EP1048464A1 - Method of printing in a rotary press - Google Patents

Abstract

The printing material is fed from a main stock drum (10) via various feed rollers toward a printing station (2). The printin station comprises of a pair of main printing drums (2b) and a pair of off-set driving drums (2a). A supple material is located o the surface of the print rollers that take the printing ink and transfer the printing pattern onto the print material. The print material is passed through a curing station before final processing.

Description

The present invention relates to a printing process, on press rotary, improved.

According to the invention, an improvement is proposed to facilitate the operation of rotary printing presses, in particular the operation of rotary presses used to date in offset. Said improvement makes it possible to remedy problems, inevitably encountered, during use, according to prior art, of this type of printing material. Said improvement is all the more interesting as its field of application is vast: it can be implemented works on any type of press, as part of any printing process using, to deposit the ink on the support to be printed, a flexible material (of soft consistency) and in particular a rubberized material (such as a blanket, offset) to print any type of support, conditioned in reels: paper, cardboard Or other.

On reading the following description of the invention, the man of the profession will understand that to date the scope of application of said invention is mainly that of offset but that in any event said invention is transposable, exploitable, beneficial in any printing context where, for deposit the ink on the support to be printed, we use a flexible material.

A large part of the printing is carried out on rotary presses, which print the support to be printed, such as paper, packaged in reels. Before the end of a support reel during printing, a bonding of the unwinding strip, with the start of a new support reel, is generally carried out by an automatic adhesive device, known per se. A new coil is thus put into service, without stopping the press. In case of rupture of the support to be printed, photoelectric cells detect the absence of band and then cause the stop of the press.

On an offset press, the media to be printed passes between cylinders printing, at least one of which is covered with a rubber called a blanket. The ink is deposited on said support by said blanket.

1) lors de la mise en pression d'une rotative offset (lors du démarrage de l'impression), il arrive relativement fréquemment que le support à imprimer, notamment le papier, reste collé sur le blanchet intervenant ou sur l'un des blanchets intervenants (plusieurs blanchets peuvent intervenir successivement dans un groupe d'impression et/ou deux blanchets interviennent simultanément pour une impression recto-verso). Ceci provoque une rupture de la bande de support et un enroulement d'au moins une partie de celle-ci autour dudit blanchet, monté sur un cylindre d'impression. Un tel enroulement peut avoir des conséquences plus ou moins graves, pouvant aller d'une simple perte de temps à la destruction partielle ou totale d'au moins un cylindre d'impression et de ses accessoires ;

2) au fur et à mesure de l'utilisation de la presse, on observe une pollution du(des) cylindre(s) d'impression portant un blanchet, pollution provoquée par le dépôt, l'accumulation, de particules qui se détachent du support à imprimer, papier ou carton. Lesdits dépôts provoquent une dégradation progressive de la qualité d'impression et sont susceptibles d'entraíner, lorsqu'ils deviennent très importants (qu'ils s'écroulent en bordure de laize et interfèrent avec le bord de la bande en défilement), la rupture dudit support à imprimer ;

3) lors des opérations de collage, pour la mise en service d'une nouvelle bobine, sans arrêt de la presse, deux autres types de difficultés apparaissent :

3a) le support issu de la fin de la bobine en cours se trouve, au niveau du joint de collage, superposé à celui issu de la nouvelle bobine. Au niveau dudit joint, on se trouve donc en présence de deux épaisseurs de support au lieu d'une. Lors de l'impression de la bande, au niveau de ce joint, la pression est temporairement excessive ; elle est d'autant plus excessive que le papier ou carton intervenant est de plus fort grammage. Cette pression excessive peut être suffisante pour provoquer la déstratification dudit papier ou carton (support), c'est-à-dire une séparation des différentes couches de fibres le constituant. Dans une telle hypothèse, une partie dudit support déstratifié s'enroule généralement autour d'un des cylindres de la presse, tandis que l'autre peut poursuivre son parcours dans la rotative. Si tel est le cas, la bande n'étant pas cassée, la presse n'est pas automatiquement arrêtée par les dispositifs de détection (de rupture de ladite bande) habituels et les conséquences de l'incident sur les organes mécaniques de la presse peuvent être fortement dommageables ;

3b) lorsque les deux bandes successives de support ne sont pas en parfait alignement, l'un des bords de la "nouvelle bande" (issue de la nouvelle bobine) se retrouve au contact de parties de cylindre d'impression chargées de particules, de salissures, déposées sur les bords de la laize. On observe alors un phénomène d'adhérence dudit bord sur le cylindre, phénomène d'adhérence susceptible de provoquer une rupture de la bande et un enroulement d'au moins une partie de celle-ci autour dudit cylindre. Un tel enroulement, comme déjà indiqué au point 1) ci-dessus, peut avoir des conséquences plus ou moins graves, pouvant aller d'une simple perte de temps à la destruction totale ou partielle d'au moins un cylindre d'impression et de ses accessoires.

