Abstract: A process for the preparation of stable aqueous polycarbodiimide dispersions, to be used as crosslinking agent, which are free of organic solvents is described. Sid process is characterized in: reacting a polyisocyanate in the presence of a carbodiimide catalyst to form a polycarbodiimide, terminating and/or chain extending the polycarbodiimide chain by the addition of formation dispersion of the resulting compound in water, wherein pH is adjusted to a value between 9 and 14 by the addition of a base and/or a buffer to the water used for the dispersion and/or to the obtained aqueous dispersion. According to the present process said terminating or chain extending with the compound containing a hydrophylic group and one or more amine functions may also occur during or after the dispersion of the polycarboiimide in water. The preferred pH of the polycarbodiimide dispersions is between 11 and 13.

Abstract: When sheets (1, 2) with different sizes are processed to a mail item, sheets (1, 2) with different sizes in conveying direction are supplied along first and second conveyor tracks, gathered into a stack and then folded. The folding of the stacked set (7) takes place with at least one predetermined folding length (a). In response to a difference between the folding length (a) and the size of the sheet (2) of the second size, which is within a predetermined range, the conveyor tracks (5, 6) are controlled by the control structure (9) for combining at least the sheets (1, 2) with leading edges (10, 11) at a mutual distance in the conveying direction (3) and with trailing edges (12, 13) at a mutual distance in the conveying direction (3) to form the set (7). From the combining until the folding, the sheets (1, 2) are mutually fixed and during folding, at least one fold (14) is provided in the sheets (1, 2).

Abstract: Postal items are assembled using a system with delivery stations and a folding station. Documents are delivered by the delivery stations. The documents are gathered into a stack having on one side substantially aligned document edges. The stack is supplied to the folding station in a direction transverse to these edges. According to the invention the documents, after being delivered, are displaced relative to each other in an area downstream of the delivery stations and upstream of the folding station until these document edges are substantially aligned on one side of the documents. By virtue of the invention, it is possible, inter alia, to use delivery stations and transport means of simple construction. There is also proposed a system with an aligning station for carrying out the method according to the invention.