Paper 24: Plastics and Rubbers in Machine Design

Abstract

The principal materials used are briefly discussed. A general approach becomes possible through a description of their ‘mechanical spectrum’. Friction of polymers depends mainly on their viscoelastic response. Wear of plastics is also closely related to their ultimate properties, but that of conventional rubbers is complicated by the superposition of chemical changes. Polymers and compounded materials can corrode and abrade even hard metals. The designer of bearings has still to rely on qualitative information; recent work on materials for gears, however, has yielded useful design data.