IT201800006425A1 - EQUIPMENT FOR CLEANING CYLINDRICAL ROLLERS, MACHINE INCLUDING SAID EQUIPMENT, AND CLEANING METHOD - Google Patents

Description

EQUIPMENT FOR CLEANING CYLINDRICAL ROLLERS, MACHINE

INCLUDING SAID APPLIANCE, AND CLEANING METHOD

DESCRIPTION

TECHNICAL FIELD

[0001] The present invention relates to an apparatus for cleaning cylindrical rollers, with smooth or engraved surface, in particular rollers intended for printing machines, fluid transfer rollers or the like, such as anilox rollers, cliché rollers, spreading rollers, finishers, laminators or other.

[0002] The invention also relates to a method for cleaning a roller.

STATE OF THE TECHNIQUE

[0003] The machines for printing web materials, such as, for example, but not limited to so-called tissue paper plies, are subject to frequent stops to allow the rollers to be cleaned, since the web material tends to easily deposit small particles or fibers of material which, being in contact with the printing liquid (ink), dirty or fill the small cells that carry the color.

[0004] These cells, which constitute the external surface of the transport roller (also called anilox roller), must be kept clean and free from deposits, so that they perform their function in the best possible way.

[0005] In fact the transferred liquid, even contaminating itself with debris released from the web material to be printed, tends to stratify inside the cells used for transporting the liquid, thus reducing its flow rate. This leads to a change in the technical and / or visual characteristics of the web material, for example due to the reduction in the density of the printing ink.

[0006] The frequent interruptions of the production line, necessary for cleaning the rollers, represent the main reason for the loss of efficiency of the line itself.

[0007] Depending on the application sector and the type of printing machine, the characteristics of the rollers may vary, as well as their structure. Machines have therefore been designed that allow a quick removal of the rollers, thus allowing them to be washed and cleaned off-line.

[0008] In other cases, situations may arise where the removal of the roller would entail very long disassembly, cleaning and reassembly times, such as for example in the sector of rollers for the treatment of corrugated cardboard.

[0009] Due to this variability, cleaning systems have been developed that operate off-line, i.e. in which the roller to be cleaned is disassembled from the production machine, as well as cleaning systems that are installed in-line, i.e. on board the production.

[0010] The cleaning systems currently available on the market can be summarized as follows:

[0011] Manual brush systems, which allow the operator to work by rubbing the roller with the addition of chemical products. These systems do not guarantee uniformity of treatment and frequently do not comply with current safety regulations;

[0012] Bi-carbonate systems, in in-line or off-line versions. They are efficient in terms of treatment, but very complex in terms of managing the machine and the product (backing powder) used, not always available with the ideal characteristics for the cleaning treatment;

[0013] Laser systems applicable in line or off line. These systems are very expensive and require the use of highly specialized personnel in order not to damage the roller to be cleaned;

[0014] High pressure hydro-cleaners;

[0015] Dry ice washing systems;

[0016] Washing systems with chemical products only. These can work online or offline. In the first case it is necessary to replace the ink. This system has the disadvantage that all the machine components are affected by the cleaning liquid, which (being very aggressive) can damage some machine components. Furthermore, the action of the detergent is not combined with a mechanical action. Therefore, to be effective, washing requires, in addition to the aggressiveness of the liquid, also very long execution times.

[0017] In the case of off-line systems, the roller to be cleaned must be removed from the production line and the machines dedicated to its cleaning are very bulky.

[0018] The cleaning systems of the current art are not fast and reliable enough. In fact, known cleaning systems make use of expensive, polluting and high environmental impact consumables (also due to the presence of operators in the immediate vicinity), or do not guarantee satisfactory results in a reasonable time.

[0019] Known cleaning systems, which use jets of cleaning liquid directed against a roller of a printing machine are described in US7,428,868; US 6,957,607; WO1997000173.

[0020] There is therefore a need to make cleaning devices for cylindrical rollers that overcome in whole or in part one or more of the drawbacks of the devices of the current art.

