Judge fenders on physical properties

Part of a four-part White Paper series aiming to provide an unbiased view of ‘what exactly makes a good fender’, ‘Compounding – A Winding Road’ found that that in fender manufacturing, chemical composition is important but physical properties are the only reliable indicator of the quality of a rubber compound that is defined by international standards.

“At the ShibataFenderTeam Group (SFT), we believe that the quality of a fender should be measured by its performance, i.e. by the degree to which a fender lives up to the requirements of its specific field of application,” said Dominique Polte, board member at ShibataFenderTeam Group.

Ratio caution

While there are international standards and guidelines in place, there are no recommendations as to how to specifically meet these in recognition of the fact that every fender project is different, stated the White Paper.

Two rubber compounds can differ in their chemical compositions but still have physical properties that meet or exceed the requirements of international standards, it explained.

It recommends that ratios of fillers and reinforcement agents such as carbon black (CB), calcium carbonate (CC) and silica should be determined by specialists with profound material knowledge, as amount and particle size greatly influence the compound as well as its performance and durability.

The paper also found that the quality of a fender cannot be determined by the amount of Carbon Black (CB) in its rubber blend. Compounds should therefore not be excluded from specifications only based on these grounds. The compound’s component ratio and the necessary CB particle size are unavoidably bound up with a fender’s desired performance and physical properties, it said.

Furthermore, the paper draws attention to the fact that rubber compounds mixed correctly with CC by experienced manufacturers comply with and surpass international testing standards.