An apparatus for processing a flexible material , comprising: - a first roller extending along a main axis (A1); - a second roller extending along a longitudinal axis (A2), the first roller and the second roller being mutually co-operating to carry out an operation on the flexible material , an interspace being defined between the first roller and the second roller so that the flexible material may pass through the interspace ; - a pressing device for pushing the first roller and the second roller one towards another; - a position adjustment device for adjusting the relative position of the first roller and the second roller , the position adjustment device being distinct from the pressing device; - a pair of contact elements mounted at a front end respectively of the first roller and second roller , and a further pair of contact elements mounted at a rear end respectively of the first roller and second roller , the contact elements of said pair being arranged in mutual contact, and the contact elements of said further pair being arranged in mutual contact, so as to define said interspace ; - wherein the pressing device comprises at least two pressing elements which are arranged in contact with angularly spaced zones of a contact element of said pair, and at least two further pressing elements which are arranged in contact with angularly spaced zones of a contact element of said further pair; - characterised in that said pressing device comprises a pair of pneumatic cylinders to which corresponding pivoting rocker arms are connected, each rocker arm being connected to a pair of support elements in a tiltable manner, the support elements supporting said pressing elements or respectively said further pressing elements . - a first roller extending along a main axis (A1); - a second roller extending along a longitudinal axis (A2), the first roller and the second roller being mutually co-operating to carry out an operation on the flexible material , an interspace being defined between the first roller and the second roller so that the flexible material may pass through the interspace ; - a pressing device for pushing the first roller and the second roller one towards another; - a position adjustment device for adjusting the relative position of the first roller and the second roller , the position adjustment device being distinct from the pressing device; - a pair of contact elements mounted at a front end respectively of the first roller and second roller , and a further pair of contact elements mounted at a rear end respectively of the first roller and second roller , the contact elements of said pair being arranged in mutual contact, and the contact elements of said further pair being arranged in mutual contact, so as to define said interspace ; - wherein the pressing device comprises at least two pressing elements which are arranged in contact with angularly spaced zones of a contact element of said pair, and at least two further pressing elements which are arranged in contact with angularly spaced zones of a contact element of said further pair; - characterised in that said pressing device comprises a pair of pneumatic cylinders to which corresponding pivoting rocker arms are connected, each rocker arm being connected to a pair of support elements in a tiltable manner, the support elements supporting said pressing elements or respectively said further pressing elements . <EOS>