EP0025759B1 - Machine for manufacturing single-faced corrugated board - Google Patents

Description

The present invention relates to a machine for the production of corrugated cardboard coated on one side, commonly called "single-sided corrugator", and more specifically relates to a device for retaining the sheet of paper on the second corrugation roller, called "lower grooved cylinder", used on this kind of machine. The invention also relates to a lower grooved cylinder usable for a tell machine.

• - le montage et le démontage des peignes est long et difficile,
• - en raison de la présence des peignes, il n'est pas possible de déposer de la colle en face de chacun de ceux-ci,
• - le papier frottant en permanence sur les peignes, l'usure est rapide et les frais de maintenance sont élevés,
• - pour décoller le papier cannelure du cylindre cannelé supérieur, les peignes doivent s'engager dans ce dernier, ce qui y implique l'usinage de gorges.

The corrugation of the paper is generally obtained in a single-sided corrugator by thermoforming between two fluted cylinders heated by their hollow interior space with saturated steam, and implemented in meshing by means of two jacks. To prevent the separation of the corrugated sheet from the second corrugation roller, called the lower fluted cylinder, it is necessary to provide a device for retaining the sheet on the latter cylinder. The retaining devices used until now are mechanical and generally consist of a set of guide fingers, or "combs", in contact with the wavy sheet in movement. Such retaining devices have a number of drawbacks:

• - the assembly and disassembly of the combs is long and difficult,
• - due to the presence of the combs, it is not possible to deposit glue in front of each of them,
• - paper rubbing permanently on the combs, wear is fast and maintenance costs are high,
• - to take off the fluted paper from the upper fluted cylinder, the combs must engage in the latter, which involves the machining of grooves.

Instead of using mechanical retaining means, consideration has long been given to using suction retaining means. U.S. Patent 3,947,206 in particular describes a single-sided corrugator in which the paper is retained on the lower grooved cylinder by suction through a large number of small radial holes. These small radial holes are supplied via longitudinal channels which can supply a maximum of three rows of holes, one row being heard along a generatrix of the cylinder.

Such a known device involves the drilling of a very large number of small holes, some of which, in the case shown diagrammatically in FIG. 11 of this US Pat. No. 3,947,206, must be drilled at an angle. The machining of such a cylinder is theoretically perfectly feasible, but so delicate that it involves a high cost of production. Furthermore, the embodiment according to FIG. 11 of this US Pat. No. 3,947,206 is difficult to think of in practical terms with more than three channels 45, so that a large number of longitudinal channels 61 is necessary, which reduces the rigidity of the grooved cylinder, rigidity which is essential to ensure proper formation of the grooves.

The single-sided corrugator of the invention does not have the drawbacks due to the devices described above. It is of the type comprising, for the formation of the groove of the paper, an upper grooved cylinder and a lower grooved cylinder applied in meshing, at least the lower grooved cylinder having a hollow interior space intended to receive saturating steam for heating. , said corrugator being of the type according to which the retention of the corrugated paper on the lower corrugated cylinder is effected by suction of the paper on the said cylinder via channels or orifices, and is characterized in that these channels or orifices open into wider cavities in the form of elongated grooves formed on circumference portions, machined transversely on the periphery of said lower grooved cylinder, extending over several corrugations thereof, and arranged in staggered rows.

The invention also relates to a grooved cylinder for a single-sided corrugator, said cylinder being of the type having a hollow interior space intended to receive saturating heating vapor, and comprising, outside said hollow interior space, separate longitudinal channels. and drilled in the peripheral part of the body of said cylinder, as well as radial channels or orifices connecting said longitudinal channels to the outside, and it is characterized in that said radial channels or orifices open therein into larger cavities which are presented under the form of elongated grooves made on circumference portions, machined transversely on the periphery of said cylinder, extending over several corrugations thereof, and arranged in staggered rows.

