Roush Dynalam Laminated Metal – applications, processing, theory, polymers for damping and low noise and vibration

NOISE & VIBRATION CONTROL PRODUCTS

DYNALAM LAMINATED METALS

Dynalam is a sandwich composite, consisting of two layers of sheet metal alloy bonded together with one of Roush’s unique, high-damping polymer adhesives. The polymer core creates the bond and damping effect necessary to dissipate unwanted and excessive vibration energy. The specific Dynalam-polymer is selected based on the exact nature of the noise and vibration application.

Dynalam can be manufactured from the following types of sheet metal layers:

- Cold-rolled steel
- Hot-rolled steel
- Electro-galvanized steel
- Hot-dipped galvanized steel
- Galvanneal steel
- Stainless Steel
- Aluminum
- Titanium

Many other sheet metal materials, in a variety of grades, can also be processed as Dynalam.

Applications

Product noise and vibration is often generated by the vibrating surfaces of stamped metal components subject to resonant behavior. Dynalam can be used in these applications to improve the inherent damping performance of such parts, making them less susceptible to this excessive vibration condition.

Typical applications include:

- Automotive
- Computer/Electronics Equipment
- Home Appliance
- Industrial Equipment

How it Works

When Dynalam experiences vibration excitation, the inner damping polymer is subject to shear strain as the structure deforms under cyclic loading.

With the proper polymer selection and treatment design, the shearing of the polymer core allows for the transfer of vibration energy into heat energy lost in the material, thus significantly reducing the vibratory stresses of the part. The actual level of component damping will vary depending on the geometry of the component and how it is configured in the product. Other parameters that affect Dynalam performance are the type and thickness of the laminate layers, as well as the frequency and temperature range of the application and the modal parameters of the structure (i.e., wavelength of vibration).

Family of Polymers
To achieve optimum results from Dynalam, it is necessary to select the polymeric core material that best suits a specific application. Listed below are the dynamic material properties for the various Roush polymers available for Dynalam.

RA925 is an acrylic pressure sensitive adhesive offering excellent damping performance at room temperature, suitable for use in a wide variety of applications. RA925 is a very stable material resistant to a variety of environmental factors, including UV exposure, temperature cycling, and static creep/relaxation.

RA970 is an acrylic pressure sensitive adhesive designed to work in low temperature applications, such as Refrigerators/Freezer appliance components. RA970 can also withstand prolonged exposure to elevated temperatures typical of paint curing processes, making this material an excellent candidate for use in the appliance industry.

RA980 was designed specifically for the computer/electronics industry, where damping performance is required at slightly elevated temperature ranges. RA980 is processed with material cleanliness in mind, offering the low outgassing characteristics required for sensitive electronic products, such as hard disk drives.

RA990 is a stabilized acrylic co-polymer designed to work well in higher temperature environments, such as underhood automotive applications. RA990 is a rugged material with excellent chemical resistance and temperature survivability.