A forming device for gathering the width of a traveling web is disclosed. The forming device includes opposing arrays of flute-forming bars that can be interlaced to define therebetween a longitudinal flute-forming labyrinth effective to reduce the width of a web traveling therethrough by a preselected take-up ratio. The flute-forming bars are curved beginning at an entry end of the forming device such that they converge in a lateral direction as they proceed in the machine direction. In this manner, individual elements of the web traveling between the respective arrays in the machine direction follow contour lines along the curved bars or between adjacent ones of the curved bars so that no such element crosses any flute-forming bar in the cross-machine direction as the web travels and is fluted. A corrugating die for introducing a near-net shape to the intermediate-fluted web is also disclosed, as are a corrugating line incorporating these operations and methods for its operation.

The invention relates to an assembly for producing an endless corrugated cardboard web laminated on at least one side, the assembly comprising a first corrugating roller and a second corrugating roller for producing a corrugated web provided with a corrugation as well as a glue application assembly. The glue application assembly comprises a glue container for receiving glue, a glue application roller for applying the glue disposed in the glue container to tips of the corrugation of the corrugated web, and at least one glue wave inhibiting assembly arranged in the glue container for inhibiting the formation of glue waves of the glue disposed in the glue container. The assembly for producing an endless corrugated cardboard web laminated on at least one side further has a pressure assembly for pressing a cover layer against the tips, provided with glue, of the corrugated web.

The object of the present invention is to provide a hot melt adhesive which is less likely to cause stringing, and has excellent thermal stability and adhesion, in particular adhesion to a paper material. The present invention relates to a hot melt adhesive comprising: (A) an olefin-based polymer, (B) a butyral resin, (C) at least one selected from the group consisting of a fatty acid and a derivative thereof, and (D) a tackifier resin.

A method of manufacturing a corrugated liner for a food container using a rotary die cutting machine, and a die element for use with such a die cutting machine. The method includes feeding a planar blank of material between opposed die and anvil cylinders of the rotary die cutting machine, cutting and perforating each planar blank with the die cylinder, and forming a plurality of die-cut products each in sheet form and having a plurality of planar polygonal liners on each sheet. Immediately adjacent ones of the planar polygonal liners on each sheet are connected to one another along immediately adjacent and mating straight peripheral portions thereof by respective perforated connection areas. The method additionally includes ejecting each die-cut product sheet from the rotary die cutting machine, and the perforated connection areas of each sheet maintain the plurality of planar polygonal liners thereof in a connected state with one another.

Process for continuously producing ribbons of corrugated fibrous material, includes: starting from a continuous ribbon of fibrous material having transversal extensibility of not less than 8%, advancing the ribbon between a pair of forming rollers presenting ribs alternating with grooves, and having a center distance such that the ribs of one roller are partially housed within the grooves of the other roller and define between them a corrugated interspace having a thickness greater than the thickness of said ribbon and a width substantially equal to the width of the flat ribbon, which at the exit presents a longitudinal undulation obtained by transversal stretching thereof, passing the longitudinally corrugated ribbon thus obtained between a pair of stabilizing rollers with complementary ribs and grooves interpenetrating such as to present a distance between them less than the thickness of the ribbon thereby subjecting the ribbon to a stabilization compression of the obtained corrugations.