• - la figure 1 est une vue latérale schématique d'une onduleuse simple-face conforme à l'invention;
• - la figure 2 est une vue perspective des cylindres cannelés supérieur et inférieur selon la direction F de la figure 1;
• - la figure 3 est une vue en coupe latérale du cylindre cannelé inférieur équipant l'onduleuse de la figure 1;
• - la figure 4 est une vue de face sur une section effectuée selon, la direction AA' de la figure 3;
• - la figure 5 est une vue agrandie d'un détail . de la figure 3;
• - la figure 6 représente schématiquement une variante de l'onduleuse précédente permettant le travail avec différentes largeurs de laize;
• - la figure 7 représente schématiqement une variante des onduleuses selon les figures 1 à 6.

The invention will be better understood with the aid of the following description of a few exemplary embodiments, with reference to the appended drawings in which:

• - Figure 1 is a schematic side view of a single-sided corrugator according to the invention;
• - Figure 2 is a perspective view of the upper and lower grooved cylinders in the direction F of Figure 1;
• - Figure 3 is a side sectional view of the lower grooved cylinder fitted to the corrugator of Figure 1;
• - Figure 4 is a front view on a section taken along the direction AA 'of Figure 3;
• - Figure 5 is an enlarged view of a detail. of Figure 3;
• - Figure 6 schematically shows a variant of the previous corrugator allowing work with different widths of width;
• - Figure 7 shows schematically a variant of the corrugators according to Figures 1 to 6.

Referring to Figures 1 to 5, the corrugated paper 2 is, in known manner, corrugated by passing between two grooved cylinders 3 and 4 placed one above the other as shown in the drawings, then glued to a paper cover 1 between the lower grooved cylinder 4 and a smooth cylinder 5, to finally exit the machine in the form of a strip of single-sided corrugated cardboard 9. The cylinders 3 and 4 are heated by steam at a temperature of 200 ° C approximately and under pressure of approximately 16 bars admitted, by a conventional device not shown, inside the cylinders which are therefore hollow as a result, which allows the paper to reach the optimum temperature for the thermoforming of the groove . The corrugated paper receives the glue by a cylinder 6 which dips in a glue tank 8. The thickness of glue deposited on the paper is adjusted by the interval existing between the cylinder 6 and an auxiliary cylinder 7.

As can be seen in the figures, the lower grooved cylinder 4 is machined, in a conventional manner, in the form of a ferrule 10 allowing the admission of steam into its interior space 11. Furthermore, a large number of longitudinal channels 12 are drilled in the body of the shell 10 so as to be regularly distributed over the entire width of the cylinder. Axial holes 13 of a smaller diameter are also drilled about every 8 cm along each channel 12 and, in accordance with the invention, put each of these in communication with larger cavities 14 machined on the exterior of the grooved cylinder 4. The cavities 14 are in the form of elongated grooves machined on circumference portions of the periphery of the cylinder 4, staggered on said periphery as seen in Figure 2, and extending on several undulations of said cylinder. As can be seen in particular in FIG. 5, the cavities 14 also have a section in the shape of an arc of a circle and, extending over several corrugations of the cylinder, have a depth P greater than that h of the groove profile.

At each end of the cylinder 4, and on the edge thereof, is installed a fixed sector, sealed, hollow and in an arc of a circle, which rests on the part of the edge of the cylinder 4 which corresponds to the retaining zone. paper on the cylinder 4 during its path between the cylinders 3 and 5. Each hollow sector 15 is connected to a vacuum pump not shown and operating continuously. Furthermore, two additional hollow and sealed sectors 25 are placed immediately following the sectors 15, one on each edge of the cylinder 4. The sectors 25 are of sufficient width to be able to include at least one of the channels 12 and are supplied by a source. compressed air not shown.

The operation of the groove paper retainer on the cylinder 4 is as follows: When the cylinder 4 rotates, each channel 12 passes alternately through the sectors 15 and then into the open air. The passage in front of the sectors 15 makes it possible to transmit the depression due to the vacuum pump in the cavities 14 which correspond to the channels 12 located in said sectors. The paper is consequently held by suction against the cylinder 4 throughout the retaining zone, encompassed by the sectors 15. Then, as can be seen in FIG. 1, each channel 12, when it escapes from the sectors 15, is returned in the open air, then enters sectors 25; there is then a blowing through the cavities 14, which facilitates the release of the corrugated paper web from the cylinder 4.

