Academic literature on the topic 'Banbury mixer'

Abstract The distributive mixing characteristics of three internal mixers are examined: a Parrel BR Banbury (1.6 L), a Farrel F40 Banbury (40 L), and a Francis Shaw K1 Intermix (5.5 L). The former two machines have two-wing tangential rotors while the latter has intermeshing rotors. The distribution of sulfur in mixed batches of an EPDM compound and an SBR compound, as measured by curemeter tests on samples taken from random locations within each batch, is used to quantify distributive mixing. The dominant influence on sulfur distribution is total rotor revolutions and a maximum of 20 rotor revolutions is adequate for distribution of powder sulfur in each mixer. The effects on distribution of rotor speed, rubber compound rheology, and mixer size are insignificant.

Abstract A number of experimental studies have improved understanding of rubber flow in internal mixers. Freakley and Van Idris obtained flow patterns and areas of fill by photographing through a transparent end plate of a small internal mixer during rubber mixing. White and Min obtained additional information by videotaping through transparent end plates and body sides of a small internal mixer during rubber mixing. Sata and associates used observations of flow of polymer solutions in a transparent Banbury mixer to help optimize rotor design. Freakley and Van Idris, Freakley and Patel, and Toki and associates used responses from pressure sensors installed in the body of Banbury mixers to infer the fill and flow directions during rubber mixing. Here we report findings based on direct examination of the contents of a Brabender mixer removed after curing in place so as to limit further flow after stopping mixing. The technique used is basically the same as that employed in the past to determine flow patterns in screw extruders. Melotto has also used this method without curing in work to optimize mixer geometry.

Abstract The early rubber industry was largely based on mixing with two-roll mills. The coming of the pneumatic-tire industry associated with the rise in popularity of the automobile brought increasing production and large quantities of fine particles and poisonous vulcanization accelerators. This made necessary the introduction of internal mixers into the rubber industry by the second decade of the 20th century. This paper treats the development of internal mixer technology from its origins in the 19th century to the late 1980's, largely through critically following the patent literature. There seems to be no other critical review of the development of internal mixer technology, and this manuscript is unique. Briefly, the technology development we will describe is as follows: There were two conflicting design approaches, one based upon a single-rotor masticator devised by Thomas Hancock in the early 19th century and a second based upon two nonintermeshing counterrotating rotors which were championed by Paul Pfleiderer later in that century and manufactured by his firm, Werner and Pfleiderer. As late as the mid 1920's, machines based on both the single rotor and two nonintermeshing rotor designs competed with each other for the internal-mixer market. The insight, perseverance, intensity, and dedication of Fernley H. Banbury and the Birmingham Iron Foundry (later merged into Farrel-Birmingham) brought about the design which proved to be the paradigm of the industry. Innovation, however, continued in internal-mixer technology. The most striking new development of the post-Banbury period was the invention and application of intermeshing counter-rotating rotor mixers in 1934 by Rupert Cooke of Francis Shaw and Company. Werner and Pfleiderer developed and worked with many internal-mixer designs and in time began to manufacture both nonintermeshing- and intermeshing-rotor machines. In the 1950's and 1960's, Kobe Steel and Pomini began to manufacture internal mixers as Farrel-Birmingham licensees. This period also saw developments of nonintermeshing-rotor internal mixers. The basic Banbury design maintained its position and its manufacturer, Farrel-Birmingham (later Farrel), devised improvements of it. Innovations in the design were also made from the late 1970's by Kobe Steel, now operating independently. Pomini also began operating independently, manufacturing not only nonintermeshing machines but a unique intermeshing-rotor machine with variable clearance between the rotors. In recent years, we have seen the development of increasingly improved control systems for the internal mixer.

Polymer/clay nanocomposites have been explored extensively over the last two decades. Many studies report nanocomposite properties. However, studies on the effect of processing conditions are still limited. This study evaluates the effect of rotor type, rotor rotation (rpm) and mixing time on mechanical properties of polyethylene organoclay composites. Samples were fabricated using two different rotors; roller and Banbury, in an internal batch mixer at various mixing conditions. The analysis shows that the Banbury rotor improved mechanical properties more than the roller rotor. Shear and diffusion mechanism, as well as material degradation, were the controlling factors at different processing conditions.

Abstract This presentation is concerned with the mixing performance of the new ST™ rotor design in Banbury® mixers operating at even speed. Rotor orientation was used to optimize machine performance in mixing a standard one-step rubber formulation, in terms of productivity, energy consumption, and product quality. Experimental data is presented on mixer discharge temperature, Mooney viscosity, and maximum rheometer torque, and their standard deviation. The effect of rotor orientation on these parameters is discussed, and optimal rotor configurations are identified.