PURPOSES AND SUMMARY OF THE INVENTION

[0021] The main object of the present invention is to provide a fast, reliable and economical apparatus, as regards the cost of the plant, and the cost of the consumable material.

[0022] The purpose of some embodiments is to obtain a cleaning device that can be easily installed, both on-line (i.e. on the machine) and off-line, in any work environment and without requiring special safety equipment, having small dimensions , low weight, limited material consumption and reduced cleaning cycle execution times. This also makes it installable on existing machines with a quick replacement of existing appliances or in addition to systems that do not have cleaning appliances.

[0023] According to a first aspect, a cleaning apparatus is provided for this purpose comprising a cleaning head with a cleaning chamber, in which a mechanical cleaning member is housed, and to which feeding members are associated for feeding a liquid detergent in the cleaning chamber. With this arrangement, the mechanical organ and the detergent liquid dispensed by the feeding organs work in a combined way inside the cleaning chamber to clean the cylindrical surface of the roller to be cleaned.

[0024] To clean or clean rollers of high axial length with a device of small dimensions, according to advantageous embodiments, the cleaning head is provided with a translation movement in a direction parallel to the axis of the cylindrical roller. The combination of the rotation motion of the roller and the translation of the cleaning head allows the entire cylindrical surface of a roller to be washed efficiently and in a small space, even with large radial and / or axial dimensions.

[0025] In advantageous embodiments it can be provided that the cleaning head is provided with an approaching and distancing movement with respect to the roller. The movement can be in an axial direction, that is, it can be such as to move the head beyond an axial end of the roller. However, in preferred embodiments, the approach and removal of the cleaning head from the lateral surface of the roller occurs with a movement perpendicular to the axis of rotation of the roller, or in any case with a movement that has at least one component orthogonal to the roller axis.

[0026] To obtain an efficient washing, it is possible to provide for moving the cleaning head and, integrally with it, the mechanical cleaning member with respect to the lateral surface of the roller to be washed, maintaining the contact between the mechanical cleaning member and the surface of the roller. However, for greater washing efficiency and to reduce mechanical stresses on the components of the appliance, it is advantageous for the mechanical cleaning organ to be equipped with a movement inside the cleaning chamber, a movement that does not involve the remaining parts of the cleaning head.

In some embodiments such movement may be a rotational movement. For example, the mechanical cleaning member can comprise a rotating brush, or preferably two counter-rotating brushes.

[0028] In currently preferred embodiments, the movement of the mechanical cleaning organ is an alternating motion, preferably in a direction parallel to the rotation axis of the roller.

[0029] To delimit the cleaning chamber (110), the cleaning head can comprise lateral sealing gaskets. These lateral sealing gaskets can have concave edges, with a curvature corresponding to that of the roller to be cleaned, or slightly lower than it, so as to embrace the roller with a possible slight elastic deformation of the gaskets, to improve the lateral sealing.

[0030] The lateral sealing gaskets can be replaceable according to the diameter of the roller to be cleaned. For example, the lateral sealing gaskets can be housed in respective side panels which form the side walls of the cleaning chamber. The side panels can be adapted to house the lateral sealing gaskets of variable dimensions, according to the variable diameter of said roller to be cleaned.

[0031] For an efficient closure of the cleaning chamber, in some embodiments the cleaning head comprises an upper sealing plate and a lower sealing plate, adapted to delimit the cleaning chamber from above and below. In advantageous embodiments, the foils can be pressurized on the roller to be cleaned to improve the seal. For this purpose, the laminae can be elastic, or they can be associated with pressure members, such as cylinder-piston actuators, or springs or other elastic stress members.

[0032] The mechanical cleaning organ can comprise at least one brush.

[0033] According to a further aspect, the present invention also relates to a machine comprising a cylindrical roller to be cleaned and an apparatus as defined above and as better described below with reference to examples of embodiment.

