A method for manufacturing straws includes the steps of predisposing a web or a discrete sheet of sheet material, wherein the web or discrete sheet extends between an end portion and tail portion; predisposing a winding body extending along an axis; completely winding the web or discrete sheet around the winding body for defining a cylindrical body of sheet material wherein the end portion and tail portion face each other for defining a mutual overlapping portion; and constraining the end portion to the tail portion in the mutual overlapping portion in order to define a straw extending between a first and second substantially circular free edges, wherein the mutual overlapping portion extends between the first and second free edges of the straw along a rectilinear direction.

A plastic film roll includes: a convolute cardboard tube including a tubular body having a tubular body wall formed by a plurality of layers of a straight rolled cardboard sheet having a weight equal to or less than 300 gsm; a plastic film wound about the convolute cardboard tube to form a plurality of plastic film windings around the convolute cardboard tube, the plastic film windings creating a radial compression force equal to or greater than 10 bar on the tubular body wall, wherein the cardboard sheet includes a plurality of fibers, at least a majority of the fibers being substantially aligned in a tangential direction relative to the tubular body to allow the convolute cardboard tube to resist the radial compression force.

A method for producing a convolute paper core of a desired width and thickness, the method including unwinding paper from a paper roll, thereby creating unwound paper, conveying the unwound paper to a cutting position in a feeding direction, cutting the unwound paper, thereby creating a paper sheet having a length L, conveying the paper sheet from the cutting position to a mandrel in a winding direction, wherein the winding direction is perpendicular to the feeding direction, adhesively and convolutely winding the paper sheet on the mandrel so as to produce a paper core, so that a width W of the paper core is equal to the length L, and repeating the steps of unwinding, conveying, cutting, conveying and adhesively and convolutely winding a plurality of paper sheets until the paper core has the desired thickness.

A method for producing a convolute paper core of a desired width and thickness, the method including unwinding paper from a paper roll, thereby creating unwound paper, conveying the unwound paper to a cutting position in a feeding direction, cutting the unwound paper, thereby creating a paper sheet having a length L, conveying the paper sheet from the cutting position to a mandrel in a winding direction, wherein the winding direction is perpendicular to the feeding direction, adhesively and convolutely winding the paper sheet on the mandrel so as to produce a paper core, so that a width W of the paper core is equal to the length L, and repeating the steps of unwinding, conveying, cutting, conveying and adhesively and convolutely winding a plurality of paper sheets until the paper core has the desired thickness.

A method and a device for repairing portions of channels, including non-round channels, is provided by a wound tube wound from a profile strip by a winding machine, the abutting edges of which strip are formed into tight joints, locked inside the wound tube which can be introduced into the portion of the channel to be repaired. A plastic profile strip is drawn from a storage spool and fed to a winding machine arranged in front of one of the openings of the channel to be repaired, the winding machine having a guide rail adapted to the cross-portion of the channel, and adjacent edge regions fed onto this rotating winding former locked in an overlapping manner to form a wound pipe and the pipe is pushed or pulled into the channel portion.

A plastic film roll includes: a convolute cardboard tube including a tubular body having a tubular body wall formed by a plurality of layers of a straight rolled cardboard sheet having a weight equal to or less than 300 gsm; a plastic film wound about the convolute cardboard tube to form a plurality of plastic film windings around the convolute cardboard tube, the plastic film windings creating a radial compression force equal to or greater than 10 bar on the tubular body wall, wherein the cardboard sheet includes a plurality of fibers, at least a majority of the fibers being substantially aligned in a tangential direction relative to the tubular body to allow the convolute cardboard tube to resist the radial compression force.

The invention relates to a polygonal container comprising a tubular polygonal body (10) with an even number of flat faces (11) numbering more than four, which is formed by a strip of corrugated cardboard (19) rolled up at least two full turns and adhered to itself by means of lines of glue (30) transverse to the channels of the corrugated cardboard, forming a multilayer wall (13); a base body (20) defined by a base panel of cut and folded stiff double-faced corrugated cardboard (24) attached around an end portion of the tubular polygonal body (10). The method comprises forming the tubular polygonal body by means of rolling the strip of corrugated cardboard around a polygonal rotary drum (51) and subsequently attaching to a base body (20).

A method for manufacturing flexible paper straws and flexible paper straws are revealed. The method includes the steps of preparing a paper tube which is a spiral tube by glue and paper, inserting a support shaft into the paper tube axially, placing the paper tube with the support shaft between a first roller and a second roller before curing of the glue while the first and second rollers are in parallel and having a plurality of circular grooves on a cylindrical surface thereof, rolling the paper tube by the first and second rollers to form a corrugated portion on a part of the paper tube, squeezing the corrugated portion to compress the corrugated portion for a period of time for curing the glue and holding shape of the corrugated portion, and removing the support shaft to get a flexible paper straw which is bendable at the corrugated portion.

A convolutely wound tube (1) is formed of a composite sheet including a first sheet (6) and a second sheet (5). The convolutely wound tube includes a first segment (66) formed of a plurality of convolute windings (2) of the first sheet, a second segment (70) formed of directly adhered and overlapping portions of the first sheet and the second sheet, and a third segment (68) formed of the second sheet wrapped about and overlying the first sheet. The second segment is an underwrap portion positioned between a layer of the first sheet and a layer of the second sheet.

A convolutely wound tube (1) is formed of a composite sheet including a first sheet (6) and a second sheet (5). The convolutely wound tube includes a first segment (66) formed of a plurality of convolute windings (2) of the first sheet, a second segment (70) formed of directly adhered and overlapping portions of the first sheet and the second sheet, and a third segment (68) formed of the second sheet wrapped about and overlying the first sheet. The second segment is an underwrap portion positioned between a layer of the first sheet and a layer of the second sheet.