Preventing damage to printed substrates conveyed in a printing system

A system, comprising:

• an image forming station, which is configured to apply droplets of one or more printing fluids to a target substrate, so as to form an image thereon;
• and
• a substrate conveyor, which is configured to grip and move the target substrate to and from the image forming station for forming the image, the substrate conveyor comprising one or more rotatable elements, which are configured to provide mechanical support to the target substrate, wherein, when the target substrate moves over the one or more rotatable elements, at least one of the rotatable elements is configured to rotate in response to a physical contact with the target substrate, by receiving a kinetic energy from the target substrate, wherein one or more of the rotatable elements are mounted on a wire, and wherein the substrate conveyor comprises one or more slots, which are configured to receive the wire at a first angle and to lock the wire at a second angle.

An apparatus to be assembled to a substrate conveyor of a digital printing system, the apparatus comprising:

• one or more rotatable elements, which are configured to provide mechanical support to a target substrate, wherein, when the target substrate moves along the substrate conveyor over the one or more rotatable elements, at least one of the rotatable elements is configured to rotate in response to a physical contact with the target substrate, by receiving a kinetic energy from the target substrate, wherein, one or more of the rotatable elements are mounted on a wire, and wherein the substrate conveyor comprises one or more slots, which are configured to receive the wire at a first angle and to lock the wire at a second angle;
• and
• a mounting element, which is configured to fix the one or more rotatable elements at one or more respective positions.