Abstract: The invention concerns a method for making flexible tube skirts comprising a step of making a cylindrical sleeve from a planar web including several plastic or metal layers followed by a step whereby said cylindrical sleeve is cut out to the desired length to obtain said skirts. It comprises a step prior to the step of making the cylindrical sleeve, wherein the web is subjected to a plastic deformation resulting in its being thinned by at least 0.5% or in producing a raised surface whereof the amplitude ranges at least between 1/30 and 5 times the thickness. The web is for instance passed through the air-gap between two substantially parallel rolls. Typically, the rolls exert on the web a force ranging between 2.5 and 500 newtons per millimetre of web width.

Abstract: The invention disclosure relates to a process for manufacturing a collapsible tube with a wall containing more than 60% by volume of plastic material from a substantially cylindrical, or tubular, blank. The inside and outside layers of the tubular blank are of polymeric plastic material, and the tube has a skirt and a necked head. In the process a shaping operation is performed where an end portion of the tubular blank is necked by bringing closer together inner and outer tools, thus producing crumpled folding of the end of the tube. Prior to the shaping operation the blank is heated in order to bring the portion of the end portion to be shaped to a temperature at the time of the shaping operation which is at least equal to the melting point of the polymeric plastic material forming of the layers the inside and outside surfaces of the wall of the blank. The polymeric plastic material is thus in a viscous molten state at the time of the shaping operation.

Abstract: A process for producing markings or lines engraved on a sheet or a tubular piece (6) made of plastic material or multi-layered metal-plastic material less than 1 mm in thickness, in which the sheet or piece (6) is gripped between a tool (1) bearing one or more marking contour(s) (2, 3) and a resilient support (9), in order to produce the engraved markings or lines. The sheet or piece (6) is at less than 50.degree. C. during the gripping stage, and in the resilient support (9) has a Shore hardness D of between 70 and 120, the markings or lines obtained being produced by plastic deformation with elastic return.