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Mixing involves blending raw rubber or masticated rubber with additives using a rubber mixer, which is the most critical process in rubber production. The internal mixer, as the most important mixing equipment, experiences rotor wear during prolonged operation, affecting the gap between the mixer rotor and the chamber wall. This wear reduces mixing effectiveness, weakens filler dispersion, and ultimately impacts rubber performance. In recent years, as research on multi-walled carbon nanotubes (MWCNTs) and nanomaterials has deepened, their broad application prospects have become increasingly apparent. The objective of the present study is to understand and quantify rotor wear in rubber blends during the mixing process as influenced by multi-walled carbon nanotubes. This study found that with the increase in MWCNT content, the proportion of abrasive wear rises, while the proportion of corrosive wear decreases, leading to reduced overall wear. Compared to rubber without MWCNTs, the Payne effect decreased by 6.78%, 9.57%, 13.03%, 20.48%, and 26.06% with the addition of 1 phr, 3 phr, 5 phr, 7 phr, and 9 phr of MWCNTs, respectively. The friction coefficients between the rubber and metal increased by 6.31%, 8.57%, 25.43%, 39.31%, and 47.61%, while the metal wear rate decreased by 9.08%, 10.73%, 13.41%, 17.46%, and 25%. Conversely, the friction coefficients were reduced by 19.39%, 22.42%, 33.94%, 66.06%, and 76.36%. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) as new materials have been the focus of materials research, while being widely used in the processing of rubber composites. To solve the problem that CNFs are easy to agglomerate, the existing methods are mainly chemical modification of CNFs (complicated processing process), blending with fillers such as carbon nanotube (expensive material and high production cost ratio). In this study, we integrated the economics and processing methods, and used pyrolysis carbon black (CBp) and CNFs for blending to prepare rubber composites to solve the filler agglomeration problem. It was found that CBp and CNFs produce a synergistic effect, and the two are isolated from each other and in contact with each other, forming a more complete filler network inside the composite. Through the synergistic effect, the filler dispersion in the rubber becomes better and the performance of the composite is greatly improved. Compared with traditional filler blending, it is more economical and can save production costs to a great extent; compared with chemical modification, the process is simple and saves production time. The recycling of rubber products can be promoted through the mass use of CBp, which has a certain environmental protection effect. This study provides new ideas for polymer composite processing, and more experiments are needed later to verify the feasibility of this method. [ABSTRACT FROM AUTHOR]

The effects of wet mixing and traditional mixing on the properties of radial-orientation basalt fiber-reinforced rubber products were studied through experiments. The results show that compared with traditional mixing, the basalt fibers under the wet mixing conditions can more effectively enhance the physical and mechanical properties of composites. The properties of the composites, such as carbon black dispersion, filler dispersion, rolling resistance and wet-sliding resistance, were the best after the latex and carbon black were premixed and then mixed by a mixer. Through extrusion experiments with the developed short-fiber radial-orientation die, it can be found that the fluidity of composites after extrusion is enhanced. Through analysis utilizing an electron microscope, it is shown that when the BFs added with KH550 (3-Aminopropyltriethoxysilane) were modified by KH560 ((3-Glycidyloxypropyl)trimethoxysilane), the interface layers of BF (basalt fiber)–KH560–NR and BF–KH550–NR were formed, which improves the adhesion between BFs and the rubber matrix. Qualitative characterization experiments on the orientation direction of the vulcanized composites were carried out through the experiments; that is, the qualitative characterization experiments on the segmented cutting and vulcanization of the composites in the radial direction showed that the short-fiber radial-orientation die could greatly improve the radial orientation degree of the short fibers in the radial direction. After adding KH560, the performance of the composites reinforced by the short fibers was improved to a certain extent compared with those without KH560. By adding DZ (N,N-Dicyclohexyl-2-benzothiazolsulfene amide) and CTP(cytidine triphosphate disodium) into the vulcanization system, the curing process of compounds in mixing and extrusion was delayed and the scorching resistance of short-fiber-reinforced composites was enhanced. Under the same conditions, the properties of the compounds after extrusion were greatly improved compared with those without extrusion. [ABSTRACT FROM AUTHOR]

