(EP496217-A1)      In a solar heater the absorber body is bored for water or other medium carrying heat, the flow bores being produced by shaping plastic material. A film is applied to a sheet which has slots of about the same width as the flow bores. The film is shaped into a channel through the slots to form part of the wall of the bore and is tightly enclosed on the other side. The film is pref. a modified ethylene-tetrafluorethylene copolymer.    ADVANTAGE -   The prod. is inexpensive and has a long service life. By using a film of the recommended type with resistance to UV, the prod. can be used in swimming bath heaters and bacteria in the water can be killed by irradiation. The film can be produced by thermoforming and then immediately welded to the adjacent material. The cover sheet in the construction provides mechanical protection.    (DE4102511-C2)      An absorber uses flexible plastics film for the flow channels and a cover plate (12) with surmounted black bearer plate (20) is slotted out (22) to a width equal to that of the flow path. The plate is connected to the film (14) which is troughed (15) to limit part of the flow path, the opposite side of the film from the trough to be sealed. The film is fixed to the plate and drawn through the plate slots, specifically welded to the plate between the troughed areas (15) giving flat weld zones (18).    Two cover plates and interposed troughed film part, thus form a tubular film system. The film is made of UV-resistant material, specifically modified ethylene-tetrafluoroethylene-copolymer. The plate slots (22) are joined together at the plate ends by cross cuts (26) so that film drawn through these (26) forms a connecting channel. The film formats are tensioned firm inside by glass fibre rings, etc.    USE/ADVANTAGE -   Used for solar heating systems. Film welded to slotted over plate forms troughed flow duct in thermally sealed design devoid of obstacles with reduced installation costs and skill requirement.    (US5323763-A)      Absorber body for direct or indirect heating of fluids by solar energy comprises a panel with elongated slot-like openings, each as wide as the desired width of a flow path (16), covered by a translucent foil (66) having shaped portions of channel-like cross section and welded to a cover panel. The foil is pref. of a modified ethylene-tetrafluoroethylene copolymer.    ADVANTAGE -   Inexpensive to produce, long life, eliminates bacteriological contamination.    (EP496217-B1)      Absorber with conduits for conveying water or another liquid heat transfer medium for the direct or indirect heating of liquids or similar flow media by solar energy, in which the conveying conduits are produced by shaping plastic, characterised in that a plate is provided with slot-shaped openings, the width of which corresponds approximately to the width (a) of the conveying conduit, and a film is applied to the plate said film being shaped into a film part with an approximately channel-shaped cross section through the openings in order to form a partial restriction in the conveying conduit and being sealed on the side remote from the channel-shaped cross section.