Grâce à leurs propriétés mécaniques et électroniques élevées, les NanoTubes de Carbone (NTC) semblent être les nanocharges idéales pour conférer des propriétés optimum à des matériaux composites, en particulier ceux qui sont élaborés à partir de matrices élastomères. Cependant, pour obtenir une amélioration significative des propriétés une bonne dispersion dans la matrice est nécessaire. La dispersion des NTC dans une matrice élastomère de type EPM est explorée ici en employant un copolymère statistique, le poly(éthylène-stat-acétate de vinyle) (EVA), comme agent dispersant. Les outils classiques de mélange des élastomères, mélangeur interne et mélangeur à cylindres, qui sont des techniques de mélange douces, ont été utilisés dans le cadre de cette étude. Nous avons montré qu’à faible taux de NTC dans la matrice leur dispersion était contrôlée par deux paramètres clés (i) la viscosité de la matrice EPM et (ii) la concentration en EVA. L’augmentation des concentrations de NTC a permis de mettre en évidence que les propriétés rhéologiques et électriques des nanocomposites variaient brusquement à partir de concentrations critiques (seuil de percolation) assez faibles permettant de justifier l’utilisation du système EPM-EVA sélectionné. Nous avons alors préparé un mélange maître EPM-EVA chargé à 20% en NTC possédant de très bonnes propriétés de conductivité. Des mélanges à base d’EPDM chargés par des nanotubes de carbone, du noir de carbone ou le mélange des deux ont également été analysés. Nous avons démontré que la dilution d’un mélange maître permet d’obtenir un élastomère chargé en NTC avec une viscosité Mooney constante et avec un impact fort sur la cinétique de vulcanisation de l’élastomère (accélération de la réaction). Un effet de synergie entre noir de carbone et NTC a été mis en évidence au niveau des propriétés mécaniques mais pas pour les propriétés électriques
The outstanding properties of Carbon NanoTubes (CNTs) make them ideal candidates for use in nanocomposites, and particularly in those based on rubber matrix. However, to obtain an improvement of the properties, a good degree of dispersion of the CNT in the matrix is crucial. The CNT dispersion in an EPM rubber is investigated here by using a statistical copolymer, the ethylene-stat-vinyl acetate (EVA), as dispersing agent. In this study, we work with the classic methods used for rubber mixing, like an internal mixer and an open two roll mill, which are soft mixing techniques. At low CNT rate in the matrix, the dispersion is controlled by two parameters such as the EPM matrix viscosity and the EVA concentration. The rheological and electrical properties varied abruptly when the CNT concentration is increased in the matrix. The low values obtained for this percolation threshold justify the use of EPM-EVA system. We have prepared an EPM-EVA master batch loaded with 20% of CNT and possessing very good conductive properties. We studied EPDM compound filled with carbon nanotubes, carbon black or the blend of both. We have demonstrated that the dilution of the master batch allows us to obtain a rubber filled with a constant Mooney viscosity but with an important impact on the vulcanization kinetics of elastomers. The synergistic effect between carbon black and carbon nanotubes has been shown on the mechanicals properties but not on the electrical ones

Polymer researchers have had a long-standing interest in understanding the evolution of blend morphology when two (or more) incompatible homopolymers or copolymers are melt blended in mixing equipment. In industry, melt blending is conducted using either an internal (batch) mixer (e.g., a Banbury mixer or a Brabender mixer) or a continuous mixer (e.g., a twin-screw extruder or a Buss kneader). There are many factors that control the evolution of blend morphology during compounding, the five primary ones being (1) blend composition, (2) rheological properties (e.g., viscosity ratio) of the constituent components, (3) mixing temperature, which in turn affects the rheological properties of the constituent components, (4) the duration of mixing in a batch mixer or residence time in a continuous mixer, and (5) rotor speed in a batch mixer or screw speed in a continuous mixer (i.e., local shear rate or shear stress). When two immiscible polymers are compounded in mixing equipment, two types of blend morphology are often observed: dispersed morphology and co-continuous morphology. Numerous investigators have reported on blend morphology of immiscible polymers, and there are too many papers to cite them all here. Some investigators (Han 1976, 1981; Han and Kim 1975; Han and Yu 1972; Nelson et al. 1977; van Oene 1978) examined blend morphology to explain the seemingly very complicated rheological behavior of two-phase polymer blends, and others (Favis and Therrien 1991; He et al. 1997; Ho et al. 1990; Miles and Zurek 1988; Scott and Macosko 1995; Shih 1995; Sundararaj et al. 1992, 1996) investigated blend morphology as affected by processing conditions. Today, it is fairly well understood from experimental studies under what conditions a dispersed morphology or a co-continuous morphology may be formed, and whether a co-continuous morphology is stable, giving rise to an equilibrium morphology, or whether it is an unstable intermediate morphology that eventually is transformed into a dispersed morphology (Lee and Han 1999a, 1999b, 2000). Let us consider the morphology evolution in an immiscible blend consisting of two semicrystalline polymers, A and B, in a compounding machine, and let us assume that the melting point (Tm,A) of polymer A is lower than the melting point (Tm,B) of polymer B.