parts that must satisfy crash requirements such as those already required for pedestrian protection can reportedly be made 20-30% lighter when the full potential of these materials is exploited.

In addition to the new Ultramid CR grades, BASF is exhibiting the following at Fakuma: