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Processing promoters: Additives for rubber compounds improve mixing and processing

The efficient mixing of rubber compounds comes with many challenges. These include effectively blending the individual raw materials, which involves breaking down and blending different types of elastomers, adequately dispersing large fractions of fillers, oils and small weighments of chemicals in a relatively short time in the internal mixer. Once mixed, the compound then must be processed, e.g., extruded, calendered or molded to form the desired shape which is then vulcanized to produce the final product. The choice of the correct processing promotor will assist in these efforts. Certain promotors function primarily as dispersing agents, whereas others act more as lubricants to speed the mixed compound through the production process. Both types improve overall compound quality and production efficiency. Compound viscosity typically is also reduced. This article will focus on a number of processing promotors offered by Rhein Chemie and their effects on rubber compound quality and processability.

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ArticlesChemicals & MaterialsFeatured

FKM and FFKM crosslinking methods and their effect on upper use temperature of seals

Fluoroelastomers (FKMs) were first introduced to market more than 50 years ago in response to performance needs in the aerospace industry. Their increased thermal stability and chemical resistance, and comparable mechanical properties relative to hydrocarbon rubber materials provided significant performance benefits. Not surprisingly, FKM compounds soon became widely adopted in seals and gaskets for many other applications across the automotive, oil and gas, semiconductor and pharmaceutical/ food processing industries, where long term durability and reliability in challenging environments was critical.

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ArticlesChemicals & MaterialsFeatured

Dynamic mechanical properties and crosslink density testing of silicone elastomers

Material evaluation tests for this article were performed using the recently developed Dynamic Mechanical Yerzley Oscillograph (DMYO). Just like the Yerzley Oscillograph (YO), the DMYO supports the ASTM D945 standard. Its design is an evolution of the YO with additional sensors,
electronic data acquisition and computer control, including automated data evaluation.

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ArticlesExtrusionFeaturedMachinery & EquipmentUncategorized

Medical rubber tubing process and die optimization: Die redesign and fine tuning

Part 1 of this contribution, published in the May 2021 edition of Rubber World, investigated a real manufacturer’s process that was set to produce medical tubing. It was found (through trials at the extruder, then through simulations) that the equipment available to the manufacturer was too large for the relatively low output that was required for this project, and consequently the polymer was degrading on the screw surface. It was ultimately determined through simulation that a smaller extruder, with a screw optimized for the low rate, would work better.

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ArticlesFeaturedMachinery & Equipment

Improving profitability through innovative technologies and processes

Performance material usage is increasing in the manufacture of tires. These materials are composed of various additives with different properties that require a high level of expertise to maintain their properties throughout the production process and to deliver the desired, consistently high level of required quality. This is just one aspect that increases complexity in the manufacturing process. Market demands for more cost-effective products are also constantly increasing. Operating costs eserve special attention because process optimization is paramount on every manufacturer՚s agenda. Specialty chemicals group Evonik Industries and plant automation supplier Zeppelin Systems are working closely together to show how the use of innovative products and processes can both improve the performance properties of tires, while making their manufacture even more economical.

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ArticlesFeaturedSilicone & Medical

Silicone and epoxy hybrid resins exhibit wide range of mechanical properties

The largest range of silicone and epoxy hybrid resins for the 3D printing of wearable devices, biomedical equipment and soft robotics has been developed by researchers from the Singapore University of Technology and Design (SUTD). In a study published in Applied Materials Today, the range of tunable functionally graded materials, which displayed over five orders of magnitude of elastic modulus, demonstrated excellent interfacial toughness, higher precision in complex structures and better fabrication control for the integration of mechatronic components.

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Progress in bio-based itaconate butadiene rubber

Bio-based itaconate butadiene rubber has been introduced by the Beijing University of Chemical Technology. This project was researched by professor Liqun Zhang’s team at the university. They started the research in 2008. After 13 years of hard work, a new generation of high performance and bio-based itaconate butadiene rubber has been successfully developed. Epoxy group functionalized poly(dibutyl itaconate-co-butadiene- glycidyl methacrylate) (PDBIBG) is the first class of macromolecular chain structures based on an itaconic acid resource which can realize the high value-added utilization of biomass resources and promote green and sustainable development within the rubber industry.

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