Research is being performed on short-cut “high performance” fibres applied in elastomers, in a joint DPI project of three groups: The Department of Elastomer Technology and Engineering (ETE) and the Laboratory of Surface Technology and Tribology (OTR) both connected to the University of Twente and the Leibniz Institute of Polymer Research (IPF), Dresden, Germany.
Elastomer Technology & Engineering
Objectives: Study the reinforcement mechanisms of rubber compounds with short aramid fibers.
Challenges: The rubber-fiber adhesion in short fiber composites is affected by different interaction mechanisms compared to long fiber composites. There is no direct method known to measure the adhesion of short fibers to the rubber matrices.
Results: Different mechanical and chemical interaction mechanisms of short fibers in rubber matrices are being investigated. Adding fibers with the proper surface treatment can result in a decrease in the loss angle of a tire tread compound, which translates into a lower Rolling Resistance of actual tires to save energy.
Lab. for Surface Technology and Tribology
Objective: Study the tribological behaviour of short fibre reinforced elastomers in a tire-road system, for different orientation of fibres.
Challenges: Developing a contact model that considers the anisotropic and viscoelastic behaviour of the reinforced elastomer, as well as developing a friction model for this system, which also includes the surface properties of the elastomer.
Results: A contact model for a viscoelastic-orthotropic material against a rigid indenter was developed. The contact area is given by:
Where depends on all the material parameters. Currently the differences in friction behaviour are being measured on a pin on disk tribometer, with disks of reinforced rubber with the fibres in different directions.