As a piece of high-intensity running equipment, the wear of an internal mixer determines the quality of rubber and its life. In general, the wear of an internal mixer is caused by the friction between the rubber and metal during the mixing process, and the most severe wear position is the end face of the equipment. In this paper, a mixture of multi-walled carbon nanotubes (MWCNTs) and carbon fibers (CFs) are added to rubber by mechanical compounding to obtain MWCNT/CF/carbon black (CB) composites. By investigating the synergistic mechanism of MWCNTs and CFs, we analyze the effect of the MWCNT/CF ratio on the frictional wear of metal on the end face of the internal mixer. At the microscopic level, MWCNTs and CFs form a spatial meshwork with CB particles through synergistic interactions. The CB particles can be adsorbed on the spatial meshwork to promote the dispersion of CB particles. In addition, the formation of oil film can be slowed down due to the spatial meshwork, which could hinder the spillage of aromatic oil. Meanwhile, the spatial meshwork serves as a physical isolation layer between the rubber and metal to reduce friction. Therefore, it dramatically impacts the dispersion degree of CB particles, the friction coefficient, the roughness of the surface, and the wear of metal. It shows that the synergistic effect of MWCNT/CF and CB particles is best when the CF content of the rubber matrix is 5 phr, showing the most stable spatial network structure, the best dispersion of CB particles, and minor wear on the end face of the internal mixer. [ABSTRACT FROM AUTHOR]

Studies show that the long-term operation of a rubber mixer results in wear at the end face of the mixer. End face wear increases the gap between the mixing chamber and the end face, resulting in leakage and a reduction in the mixing performance, affecting the final product's quality. Therefore, it is essential to investigate the wear of the metal face during the mixing process. The present study added aramid fibers to a rubber compound using a mechanical blender to obtain a composite material. Then, the influence of the aramid fibers on the metal friction and wear of the end face of the mixer was analyzed. This article introduces the concept of the wear ratio and explores the friction and wear of metals from the perspective of formulation technology for the first time. With the addition of aramid fibers, the proportion of abrasive wear of rubber on metal decreased, and the proportion of corrosive wear increased during the mixing process; however, when the addition of aramid fibers exceeded 3 phr, the balance of abrasive wear of rubber on metal increased and the proportion of corrosive wear decreased. It was found that aramid fibers have the property of friction reduction, which reduces the wear of the rubber blend on the metal. When the amount of aramid fibers added was 3 phr, the amount of abrasion of the rubber compound on the metal was the lowest. [ABSTRACT FROM AUTHOR]

GF/rubber composites have sound insulation characteristics, heat resistance, good corrosion resistance, and high mechanical strength. The compounding machine's long working hours will inevitably wear the metal on the end face of the compounding machine. The wear of the end face metal will increase the gap between the chamber and the end face, which will lead to material leakage, reduce the mixing effect, and eventually affect the performance of GF/rubber composites. To ensure the implementation of GF/rubber composites, it is necessary to study the frictional wear behavior of GF/rubber composites on metals. In this paper, the effect of blending rubber with different amounts of GF on the frictional wear of metal on the end face was analyzed from the perspective of the formulation process, and the ratio of corrosion wear and abrasive wear was calculated for the first time. [ABSTRACT FROM AUTHOR]

Carbon based materials with excellent conductivity such as conductive carbon black, graphene, and carbon nanotubes (CNTs) are often used in the preparation of conductive polymer composites. Pyrolysis carbon black, as a recycled material of waste rubber, can be used as a substitute for other carbon black in some fields, which can greatly reduce the production cost and promote reuse of used rubber. In this article, pyrolysis carbon black is mixed with CNT and added to natural rubber by mechanical blending method to get the composite material. The synergistic effect of pyrolysis carbon black and CNT, 3D network structure and formation of conductive network are investigated, and the properties of composites are analyzed. The results show that the 3D "grape cluster" network structure formed by the synergistic action of the pyrolysis carbon black and CNT, which led to the improvement of the curing properties and mechanical properties of the composites, increase the Payne effect, decrease the dispersion of the filler, and significant reduction the volume resistivity of the composites. With the increasing of CNT content, the variation of the properties of the composites changed and stabilized. In general, when 40 phr pyrolysis carbon black and 4 phr CNT are mixed into rubber matrix, the composite has the best comprehensive performance, and the volume resistivity is 9.25E5. Our results provide new thoughts in preparing natural rubber conductive composites. By adding highly CNT and inexpensive pyrolysis carbon black, the problem of easy aggregation of a single filler is overcome, which is more economical than adding two highly conductive fillers, and the process is simpler and time‐saving compared to the modified solution. More studies need to be done in order to reveal the effects of pyrolysis carbon black in practical conductive composites. [ABSTRACT FROM AUTHOR]

