CHEMICAL ENGINEERING TRANSACTIONS
VOL. 39, 2014
A publication of
The Italian Association
of Chemical Engineering
www.aidic.it/cet
Guest Editors: Petar Sabev Varbanov, Jiří Jaromír Klemeš, Peng Yen Liew, Jun Yow Yong
Copyright © 2014, AIDIC Servizi S.r.l.,
ISBN 978-88-95608-30-3; ISSN 2283-9216 DOI: 10.3303/CET1439281
Please cite this article as: Suigenbayeva A., Brener A., Sabyrkhanov D., Sakibayeva S., 2014, Modelling dispersive mixing
of the ingredients of rubber compounds, Chemical Engineering Transactions, 39, 1681-1686 DOI:10.3303/CET1439281
1681
Modelling Dispersive Mixing of the
Ingredients of Rubber Compounds
Alya Suigenbayeva*, Arnold Brener, Darkhan Sabyrkhanov, Saule Sakibayeva
State University of South Kazakhstan, Tauke Khan, 5, Shymkent, Kazakhstan
amb_52@mail.ru
The objectives of this work are to carry out the theoretical description of the mixing process accompanied
by dispersing the polymer blends and to submit the fractal model of the dispersive mixing process which
can be useful for engineering calculation of the apparatuses for mixing the ingredients of rubber blends.
Rubber mixing process is extremely complex in its mechanism. In fact, there are two basic processes
combined - mixing and dispersing with a simultaneous increase in the specific surface area of the interface
between the blend components. The paper offers for discussion the theory of dispersive mixing process
which is based on the model of generated Brownian diffusion over the fractal medium. The results of
mathematical modeling and natural experiments have been presented.
1. Introduction
The process of mixing the filler ingredients with rubber compounds is a critical stage in technology of
rubber production (Amash et al., 2001). The intensity of rubber mixing process largely determines the
basic quality indicators of finished rubber (Barkanui et al., 2011).
Rubber mixing process is extremely complex in its mechanism (ten Brinke et al., 2003). In fact, there are
two basic processes combined, namely: mixing and dispersing with a simultaneous increase in the specific
surface of the contact between the blend components (Rodgers, 2004). Physical mechanisms of rubber
mixing processes and rubber production can be described with the help of the regularities of rheology of
viscous flow and deformation of polymers (ter Brinke et al., 2003). The mixing process occurs in conditions
of non-stationary field of deformation speed and temperature (Nakajima, 1994). It is accompanied by
transformations in the internal structure of the polymers and by changes in their physical and chemical
properties (Nazir and ratnan, 1989).
Two groups of problems linked to the investigation of the mixing process can be assigned (Blackley,
1983). The first problem is in studying the characteristics of the components to be mixed, i.e., in
determining the quality of the mixture, and the second problem is the description of the process of
changing the quality over time (Chukwu, 2011).
There are a lot of approaches to the classification of mechanisms of mixing of the disperse materials
(Cazerta et al., 2013). For example, the mixing processes can be classified by temporary phases of the
mixing device. In the early stages of the process the convective mixing dominates, what manifests in the
intensive displacement of whole groups and layers of components into the working volume (White and
Kim, 2008).
The diffusion transfer, however, at this stage is not intensive, as the specific interface between the
components is small. Segregation (separation) of the mixture at this time is also negligible due to the
immobility of the particles inside the movable layers. The mixing process mainly determines the character
of the movement of components in a mixer (Erman et al., 2013).
The rates of convective mixing and diffusion transfer become comparable only after the initial distribution
of the components into the working volume (Youwai and Bergado, 2003). Diffusive mixing becomes
prevalent when the interfacial surface between the phases reaches a certain value. In the case of mixtures
consisting of dispersed solids with different physical-mechanical properties, as it occurs generally in
practice, movement trends of different components are different (Sui et al., 2007). The rates of