SHAPE FORMING
❝There are not many additives which can reach the desired level of electrical conductivity without affecting the colour
needs for stable levels of conductivity and easier compounding, or offer suitable mechanical properties and softness requirements. To be effective in the host material, the required concentration of thick and short MWCNTs is tens or even hundreds of times higher than that of long and thin SWCNTs. Despite the similarity in names,
multi-wall carbon nanotubes and single wall carbon nanotubes – two allotropes of carbon – have hardly anything in common, and thus they impart a number of very different properties.
Graphene nanotube visualisation
This forklift is shod with non- marking tyres
Captions to go here
While MWCNTs feature many
tubes of decreasing diameter that are coiled inside each other, SWCNTs can be thought of as an extremely thin rolled-up sheet of graphene, and thus they are widely referred to as graphene nanotubes. Being an excellent conductor similar to copper and 100 times stronger than steel, graphene nanotubes gain traction starting from a loading of just 0.01%. Even such an ultra-low concentration is enough to enable conductivity without a negative effect on the material’s mechanical properties or viscosity.
Currently, graphene nanotubes
are the most innovative additive that facilitates efficiency, durability and affordability in solid tyres, particularly for coloured or non- marking applications where anti- static or conductive properties are required for tyres to dissipate the static charge. To impart conductive properties to
white filler-based rubbers, conductive fillers need to be added during the compounding process. There are not many additives which can reach the desired level of electrical conductivity without affecting the colour. Depending on the particular application, it could be copper powder, silver- and nickel-coated graphite, copper or aluminium – while these do provide the required conductive properties, adding them also leads to a number of negative trade-offs in flexibility, elasticity and high price. For conventional polymer-based
additives which are more commonly used due to their low price, the high working dosages required result in a number of drawbacks in the rubber’s mechanical properties and a reduced life cycle of the final products. These shortcomings severely restrict the potential range of non-marking solid tyre applications. Furthermore, conventional polymer-based additives are normally humidity-dependent and subject to migration, so the rubber’s
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