The main problems, inevitably encountered when using rotary presses (mainly offset, to date) are briefly discussed below:

1) during the pressurization of an offset press (when printing starts), it relatively frequently happens that the support to be printed, in particular paper, remains stuck on the blanket involved or on one of the blankets interveners (several blankets can intervene successively in a printing unit and / or two blankets intervene simultaneously for a double-sided printing). This causes a rupture of the support strip and a winding of at least part of it around said blanket, mounted on a printing cylinder. Such a winding can have more or less serious consequences, which can range from a simple waste of time to the partial or total destruction of at least one printing cylinder and its accessories;

2) as the press is used, pollution of the printing cylinder (s) bearing a blanket is observed, pollution caused by the deposition, accumulation, of particles which detach from the print media, paper or cardboard. Said deposits cause a gradual deterioration of the print quality and are likely to cause, when they become very large (that they collapse at the edge of the width and interfere with the edge of the moving tape). said support to be printed;

3) during bonding operations, for the commissioning of a new coil, without stopping the press, two other types of difficulties appear:

3a) the support coming from the end of the current reel is, at the glue joint, superimposed on that coming from the new reel. At the level of said joint, we are therefore in the presence of two thicknesses of support instead of one. When printing the strip, at this joint, the pressure is temporarily excessive; it is all the more excessive as the paper or cardboard involved is of heavier grammage. This excessive pressure may be sufficient to cause delamination of said paper or cardboard (support), that is to say a separation of the different layers of fibers constituting it. In such a case, part of said destratified support is generally wound around one of the cylinders of the press, while the other can continue its journey in the press. If this is the case, the belt not being broken, the press is not automatically stopped by the usual detection devices (rupture of said band) and the consequences of the incident on the mechanical parts of the press can be highly damaging;

3b) when the two successive bands of support are not in perfect alignment, one of the edges of the "new band" (from the new reel) is found in contact with parts of the printing cylinder loaded with particles, dirt, deposited on the edges of the width. We then observe a phenomenon of adhesion of said edge on the cylinder, adhesion phenomenon capable of causing a rupture of the strip and a winding of at least part of it around said cylinder. Such winding, as already indicated in point 1) above, can have more or less serious consequences, which can range from a simple waste of time to the total or partial destruction of at least one printing cylinder and its accessories.

1) en référence au problème n° 1, que l'on pourrait qualifier de collage au démarrage, il a été proposé, dans le cadre de savoirs-faire, de projeter, de l'eau, voire de l'eau siliconée, sur le(s) blanchet(s) en cause. Une telle eau n'intervient qu'au démarrage (le(s) blanchet(s) n'étant pas encore pollué(s)) ;

2) en référence au problème n° 2, que l'on pourrait qualifier de pollution en cours d'impression, l'imprimeur dispose à ce jour de deux technologies (pour éliminer les dépôts) :

• soit il arrête la presse et il effectue un lavage manuel du(des) blanchet(s) à l'aide d'un solvant approprié et/ou d'eau, suivant la nature du dépôt ;
• soit il effectue un tel lavage, sans arrêt de la presse, grâce à un dispositif de lavage automatique de blanchets que l'on trouve à ce jour sur le marché. On trouve en fait deux types de tels dispositifs : ceux qui frottent le blanchet avec un substrat textile humidifié et ceux qui frottent ledit blanchet avec une brosse ou tout autre moyen mécanique équivalent.

Ces deux technologies de lavage sont loin d'être satisfaisantes.Dans le cas d'un lavage manuel, il y a obligation de stopper la presse, ce qui engendre, à la fois : une gâche de papier importante, lors du redémarrage ; et une perte de production pendant toute l'opération de nettoyage. Une telle opération de nettoyage peut être relativement longue et doit être mise en oeuvre sur tous les cylindres blanchets que comporte le groupe d'impression.Par ailleurs, une telle opération de nettoyage n'est pas valorisante (elle n'est guère appréciée des opérateurs, dans la mesure où elle est pénible, salissante et fastidieuse) et elle génère de la pollution : des substrats de nettoyage, type chiffons ou éponges, chargés en encre, solvants et divers constituants du support à imprimer, d'une part et des solvants et/ou eaux souillés, d'autre part, qu'il convient, par la suite, de traiter.Dans le cas de l'utilisation de laveurs automatiques, quel que soit leur type, on est également confronté à de nombreux problèmes. Ainsi, avec les laveurs utilisant un substrat textile, on doit gérer la consommation et la destruction dudit substrat (généralement un nontissé). Lesdits laveurs sont par ailleurs relativement encombrants, peuvent entraíner des gênes à la mise en oeuvre de l'impression, requièrent de la maintenance. Enfin, le fait d'exercer un frottement sur le blanchet provoque une abrasion et entraíne donc une usure plus importante de celui-ci.Ainsi, avec les laveurs utilisant une brosse ou tout autre moyen mécanique équivalent, on doit gérer le nettoyage de ladite brosse ou dudit autre moyen. Lesdits laveurs sont par ailleurs également relativement encombrants, peuvent aussi entraíner des gènes à la mise en oeuvre de l'impression et requièrent également de la maintenance (notamment en référence à l'usure de la brosse ou du moyen équivalent). Leur intervention est également responsable d'une usure, par abrasion, des blanchets nettoyés.Ces solutions de l'art antérieur, au problème n° 2 identifié et précisé ci-dessus, ne sont donc pas pleinement satisfaisantes.En référence auxdits problèmes n°1 et n°2, on peut encore mentionner l'enseignement de la demande FR-A-2 767 498. Selon ledit enseignement, le dépôt d'un liquide actif à action(s) nettoyante, dissolvante, fluidifiante et/ou diluante est préconisé sur la bande à imprimer, en défilement.

3)

3a) en référence au problème n° 3a, que l'on pourrait qualifier de déstratification, il n'a pas vraiment été proposé de solution. Au mieux, l'imprimeur augmente le mouillage du cylindre plaque (en amont du cylindre blanchet), au moment du collage. Un tel mouillage n'est toutefois pas une solution qui résout à tout coup le problème...;

3b) en référence au problème n° 3b, que l'on pourrait qualifier de collage sur l'un des bords, il a été préconisé, dans le cadre de savoir-faire une application d'huile sur les bords de la nouvelle bobine. Une telle application, locale, a en effet pour effet de neutraliser les conséquences du mauvais alignement des bandes. Sa mise en oeuvre, à l'échelle industrielle, reste délicate.

