TABLE OF CONTENTS Rubber is a unique material that is both elastic and viscous. Rubber parts can therefore function as shock and vibration isolators and/or as dampers. Although the term rubber is used rather loosely, it usually refers to the compounded and vulcanized material. In the raw state it is referred to as an elastomer. Vulcanization forms chemical bonds between adjacent elastomer chains and subsequently imparts dimensional stability, strength, and resilience. An unvulcanized rubber lacks structural integrity and will "flow" over a period of time.
Rubber has a low modulus of elasticity and is capable of sustaining a deformation of as much as 1000 percent. After such deformation, it quickly and forcibly retracts to its original dimensions. It is resilient and yet exhibits internal damping. Rubber can be processed into a variety of shapes and can be adhered to metal inserts or mounting plates. It can be compounded to have widely varying properties. The load-deflection curve can be altered by changing its shape. Rubber will not corrode and normally requires no lubrication.
This chapter provides a summary of rubber compounding and describes the static and dynamic properties of rubber which are of importance in shock and vibration isolation applications. It also discusses how these properties are influenced by environmental conditions.
Typical rubber compound formulations consist of 10 or more ingredients that are added to improve physical properties, affect vulcanization, prevent long-term deterioration, and improve processability. These ingredients are given in amounts based on a total...
