Meaning
Dissipation of vibrational energy through the internal friction of a polymeric material represents a standard technique for reducing noise and mechanical stress in molded assemblies. Utilizing elastomeric dampening in the design of multi-component parts allows manufacturers to isolate sensitive electronic enclosures or mechanical hinges from high-frequency shocks. This process relies on the viscoelastic properties of thermoplastic elastomers, which absorb kinetic energy and convert it into heat.
The material selection is made during the sourcing stage, where the loss factor and hardness are specified.
Vibration Control
Attenuation of structure-borne noise is achieved by positioning a soft elastomer between two rigid plastic or metal components. Through elastomeric dampening, the amplitude of vibrations is decreased before they can propagate to other sections of the assembly. This mechanical isolation is especially useful in automotive interiors and medical devices where quiet operation is required.
The thickness of the elastomer must be calculated to match the frequency of the disturbance.
Moulding Process
Integration of the soft component into the rigid substrate is typically completed using overmolding or two-shot injection molding. This manufacturing step determines the bond strength between the two materials, which is crucial for maintaining elastomeric dampening over the lifespan of the product. If the melt temperatures are incorrect, poor adhesion will cause the layers to delaminate under stress, leading to a complete failure of the vibration reduction system.
Performance Limit
Temperature fluctuations can alter the damping efficiency of the thermoplastic elastomer. Excessive heat softens the polymer chains, while extreme cold increases their rigidity, both of which degrade elastomeric dampening performance.
