Quiet Steel Moves Into Body Applications
Quiet Steel from MSC Laminates & Composites Inc. (Material Sciences Corporation) continues to make its mark as the design material of choice for the cost-effective reduction of noise and vibration in today's light vehicle assemblies. Ford Motor Company's recent release of the 2001 Explorer Sport Trac with a Quiet Steel dash panel bolsters the excitement around utilizing Quiet Steel for body-in-white applications.
"We have had tremendous successes with our Quiet Steel materials, particularly in the area of powertrain applications over the last 15 years. The recent adoption by Ford of Quiet Steel for a significant body-in-white part will set the stage for additional implementation of Quiet Steel into other light vehicle body-in-white applications, not only at Ford but at GM and Daimler Chrysler as well. We are excited about the enthusiasm application engineers are showing for the concept of ‘designing in the quiet' in their body-in-white designs," states L&C VP Jim Carlen.
Quiet Steel from MSC L&C comprises two metal skins surrounding a 25 micron-weldable viscoelastic polymer core. Manufactured in continuous coil, these products can be delivered 72" wide at 50,000 lbs. to automotive stamping plants and utilized in standard transfer press operations. Metal skin type and thickness can be optimized at the design engineer's discretion to ensure structural integrity of the part, while the viscoelastic polymer can be tailored to meet the specific noise reduction needs of the application.
In the 2001 Ford Explorer Sport Trac, key engineering targets were to provide a high level of riding comfort, noise reduction, weight and cost savings in a rugged SUV. To meet the stated engineering targets, Quiet Steel, a weldable laminate, was selected for the instrument dash panel. In this Ford Explorer Sport Trac application, Quiet Steel not only satisfied the structural needs of the vehicle, but also provided significant NVH benefits, allowing engineers to remove additional add-on materials, ultimately simplifying the entire vehicle assembly process. In addition, Quiet Steel is 100% recyclable. This is very important to the automotive industry today, as it seeks to increase the use of more "green" materials. Many NVH materials used today are not environmentally friendly and must be separated during the recycling process.
Addressing these issues, L&C engineers worked with Ford to develop a dash system which accomplished three distinct goals, all deemed beneficial in overall vehicle development cost.
First, the primary goal was noise reduction. To better quantify the performance of Quiet Steel and other interior improvements, Ford engineers utilized the "Aachen Head", named for the university in Germany where it was developed. This head, complete with microphoned ears, replicates how a human picks up sound. During testing, the ears "hear" interior noise and record it on a digital tape stored inside the head for later replay and assessment in the test lab.
The sound tests were conducted in all road conditions, from acceleration to cruising speeds. Ford engineers went to work to reduce the unwanted noise, plotting the sounds and evaluating performance.
The Explorer Sport Trac, utilizing Quiet Steel as a major building block to reduce structure-borne noise in the vehicle, scored 95% in speech intelligibility testing at a constant steady driving speed of 2500 rpm or about 35 mph. This means, while driving at 35 mph, occupants heard 95% of the audible speech. A 100% rating can only be achieved in a fully insulated sound room.
Similar tests were performed on the 2001 Explorer Sport (SUV) with a Quiet Steel dash and the same results were achieved.
The second goal was weight reduction on the overall dash panel system. In the conventional build-up, four components made up the system. A dash insulator, steel dash doubler, mastic deadener, steel dash panel and engine side fiberglass dash insulator required assembly and weighed 27 lbs. total.
In the proposed system, a Quiet Steel laminated dash panel and fiberglass dash insulator alone were required. Assembly time was reduced, space savings were realized and the total system weighed only 20 lbs.
The third goal achieved was overall cost savings.
In this application, direct material savings were realized. Owing to the reduction in manufacturing and assembly, L&C product and technical development personnel have projected even higher overall cost savings, plus improved performance, as well as the weight reduction which results in better fuel efficiencies.
According to Jim Carlen, numerous other body applications are now under development and will be introduced in new vehicles shortly. These applications include other dash panels, floor pans, roof panels, trunk floors and others. "With the recent commissioning of a 72" wide line at our Walbridge, Ohio plant, " states Carlen, "we're positioned to supply more body applications as well as increase our overall capacity for service to auto OE customers."
L&C VP Jim Carlen concluded, "The upsides of laminated steels are many and we're exploring all the possibilities, at this point. While just two years ago, we were in the talking phase with body engineers, we are today rolling out the applications. The combination of performance and cost benefits on Quiet Steel are, you might say, making a ‘material difference' in body applications."
Quiet Steel is available in up to 72" wide coils, as well as pre-slit coil, sheets and blanks for processing and fabrication.
Powertrain applications already on-the-road include valve covers, oil pans, heat shields and transmission pan covers, among others, such as disk brake dampers.
MSC Laminates and Composites operates a comprehensive Tech Center, which boasts full FEA, weatherometer and brake dynamometer capabilities for product work-up, modal analysis and material application evaluation.
The company's product development, sales and marketing team dedicated to auto OE and aftermarket is located in Southfield, Michigan.
For more information, please contact: MSC LAMINATES AND COMPOSITES INC