Paper to the 3rd International Conference on Reactive Processing, Strasbourg, 4th-7th September, 1984.

S F Bush

Abstract

The paper presents an analysis which attempts to define the mixing performance available from various possible mechanical configurations applicable to reaction injection moulding. Both active systems, i.e. those with moving surfaces, and passive systems, i.e. where the mixing is induced solely by fixed surfaces, are considered. The motivation for the analysis is to give guidance on the minimum mixing requirements imposed by particular resins and the resultant degree of freedom available for optimization in machine and mould design.

The analysis is carried out by expressing the required mixing scale, suitably defined, as a function of the chemical rate constants and molecular diffusivities. The mixing produced by the various configurations is expressed as functions of the main geometrical parameters, reactant flow rates and viscosities. Some experimental observations from two widely different chemical systems, namely isocyanate-polyol and phenol-formaldehyde are included.