A sheet processing apparatus is configured to press a fold line that is formed on a sheet. The sheet processing apparatus includes: a sheet supporting unit configured to support the sheet in a pressing direction for pressing the fold line; a pressing unit configured to press the fold line that is formed on the sheet that is supported by the sheet supporting unit; and a pressing-force generating unit configured to generate a pressing force for pressing the sheet supporting unit against the pressing unit at a central part in a direction along which the fold line is formed.

The application relates to a method for zigzag folding a material web, the method having the following steps: continuously feeding a material web to be folded into a folding apparatus along a feed direction, alternately gripping the material web in a proximal region of the folding apparatus by means of gripping devices, holding and conveying the material web by means of the gripping devices into a distal region of the folding apparatus, the material web being zigzag folded thereby, and releasing the material web from the gripping devices and depositing the material web in a stack (9) with folds in the distal region, a distance between adjacent gripping devices (4, 5) being equal to a fold length. Furthermore, the application also relates to an apparatus for zigzag folding a material web.

The application relates to a method for zigzag folding a material web, the method having the following steps: continuously feeding a material web to be folded into a folding apparatus along a feed direction, alternately gripping the material web in a proximal region of the folding apparatus by means of gripping devices, holding and conveying the material web by means of the gripping devices into a distal region of the folding apparatus, the material web being zigzag folded thereby, and releasing the material web from the gripping devices and depositing the material web in a stack (9) with folds in the distal region, a distance between adjacent gripping devices (4, 5) being equal to a fold length. Furthermore, the application also relates to an apparatus for zigzag folding a material web.

An apparatus for treating a stack of sheets of sheet material includes a means for moving the stack of sheets of sheet material towards a first and second fold roller means. The first and second fold roller means are arranged to assist with folding of the stack of sheets of sheet material. The apparatus also includes a first and a second clamping jaw defining a gap. The first and second clamping jaws are arranged to be movable relative to each other to increase and decrease the gap for selective application of a clamping force to the stack of sheets of sheet material having passed between the first and second fold roller means. The first and second fold roller means are mounted in a manner allowing for an increase and decrease in separation and thus between a stack-guiding configuration and a stack compressing configuration.

A sheet processing device can prevent a folded sheet bundle from being opened upon accumulation to prevent a reduction in accumulation amount thereof. The sheet processing device includes a pair of pressing rollers pressing a folding loop of a folded sheet bundle in a thickness direction, a support unit mounted to a device frame and supporting a plurality of rows of the pressing roller pairs such that intervals therebetween in the row direction are reduced stepwise, and a gripper member that makes the folding loop of the folded sheet bundle pass through the support unit in a direction that the intervals of the plurality of rows of pressing roller pairs in the row direction are reduced stepwise. The folded sheet bundle passes through the support unit by the gripper member to cause the folding loop to be sequentially pressed by the plurality of rows of pressing roller pairs.

A sheet processing apparatus includes two pressing members and an advancing-receding unit. The pressing members nip and press against a fold section of a sheet. The advancing-receding unit causes the pressing members to repeatedly press against the fold section by causing at least one of the pressing members to advance to and recede from the other pressing member. The advancing-receding unit varies a reception separation amount and a post-receding separation amount from each other and sets the post-receding separation amount to be smaller than the reception separation amount. The reception separation amount is a separation amount by which the pressing members are separated from each other when the fold section is to be received between the pressing members. The post-receding separation amount is a separation amount by which the pressing members that have pressed against the fold section are separated from each other after receding from the fold section.

The present sheet processing apparatus is to obtain that folding in the center portion in the width direction of sheets is made, folding in the end portion is made more reliably by repeatedly pressing the end portion in the width direction, the folded sheets are harder to open, the appearance is also enhanced, and that collection characteristics are improved in stacking bunches of folded sheets, a sheet processing apparatus is provided with pairs of press members (press rollers 70) that press a folded loop BL of folding sheets BS, and a support unit 56 that shifts in the width direction of the folding sheets, while supporting a plurality of rows with a distance between the press members narrowed stepwise in the shift direction.

A folding machine for folding a stack of sheets, the folding machine comprising: a frame; mechanism for pre-folding a stack of sheets along a crease line into a main plane such that a booklet with a straight back is obtained; mechanism for keeping the pre-folded booklet relative to the frame; mechanism for finishing the fold; and a transport plate having a leading edge around which the stack of sheets is folded, the transport plate being movable along the mechanism for pre-folding and the mechanism for finishing the fold.

A fold-enhancing device includes a pressing member, at least one retaining member, and a moving mechanism. The pressing member presses against a fold line of a recording-medium bundle folded into a booklet shape. The recording-medium bundle is obtained by stacking multiple sheets of recording media. The retaining member retains the recording-medium bundle and is provided at a position located away from the fold line in a direction intersecting the fold line and not in contact with the pressing member. The moving mechanism moves the pressing member and the retaining member in a direction extending along the fold line.

A printing control apparatus configured to control a binding unit configured to perform a binding processing for binding sheets without using a staple includes a control unit that controls the biding unit to divide sheets subjected to printing into sheet groups in units of a number of sheets bindable by the binding unit, and to apply the binding processing to each of sheet groups or controls another binding unit to bind the sheets subjected to printing using a staple.