[0034] According to yet another aspect, the invention relates to a method for cleaning a roller, comprising the following steps:

approaching a lateral cylindrical surface of the roller with a cleaning head comprising a cleaning chamber open towards the cylindrical surface of the roller and containing inside it a mechanical cleaning member and members for feeding a detergent liquid into the cleaning chamber;

bring the mechanical cleaning organ into contact with the cylindrical side surface of the roller to be cleaned, so as to essentially close the cleaning chamber from the front side;

move the mechanical cleaning organ in contact with the lateral surface of the roller by delivering detergent liquid into the cleaning chamber.

[0035] Further aspects and embodiments of the apparatus and method according to the present invention are described below with reference to the attached drawings and are defined in the attached claims, which form an integral part of this description.

DETAILED DESCRIPTION OF FORMS OF CONSTRUCTION

[0036] The present invention will be better understood by referring to the attached Figures, which show an application thereof, but do not limit the scope of the present invention. In the attached drawings, they show:

Fig.1: an overall view of an embodiment of the apparatus of the present invention, installed on a printing machine;

Fig. 2: a partial sectional view of the cleaning head of the apparatus obtained according to II-II of Fig.3;

Fig.3A: a front view of the cleaning head of Fig.2;

Fig. 3B: a side view of the cleaning head;

Fig.3C: an axonometric view of the cleaning head;

Fig. 4: an axonometric view of the mechanical cleaning organ;

Fig. 5: a side view of the mechanical cleaning organ of Fig.4;

Fig. 6: an isometric view of two cleaning heads of the same function but of different dimensions,

Fig.7: an axonometric view of a further embodiment of the cleaning head, with lateral rinsing chambers.

DETAILED DESCRIPTION OF FORMS OF CONSTRUCTION

[0037] In the following the cleaning apparatus is described in combination with an anilox roller of a printing machine. However, it must be understood that a cleaning apparatus of the type described here can find advantageous application also for the cleaning of other rollers for which similar problems arise.

[0038] Fig. 1 shows an overall view of a printing machine generally indicated with 10, intended for example for the printing and decoration of a web-like web material (not shown), which houses a cleaning apparatus 20 object of the invention. The cleaning apparatus 20 is basically composed of two parts, indicated respectively with 30 (cleaning head) and 40 (movement unit).

[0039] The cleaning head 30 acts, in the illustrated example, on a so-called anilox roller or anilox roller 50, which has on the surface a coating of hard material, for example of ceramic material, engraved with tiny cells, which carry the printing liquid, typically an ink. These cells (not shown) can be at least partially occluded due to debris consisting of paper and ink particles. When this happens, the anilox roller 50 becomes unusable and requires a cleaning operation. For this purpose, the cleaning head 30 is brought into close proximity to the anilox roller 50 and is subsequently made to translate in a direction parallel to the axis of the roller 50, as better described below.

[0040] With reference to Figs. 3A, 3B, 3C, the cleaning head 30 comprises several components, including a mechanical cleaning tool 60, which can be a brush or the like. The cleaning head further comprises a pair of nozzles 70 for spraying a detergent liquid, upper and lower sealing plates 80 and lateral sealing gaskets 90. When the cleaning head 30 is in the working position and cooperates with the anilox roller 50, the assembly consisting of the upper and lower foils 80 and the side seals 90 forms, together with the cylindrical surface of the roller 50, a cleaning chamber 110 a liquid tightness.

[0041] In advantageous embodiments, the foils 80 are adjustable and kept under pressure against the roller 50 to be cleaned by adopting compression members 100 (Figs.3B, 3C) exemplified here in the form of springs, which allow the liquid seal in the upper and lower part of the cleaning chamber 110 even when the diameter of the roller 50 to be cleaned varies, since the foils 80 are always in contact and with a certain pressure against the roller 50.

[0042] The side seals 90 are supported by respective side panels 120 which, like the foils 80, can accommodate seals 90 of different sizes, or better with a concave profile 130 adapted to the variable diameter of the roller 50. This means that, with the the same cleaning head 30 and the same side panels 120 it is possible to clean rollers 50 of various diameters, since the cleaning chamber 110 will in any case remain immune to liquid leakage or leaks, thanks to the spring adaptability of the foils 80 and the simple replacement of the side seals 90.