Studies show that long‐term operation of the rubber mixer results in wear at the end face of the mixer. End face wear increases the gap between the mixing chamber and the end face, which results in leakage and reduces the mixing performance, thereby affecting the quality of the final product. Therefore, it is of significant importance to investigate the wear of metal face during the mixing process. In the present study, calcium powder was added to the rubber compound using a mechanical blender to obtain a composite material. Then the influence of the calcium powder on metal friction and wear of the end face of the mixer was analyzed. The obtained results show that the calcium powder has anti‐friction properties, which can greatly reduce the compound wear on the metal. The lowest corrosion and wear of the compound on the metal was achieved with 5 phr of calcium powder. Meanwhile, it is found that the tensile and tear‐resistance properties of the compound with 5 phr of calcium powder are slightly lower than those without calcium powder. However, the compound with 5 phr of calcium powder has higher friction, cold resistance, wet slip resistance, and lower rolling resistance. [ABSTRACT FROM AUTHOR]

The function of silane coupling agent in rubber mixing field is to combine inorganic matrix with rubber organic matrix. Silica is commonly used in the rubber mixing field to strengthen rubber. The size and amount of silica aggregates in the mixing process are important factors affecting the wear of the mixing chamber. The wear of the mixing chamber would lead to a increasing gap between the mixer chamber and the rotor, which caused the mixing efficiency reducing. It also affected the dispersion effect, then affected the mechanical and physical properties of the vulcanized rubber. In this paper, the effects of rubber compound on metal friction and wear were studied by using four silane coupling agents commonly used in rubber mixing field. The experiment was carried out at 15°C, and the attention should be paid to drying during sample preparation to avoid the deviation of the experiment caused by hydrolysis of silane coupling agent. The results showed that silanization reaction occured between silica and silane coupling agent in the mixing process. The mixing temperature was usually maintained at 145 to 155°C for 1 min in the mixer, and the silanization reaction rate was the fastest during this time. We took this rubber compound as the research object and studied the friction and wear of the rubber compound on the mixing chamber in the mixing process. The products of the silylation reaction are alcohol and water. This paper studies the corrosion and abrasion of the mixing chamber by water at high temperatures. In the mixing process, abrasive wear was the main wear form, but the corrosion wear caused by high temperature steam still occupied a large proportion. [ABSTRACT FROM AUTHOR]

Prolonged operations of mixers cause wear of mixer rotors and chamber walls and affect the clearances between the rotors and chamber walls, which reduce the mixing effect, weaken the dispersion of the packing, and affect the quality of rubber products. In this study, the effects of traditional mixing and wet mixing on the friction and wear of the chamber, and the properties of rubber were compared by using 60 phr of a silica natural rubber formulation system. The results show that a silanization reaction occurs between silica and the silane coupling agent during the mixing process and that the reaction rate is fastest when the temperature of the mixing chamber is maintained between 145 and 155°C for 1 min during the mixing process. The products of silanization reaction are ethanol and water; the water vapor that forms at high temperatures corrodes the mixing chamber of the internal mixer and aggravates wear and tear. Due to the high dispersion of silica during wet mixing, the silanization reaction is more complete and water vapor is produced at a high temperature. Hence, the rubber compound obtained by wet mixing has more significant wear on the mixing chamber. [ABSTRACT FROM AUTHOR]

Internal mixers play a critical role as blending equipment in the rubber industry, operating for extended hours under high intensity. Investigating the wear patterns of internal mixers holds paramount importance in curbing dust leakage and prolonging their operational lifespan during the mixing process. Thermal cracked carbon black (CBp), an economically viable material derived from waste rubber, stands as a potential substitute for other carbon blacks in specific applications. This substitution aids in waste rubber recycling, thereby promoting ecological sustainability. This study centers on the amalgamation of CBp and graphene oxide (GO) in varying proportions, incorporated into the rubber matrix via mechanical blending. The objective is to produce composite materials, namely CBp/GO/NR, and comprehend the synergistic mechanisms between CBp and GO. Furthermore, the study analyzes the impacts of different CBp/GO ratios on metal friction and wear at the internal mixer's end faces. Scanning electron microscopy (SEM) observations divulge a collaborative behavior between GO and CBp particles within the rubber matrix, culminating in a spatial "honeycomb" network structure. On one hand, GO's two-dimensional planar network structure aids in CBp particle dispersion. Conversely, this planar network restricts the overflow of aromatic oils in CBp particles, influencing oil film formation on the rubber surface. Simultaneously, the planar network of GO creates a physical isolation layer between the rubber and the metal components. The inclusion of GO in the rubber matrix introduces notable alterations in CBp particle dispersion, friction coefficient, metal surface roughness, and metal wear. In summary, the optimum interaction between GO and CBp particles is achieved when the GO content in the composite material reaches 4 phr. This interaction leads to superior CBp particle dispersion and minimal metal wear in the composite material. • Produce CBp/GO/NR composites, understand CBp and GO synergy. • Analyze CBp/GO ratios on metal friction/wear at mixer faces. • SEM shows collaborative GO and CBp behavior, "honeycomb" structure. • Optimal GO-CBp interaction at 4 phr in composite material. [ABSTRACT FROM AUTHOR]

