SHAPE FORMING
properties are not stable because of this migration to the surface and release during the tyre’s life cycle. Historically, there have been
several technical barriers that have prevented the mass application of graphene nanotubes in various industries, including elastomers. The main challenge was related to the diff iculty in achieving uniform and homogeneous dispersion in the material matrix and in preventing further agglomeration. However, recent materials technology advances have enabled easy-handling nanotube concentrates that are compatible with industry-standard formulations and manufacturing processes, without requiring any specifi c changes or additional tools. ●
The wheels of industry
OCSiAl recently developed the Tuball Matrix solution with pre-dispersed nanotubes to eff ectively solve the issue of producing non-marking anti- static solid tyres to ensure safe operation of industrial vehicles operating in dangerous environments by avoiding the accumulation of static electricity. Using graphene nanotubes is the only cost-eff ective solution to fully comply with EN and ISO ESD standards without impacting the durability of tyres. Studies have shown
that even a minor amount (0.22 wt.%) of Tuball graphene nanotubes can strongly increase electrical conductivity without the negative eff ects on mechanical properties which normally occurs with conventional conductive fi llers. The eff ect
on electrical conductive properties of 6.9 wt.% of the anti-static plasticiser is negligible and can not meet the requirements for dissipative tyre properties. Higher dosages of plasticiser would result in an even worse eff ect on mechanical properties. Introduction of 2.2 wt.%
of Matrix 618 beta into a standard NR/BR and silica- fi lled solid tyre formulation improved the moduli of the rubber, increased its tear strength and improved the stability of properties after heat ageing compared with a conventional anti-static additive used as a reference. Adding the properly
dispersed graphene nanotubes provides consistent electrical conductive properties without migration of the carrier onto the surface which remains stable after heat ageing. The low required dosage of the graphene nanotubes allows the colour of the rubber to be maintained, without any carbon release, which is crucial for non-marking solid tyres. As well as tyres, nanotubes are now widely used in a variety of other applications such as conveyor belts, electronics, and printing and industrial rollers.
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