[0043] Since the range of variation of the diameter of the rollers 50 to be cleaned ranges from about 150 mm to about 300 mm, in some embodiments the side panels 120, and with them the entire cleaning head 30, can cover about half of the range indicated above. This means that it will be possible, for example, to have a first cleaning head 30, and relative side panels 120, to be installed on the cleaning apparatus 20 for rollers 50 with a diameter ranging from about 150 mm to about 220 mm, and a second different one (larger ) cleaning head 30 with side panels 120 larger than the previous ones, for rollers 50 with a diameter between about 220 mm and about 300 mm. Fig.6 shows an axonometric view compared to each other two cleaning heads 30 of different sizes to cover the entire range of diameters of the roller 50 to be cleaned.

[0044] In this way, with two different cleaning heads 30, of different sizes, it will be possible to clean rollers 50 of any diameter between about 150 mm and about 300 mm. In fact, it will be sufficient to install the head 30 on the cleaning appliance 20 with larger or smaller side panels 120 depending on the diameter of the roller 50 to be cleaned.

[0045] In the event of a small variation in the diameter of the roller 50, there will be no need to change the side panels 120, but it will be sufficient to replace the side gaskets 90 corresponding to the new diameter of the roller 50 to be cleaned.

[0046] As mentioned above, inside the cleaning chamber 110 there is a mechanical cleaning member, in this case a brush 60. Advantageously, the brush 60 is brought into alternating translation in a direction parallel to the axis of the roller 50. In this way the combined action of the liquid injected at low pressure from the nozzles 70 and the reciprocating motion of the brush 60 allows a rapid, efficient and low cost cleaning of the cylindrical surface of the roller 50. In the example illustrated, the movement of the brush or other mechanical cleaning member 60 is obtained with an actuator, for example a pneumatic motor 61, and a motion transmission for example by means of a cam and eccentric or the like schematically indicated with 62, but it is not excluded to use other systems known in the art.

[0047] In some embodiments, the brush 60 is advantageously formed by two parts 140 (Fig. 4) extending in a transverse direction (parallel to the axis of the roller 50), so as to leave a channel 180 between the two parts 140 In this way, a small quantity of detergent liquid coming from the nozzles 70 is kept in direct contact both with the roller 50 and with the bristles forming the two parts 140.

[0048] The two parts 140 of the brush 60 advantageously have a dovetail shape (see in particular Figs. 2 and 5), so as to bring the bristles of the two parts 140 as close as possible to the roller 50 to be cleaned, and such as to create a binding sliding path for the cleaning liquid (maximizing the contact time of the cleaning liquid on the roller and consequently its removal efficiency).

[0049] More particularly, as shown in Fig. 5, each of the two parts 140 of the brush 60 has a surface (formed for example by the tips of the bristles which make up each part 140 of the brush 60) which forms an angle α with a plane vertical. The angle α can be for example from about 5 ° to about 20 °, preferably from about 10 ° to about 15 °, preferably about 12 °. The aforesaid inclined surfaces of the parts 140 of the brush 60 have opposite inclinations, so as to essentially arrange themselves on the two sides of an opening "V" (180-2α) degrees, so that the two parts 140 of the brush 60 embrace as much as possible the cylindrical surface of the roller 50.

[0050] The brush 60 can be provided with bristles of various thickness and material, for example the bristles can have dimensions between 0.05 and 0.5 mm, advantageously between 0.1 and 0.2 mm and consist of filaments of brass, steel, plastic or animal material, or other. The aforementioned parameters and materials may vary according to the shape and material of the surface to be cleaned, as well as the pressure required and the expected duration of the bristles themselves. The possibility of using brushes 60 provided with mixed bristles, i.e. of different materials, for example harder and softer bristles, which can be variously arranged, is not excluded. For example, tufts or groups of bristles of a first type can be arranged alternately with tufts or groups of bristles of a second type.