To said main problems, it has been proposed, according to the prior art, various solutions, specific, more or less satisfactory. So :

1) with reference to problem n ° 1, which could be described as bonding at start-up, it has been proposed, in the context of know-how, to spray water, or even silicone water, onto the blanket (s) in question. Such water only intervenes at start-up (the blanket (s) not yet being polluted);

2) with reference to problem n ° 2, which could be described as pollution during printing, the printer currently has two technologies (to remove deposits):

• either it stops the press and it performs manual washing of the blanket (s) using an appropriate solvent and / or water, depending on the nature of the deposit;
• or it performs such a washing, without stopping the press, thanks to an automatic blanket washing device which is currently found on the market. There are in fact two types of such devices: those which rub the blanket with a damp textile substrate and those which rub said blanket with a brush or any other equivalent mechanical means.

These two washing technologies are far from satisfactory. In the case of manual washing, there is an obligation to stop the press, which generates, at the same time: a significant waste of paper, during restarting; and a loss of production during the entire cleaning operation. Such a cleaning operation can be relatively long and must be carried out on all the blanket cylinders that the printing unit comprises. Furthermore, such a cleaning operation is not rewarding (it is hardly appreciated by operators , to the extent that it is painful, dirty and tedious) and it generates pollution: cleaning substrates, such as cloths or sponges, loaded with ink, solvents and various constituents of the support to be printed, on the one hand and solvents and / or soiled water, on the other hand, which should then be treated. In the case of the use of automatic washers, whatever their type, there are also numerous problems. Thus, with the scrubbers using a textile substrate, it is necessary to manage the consumption and the destruction of said substrate (generally a nonwoven). Said washers are also relatively bulky, can cause discomfort in the implementation of printing, require maintenance. Finally, the fact of exerting friction on the blanket causes abrasion and therefore leads to greater wear thereof. Thus, with scrubbers using a brush or any other equivalent mechanical means, one must manage the cleaning of said brush or said other means. Said washers are also also relatively bulky, can also cause genes in the implementation of printing and also require maintenance (in particular with reference to the wear of the brush or equivalent means). Their intervention is also responsible for wear, by abrasion, of the cleaned blankets. These solutions of the prior art, to problem n ° 2 identified and specified above, are therefore not fully satisfactory. With reference to said problems n ° 1 and No. 2, one can also mention the teaching of application FR-A-2 767 498. According to said teaching, the deposition of an active liquid with action (s) cleaning, dissolving, thinning and / or diluting is recommended on the tape to print, scrolling.

3)

3a) with reference to problem no. 3a, which could be described as delamination, no solution has really been proposed. At best, the printer increases the wetting of the plate cylinder (upstream of the blanket cylinder), during bonding. Such wetting is not, however, a solution that suddenly solves the problem ...;

3b) with reference to problem 3b, which could be described as bonding on one of the edges, it was recommended, in the context of know-how, the application of oil to the edges of the new coil. Such a local application has the effect of neutralizing the consequences of the misalignment of the bands. Its implementation, on an industrial scale, remains delicate.

Confronted with these various technical problems, which at the knowledge of the inventor, according to the prior art, it was only proposed solutions, distinct, specific, more or less satisfactory vis-à-vis, therefore, a only one of said problems (see above), said inventor is currently proposing a unique original, global, complete and satisfactory solution vis-à-vis all said problems. This solution - original intervention of a fatty solvent (therefore having lubricating properties) - constitutes the basis of the invention currently claimed.

The process of the invention is a printing process, on press rotary, of a support delivered in the form of a strip from a reel. Said rotary press includes a printing unit using, to deposit ink on said support, a flexible material. This type of printing process is familiar to the skilled person. Today it is mainly offset printing which, to deposit the ink on the support, involves a blanket. So general, the improvement within the meaning of the invention can be exploited in any context where the ink is therefore deposited on the print medium via a flexible material, and in particular a rubberized material (context limited to date to that of offset but undoubtedly called to expand in the future).

In this context of printing, on a rotary press, with use a flexible material for depositing the ink on the printing medium, it is proposed, according to the invention, to deposit, intermittently, fatty solvent over the entire width of the strip to be printed, during the running of said strip; this deposit being made on said strip upstream of the printing unit.

Said fatty solvent is deposited over the entire width of the strip in scrolling, upstream of the printing group, between said printing group and the system for supplying the latter with said support strip to be printed. Said fatty solvent can be deposited on the front or / and on the back of said strip intended to be printed, usually on one side only or on both sides. In fact, all cases are possible.

Within the framework of an advantageous variant, the printing is put in double-sided work and the fatty solvent is deposited on both sides of the strip in scroll.

The improvement, object of the present invention, is based on the concept of using the print medium itself to convey a solvent for effective cleaning of the printing unit cylinder (s) (more particularly the printing cylinder (s), blanket cylinder (s) offset), to constitute itself a cleaning tool; said support is comprising as a sponge capable of at least partially returning the solvent, with which it was impregnated upstream, during its successive passages between the cylinders of the printing unit. With reference to problem n ° 2 mentioned above, said print medium is a good substitute for rags, sponges, textile substrates, brushes or equivalent mechanical means which should be intervene according to the prior art and this, in a completely unexpected manner. Indeed, print media, particularly paper, being relatively materials fragile and scrolling, on the presses, generally very tight, it was by no means acquired in advance that they can be used, successfully (without breaking) for transport (cleaning) liquid. However, it has proved quite possible have this function performed.

