Emulsification processes – Techniques and equipment

In many industries (food, pharmaceuticals, cosmetics, but also chemicals), many of the products manufactured – whether intermediates or finished products – are in the form of emulsions. Bringing immiscible phases into contact to obtain a stable pseudo-homogenous product requires a certain amount of technological knowledge and know-how. Scaling up to large-scale production, based on the results of the development phase, often proves difficult: indeed, the phenomena involved in emulsion formation are numerous and complex, and linked to the type of technology used, so that for a given formulation and operating conditions, there is no single solution for obtaining a stable emulsion.

This article, which follows on from the one on emulsion formation mechanisms published in the same series [J 2 152] , aims to guide the user's choice by describing, explaining and comparing the main industrial processes for preparing emulsions: classic mechanical agitation techniques (propellers, turbines, rotors-stators), coaxial mixers, static mixers, colloidal mills, high-pressure techniques, ultrasound, membrane techniques, microfluidics, phase inversion... In each case, for comparative purposes, the technology, operating parameters, properties of the emulsions generated and fields of use are specified. The aim here is to provide the user with the essential information needed to produce emulsions, in order to help in the decision-making process.

Readers can also consult the articles [J 2 150] and [J 2 158] as well as the reference .