[0051] In order to be able to adapt to rollers 50 to be cleaned of different diameters, the brush 60 can be supported in a sliding manner also in the approach direction (indicated by Z in Fig.2) to the roller 50 to be cleaned. This advancement movement according to the Z direction has the dual purpose of compensating for any differences in diameter of the roller 50 to be cleaned, and of regulating the pressure that the bristles 140 exert on the roller 50. This last characteristic can also be used to compensate for a partial wear of the bristles, so that the effectiveness of the action of the brush 60 remains almost constant, allowing a longer useful life of the brush 60. With 71 (Fig.2) a fixing and adjustment column is indicated along which the cleaning head 30 can move to get closer to the axis of the roller 50.

[0052] For the same reason, the cleaning head 30 can be carried by an arm (not shown) which is adjustable in length, so that the seal of the foils 80 and of the side seals 90 is guaranteed against the leakage of cleaning liquid and any residues removed from the roller 50.

[0053] As mentioned initially, the cleaning head 30 (see Fig. 1) is mounted on a handling unit 40 which controls the translation of the cleaning head 30 in a direction parallel to the axis of the roller 50. The movement is indicated by the double arrow X in Fig.1 and is an advantageously bidirectional movement, so that the cleaning head 30 can translate in both directions to act on the entire cylindrical surface of the roller 50. The translation movement can be imparted to the head 30 by any known handling system. In the case shown, a rack-and-pinion system is used, but the use of other known systems, such as belt and pulley, gear, ball screw, or other is not excluded.

[0054] In some embodiments, in the lower part of the cleaning chamber 110 there are one or more holes 160 (Fig.2) to which pipes 165 (Fig.3A) are connected to collect and recover the detergent liquid and any debris detached from the roller 50. The evacuation of the residual detergent liquid and any debris can take place by simple gravity or by depression, either induced from the outside, or by slight overpressure that is created in the cleaning chamber 110.

[0055] The lateral sealing gaskets 90 can be housed in respective seats, obtained in negative in the side panels 120, so that gaskets 90 with concavity 130 of different diameter (to work on rollers 50 of different diameter), can in any case be installed on the same side panels 120. This makes the cleaning head 30, and therefore the entire cleaning device, extremely versatile. Furthermore, the shape of the gaskets 90 is such that replacement is made very easy without the aid of special tools.

[0056] In fact, as described above, by simply replacing the side seals 90, it is possible to obtain an effective cleaning of rollers 50 of very variable diameter, for example in a range between about 150 and about 220 mm, or between about 220 and about 300 mm. Advantageously, also the foils 80 contribute to this flexibility of the apparatus, since for the aforementioned range of diameters of the roller 50 to be cleaned, the simple action of the springs 100 (Fig.3A) is sufficient to guarantee the seal in the direction of rotation of the roller 50, both in the upper part and in the lower part of the cleaning chamber 110.

[0057] The lateral sealing gaskets 90 can be of various materials, as long as they are sufficiently resistant to sliding friction and capable of not overheating. A particularly suitable material was found to be “EVA” Closed cell polyethylene foam with density between 50 ÷ 120 Kg / m³. However, the use of other materials with similar or improved characteristics with respect to this is not excluded.

[0058] The apparatus described so far works as follows.

[0059] The cleaning head 30 of the appliance 20 is brought in close proximity to the roller 50 to be cleaned. By slightly advancing the head 30 in the direction of the roller 50, the cleaning chamber 110 is closed, delimited laterally by the side seals 90, which may have a concave front part 130 with a radius of curvature equal to or slightly less than the radius of the roller 50 The lateral gaskets 90 can be approached to the roller 50 with a slight pressure against the cylindrical lateral surface of said roller 50. Above and below the cleaning chamber 110 is delimited by the foils 80 held under pressure against the roller 50 by the springs 100 or other. suitable member, for example another elastic member, a cylinder-piston actuator, or other suitable means. The particular conformation of the plates 80 and of the gaskets 90 ensures that the cleaning chamber 110 remains sealed regardless of the direction of rotation of the roller 50. The cylindrical surface of the roller 50 completes the front closure of the cleaning chamber 110, while a wall 31 (Fig.2) of the cleaning head 30 closes it at the rear.

