A folding device for placing an elastomer thin sleeve on a retainer includes a mandrel, one or more rollers, and a drive system. The mandrel is configured to translate relative to a portion of the folding device. The mandrel is adapted to releasably receive the retainer. The one or more rollers are configured to rotate relative to the mandrel. The rotation of the one or more rollers being configured to fold the sleeve onto the retainer. The drive system is configured to translate the mandrel and turn the one or more rollers.

A folding roller for folding signatures in a folding apparatus comprises a cylindrical folding roller element comprising a jacket surface at least partially having an elastic coating that is compressible. As such, different folded products and/or folded products of different thicknesses can be produced without a change of the nip between the folding roller pair with consistent folding quality, and an adjustment of the nip is also not required during a production run printing or an ongoing production.

A folding roller for folding signatures in a folding apparatus comprises a cylindrical folding rolling element comprising a jacket surface at least partially having an elastic coating that is compressible. As such, different folded products and/or folded products of different thicknesses can be produced without a change of the nip between the folding roller pair with consistent folding quality, and an adjustment of the nip is also not required during a production run printing or an ongoing production.

Systems and methods for folding a stack of substrate sheets are provided. The system may include a roller assembly and a positioning mechanism. The roller assembly is configured for folding the stack of substrate sheets and the positioning mechanism is configured to position the substrate or stack for entry into the roller assembly. The positioning mechanism includes an upper curved form and a lower curved form to guide the stack of substrate sheets into a curved position for folding. The positioning mechanism further includes a folding blade positioned to extend through the gap between the upper and lower curved forms. The roller assembly can move the folded stack of substrate sheets in at least two directions.

A folding device for placing an elastomer thin sleeve on a retainer includes a mandrel, one or more rollers, and a drive system. The mandrel is configured to translate relative to a portion of the folding device. The mandrel is adapted to releasably receive the retainer. The one or more rollers are configured to rotate relative to the mandrel. The rotation of the one or more rollers being configured to fold the sleeve onto the retainer. The drive system is configured to translate the mandrel and turn the one or more rollers.

A sheet processing apparatus includes a conveyor, a first folding roller, a second folding roller, a return conveyance passage, and a third folding roller. The conveyor conveys a sheet along a main conveyance passage in a conveyance direction. The second folding roller facing the first folding roller across the main conveyance passage conveys the sheet by a first conveyance amount. The return conveyance passage having a curvature is branched from the main conveyance passage at a branching position and is merged to the main conveyance passage at a merging position. The third folding roller facing the second folding roller across the return conveyance passage conveys the sheet by a second conveyance amount smaller than the first conveyance amount of the second folding roller. The second folding roller is on an outer peripheral side and the third folding roller is on an inner peripheral side of the return conveyance passage.