A method for the quantitative measurement of rubber coverage using a potentiostat

To produce a heavy-duty steel radial tire, the cords of brass plated ultra-high strength thin wires are embedded into rubber. The adhesion between the cords and rubber is mainly controlled by a thin layer of chemical compounds (for example, (Cu)_<1.97>S) formed between them during vulcanlzation and/or driving. The adhesive strength of them is usually measured by pulling out a cord from CER (Cords embedded in rubber) in tension (ASTM., AM., or SWAT. method) or by peeling out the cords from CER in tearing (peeling test). The adhesive force (kgf) is naturally controlled by both the interfacial adhesive stress (kgf/(mm)^2) and the adhered surface area ((mm)^2). The latter area in the above tests is often examined intuitively for convenience sake and the degree of adherence to surface area, that is the rubber coverage, is expressed into ten grades