With reference to said problem n ° 2, the deposition of fatty solvent, according to the invention is implemented, discontinuously, at will, when it turns out necessary and of course, without stopping the machine.

For an optimization of the expected cleaning, the fatty solvent is advantageously deposited on a length of the strip (in movement) at least equal to the circumference of the (first) impression cylinder called to contact said strip. Said cylinder can be unique or the first of n cylinders (n, integer, greater than or equal to 2) which intervene one after the other, in the printing group.

The intervention of the fatty solvent, according to the invention, during the implementation press pressure (when printing starts) prevents breakage of the print media tape and therefore also avoids problem # 1, mentioned above.

Likewise, those skilled in the art will have understood that said intervention of the fatty solvent according to the invention is beneficial during operations bonding, for the commissioning of a new coil, and this with reference to problems 3a and 3b, mentioned above.

The deposit of fatty solvent according to the invention therefore proves to be the remedy unique, effective, to said problems 1, 2 and 3 mentioned above.

a) au démarrage, pour supprimer le risque de collage au blanchet ;

b) en même temps ou juste après le collage, pour éviter les risques de déstratification et de collage. Dans le cadre de cette variante du procédé de l'invention, le dépôt de solvant gras est effectué sur la bande en défilement, en fin d'une bobine de support à imprimer, en même temps que ou juste après, la solidarisation, par collage, de ladite fin de ladite bobine et du début de la bobine suivante. Ledit dépôt, en amont du joint de collage est avantageusement prolongé pour au moins couvrir ledit joint de collage. Il est avantageusement prolongé en aval dudit joint de collage de sorte que ledit solvant gras est déposé de part et d'autre dudit joint ;

c) en cours de tirage pour effectuer automatiquement un lavage intermédiaire des blanchets ;

d) en fin de tirage pour effectuer automatiquement un nettoyage complet desdits blanchets.

It is, as indicated above, advantageously implemented:

a) at start-up, to eliminate the risk of sticking to the blanket;

b) at the same time or immediately after bonding, to avoid the risks of delamination and sticking. In the context of this variant of the method of the invention, the deposition of fatty solvent is carried out on the moving strip, at the end of a support coil to be printed, at the same time as or just after, the joining, by bonding , from said end of said reel and from the start of the next reel. Said deposit, upstream of the bonding joint is advantageously extended to at least cover said bonding joint. It is advantageously extended downstream of said bonding joint so that said fatty solvent is deposited on either side of said joint;

c) during drawing to automatically carry out an intermediate blanket wash;

d) at the end of the draw to automatically carry out a complete cleaning of said blankets.

A person skilled in the art will know how to optimize the intervention of the fatty solvent in purposes of the invention, in particular in terms of quantity, in terms of length of impregnated strip (see above, the reference to the circumference of the cylinders called to contact said band) and timing. So it turns out particularly appropriate to use said fatty solvent, during a coil change by bonding (solution or problem n ° 3), in an amount such that it also ensures cleaning the blanket (s) (solution to problem 2) ...

We talked indifferently about printing cylinders and cylinders blankets insofar as, as already indicated, the context of the invention is mainly that of offset, while being in no way limited to it.

To deposit fatty solvent, within the meaning of the invention (by intermittently, on the moving strip, over the entire width (width) of the said tape), various technologies can be implemented. Said fatty solvent can in particular be deposited by spraying or by direct application, by means of minus a brush or roller. Advantageously, the width of said deposit is adjustable, adaptable according to the width of the material to be printed.

Advantageously, said deposit is implemented by spraying, at using at least one spray nozzle.

The most suitable sequences of said deposit are chosen, taking in particular take into account the properties of the printing medium used. So a automatic spray trigger can be perfectly synchronized with the end of the gluing cycle, which guarantees a minimum waste of paper and perfect repeatability of the operation.

The fatty solvent deposited is obviously capable of penetrating the pores of the print medium, to exert a cleaning and non-sticking action, while remaining compatible with all the packing materials of the different rollers and cylinders of a rotary press. It is advantageously a fatty solvent of the type of solvents marketed to date for washing automatic blanket offsets. Thus, do we recommend, in particular, the use, according to the process of the invention, of mixtures of organic solvents, marketed by TECHNIWEB under the names "WEB TECHNOCLEAN" and "WEB TECHNOCLEAN P".

It is emphasized here that, in the context of the process of the invention (extended framework for the maintenance and upkeep of rotary presses, assistance to start-up of said machines and connection of two coils, during bonding operations, for the implementation, without stopping the press, of a new coil), it does not intervene any liquid with cleaning action, it intervenes a fatty solvent. Tests have shown that the property lubricant of the product applied to the printing medium is essential for good operation of the process.

