A paper roll carrying device is equipped with movable-type paper clamping arms for clamping paper rolls with different widths. The paper roll carrying device includes two paper clamping arms and two supporting mechanisms. The supporting mechanisms are respectively installed on the corresponding paper clamping arms. Each supporting mechanism includes a first support member, a second support member and a third support member. The supporting mechanism is specially designed to have the take-out slant surfaces on the supporting members. The supporting mechanism can be used to support paper cores with different diameters. When the user intends to remove the paper roll, it is not necessary to release the paper clamping arms.

A roll substrate holding device has improved versatility of a winding core and sufficient holing strength. The roll substrate holding device that holds a roll substrate wound around a winding core without a shaft includes: a holding member that is inserted into an opening of a first winding core having a first inner diameter and that comes into contact with the first winding core to rotatably hold the first winding core; and a conversion adapter that is mounted in an opening of a second winding core having a second inner diameter larger than the first inner diameter, wherein the holding member is inserted into an opening of the conversion adapter that is mounted in advance on the second winding core, and comes into surface contact or line contact with an inner peripheral surface of the conversion adapter having the first inner diameter to rotatably hold the second winding core.

An unwinder for unwinding reels of paper includes a supporting structure partially closed and defining an internal space suitable for unwinding at least one reel; the supporting structure includes: a first lateral support; a second lateral support spaced from the first support; a crosspiece interposed above between the first and the second support defining with the first support and second support the partially closed structure; the unwinder further includes: a first axial unwinding system placed at the first support and configured to axially unwind a first reel; a second axial unwinding system placed at the second support and configured to unwind a second reel; a joining device placed at the crosspiece and configured to make a joint between a first ply belonging to the first reel and a second ply belonging to the second reel to perform a reel exchange.