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.

The invention relates to a method for producing a butt-welded joint between tube segments of a tube made of a weldable plastic material using a welding machine and to a welding machine (10), two tube segments each being held by a clamping apparatus (11) of a welding device (21) of the welding machine, welding contact surfaces of tube end cross sections of the tube segments being fused by means of a heating element (22) of the welding device and the welding contact surfaces subsequently being pressed against each other by a handling apparatus (18) of the welding device using a joining pressure to form a butt-welded seam connecting the tube segments to each other in a joining plane, the welding device being controlled by a control device of the welding machine, a data model of a tube system having at least one tube and a plurality of butt-welded joints being stored in the control device of the welding device, the data model comprising at least one object dataset representing the corresponding butt-welded joint and each having attributes, the control device detecting at least one weld parameter of the welding device as another attribute for the corresponding butt-welded joint and adding this weld parameter to the object dataset.

An apparatus for welding polymeric pipes such as pipe segments in a pipeline welds first and second pipes around a circumferential weld zone and has one or more welding heads, a carriage for guiding the one or more welding heads around the circumferential weld zone and a drive arrangement for effecting relative rotation between the pipes and the or each welding head. The or each of the welding heads has a body and a heating element carried by the body for supplying heat to the circumferential weld zone to cause melting thereof. The heating element is arranged to reciprocate relative to the body of the welding head between a retracted and an extended configuration such that as the heating element moves from the retracted to the extended configuration the heating element melts and penetrates the surface of the circumferential weld zone forming a weld.