In FIG. 6, an improved variant of the previous device has been shown diagrammatically, making it possible to work with widths of corrugated paper of different sizes. According to this variant, two annular plates 16, on which are welded tubes 17 sliding in the ends of each channel 12, are made integral with the grooved cylinder 4 and therefore rotate with it. The value of the insertion of the tubes 17 into the channels 12 is regulated by two screws 23 which are screwed longitudinally in the body of the grooved cylinder 4.

In the tubes 17 and in the upper part of these are pierced several holes (18, 19, 20) spaced so that their edges situated towards the edge of the cylinder 4 are distant from the interval separating two holes 13 and so that their diameter is equal for the first hole 18 to the diameter d of a hole 13, then to 2d for the second hole 19 and to 3d for the third and last hole 20.

In the sliding position 0 shown in the drawing, each of the three holes 18, 19, 20 is opposite one of the orifices 13 so that the vacuum is transmitted to the corresponding cavities 14, which allows working at full width L as shown in the drawing.

If we want to work in narrower width A, we cause, by rotation of each screw 23 outward, the output of each cylinder 17 by an amount d, so that each first orifice such as 13a is blocked while all the following ports such as 13b and 13c are still connected to the vacuum pump.

Similarly, for an even narrower width B, a 2d sliding towards the outside is caused. The first hole 18 is no longer in correspondence with its orifice 13a and the second hole 19 is also no longer in correspondence with its orifice 13b, so that one sucks well on the width B and not on the outside.

For an even smaller width C, a 3d displacement is likewise caused so as to block the third orifice 13c. We could continue so on with longer tubes 17.

Thanks to this additional device, it only sucks in the area actually covered by the corrugated paper even for widths less than the full width.

Figure 7 shows schematically a variant of the two previous devices, relating to the case where, depending on the speed and quality of the paper, it is necessary to move the point A corresponding to the start of the plating by suction of the paper on the cylinder 4. A toothing 21 is then cut in each of the sectors 15, and this toothing meshes with a pinion 22 mounted on the shaft of a motor not shown. By turning the motor in one direction or the other, the pinion 22 rotates the sector 15 correspondingly by means of the toothing 21. By means of a tachymeter generator, mounted on the drive of the entire single-sided corrugator and connected to the drive motor of the two pinions 22, it is then easy to control the position of the two sectors 15 as a function of the speed of the corrugator.

Claims (2)

1. Single facer for corrugated cardboard, of the type comprising, for forming the corrugation in the paper, an upper corrugating roll (3) and a lower corrugating roll (4) interacting by meshing, at least the lower corrugating roll possessing a hollow interior space (11) intended for receiving the saturating steam for heating, the said single facer corrugating machine being of the type in which the corrugated paper is held on the lower corrugating roll by suction of the paper onto the said roll via channels (13) or orifices, characterised in that the channels or orifices emerge in wider cavities which are in the form of elongate grooves (14) produced over portions of the circumference, machined transversely on the periphery of the said lower corrugating rool, extending over several grooves in the cylinder and arranged in a staggered formation.

2. Corrugating roll for a single facer machine, the said roll being of the type possessing a hollow interior space (11) intended for receiving the saturating steam for heating, and comprising, outside the said hollow interior space (11), separate longitudinal channels (12) made in the peripheral part (10) of the body of the said cylinder, and also radial channels (13) or orifices connecting the said longitudinal channels (12) to the outside, characterised in that the said radial channels (13) or orifices emerge in wider cavities which are in the form of elongate grooves (14) produced over portions of the circumference, machined transversely on the periphery of the said cylinder, extending over several grooves in the latter and arranged in a staggered formation.

Images