• In this study, based on the viscoelastic solid theory of the rubber mixing process and the friction mechanism between rubber and metal, combined with the discrete element method, a dynamic simulation model for the wear of the synchronous quadrilateral rotor of an internal mixer is established. • The simulation results are compared under different mixing parameters. Analysis is performed, and a control experiment is set up to verify the feasibility of the discrete element software (EDEM) rotor wear dynamic simulation model. As the core component of an internal mixer, the rotor is subjected to friction from rubber and its filler during the mixing process, which causes the surface of the rotor to wear and can also affect the gap between the rotor edges as well as the gap between the rotor and the mixing chamber wall. The more significant the rotor wear, the larger the gap between the rotor ribs and the wall of the mixing chamber, which results in weaker shearing effect of the rotor on the rubber and even leads to uneven dispersion of filler in the rubber, eventually affecting the mixing effect and mixing quality of the glue. In this study, based on the viscoelastic solid theory of the rubber mixing process and the friction mechanism between rubber and metal, combined with the discrete element method, a dynamic simulation model for the wear of the synchronous quadrilateral rotor of an internal mixer is established. The simulations are performed in the EDEM software, and the results are analyzed and compared under different mixing parameters. Further, a control experiment is established to verify the feasibility of the proposed dynamic model for rotor wear. [ABSTRACT FROM AUTHOR]

As an essential rubber mixing equipment in continuous production, an internal mixer should have a long service life while operating at high intensity. Studies show that at these severe operating conditions, end face wear of the internal mixer is inevitable. It is worth noting that the end face is an important part of the closed mixing chamber. The head of the rotor shaft is inserted into the copper ring of the sealing plate, the sealing plate and the mixing chamber are pressed together by bolts. There is a gap between the rotors and the mixing chamber. During the mixing process, the mixed rubber in the mixing chamber is in direct contact with the end face, the end face metal is frictional and abraded. Wear of the end face may result in a gap between the mixing chamber and the end face, leading to material leakage. As the leakage intensifies, the gap between the end face and the mixing chamber further increases, thereby forming negative feedback. This phenomenon not only affects the chemical composition of the rubber but also reduces the mixing efficiency and decreases the performance of the rubber compound. The end surface material is cobalt chromium molybdenum tungsten alloy. The alloy model is Stellite 6B. In the present study, the influence of different amounts of CF on the friction and wear of the end face is analyzed from the chemical composition perspective. Moreover, the ratio of corrosion wear to abrasive wear is calculated. The obtained results show that as the amount of CF in the compound increases, the proportion of the corrosive wear of the compound to the metal increases, while the proportion of abrasive wear decreases. The highest proportion of corrosive wear and the lowest amount of metal wear can be achieved for the CF amount of 9 phr. As the CF content in the composition increases, the ratio of the corrosive wear of the rubber compound to metal decreases, while the proportion of abrasive wear and the total amount of wear to metal increases. • Studies show that at these severe operating conditions, end seal wear of the internal mixer is inevitable. • This study analyzed the effect of different additions of CF on the friction and wear of the end seal. • The highest proportion of corrosive wear and the lowest amount of metal wear can be achieved for the CF amount of 9 phr. [ABSTRACT FROM AUTHOR]

