The method includes the step of pulling the corrugated board along hot plates by means of an upper flexible member and a lower flexible member driven by two electric motors. By at least one electric parameter of the drive motor of the lower flexible member, the correct operation of the traction device and in particular the correct ratio of the linear feeding speeds of the two flexible members is checked. The method provides an iterative check of the controlled electric parameter and a possible correction of the speed of the flexible members to maintain the desired speed ratio.

The method includes the step of pulling the corrugated board along hot plates by means of an upper flexible member and a lower flexible member driven by two electric motors. By at least one electric parameter of the drive motor of the lower flexible member, the correct operation of the traction device and in particular the correct ratio of the linear feeding speeds of the two flexible members is checked. The method provides an iterative check of the controlled electric parameter and a possible correction of the speed of the flexible members to maintain the desired speed ratio.

Systems and methods for forming corrugated boards are disclosed. The system includes a single face unit configured to form a single face board having a fluted layer and an outer liner. The system also includes a single face buffer configured to store or hold a length of the single face board. The system has a glue station configured to attach a second outer liner to the single face board to form a single wall board. The system also has an ultrasonic unit configured to apply ultrasonic vibrations to the single wall board. The ultrasonic vibrations are configured to remove moisture from the single wall board, activate, heat, and/or dry an adhesive used to attach the fluted layer and the outer liners, and/or cause the fibers of the fluted layer and the outer liners to weave, intertwine, or otherwise stick together.

A fluid circulation heating roller according to an embodiment of the present invention includes a roller body having a hollow cylindrical shape, a rotation shaft extending from each of opposite end portions of the roller body and disposed in the same center line, multiple first ducts extending in an axial direction in the roller body so as to heat the outer circumferential portion of the roller body, multiple second ducts extending in the axial direction on the outer circumferential portion of the roller body, wherein the number of second ducts are the same as the number of first ducts, and an insert inserted into at least one of the first or second ducts and extending in the axial direction. The generation of turbulence flow of fluid can be suppressed and laminar flow can be induced, whereby it is possible to maintain fluid-flowing speed and facilitate steam circulation and heat transfer.

A corrugated cardboard plant comprises at least one device for producing a respective corrugated cardboard web laminated on one side; a lamination web dispensing device; a lamination web printing device disposed downstream of the lamination web dispensing device; and a device, disposed downstream of the lamination web printing assembly, for producing a corrugated cardboard web laminated on two sides from the at least one corrugated cardboard web laminated on one side and from a lamination web. The at least one device for producing a respective corrugated cardboard web laminated on one side is configured and/or disposed in such a manner that the at least one corrugated cardboard web laminated on one side, at least in a manner adjacent upstream of the device for producing a corrugated cardboard web laminated on both sides, has a respective upwardly directed corrugation. The lamination web in the device for producing a corrugated cardboard web laminated on two sides is guided in such a manner that said lamination web therein runs above the at least one corrugated cardboard web laminated on one side.

The invention concerns a corrugator machine with an intermediate web dispensing device for dispensing an intermediate web, a top layer dispensing device for dispensing a top layer, a printing arrangement located downstream of the top layer dispensing device for printing the top layer, a device located downstream of the intermediate web dispensing device and the printing arrangement for producing a corrugated board web laminated on one side from the intermediate web and the top layer, a lamination web dispensing device for dispensing a lamination web, and a connection device for connecting the corrugated board web laminated on one side and the lamination web with each other whilst forming an at least three-layered corrugated board web.

The single facer includes a first feed path for feeding a first paper web towards a corrugating nip defined between a first corrugating roller and a second corrugating roller. The single facer also includes a second feed path for feeding a second paper web towards a pressure nip defined between the first corrugating roller and a pressure member co-acting with the first corrugating roller. A respective heating system is provided along each feed path. Each heating system includes at least a pair of heating plates.

The method includes the step of pulling the corrugated board along hot plates by means of an upper flexible member and a lower flexible member driven by two electric motors. By at least one electric parameter of the drive motor of the lower flexible member, the correct operation of the traction device and in particular the correct ratio of the linear feeding speeds of the two flexible members is checked. The method provides an iterative check of the controlled electric parameter and a possible correction of the speed of the flexible members to maintain the desired speed ratio.

The hot plate (11) includes an upper plate (61) joined to a lower plate (63) along respective sides parallel to each other. A heat transfer fluid circulation chamber (65) is defined between the upper plate (61) and the lower plate (63), with at least a first inlet (83) of the heat transfer fluid and at least a first outlet (87) of the heat transfer fluid. The lower plate (63) has two downwardly bent edges (63.2), extending along the sides of the upper plate joined to the lower plate. Stiffening ribs (79) are joined to the lower plate (63), along the heat transfer fluid circulation chamber, and to the downwardly folded edges (63.2s) of the lower plate (63).

The method includes the step of pulling the corrugated board along hot plates by means of an upper flexible member and a lower flexible member driven by two electric motors. By at least one electric parameter of the drive motor of the lower flexible member, the correct operation of the traction device and in particular the correct ratio of the linear feeding speeds of the two flexible members is checked. The method provides an iterative check of the controlled electric parameter and a possible correction of the speed of the flexible members to maintain the desired speed ratio.