A web processing system which includes two rollers configured to rotate at the same phase while being in contact with a web which continuously exists along a movement passage and a suppressing mechanism for suppressing a tension variation of the web between the two rollers.

A web processing system which includes two rollers configured to rotate at the same phase while being in contact with a web which continuously exists along a movement passage and a suppressing mechanism for suppressing a tension variation of the web between the two rollers.

A printing plate unit to be demountably mounted on a printing plate mounting portion of a plate cylinder includes a printing plate and a printing plate coupling member. A length of the printing plate coupling member is larger than a width of the printing plate so that the printing plate coupling member is provided with a projecting portion projecting from the printing plate formed cylindrically in an axial direction. The printing plate unit is fitted to the printing plate mounting portion from one end side, and is demounted from the same one end side by gripping the projecting portion of the printing plate coupling member in a state both end portions of the printing plate formed into a cylindrical shape are coupled to each other by the printing plate coupling member.