A sheet processing device inserts a sheet-shaped medium into a two-ply sheet in which two sheets are overlaid and partially bonded. The sheet processing device includes control circuitry to execute a single insertion mode in which one sheet-shaped medium is inserted into the two-ply sheet and a multiple insertion mode in which a plurality of sheet-shaped media are inserted into the two-ply sheet along a conveyance direction. The control circuitry inserts the one sheet-shaped medium into the two-ply sheet in the single insertion mode and the plurality of sheet-shaped media into the two-ply sheet in the multiple insertion mode, with the two-ply sheet being stopped.

A sheet processing apparatus includes circuitry configured to acquire a size of a two-ply sheet, in which two sheets are bonded together at one end, and a size of an insertion sheet; and control a sheet processing operation based on the size of the two-ply sheet and the size of the insertion sheet. The sheet processing operation includes inserting the insertion sheet in the two-ply sheet.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet. The sheet separation device includes a winding roller and a gripper. The winding roller rotates and winds the two-ply sheet to separate the two-ply sheet. The gripper is disposed in the winding roller and configured to grip a gripped portion of the two-ply sheet at one end of the two-ply sheet without abutting a tip of the gripped portion at the one end of the two-ply sheet on a member.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end of the two-ply sheet. The sheet separation device includes a separator that includes a first separator and a second separator. The first separator is inserted into a gap between the two sheets of the two-ply sheet. The second separator is inserted between the two sheets at said another end of the two-ply sheet that is opposite to the one end of the two-ply sheet and moves in a width direction of the two-ply sheet after the first separator is inserted into the gap and relatively moves from the one end to said another end.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet. The sheet separation device includes a separator, an abnormality detection device, and circuitry. The separator is configured to move to be inserted into a gap formed between the two sheets of the two-ply sheet. The abnormality detection device is configured to detect an abnormal state in which the gap larger than a predetermined size is not formed between the two sheets before the separator is inserted into the gap. The circuitry is configured to control movement of the separator based on a result detected by the abnormality detection device.

In a method for producing a collection of pre-products by wrapping a second pre-product around a first pre-product, it is provided according to the invention that said method comprises a number of steps. In one step, a first pre-product is provided, which has an edge region. In another step, a second pre-product is provided. In a further step, the second pre-product is conveyed into a wrapping position. In a further step, the first pre-product is conveyed, with the edge region in front, against the second pre-product located in the wrapping position, as a result of which a wrapping operation is initiated on the second pre-product.

A sheet processing apparatus includes circuitry configured to acquire a size of a two-ply sheet, in which two sheets are bonded together at one end, and a size of an insertion sheet; and control a sheet processing operation based on the size of the two-ply sheet and the size of the insertion sheet. The sheet processing operation includes inserting the insertion sheet in the two-ply sheet.

A sheet processing device sandwiches a sheet-shaped medium in a two-ply sheet in which two sheets are overlaid and partially bonded. The sheet processing device includes a separator, a conveyor, and a switching member. The separator separates the two sheets of the two-ply sheet. The conveyor is disposed downstream from the separator in a sheet conveyance direction and conveys the two-ply sheet. The switching member is disposed downstream from the conveyor in the sheet conveyance direction. The switching member switches a conveyance path of the two-ply sheet to convey the two-ply sheet to a fixing path on which fixing processing is performed on the two-ply sheet or a non-fixing path on which no fixing processing is performed on the two-ply sheet.

A sheet processing device is configured to separate a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end as a bonding portion of the two-ply sheet. The sheet processing device includes a first sheet feeder configured to feed the two-ply sheet, a second sheet feeder configured to feed an inner sheet to be inserted between the two sheets of the two-ply sheet in a state in which the non-bonding portion of the two-ply sheet is separated, and circuitry configured to cause the first sheet feeder to feed the two-ply sheet, perform a sheet separating operation on the two-ply sheet to separate the non-bonding portion of the two-ply sheet, and cause the second sheet feeder to start feeding the inner sheet before completion of the sheet separating operation on the two-ply sheet.

In a method for producing a collection (20) of pre-products by inserting a first pre-product (1) into a second pre-product (3), it is provided according to the invention that a first pre-product (1) and a second pre-product (3) are provided, wherein the second pre-product (3) has a wrapping fold (4) with a fold inner side (5). The second pre-product (3) is conveyed into an insertion position, in which the second pre-product (3) is opened and faces with the fold inner side (5) toward the first pre-product (1). The first pre-product (1) is conveyed into the opened second pre-product (3) and against the fold inner side (5) so as to form the collection (20), the second pre-product (3) assumes the conveying direction of the first pre-product (1), and the collection (20) is provided for further processing.