Stencil printing machine and a wrinkle preventing method on a stencil sheet of the stencil printing machine

A wrinkle preventing method for preventing a wrinkle on a stencil sheet, the method comprising the steps of:

• providing a stencil printing machine which includes:
• a rotary cylindrical drum rotatable about its own axis, the rotary cylindrical drum including an ink-permeable cylindrical circumferential wall having an outer peripheral surface around which a stencil sheet subjected to a stencil making process can be wound;
• a contact member capable of contacting with an inner peripheral surface of the circumferential wall, the contact member being disposed in the rotary cylindrical drum;
• and
• a move mechanism capable of moving the contract member to a contact position at which the contact member is brought into contact with the inner peripheral surface of the circumferential wall or a distance position at which the contact member is spaced with a predetermined interval from the inner peripheral surface of the circumferential wall;
• discharging the stencil sheet from the rotary cylindrical drum so that the rotary cylindrical drum is placed in a state in which the stencil sheet is not wound around the circumferential wall of the rotary cylindrical drum;
• rotating the rotary cylindrical drum while placing the contact member at the contact position relative to an ink permeable portion of the circumferential wall;
• placing the contact member at the distance position relative to the ink permeable portion of the circumferential wall;
• and
• winding, around the outer peripheral surface of the circumferential wall of the rotary cylindrical drum, a stencil sheet subjected to the stencil making process.