Kautschuke

Characterization of Carbon-Black Loaded Rubbers by the Use of the Dynamic Indentation Method

In the present paper a new dynamic indentation method for the investigation of carbon black loaded rubbers will be presented. For the characterization of these systems the Payne effect was used. A comparison of the results obtained by the indentation with the conventional method will be demonstrated. By creating mechanical images a local resolution of […] mehr...

28.April 2003 - Neues aus der Forschung

Institute & Verbände

FEM-Analyse der Kautschukvulkanisation unter Einbeziehung einer Wärmeentwicklungskinetik

Eine handelsübliche FEM-Software wurde mit einer kinetischen Rückrechnung basierend auf Ergebnissen aus einer ebenfalls handelsüblichen multivariaten Reaktionskinetik verknüpft. Die multivariate Reaktionskinetik ist in der Lage, die Meßkurven (DSC und/oder Vulkameterkurven) mit bis zu 4-stufigen Reaktionsmodellen zu beschreiben. Es konnten mehrdimensionale Temperatur- und Umsatzgradfelder unter Einbeziehung der freiwerdenden Reaktionswärme berechnet werden. FEM-Analysis of SBR-Vulcanization compted with […] mehr...

28.April 2003 - Neues aus der Forschung

Technische Produkte

High Temperature Creep Performance of Nylon 6.6 Tyre Cords

A high temperature creep measuring apparatus capable of operating at different stress levels over a wide range of temperatures and humidities was built. The apparatus was used to investigate creep behaviour of nylon6.6 tyre cords, under isothermal and non-isothermal (cyclic) operating modes. Under both operating conditions, cords exhibited instantaneous extensions on loading followed by steady […] mehr...

28.April 2003 - Neues aus der Forschung

Technische Produkte

Effects of Different Ingredients and Cure Parameters on Physical Properties of a Tyre Tread Compound

The effect of polymer blends, viz. NR/BR, NR/SBR and SBR/BR, and cure parameters such as cure time and cure temperature on the hardness of a tyre tread compound has been investigated. Along with the hardness, other physical properties have also been measured with variation of the above blend compositions and cure parameters. The empirical relationships […] mehr...

28.April 2003 - Neues aus der Forschung

Additive & Füllstoffe

Effects of Mixing Conditions

The addition of a coupling agent to silica-rubber compounds enhances the filler-matrix compatibility. Under certain mixing conditions the surface of the filler may be only partly activated, which may have an adverse effect on the properties in the final product. A mixing temperature of at least 130°C is necessary to ensure that the reaction between […] mehr...

28.April 2003 - Neues aus der Forschung

Fachartikel

Akkreditierung von Prüf- und Inspektionstätigkeiten – DIN EN ISO/IEC 17025 und DIN EN 45004

Die Regelwerke DIN EN ISO/IEC 17025 „Allgemeine Anforderungen an die Kompetenz von Prüf- und Kalibrierlaboratorien” und DIN EN 45004 „Allgemeine Kriterien für den Betrieb verschiedener Typen von Stellen, die Inspektionen durchführen” liefern eine Grundlage für einen kompetenten Betrieb solcher Stellen. Der Nachweis dieser Kompetenz erfolgt durch eine Akkreditierung. Das Deutsche Akkreditierungssystem Prüfwesen DAP führt derartige […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Silica Reinforcement of Styrene-Butadiene Rubbers

In addition to infrared and birefringence measurements used to characterize the orientational behavior of silica-filled styrene-butadiene copolymers, mechanical properties carried out at low and large strains are discussed. Results of equilibrium swelling experiments are also reported and correlated with the orientational data. Kieselsäureverstärkung von Styrol-Butadien-KautschukZusätzlich zu Infrarot- und Doppelbrechungsmessungen, die üblicherweise zur Charakterisierung der Richtungsabhängigkeit […] mehr...

28.April 2003 - Neues aus der Forschung

Recycling

Market cycle and investment behavior of polyolefin producers

In this article, the development of the yield of the polyolefin sector as well as of the individual companies was investigated without differentiation in products or market segments. The main driving factors were identified using as source of information the annual reports of 19 international polyolefin producing companies (resp. Business units) in the period from […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Monitoring Thermal Oxidation of Sulfur Crosslinks in SBR- Elastomers using Sulfur K-edge XANES: A feasibility study

Sulfur K-edge X-ray Absorption Near Edge Structure (XANES) measurements were used to monitor the processes occuring at the sulfur-crosslinks during high temperature oxidative aging for a number of SBR compounds. Variations included sulfur links of different type and density, filler material and use of antidegradants. We find a general mechanism of the aging process which […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Advanced Polymer Architecture

Fluoroelastomers were originally designed to provide a means of sealing in the most arduous applications where the consequences of failure are catastrophic. High part costs were acceptable in these early applications since production costs were considered largely unimportant compared to end use performance. These days fluoroelastomers are used in high volume automotive applications where the […] mehr...

28.April 2003 - Neues aus der Forschung

Additive & Füllstoffe

Investigations on the Use of Protective Coating Material as an Antiozonant for Natural Rubber under Static Deformation

The following study was set to investigate the effectiveness of a liquid nitrile-butadiene rubber coating, applied as an antiozonant for natural rubber under static conditions. Two natural rubber compounds were used, one with a combined system of a specified wax and a chemical antiozonant and the other without any antiozonant additives. The liquid rubber material […] mehr...

28.April 2003 - Neues aus der Forschung

Technische Produkte

Sliding Behavior of Rubber on Snow and Concrete Surfaces

Over the last years great efforts were directed to the numerical description of the sliding behavior of rubber blocks on various surfaces by means of the Finite Element (FE) Method. Two major mechanisms of the load transfer of traction forces can be observed depending on the characteristics of the sliding surface. On “soft” surfaces, i. […] mehr...

28.April 2003 - Neues aus der Forschung

Additive & Füllstoffe

Reinforcing Properties of a Modified Carbon Black in NR and in an NR-NBR Blend

Carbon black was modified with a long chain unsaturated hydroxy organic acid in presence of dicumyl peroxide and used as a reinforcing filler in NR and NR/BR blend in order to put the acid moiety as a flexible bridge between carbon black particles and the polymer chain for improving processing and vulcanizate properties. Processing behaviour […] mehr...

28.April 2003 - Neues aus der Forschung

Institute & Verbände

Die Entwicklung von Sauggreifern mit Hilfe der Finite-Elemente-Methode

Der Beanspruchungszustand von Sauggreifern aus Elastomeren wurde mit einer iterativen FE-Berechnung ermittelt. Der Einfluß der Parametergrößen Normalbelastung, Reibungszahl, Temperatur, Werkstoff und Unterdruck wurde untersucht. Durch die Variation geometrischer Abmessungen kann eine Bauteiloptimierung erreicht werden. The Development of Suck-pickers by the Finite Element MethodStresses and deformations in Elastomer Suck-pickers have been investigated by a iterative Finite […] mehr...

28.April 2003 - Neues aus der Forschung

Technische Produkte

Rubber-Metal Bonding as an Electrochemical Process

Rubber-brass bonding during vulcanization has already been previously discussed as a result of ionic reaction mechanisms. If electrically charged species (e. g. metal and sulfide ions) are formed, the bonding process should be influenced by an electric field. An experimental set-up for the application of a voltage during vulcanization and the preparation of test specimens […] mehr...

28.April 2003 - Neues aus der Forschung

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