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Wangenheim M.,Leibniz University of Hanover | Zimmermann M.,Leibniz University of Hanover | Hermann A.,Freudenberg Sealing Technologies
BHR Group - 22nd International Conference on Fluid Sealing 2013 | Year: 2013

The fnctional loss of pneumatic seals shall be reduced by a model-based approach. In an unlubricated contact of rod and rod wiper seal the following factors were varied to find an optimum combination: seal material, counter surface topography, and seal surface topography. Experimental results are used to validate the model approach. While seal surface topography seems not to play an important role in dry contact, the deliberate selection of seal material and rod surface can result in a friction reduction of as much as 80% in comparison to standard sealing systems. © BHR Group 2013. Source


Yeoh O.H.,Freudenberg Sealing Technologies
Rubber Chemistry and Technology | Year: 2012

It is often useful to describe vulcanization reaction kinetics in terms of a mathematical model so that curing behavior may be predicted for different heat histories. Commonly used models for describing vulcanization kinetics are reviewed and discussed with emphasis on the mathematical relationships between them. The Deng-Isayev, Sestak-Berggren, and Kamal models are regarded as members of a hierarchy of increasing complexity. Simpler members are preferred for robustness. Tests of their validity against experimental data are recommended to guide the choice of models. Source


Hanenkamp N.,Freudenberg Sealing Technologies
Productivity Management | Year: 2013

Optimization of the program planning through resource management Balancing supply and demand is a major challenge in complex supply chains. This article describes an innovative resource management concept that targets stability and risk avoidance in delivery performance, quality and productivity losses. In order to achieve these outcomes, a unique IT system was developed and implemented with a major automotive manufacturer. © GITO Verlag. Source


Sundararaman S.,Freudenberg Sealing Technologies
SAE Technical Papers | Year: 2013

One of the commonly used methods for evaluating friction and wear behavior of hard plastics is described in ASTM 3702 test specification. Wear tests conducted using this test method show that friction coefficient is dependent on temperature (generated due to friction), especially for filled plastics. Tests with high load and / or speed result in melting of the plastic due to excessive temperature build up. In the present study, a method has been developed to conduct dry and lubricated wear tests while controlling test temperature. Controlling temperature ensures that the failure mode of the test specimen is due to wear and not due to melting resulting from excessive temperature build up. The details of temperature control for both dry and lubricated wear tests are outlined and wear rate / friction for different combinations of loads and speeds are presented. The wear rates and friction coefficients obtained from temperature controlled tests can directly be used to rate materials for wear / friction performance. Copyright © 2013 SAE International. Source


Walker F.J.,Freudenberg Sealing Technologies
SAE Technical Papers | Year: 2014

According to the International Energy Agency (IEA), the United States consumes 20 million barrels of crude oil per day (840,000,000 gallons)1. More than half of this quantity is imported. It is expected that by 2025 this quantity is expected to rise to 26 million barrels per day with an estimated sixty percent of the consumed quantity being imported. With the prices of oil to continue to be above $90/barrel, the expected annual expenditures on imported oil is estimated to be >$250 billion. With the cost of fossil fuel continuing to increase as its quantity is depleted, there is a strong driver for continued investment in renewable fuel sources. One such approach is the use of plant-based feedstock to augment conventional fossil fuel for diesel applications. Use of such feedstock has given rise to the biodiesel fuel industry (BD). Studies have documented fuel-oil dilution issues in diesel applications. The presence of BD in the engine oil reduces the life of the oil as well as its effectiveness2. Since the BD is a naturally miscible in engine oil several undesirable characteristics can result. These negative effects include: reduced oil viscosity; increased engine wear; acid formation leading to corrosion; low oil pressure. This study will focus on the effects of bio-derived diesel fuel (BD), B20 and B100, and its effects on 15 common sealing elastomers. In addition, the effect of 5% biodiesel B20 and B100 dispersed in conventional 15W-40 engine oil will be examined for its effects on these same sealing materials. Copyright © 2014 SAE International. Source

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