[0060] Once the cleaning chamber 110 has been approached and closed, the brush 60, which for the advancement of the head 30 towards the roller 50 comes with the bristles 140 in contact with the surface to be cleaned of the roller 50 , begins to move inside the cleaning chamber 110 in a direction transverse to the roller, i.e. parallel to the axis of the latter, so as to bring the bristles of the brush 60 or other mechanical cleaning member to rub against the surface to be cleaned of the roller 50.

[0061] At the same time, detergent liquid is injected from the nozzles 70, which can be constituted by water, an aqueous solution of detergent, or other liquid product with a detergent action. The combined action of the rubbing of the brush 60 by the bristles that compose it and the detergent liquid, ensures that the portion of the surface to be cleaned of the roller 50 affected and circumscribed by the cleaning chamber 110 is easily cleaned. Particles of paper, ink, or any other processing residues that have lodged in the cells of roller 50 are easily removed. The exhausted cleaning liquid flows downward, dragging the debris towards the hole (s) 160, from which it is removed through the pipe (s) 165. The supply of the cleaning liquid and its removal can take place discontinuously or preferably continuously.

[0062] In particular cases, for example in conditions of particularly stubborn dirt, it is possible to use a heated cleaning liquid, so that this has even greater effectiveness against the dirt to be removed. The detergent liquid can be water or any detergent product, pure or diluted, and can be heated for example to a temperature between 25 ° C and 50 ° C, preferably between 30 ° C and 45 ° C.

[0063] To clean the entire cylindrical surface of the roller 50 it is sufficient that the roller 50 is rotated to cover the entire circumference of the roller itself. By simply translating the cleaning head 30 in the X direction (Fig.1), parallel to the axis of the roller 50, it is possible to gradually clean the various annular portions of the roller from one end to the other. By providing for operation with continuous movements, i.e. with continuous rotation of the roller 50 and continuous translation of the cleaning head 30, rapid and efficient cleaning can be obtained with a simple apparatus, which requires little working space around the roller 50 to be cleaned.

[0064] According to further embodiments, the cleaning head 30 can provide means to avoid or limit the lateral leakage of detergent liquid during use. For example, Fig. 7 shows a configuration of a cleaning head 30 with a double containment chamber. Same numbers indicate parts that are the same or equivalent to those already described with reference to the previous figures, and which will not be described again. The main difference between the cleaning head 30 of Fig.7 and those illustrated in the previous figures substantially consists in the fact that laterally on the left and right sides of the cleaning head 30, a further lateral sealing gasket 91 is added adjacent to the respective gasket seal 90 described above.

[0065] An empty chamber 92 is formed between the two side seals 90, 91 of each side of the cleaning head 30. Nozzles 93 open into said chamber 92, through which a rinsing liquid, for example simple water, can be introduced.

[0066] With this configuration of the cleaning head 30 it is possible to manage both the cleaning step of the roller 50 using liquid detergents, and the subsequent rinsing step.

[0067] The possibility of adding, possibly in a further lateral chamber for each side, a suction system for the detergent and / or rinsing liquid is not excluded.

[0068] In summary, the advantages obtainable with embodiments of the apparatus according to the present invention are:

- the cleaning treatment can combine the action of any detergent

chemical to the action of a mechanical organ;

- with the same treatment efficacy, the system is cheaper than

existing systems;

- it is possible to treat any type of engraving profile and up to rulings

very high (600 lines / cm);

- there are no detergent product dispersions;

- the quantity of detergent used is very small;

- with the same treatment efficacy, the system is faster than the existing systems;

- it can be used in any work environment without the need for the operator for special protection and / or safety equipment;

- use is very simple and does not require special training by the operator.

