FOERFARANDE FOER FRAMSTAELLNING AV FOEREMAOL AV FILTERPAPPER.

摘要

A process for manufacturing articles of filter paper in which the wet strength of the regions of weak points resulting from mechanical working is increased by the application of a wet strengthener of cross-linked cationic polyalkylenimines. For this purpose, the wet strengthener is applied only to the regions of the weak points after the filter paper has been manufactured. Seams or edge reinforcements are formed by relief printing before the application of the wet strengthener and a heat treatment takes place after application of the thermoplastic wet strengthener to cause the wet strengthener to harden. The application of the wet strengthener is effected in measured doses so that the legally prescribed maximum amounts to be added are not exceeded.