Abstract: A continuously conveyed tubular plastic foil is perforated by a laser beam which is focused by a mirror or lens on the perforation forming plane, lying at the focal point of the mirror or lens, of a tautly conveyed tubular plastic foil. For taut conveyance of the tubular foil it is guided over a support placed in the tubular foil, or over supporting plates, lying outside the tubular foil and provided with a foil suction device and with laser beam transmission apertures. The slightly tapering perforations with a minimum aperture at the inside of the tubular foil form, on the one hand, a pattern of parallel lines running in the lengthwise direction and, on the other hand, a pattern of parallel lines which run at an angle relative to the longitudinal axis of the flattened tubular foil. A bag can be formed from the tubular foil.

Abstract: Welding sleeve comprising electrically conductive material embedded in the thermoplastic material of the wall of said sleeve.In a sleeve at least two connecting means are present which each comprise at least two metal parts which can cooperate in clamping contact with the electrically conductive material.One metal part is inserted from the inside of the sleeve and one part from the outside; appropriate coaxial bores being present to allow passage of a pin on the lower part and the body of the upper part.Upon mounting the upper part and lower part are connected with use of a force; the electrically conductive material is clampingly contacted.The invention also relates to a method for forming a welding sleeve according to the invention and to an equipment for use in carrying out such a method.