• la mise en oeuvre du procédé n'entraíne pas un coût d'exploitation élevé : la consommation de solvant est faible et aucun consommable autre que le solvant et l'eau n'est utilisé. On mentionne ici l'eau, dans la mesure où il est en effet nullement exclu du cadre de l'invention, de faire intervenir, indépendamment ou pas du solvant gras, de l'eau. Ladite eau peut avantageusement emprunter le même circuit (voir plus loin) que ledit solvant gras. Elle peut aussi être acheminée et délivrée par d'autres moyens. En tout état de cause, son intervention, de temps en temps, est particulièrement opportune pour se débarrasser de substances minérales, type kaolin, qui se sont détachées du support à imprimer ;
• la mise en oeuvre dudit procédé n'entraíne ni pollution du groupe d'impression, ni pollution du système alimentant ledit groupe en support d'impression, ni pollution supplémentaire, en général. En effet, les produits de lavage, solvant, eau et les résidus sont éliminés par la bande. Dans le cas d'une rotative à sécheur, lesdits solvants sont entièrement évaporés et traités automatiquement par le système de postcombustion de l'installation. Il n'y a pas de risque d'explosion, au vu de la faible quantité de solvant intervenant. Dans les autres cas, la faible quantité de solvant imprégnant le support d'impression limite la quantité de résidus entraínés par la bande ; ce qui n'entraíne pas de salissure des organes de la plieuse. La densité desdits résidus ne nécessite pas de traitement particulier, le recyclage du support d'impression peut s'effectuer de manière classique ;
• la qualité d'impression reste constante tout au long du tirage ;
• la mise en production est grandement facilitée du fait de la suppression du risque de collage du support d'impression au blanchet, lors de la mise en pression de la presse rotative ;
• le support d'impression lubrifié par le solvant exerce, grâce à un léger glissement lors de l'écrasement du blanchet, un frottement infime mais suffisant pour nettoyer parfaitement celui-ci ;
• grâce au principe énoncé ci-dessus, la vie des blanchets se trouve prolongée ;
• le coût énergétique d'un lavage du blanchet, selon l'invention, par le support d'impression, est nettement inférieur à celui de lavages manuels ou automatiques de l'art antérieur ;
• le procédé permet de réduire le nombre de postes de lavage à implanter sur la machine, ce qui réduit le coût de l'investissement et la quantité de solvant employée.

Considering the above remarks and the examples appended to the present description, those skilled in the art will not fail to grasp all the advantages of the process of the invention. Some of these are listed below:

• the implementation of the process does not result in a high operating cost: the consumption of solvent is low and no consumable other than the solvent and water is used. Water is mentioned here, insofar as it is in no way excluded from the scope of the invention, to involve, independently or not of the fatty solvent, water. Said water can advantageously take the same circuit (see below) as said fatty solvent. It can also be routed and delivered by other means. In any event, its intervention, from time to time, is particularly appropriate to get rid of mineral substances, kaolin type, which have detached from the support to be printed;
• the implementation of said method causes neither pollution of the printing unit, nor pollution of the system supplying said group with printing medium, nor additional pollution, in general. In fact, the detergents, solvent, water and residues are eliminated by the strip. In the case of a dryer rotary press, the said solvents are completely evaporated and treated automatically by the post-combustion system of the installation. There is no risk of explosion, given the small amount of solvent involved. In other cases, the small amount of solvent impregnating the print medium limits the amount of residue entrained by the strip; which does not cause soiling of the folder organs. The density of said residues does not require any particular treatment, the recycling of the printing medium can be carried out in a conventional manner;
• the print quality remains constant throughout the print run;
• production is greatly facilitated due to the elimination of the risk of sticking of the printing medium to the blanket, when the rotary press is pressurized;
• the printing medium lubricated by the solvent exerts, thanks to a slight sliding during the crushing of the blanket, a small but sufficient friction to clean it perfectly;
• thanks to the principle stated above, the life of blankets is extended;
• the energy cost of washing the blanket, according to the invention, by the printing medium, is much lower than that of manual or automatic washing of the prior art;
• the process makes it possible to reduce the number of washing stations to be installed on the machine, which reduces the cost of the investment and the quantity of solvent used.

We now propose to describe the invention in its aspect device.

The device, which is suitable for implementing the method described above includes a rotary press of the prior art with which it is associated adequate means for the intermittent deposition of the fatty solvent over the entire width of the strip in movement, for its printing.

Said rotary press comprises, conventionally, a group printing (including at least one plate cylinder and one blanket cylinder, associated, in offset) and, upstream of this, a system for its supply of a continuous strip of the printing medium conditioned in reels. Said system includes at least one unwinder, which unrolls the reel and transmitting the unwound tape to the printing unit. It also includes, advantageously, arranged downstream of said unwinder, a debtor. Such a debtor is a regulator of the tension of the delivered printing medium. He delivers said support at a constant rate.

Characteristically, according to the invention, it is associated with said press rotary, means for intermittently depositing (at will) a fatty solvent over the entire width of the strip to be scrolled. Said means are positioned in downstream of the feed system of said rotary press (system comprising a unwinder and advantageously a unwinder and a debtor) and upstream of the group printing of it.

The printing medium, impregnated at this level with said fatty solvent, can develop the beneficial actions described above, while limiting to maximum pollution generated.

The means involved in depositing the solvent can in particular consist of at least one brush or roller. It is advantageously means which are suitable for spraying said fatty solvent. So, do said means advantageously comprise at least one nozzle spraying, arranged above and / or below the strip to be scrolled and more advantageously still several spray nozzles on two booms, arranged respectively above and below said strip. The so-called nozzle (s) must be suitable for spraying the fatty solvent over the entire band width. It (s) is (are) connected (s) to a device for supplying said oily solvent and subject to control means.

To avoid clogging of such spray nozzles, it is strongly recommended to spray compressed air at the end of each oily solvent spray. Said nozzles may also be suitable for a water spray (see above).

The spraying technique that can be used in the framework of the present invention is perfectly controlled by those skilled in the art. Drilled blocks can allow the distribution of different controlled fluids (solvent, water, compressed air). Solenoid valves adapted to different fluids and at the frequencies used may allow said routes to be sent on demand fluids to the spray nozzles. With such a process, it is possible to do pass through each nozzle, successively or simultaneously, from 1 to 3 fluids different. These solenoid valves can be managed by a PLC programmable or any other industrial computer-based system.

