Trelleborg Marine Systems has launched a new whitepaper and webinar, recommending that the industry moves to using modulus as a measure of fender performance.
The new materials aim to raise awareness of the importance of ingredient selection, mixing and the manufacturing process in marine fenders, and the importance of utilising the test method to determine their quality.
Building on previous research into the importance of ingredient selection in fender performance, the new materials prove by experiment and supported by theory, the fact that modulus – the relationship between stress and strain in a cured rubber sample – is a far more effective and robust measure of fender performance than hardness, which is currently used as the traditional measure of performance in the marine industry.
Richard Hepworth, President of Marine operations at Trelleborg, said: “We’re committed to our research and development programme in the field of fender performance. The latest research we have conducted has proven beyond doubt the need for a new measure of fender performance: we suggest that the industry begins to move towards measuring the modulus of rubber compounds, to ensure the performance characteristics of the fender are truly understood.
“Also discussed in the research is the importance of the mixing process. We have discovered that even a superior rubber formulation – one which uses natural rubber and reinforcing fillers – can be degraded if it is subjected to an inferior mixing process, ultimately producing a low performance compound and a low performance fender.”
Trelleborg has established the criticality of filler dispersion within the rubber compound and its impact on the quality of the final product.
Poor dispersion can lead to damaging effects such as reduced service life, poor performance, poor appearance and even poor product uniformity.
There are a number of machinery parameters that affect filler dispersion in the final mix, including ram pressure, rotor speed and design, coolant temperature and mixing sequence.