Steel cord fabrics used to reinforce thermoplastic components to be produced by injection molding could signal a new class of automotive components.
There is a tendency in some areas of the auto industry’s safety focus to regard electronics as the salient way forward for new systems, but much can still be achieved in what, from a public relations point of view, might be regarded as the less exciting area of materials development.
BASF, Voestalpine Plastic Solutions, and Bekaert are working together to develop steel-cord-reinforced injection molded parts that the companies believe will make a significant contribution to safety. The project involves the use of injection molding to produce thermoplastic components reinforced with steel cord fabrics. Known as EASI (Energy, Absorption, Safety, and Integrity) technology, the companies believe it heralds an entirely new performance class.
“In contrast to known types of reinforcements like continuous fiber-reinforced laminates or other carbon or glass fabrics, the steel cord inserts ensure especially the high integrity of the molded part’s function in a crash situation,” said Dr. Andreas Radtke, high-performance lightweight design specialist at BASF’s European engineering plastics facility.
The steel cord application is designed to ensure that an injection molded part retains its structural integrity. So if EASI parts are damaged in a crash, they can still absorb energy and lead it further into the structure, explained Radtke.
He regards it as a “decisive” innovation compared to molded plastic parts with conventional reinforcement that normally fracture on failure: “So the material is for regions that are intended for absorption and harmonic distribution of crash energy.”
Radtke also believes that the resultant level of performance cannot be reached with other types of reinforcing technology.
Specific components to which the technology could be applied include vehicle front ends, bumper beam carriers, and various BIW (body-in-white) parts.
The three companies have specific roles in the development program, which are then integrated. BASF is continuing to develop its crash-optimized short- or long-fiber reinforced polyamide solutions in its Ultramid product line for use in combination with the steel cord inserts. Bekaert has expertise in the manufacture of steel cord fabrics, and Voestalpine Plastic Solutions looks after processing technology and part production in injection molding.
BASF’s Radtke states that injection molding of thermoplastics such as Ultramid facilitates the production of complex parts and is an established and highly automated process for high-volume production: “The three companies believe that combining polyamide injection molding and steel cord reinforcement provides optimal access specifically to parts that must retain their supporting function and structural integrity to further distribute crash forces.”
Ultramid has a wide component application capability, and Volkswagen has just started to use Ultramid A3WG6 HRX material for molded thermostat housings. It was developed for applications requiring high hydrolysis resistance together with high strength.
Compared to an aluminum housing, it brings cost and weight benefits and does not need to have a machined finish. Also, dimensional accuracy of sealing surfaces is more easily achieved, according to BASF.
Supports, holders, and valve seats can be integrated without difficulty into the molded component. High surface quality also counteracts coolant abrasion.