Project Call

Impact of Filler Dispersion on Mechanical Performance and Lifetime of ‎Elastomers

The project aims are to develop and improve methods for the analysis of lifetime relevant particle size ‎distributions in filler reinforced rubber compounds. This is promising to reduce the development costs for ‎high-performance compounds, especially considering durability.‎

State of the Art
In compounding and further manufacturing of elastomer parts, the filler dispersion is well known as a ‎crucial property for the final article performance. While the micro-dispersion - referring to particle sizes ‎below e.g. 1 micrometer - affects the strength of the matrix due to the reinforcement effect, the macro-‎dispersion above e.g, 10 micrometers refers to typically more seldom particle sizes but reflects the ‎amount of unwanted stress raisers which may initiate cracks. Especially considering lifetime under ‎dynamic load, insufficient dispersion of filler or other additives has been found to shorten the lifetime ‎endurance of dynamically tested specimens tremendously.‎
Hence, it is of high interest to define reliable and preferably quick methods for the dispersion evaluation ‎on both scales. Whereas well-established methods like Dispergrader and DIAS have been proven useful ‎for the evaluation of macro-dispersion in principle, they are of limited use for life-time relevant but ‎seldom big particles due to their small effective test volume. Here, Computed tomography (CT) proves ‎to be useful, a new method allowing for the investigation of volumes bigger by several decades in only ‎one measurement, overcompensating for a longer evaluation time.‎
Since CT is not yet generally accepted for compound analysis, systematic tests with parameter ‎verification are required to develop reproducible procedures for filler dispersion analysis. By comparison ‎of the abovementioned dispersion analytical methods and evaluation of their result correlation with ‎laboratory mechanical performance and lifetime tests, valuable information for compound development ‎and processing can be generated, which is promising to shorten development time and increase ‎efficiency.‎

•    Development of well-defined particle dispersion analytical methods especially with CT
•    Evaluation of the correlation of compounding methodology with particle size distribution
•    Modelling of the influence of distinct particle size classes on mechanical properties and ‎application relevant lifetime performance
•    Comparison of the optical methods with the aim to define of more reliable tolerance bounds for ‎online-quality control.‎

Materials & Methods
Various compounds relevant to practice according to the project partners requirements, based on ‎technical polymers, with carbon black or silica/silane.‎
•    Compounding with variation of mixing procedures.‎
•    Rheological measurement (Rubber Process Analyzer)‎
•    Optical standard dispersion analytical method (DIAS, Dispergrader)‎
•    Transmission Electron Microscopy (micro-dispersion)‎
•    CT analysis with varying parameters, testing for reproducibility, sensitivity and to balance the ‎available resolution with the choice of test volume
•    Mechanical measurement of endurance in dynamic fatigue (Wöhler), fatigue crack growth ‎‎(Paris-Erdogan), DMTA, physical properties
•    Evaluation of the match of the dispersion analytical methods, together with the correlation with ‎the mechanical test results; quantitative lifetime simulations

Time and project management
The project is designed for two years with optional third year. The project period covers the period from ‎‎1st April 2021 to 31st March 2023, optional to 2024.‎

Every three to four months, project meetings will take place between the DIK and the project partners ‎with report on the project interim situation. DIK also undertakes to provide a conference call for these ‎project meetings. The meetings are also intended to coordinate the progress of the project and, if ‎necessary, to adapt the work plan on the basis of existing results.‎

Project deliverables
Within the scope of the project it is planned to deliver the following results to the partners:‎
•    Data of the compounding, analytics and performance experiments carried out within this project
•    Insights into the scope of application of methods to be used, in particular for the computed ‎tomography in the determination of flaw size statistics.‎
•    Documentation on the evaluation procedures developed for particle size distribution
•    One intermediate and a final report

After material and labour costs, the following costs are incurred:‎
Total costs per year:‎    ‎ ‎        ‎90,000 EUR excl.VAT
Total project costs over 2 years: ‎    ‎180,000 EUR plus the legal costs. VAT‎
Possible as bilateral or multi-client project, where the costs will be devided by the number of partners.‎

Use of personnel
The project will be carried out by one scientific co-worker (PhD-student) and will be supervised by Dr. ‎Jens Meier and Dr. Harald Geisler. In addition, a student assistant is hired as required.‎
Contact information:
DIK ‎    Dr. Jens Meier    ‎+49 511 84201-28‎
DIK ‎    Dr. Harald Geisler    ‎+49 511 84201-12‎




Dr. Harald Geisler

Telefon: +49 511 84201-12



Dr. Jens Meier

Telefon: +49 511 84201-28