Internal mixer is an important mixing component in industrial applications. Studies show that when a mixer operates for a long time, wear may appear at the end face of the internal mixer. On the other hand, abrasion of the end face increases the gap between the mixing chamber and the end face. Then, leakage occurs, which reduces the mixing effect and affects the rubber performance. Therefore, it is of significant importance to study the wear of the end face during the mixing process. Graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) have excellent electrical characteristics and thermal conductivity so that they have been widely used in various fields such as synthesized composite rubbers. GO and MWCNTs are mechanically blended into natural rubber to obtain GO/MWCNTs composite material. In the present study, the influence of the GO/MWCNTs ratio on the friction and wear of the end face of the internal mixer is analyzed. The obtained results show that MWCNTs and GO molecules interact to form a three-dimensional network structure, which has a greater impact on the degree of silica dispersion, silanization reaction, and metal wear. As the GO content increases, the average friction coefficient between rubber and metal, metal roughness, the proportion of abrasive wear, and the amount of metal wear gradually decrease. The lowest values can be achieved when the amount of added GO is set to 3 phr. When the GO in the mixture exceeds 3 phr, the friction coefficient between rubber and metal, and the metal roughness change, thereby affecting the proportion of abrasive wear and increasing the amount of metal wear in the mixing process. In this experiment, the amount of CNT that reduces GO aggregation is 6 phr. On the whole, when the ratio of GO/MWCNTs is 3/6, the synergistic effect of MWCNTs and GO molecules is maximized, the area of the three-dimensional network structure of GO/MWCNTs is the largest, the dispersibility of SiO 2 is the best, and the amount of wear of the composite material on the metal is the lowest. • In the present study, the influence of the GO/MWCNTs ratio on the friction and wear of the end face of the internal mixer is analyzed. • The obtained results show that MWCNTs and GO molecules interact to form a three-dimensional network structure. • It is concluded that the metal wear is minimized when the ratio of GO/MWCNTs in the GO/MWCNTs composite is set to 3/6. [ABSTRACT FROM AUTHOR]

The gap between the rotor and the mixer chamber wall is an important factor in determining filler dispersion in rubber compounds. The inner wall of a mixer will wear after working for a long time, which will cause poor filler dispersion and affect the quality of rubber products. In this study, MoDTC was added to carbon black as a kind of filler, and the effect on filler dispersion, the properties of the rubber product, and the friction and wear of rubber and metal in the mixing process were examined. Experimental data showed that after adding 3 phr of MoDTC, carbon black dispersion was greatly improved, the curing time was shortened, and the performance remained stable. It was also found that the Mo element of the compound with 3 phr MoDTC dispersed better than that of the other compounds. Most importantly, adding 3 phr of MoDTC greatly reduced the amount of wear on the metal during the mixing process. However, the opposite effect occurred when the MoDTC content was high. The method proposed in this study can not only improve filler dispersion in rubber but also reduce metal wear to prolong the service life of the mixing chamber when applied to an actual mixing process. [ABSTRACT FROM AUTHOR]

As the basic equipment in the rubber field, the internal mixer is suitable for long-term rubber mixing. For the continuous production of the factory, the wear of the internal mixer is a problem that cannot be ignored. This article mainly studies the wear of the end face of the internal mixer. The end face of the mixer is connected to the mixing chamber. With the increase in mixing time, the end face of the mixer is inevitably worn. The abrasion of the end face of the internal mixer causes the gap between the end face of the internal mixer and the mixing chamber to increase, and the materials in the mixing chamber leak out. This affects the ratio of materials and reduces the mixing effect. And with the increase in material leakage, the abrasion of the end face of the internal mixer is intensified, which eventually leads to a decrease in the compound's performance. BF is a pure natural inorganic non-metallic material. It has good high-temperature resistance, and high compressive strength can be used in various environments and is inexpensive and cost-effective. Based on this, BF is increasingly used in the rubber field. In this paper, the effect of adding different amounts of BF on the friction and wear of the end face of the internal mixer is studied, and the proportions of varying wear forms are distinguished for the first time. The study finds that with the increase of BF in the compound, the proportion of abrasive wear first decreased and then increased, the balance of corrosion wear first increased and then decreased, and the amount of metal wear first decreased and then increased. It is found that the lowest wear of the rubber compound on the metal can be achieved when the amount of BF reaches 10 phr. When the BF amount increases, the corresponding amount of metal wear increases. • With the increase of mixing time, the end face of the mixer is inevitably worn. • This paper studied the effect of different BF additions on the friction and wear of metals. • It is found that the lowest wear of the rubber compound on the metal can be achieved when the amount of BF reaches 10 phr. [ABSTRACT FROM AUTHOR]