The present disclosure relates more to processes for making a filter element that includes a filter membrane having a strip of thermoplastic polymer material laminated thereto, for example, as a strip along an edge of the filter membrane. For example, one such process includes providing a sheet of filter membrane having a first surface and an opposed second surface; providing a strip of thermoplastic polymer material having a first surface and an opposed second surface; contacting the first surface of the strip of thermoplastic polymer material with the first surface of the filter membrane; and softening the strip of thermoplastic polymer material at at least its first surface by irradiation with laser radiation; such that the softened polymer material of the first surface of the strip of thermoplastic polymer material bonds to the first surface of the filter membrane upon hardening.

Method for manufacturing a cell-like honeycomb structure, formed from a plurality of thermoplastic sheets attached to each other, wherein contoured areas are provided in each sheet, and each free sheet is attached to an adjacent sheet of an intermediate block formed by the different sheets previously attached therebetween, welding at least some of the flat areas contacting this free sheet and this adjacent sheet with a laser source along a continuous line parallel to the contour axis.