Mixing of Vulcanisable Rubbers and Thermoplastic Elastomers

This report describes the current state of the art in mixing from a practical viewpoint. Developments that have taken place in mixing equipment over the last eight or nine years have been significant, with almost all major machinery makers having made innovations of one type or another. Some developments have been as small as re-profiling rotors of relatively conventional design. Others have been the introduction of completely new rotor designs, both intermeshing and tangential. This report begins by offering historical background against which the latest developments are set. It considers both batch and continuous systems, containing details of key developments by equipment manufacturers such as Kobe Steel, Techint Pomini, Farrel and ThyssenKrupp Elastomertechnik, with the different concepts discussed in layman's terms. The report also summarises the range of mixing techniques applied in the industry. The quality of rubber mixing depends not only on the mixer itself, but also on control of the whole mixing process, from raw materials to the moment the compound leaves the mill room for further processing, and this review offers the relevant developments in ancillary equipment such as the drive, hopper arrangement, temperature measurement system and discharge system. Methods for monitoring mixing quality both off- and on-line are also covered, Recent academic research in rubber mixing is briefly considered, providing an indication of possible future practical advances in this field. This review of rubber mixing is supported by an indexed section containing several hundred key references and abstracts selected from the Polymer Library.