Plastics in Engineering Design: An Overall Analysis
September 25th, 1984
Invited paper to 7th Engineering Design Conference, Birmingham, England, 25th-27th September 1984.
S F Bush
Abstract
The paper sets out to examine the relevance of plastics to engineering through the application of particular design concepts. The objective is to provide an overall analytical view of the factors which determine the choice of the material and manufacturing technology combination. Design of a system or artefact is seen as the specification of elemenatary functions and components and their interconnections. The complexity of a system is then characterised as the sum of these. The cost and some major properties of different polymeric materials are related to a simple definition of their chemical complexity.
The application of particular materials is governed by their utility expressed as the sum of their effects on (a) a component and (b) the whole system. To determine this, the manufactured cost is expressed as simple functions of the raw material, process and artefact complexities, and the scale of production. The main advantage of polymeric materials is found through new decompositions of the overall design.