Rotary cutter unit

A rotary cutter unit comprising:

• a cutter roll comprising a roll body having an outer circumferential surface, and a cutting blade positioned at the outer circumferential surface, the cutting blade having a cutting geometry;
• an anvil roll disposed parallel to the cutter roll, the anvil roll comprising a roll body having an outer circumferential surface configured to receive the cutting blade;
• a pair of rotatably-supporting portions each disposed at a respective one of opposite ends of the cutter roll;
• a pair of rotatably-supporting portions each disposed at a respective one of opposite ends of the anvil roll;
• a pair of air springs A each installed to apply pressure to a respective one of the pair of rotatably-supporting portions of one of two rolls consisting of the cutter roll and the anvil roll;
• and
• a pair of spring means B each installed to apply pressure to a respective one of the pair of rotatably-supporting portions of the other roll, in a direction opposed to a direction of the pressure application of the pair of air springs A,
• wherein the pair of air springs A and the pair of spring means B apply pressures to respective corresponding ones of the pairs of rotatably-supporting portions, in opposite directions sandwiching the two rolls,
• and wherein each rotatably-supporting portion of the pairs of rotatably-supporting portions of the two rolls is slidable in directions which cause the pressure applied from a corresponding one of the pair of air springs A and the pair of spring means B to increase and decrease.