It may therefore be perfectly possible to program automatic sprays, a first, at the start of the printing process, then others synchronized at the end of two coils bonding cycles successive ...

Furthermore, the device of the invention advantageously comprises, in a manner known per se, at the level of its system for supplying the printing unit with the printing support strip (at the level of its unwinder) an automatic device for joining by bonding of two coils, used successively. Such devices are known per se .

Considering the above remarks, we realize the extreme simplicity means necessary for the implementation of the very advantageous method of the invention.

• il ne comporte pas d'organe mobile et sa maintenance est donc simplissime ;
• son réglage est aisé. Il n'y a pas lieu de procéder à un réajustement de son positionnement ;
• les problèmes d'obturation des buses peuvent quasi être réduits à néant par la qualité de filtration des fluides intervenants et ceci grâce également au cycle d'auto-nettoyage à l'air comprimé, effectuée à la fin de chaque pulvérisation ;
• le faible encombrement dudit dispositif permet son implantation, facile, sur tous types de machines ;
• il peut éventuellement être posé et déposé avec une grande facilité, si cela s'avère réellement nécessaire pour d'éventuelles interventions sur la machine ;
• il ne gêne a priori pas l'opérateur, lors des opérations de changements de plaque ou de blanchet ;
• son montage sur une presse en exploitation est extrêmement facile et n'impose qu'un temps d'immobilisation très court ;
• son utilisation est très simple et ne nécessite donc qu'une très courte période d'enseignement ;
• son utilisation apporte un confort de conduite extrêmement important ;
• un tel dispositif est polyvalent. Il est susceptible d'intervenir dans des contextes autres que l'offset.

It is proposed to list below, in no way limiting, advantages of the device of the invention, incorporating at least one spray nozzle:

• it does not have a movable member and its maintenance is therefore very simple;
• its adjustment is easy. There is no need to readjust its positioning;
• the problems of blocking the nozzles can almost be reduced to zero by the quality of filtration of the intervening fluids, and this also thanks to the self-cleaning cycle with compressed air, carried out at the end of each spraying;
• the small size of said device allows its easy installation on all types of machines;
• it can possibly be installed and removed with great ease, if this proves to be really necessary for possible interventions on the machine;
• a priori, it does not interfere with the operator, during plate or blanket change operations;
• mounting it on a press in operation is extremely easy and requires only a very short downtime;
• its use is very simple and therefore requires only a very short teaching period;
• its use provides extremely high driving comfort;
• such a device is versatile. It is likely to occur in contexts other than offset.

It is understood that the list of advantages of the invention, also analyzed both in terms of process and device, is impressive.

• un système 1 pour l'alimentation d'un groupe d'impression 2 en une bande 20 de support d'impression à imprimer ;
• ledit groupe d'impression 2 ;
• un four de séchage 3 ;
• un refroidisseur 4.

It is now proposed to describe said invention with reference to the single appended figure. On this, there is shown schematically a rotary press of the invention. This includes, from upstream to downstream, conventionally;

• a system 1 for supplying a printing unit 2 with a strip 20 of print medium to be printed;
• said printing unit 2;
• a drying oven 3;
• a cooler 4.

Said system 1 comprises an unwinder 1a and a debtor 1b. Said unwinder contains an automatic fastening device 6 by bonding coils used successively 10,10 '.

10 shows the spool of printing support being unfolding (during printing). Said coil 10 delivers the tape 20. The coil 10 ', new, will intervene when said coil 10 is exhausted.

Said printing unit 2 comprises two plate cylinders 2a and 2a ' and two blanket cylinders 2b and 2b '. We represented symbolically (not scale) blankets 8 intervening. On consideration of this figure, the man those skilled in the art have already understood that the printing in question is a double-sided offset printing. 5 shows a tape breakage detection cell 20.

Characteristically, it intervenes on either side of said strip 20, at the outlet of the debtor 1b, spray nozzles 30. They are capable to impregnate with fatty solvent the front and back of said strip 20, at will.

• au démarrage de l'impression (en référence au problème n° 1)
• à chaque changement de bobine 10 (en référence aux problèmes n° 3a, 3b et 2) ; et
• en fin de tirage (en référence au problème n° 2) ;

The impregnation is advantageously implemented:

• when printing starts (with reference to problem 1)
• at each change of coil 10 (with reference to problems n ° 3a, 3b and 2); and
• at the end of the draw (with reference to problem n ° 2);

It can also be implemented during printing, at any moment (with reference to problem 2).

It is implemented without stopping the running of the tape 20. It causes some waste of print media but avoids many problems which translate, them, by a bigger waste of paper, by printing stops or even breakage.

The presently claimed invention is illustrated by Examples 1 and 2 below, more specifically by Examples 1b and 2b, below, Examples la and 2a illustrating the prior art. Considering these comparative examples, a person skilled in the art will not fail to grasp the whole interest of the invention.

