The material with built-in noise-damping

Laminated Visco-Lam is a material with built-in noise-damping qualities that could gain significant use in the manufacture of everything from automobiles to computers and white goods.

Customers are progressively demanding more in terms of comfort in cars, and quieter passenger compartments can translate into a competitive advantage. The received practice of mounting noisedamping components under body panels has negative environmental ramifications, especially when it comes to recycling of sheet metal. In addition, this approach adds weight to the end product.

However, there are effective solutions that are more environmentally friendly. The chief product of Trelleborg Rubore (within Trelleborg Automotive) is shims that are installed on brake assemblies.

But the company also produces laminates with intrinsic noise-damping qualities that can be used in the production of car parts. Visco-Lam, among other products, belongs to this product ategory.

Visco-Lam is being used today primarily in the manufacture of oil pans and other engine components. Testing is underway with regard to body-component applications.

Customers include a number of the major car manufacturers. The product consists of two layers of sheet metal that are laminated with an interlayer of visco-elastic acrylic-based polymer. Most metals can be used for the metallic layers and total thickness ranges between 0.6 and 2.5 millimeters. “The propagation of vibrations to the metallic layers generates micro-movements between them,” explains Bengt Nilsson, product development manager for Visco-Lam. “The interlayer damps these micromovements.

A significant advantage is that the polymer can be configured for differentapplications involving different temperature ranges. For an engine, the damping effect should peak at about 80 degrees Celsius. In a body panel, damping should be effective at from ten to 15 degrees Celsius.”
Visco-Lam’s exceptional weldability is another significant advantage of the product. Both GM and Chrysler have approved Visco-Lam for welding applications. The material is also highly moldable and can be processed using standard metal-processing equipment.

Bengt Nilsson emphasizes that the automotive industry is not the only industry in which Visco-Lam can have in impact. “We supply harddisk locking mechanisms in stainless steel and aluminium, but demand for quieter computers is on the rise. There is enormous potential here, considering the size of the global market. Many potential applications also exist for the white goods and electronics industries. In addition, we are supplying a specially developed ceiling material to the construction industry on a trial basis. This type of material is also used within the rail industry and I expect that utilization will only increase.” Bengt Nilsson hopes there will be a significant market breakthrough in 2007. Three major automobile manufacturers are testing the material and the future looks bright. “The trend in the automotive industry is towards diesel engines, reduced weight and higher injection pressures, which exacerbate vibrations in engines and engine blocks. We also see a rise in body panel applications.” The route to success for Trelleborg’s laminate products involves being at the head of developments in structural damping. “We need to work hard to show customers new areas of application and to get a few major projects going that can serve to break the ice,” says Bengt Nilsson.

Visco-Lam is a structural damping material
Visco-Lam is a sandwiched material with two outer layers of metal and a core of visco-elastic acrylic-based polymer. The properties of the material can be tailored by adapting the polymer. Total thickness is between 0.6 and 2.5 millimeters. Most metals, including finished metal products and alloys, can be used. Visco-Lam can be used for a number of noise-damping applications within the automotive industry and a number of other industries. Visco-Lam’s advantages include exceptional structural-damping properties, weldability, moldability and durability. The product group also includes Duru-Lam and Rub-Lam. ADM (Applied Damping Material) is a new solution with special applicability to cast components.