Crumbs of end-of-life tyres represent roughly 20% of tyre wastes. Share of crumbs of industrial scraps are unknown but certainly inferior.
Crumb is a friendly environmental way to recycle tyres and rubber goods. Several outputs are used:
* Moulding of pure crumb: the end products have poor performances and limited applications.
* Additives for rubber goods: the loading level must be studied to preserve fair properties. A particular case, use with polyurethane, is developed for sports and leisure surfaces.
* Addition to plastic is a way to obtain particular properties.
* Additives for asphalts allowing enhancement of the properties of pavements.
Crumbs are very diversified, recipes of compounds can vary to infinity and consequently the remarks and data included in the following are examples and can't be taken for rules..
The characteristics of the compound decrease and the processing becomes difficult, the more so as the crumb is coarser. Generally the level of crumb is limited to 10-20%, which decreases the sensitivity to the granulometry of the used crumb.