Example 1a (Prior Art)

• Nombre d'arrêt(s) généré(s) par le collage au blanchet lors du démarrage (problème n° 1) :   1
• Nombre d'arrêt(s) nécessaire(s) au nettoyage manuel des blanchets (problème n° 2) :   2
• Temps nécessaire pour chaque nettoyage manuel des blanchets :   15 min
• Temps nécessaire au passage manuel de la bande dans la machine et au redémarrage (à chaque redémarrage) :   10 min
• Gâche engendrée lors de chaque collage :   100 cahiers*
• Gâche engendrée lors de chaque démarrage :   200 cahiers*
• Temps nécessaire au lavage final des blanchets :   20 min
     Temps total perdu lors de ce tirage : 1 h**
        Durée totale du tirage : 7 h

A two-sided offset printing is implemented, in a conventional manner, with 9 reels of paper 10 km long each successively on a 16-page rotary press (comprising an unwinder with automatic gluing system of successive reels, a debtor and 4 units color printing), operating at the speed of 25,000 copies per hour, for a print run of 150,000 copies. The paper used is coated paper, a grammage of 90 g / m ² and a width of 960 mm. The n ^th reel is automatically, at the unwinder, secured to the (n-1) ^th , by gluing. The following performances are recorded:

• Number of stops generated by the blanket gluing during start-up (problem n ° 1): 1
• Number of stops required for manual blanket cleaning (problem 2): 2
• Time required for each manual blanket cleaning: 15 min
• Time required for manual passage of the tape in the machine and for restarting (each restart): 10 min
• Waste generated during each collage: 100 notebooks *
• Waste generated during each startup: 200 notebooks *
• Time required for the final blanket wash: 20 min
  Total time lost during this draw: 1 h **
  Total length of the draw: 7 h

Example 1b (Invention)

Printing is carried out with the same equipment, under the same conditions (on the same press, operating at the same speed, for the same printing, on the same printing medium), with however intervention according to the invention, each time the coil is changed, a fatty solvent. Said fatty solvent, the nature of which is specified below, is uniformly sprayed, under the conditions indicated below, on either side of the 960 mm in width of the strip of paper put on to pass. It is sprayed from 10 spray nozzles, distributed uniformly on two booms, arranged 54 mm above and below the support placed to scroll. Said spray nozzles are of the H 1/8 ^th type - VVII-001, sold by the company SPRAYING EMANI SYSTEM (USA).

Characteristics of the spraying according to the invention:
Solvent: mixture of organic solvents, marketed under the name "WEB TECHNOCLEAN" by the company TECHNIWEB;

Spraying of the solvent: the said solvent is sprayed for 0.8 s, under a pressure of 1.6 bar, which delivers 0.8 dl on each spray. Given the paper running speed, said 0.8 dl are distributed over a length 3.3 m of paper (this length corresponds to 5.5 revolutions of the blankets, it is symmetrically distributed on either side of the bonding joint).

Self-cleaning of the spray nozzles: after each spraying of solvent, compressed air is delivered through the nozzles for 2 times 1 s, with a pause of 0.5 s between each time.

• Nombre d'arrêt(s) généré(s) par le collage au blanchet lors du démarrage (problème n° 1) :   0
• Nombre d'arrêt(s) nécessaire(s) au nettoyage manuel des blanchets (problème n° 2):   0
• Temps nécessaire pour le nettoyage des blanchets :   0
• Temps nécessaire au passage manuel de la bande dans la machine et au démarrage (lors de l'unique démarrage) :   10 min
• Gâche engendrée lors de chaque collage :   100 cahiers
• Gâche engendrée lors de chaque démarrage :   200 cahiers
• Temps nécessaire au lavage final :   0
     Temps total perdu lors de ce tirage :   0
        Durée totale du tirage :   6 h

The following performances are recorded:

• Number of stops generated by the blanket gluing during start-up (problem n ° 1): 0
• Number of stops required for manual blanket cleaning (problem 2): 0
• Time required for cleaning blankets: 0
• Time required for manual passage of the tape in the machine and for start-up (during the single start-up): 10 min
• Waste generated during each collage: 100 notebooks
• Waste generated during each startup: 200 notebooks
• Time required for final washing: 0
  Total time lost during this draw: 0
  Total length of the draw: 6 h

By implementing the method of the invention, therefore, a saving, in production time of 1 hour, which corresponds to a saving substantial in production cost (see above). As a percentage, the gain of production is around 14.3%. The print quality remains constant. Finally, we save 600 notebooks, that is to say, we consume, in percentage, 0.375% less paper.

Example 2a (Prior Art)

The same type of offset printing is implemented (on a 16-page rotary press operating at the speed of 20,000 copies per hour, (a little slower than in Examples 1a and 1b), for a print run of 150,000 copies) , using coated paper, a grammage of 200 g / m ² and a width of 960 mm. 20 coils 4.5 km long each of said paper are used successively, the passage from one reel to the next being carried out by automatic gluing.

• Nombre d'arrêt(s) généré(s) par le collage au blanchet lors du démarrage (problème n° 1) :   0
• Nombre d'arrêt(s) généré(s) par l'enroulement du papier autour du blanchet lors du collage (problèmes n° 3, dû à l'épaisseur du papier) :   1
• Temps nécessaire à la remise en état mécanique de la machine (re-synchronisation des cylindres) :   1 h
• Nombre d'arrêt(s) nécessaire(s) au nettoyage manuel des blanchets (problème n° 2):   3
• Temps nécessaire pour chaque nettoyage manuel des blanchets :   15 min
• Temps nécessaire au passage manuel de la bande dans la machine et au redémarrage, à chaque redémarrage :   10 min
• Gâche engendrée lors de chaque collage :   100 cahiers
• Gâche engendrée lors de chaque démarrage :   200 cahiers
• Temps nécessaire au lavage final :   20 min
     Temps total perdu lors de ce tirage :   2 h 45 min*
        Durée totale du tirage :   10 h 15 min

The following performances are obtained:

