The anisotropic reinforcement of elastomers by short fibres has been known for a long time. So far, specially prepared synthetic products have mostly been used for this purpose. Natural or lyocell fibres have received little attention in the industry because they cause major problems when distributed and separated in the polymer matrix.
By using fibre granulates, such difficulties can be avoided. A process for such granulates was developed at TITK. They consist of the cellulosic component and low-melting thermoplastic fibres. Length and cellulose content can be varied over a wide range. Within the framework of developments on different rubber compounds and also on various TPEs, it was proven that these granulates can be handled easily and processed in the internal mixer without any problems. Clear anisotropic reinforcements of the elastomers can also be demonstrated in large-scale applications.
Lyocell has better fineness and brittleness and in fact Lyocell - despite lower stiffness - has a higher reinforcing effect than flax in most of the cases compared here.