In some examples, a roll unwinder for a flying roll change includes a roll station for receiving a first material roll to be unwound, and a roll station for receiving a second material roll to be unwound after a roll change has occurred. A cut-off tool can sever a first web unwound from the first material roll, and includes a pressing element, to press the web against the outer surface of the second material roll. A supporting device can be transferred from an idle state into a working state in which the supporting device supports the web to be unwound, at least at the time of the severing process. The supporting device supports the web in a web path upstream from the cut-off tool. A receiving unit at a frame that carries the cut-off tool is movably mounted in the stand of the roll unwinder.

The roller comprises a covering layer made of a fibre composite material and a cylindrical roller main body having an outer first lateral surface, a first end section and a second end section. The covering layer completely surrounds the first lateral surface in the circumferential direction. A first edge region of the covering layer extends beyond the first end section, is folded over inwards and is fixed in relation to the roller main body. In a crosslapper, the roller can be provided as a deflection roller of a conveyor belt. In a carding machine, the roller can be provided as an engagement roller for engagement with fibre material.