• Number of stops generated by the blanket gluing during start-up (problem n ° 1): 0
• Number of stops generated by winding the paper around the blanket during gluing (problems n ° 3, due to the thickness of the paper): 1
• Time required to mechanically restore the machine (re-synchronization of the cylinders): 1 h
• Number of stops necessary for manual blanket cleaning (problem 2): 3
• Time required for each manual blanket cleaning: 15 min
• Time required for manual passage of the tape through the machine and for restarting, each time it is restarted: 10 min
• Waste generated during each collage: 100 notebooks
• Waste generated during each startup: 200 notebooks
• Time required for final washing: 20 min
  Total time lost during this draw: 2 h 45 min *
  Total length of the draw: 10 h 15 min

Example 2b (Invention)

Printing is carried out with the same material, within same conditions (on the same press, operating at the same speed, (20,000 copies / hour), for the same print run, on the same print medium) as which was described above in Example 2a. However, it intervenes at each change of coil, under the conditions described in Example 1b, the fatty solvent, as also defined in said example 1b. Said solvent is sprayed on both sides for 0.7 s, under a pressure of 1.6 bar; which delivers 0.26 dl each spray. Said 0.26 dl are distributed over a length of 2.33 m paper. This length corresponds to 3.8 revolutions of the blankets, it is symmetrically distributed on either side of the bonding joint. We implement, after each spraying of solvent, a self-cleaning sequence of the spraying, as described in Example 1b.

• Nombre d'arrêt(s) généré(s) par le collage au blanchet lors du démarrage (problème n° 1) :   0
• Nombre d'arrêt(s) généré(s) par l'enroulement du papier autour du blanchet lors du collage (problèmes n° 3) :   0
• Temps nécessaire à la remise en état mécanique de la machine (re-synchronisation):   0
• Nombre d'arrêt(s) nécessaire(s) au nettoyage des blanchets (problème n° 2):   0
• Temps nécessaire au nettoyage des blanchets :   0
• Temps nécessaire au passage manuel de la bande dans la machine et au redémarrage, lors de l'unique démarrage :   10 min
• Gâche engendrée lors de chaque collage :   100 cahiers
• Gâche engendrée lors de l'unique démarrage :   200 cahiers
• Temps nécessaire au lavage final :   0
     Temps total perdu lors de ce tirage :   0
        Durée totale du tirage :   7 h 30 min

The following performances are recorded:

• Number of stops generated by the blanket gluing during start-up (problem n ° 1): 0
• Number of stops generated by wrapping the paper around the blanket during gluing (problems n ° 3): 0
• Time required to mechanically restore the machine (re-synchronization): 0
• Number of stops necessary for cleaning blankets (problem 2): 0
• Time required to clean the blankets: 0
• Time required for manual passage of the tape in the machine and restarting, during the single start: 10 min
• Waste generated during each collage: 100 notebooks
• Waste generated during the single start: 200 notebooks
• Time required for final washing: 0
  Total time lost during this draw: 0
  Total duration of the draw: 7 h 30 min

By implementing the method of the invention, therefore, a economy, in production time of 2 h 45 min, which corresponds to a substantial savings in production costs (see above). As a percentage, the production gain is around 27%. The print quality remains constant. Finally, we save 800 notebooks, that is to say, we consume percentage, 0.5% less paper.

Claims (11)

Method of printing on a rotary press, a support cut under strip form (20) from a reel (10), said rotary press comprising a printing unit (2) using, to deposit the ink on said support, a flexible material (8), said method comprising intermittently, during the scrolling of said strip (20), upstream of said printing unit (2), a deposit of product over the entire width of said strip (20) to be printed, characterized in that said deposited product is a fatty solvent. Method according to claim 1, characterized in that the deposition of fatty solvent is carried out on the moving strip (20), at the end of a reel of support to be printed, at the same time or just after, the joining, by gluing, from said end of said reel and from the start of the next reel. Method according to claim 2, characterized in that said solvent grease is deposited on either side of the bonding joint of the two successive coils. Method according to any one of claims 1 or 3, characterized in that said support is printed on both sides and in that said fatty solvent is deposited on both sides of the moving strip. Method according to any one of claims 1 to 4, characterized in that it is an offset printing process. Method according to any one of claims 1 to 5, characterized in that said fatty solvent is deposited by spraying or by application to the using at least one brush or roller. Method according to any one of claims 1 to 6, characterized in that said fatty solvent is of the type of solvents marketed for washing automatic blanket offsets. Method according to any one of claims 1 to 7, characterized in that said fatty solvent is deposited over a length at least equal to the circumference of the (first) printing cylinder (2b, 2b ') called to contact said strip (20). Process according to any one of Claims 1 to 8, implemented works on a rotary press which includes a printing unit (2) and a system (1), unwinder (1a) with or without debtor (1b), for feeding said printing unit (2) in a continuous strip (20) of the printing medium packaged in reels (10,10 '), characterized in that said rotary press further comprises positioned downstream of said supply system (1) and upstream of said printing unit (2), means (30) for depositing, by intermittently, a fatty solvent over the entire width of said strip (20), scroll. Method according to claim 9, characterized in that said means (30) for intermittently depositing said fatty solvent, comprise at at least one spray nozzle, arranged above and / or below said strip (20) scrolled, advantageously several spray nozzles on two ramps, arranged respectively above and below said strip scrolling; said nozzle (s) being connected to a supply device in said fatty solvent and subject (s) to control means. Method according to one of claims 9 or 10, characterized in that that said supply system comprises an automatic device for joining (6) by gluing, of the two coils (10,10 '), used successively.

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