Abstract: The blanks punched out from a film web and folded to form the jacket are then heated for a short time and cooled again in order to eliminate stresses in the jacket material which give rise to deformations and are also produced by the action of heat during processing of the material.

Abstract: In a protective jacket for disk-shaped recording media, for example magnetic films, fixed magnetic disks, grammophone disks or video disks, the fleece covering in the jacket is fastened close to the outer edges of the jacket and close to the contour lines of the openings by means of heat welded points a short distance apart and in the region inbetween at a distance apart which is several times as large. As a result of the cushions thus formed, a more advantageous cleaning effect is achieved.

Abstract: A recording medium possessing an envelope has at least one identification part which is mounted so that its position can be altered but it cannot be accidentally lost, and which is symmetrical about at least one axis, in particular a middle axis, and is associated with at least one wall of the envelope. To permit error-free assembly/handling, the identification part advantageously has a shape which permits at least two equivalent mounted positions on the envelope.

Abstract: A protective jacket for recording media, in particular flexible recording media, is provided with a network or grid of conductor paths (6) to counteract electric charges, Advantageously, the jacket blank (1) is coated uniformly, in particular on both sides, with linear conductor paths (6). The protective jacket can be used for storing any recording media outside a recording/playback apparatus, or for operating any recording media inside such an apparatus. It is advantageous if, in the areas in which the blank (1) is welded to form a partially or completely closed jacket after folding, a conductor path grid or network is provided so that areas which are free of the conductive layer and are of prescribed dimensions are available between the conductor paths, such areas being necessary for welding.

Abstract: The jacket blanks punched out from a film web are folded to give jackets and then closed by spot welding with the aid of a wavy resistance belt, the welding temperature being produced for a short time by means of a current pulse in the resistance belt.

Abstract: A protective jacket, in particular for recording media, preferably magnetic films, is provided with at least one stiffened region in the immediate vicinity of the read/write area, thus permitting more thorough cleaning of the recording medium and smoother running of the latter. Stiffened region(s) can be produced economically by printing on strips of ink.