[0069] It is understood that what has been described up to now represents only an example of the invention object of the invention, this invention being able to vary in shape and layout without departing from the scope of protection constituted by the attached claims.

Claims (26)

EQUIPMENT FOR CLEANING CYLINDRICAL ROLLERS, MACHINE INCLUDING SAID APPLIANCE, AND CLEANING METHOD CLAIMS 1) A cleaning apparatus (20) for cleaning a cylindrical roller (50), comprising a cleaning head (30) with a cleaning chamber (110), in which a mechanical cleaning member (60) is housed, and at the which feed members (70) are associated for feeding a cleaning liquid into the cleaning chamber (110); in which the mechanical organ (60) and detergent liquid dispensed by said feeding organs work in a combined manner within said cleaning chamber (110). 2) Apparatus as per claim 1, in which the cleaning head (30) is equipped with a translation movement in a direction parallel to the axis of the cylindrical roller (50). 3) Apparatus as per claim 1 or 2, in which the cleaning head (30) is equipped with an approaching and moving away from the roller (50), having at least one component orthogonal to the axis of the roller (50). 4) Device as per claim 1 or 2 or 3, in which the mechanical cleaning organ (60) is equipped with a movement inside the cleaning chamber (110). 5) Apparatus as per claim 4, in which said movement of the mechanical cleaning organ (60) inside the cleaning chamber (110) is an alternating motion. 6) Apparatus as per claim 4 or 5, in which said movement of the mechanical cleaning organ (60) inside the cleaning chamber (110) is an alternating movement according to a direction parallel to the axis of the roller (50). 7) Apparatus according to one or more of the preceding claims, in which said mechanical cleaning member (60) is provided with a movement, with respect to the cleaning chamber (110), of approaching and distancing with respect to the roller (50). 8) Apparatus according to one or more of the preceding claims, wherein the cleaning head (30) comprises lateral sealing gaskets (90) of said cleaning chamber (110). 9) Apparatus as per claim 8, in which the lateral sealing gaskets (90) are elastically yielding to adapt to the lateral surface of the roller (50) to be cleaned. 10) Apparatus as per claim 8 or 9, in which the lateral sealing gaskets (90) can be replaced according to the diameter of the roller (50) to be cleaned. 11) Apparatus as per claim 10, in which the lateral sealing gaskets (90) are housed in respective side panels (120), said side panels (120) being suitable for housing lateral sealing gaskets (90) of variable dimensions, depending on the variable diameter of said roller (50) to be cleaned. 12) Apparatus as per claim 11, in which the side panels (120) are designed to house replaceable lateral sealing gaskets (90) to cover a range of diameters of the roller (50) to be cleaned between 150 and 220 mm, or between 220 and 300 mm. 13) Apparatus according to one or more of the preceding claims, in which the cleaning head (30) comprises an upper sealing plate (80) and a lower sealing plate (80) suitable for delimiting the cleaning chamber (110), said laminae (80) being held under pressure on the roller (50) to be cleaned by means of pressure members (100). 14) Apparatus as per claim 13, when dependent at least on claim 11, in which the upper sealing plate (80) and the lower sealing plate (80) are supported by said side panels (120). 15) Apparatus as per claim 13, when dependent at least on claim 8, in which the cleaning chamber (110) is made liquid-tight, by means of the combination of said lateral sealing gaskets (90) and said sealing plates ( 80) in cooperation with the lateral surface of the roller (50) to be cleaned. 16) Apparatus according to one of the preceding claims, in which the cleaning head (30) comprises lateral chambers (92) for containing the detergent liquid, open towards the lateral surface of the roller (50) to be cleaned. 17) Apparatus as per claim 16, when dependent at least on claim 8, in which the side chambers (92) are arranged along the side sealing gaskets (90) or inside them. 18) Apparatus as per claim 17, in which nozzles (93) for feeding a rinsing liquid open into the side chambers (92). 19) Apparatus as per one or more of the preceding claims, in which the mechanical cleaning organ (60) comprises at least one brush. 20) Apparatus as per one or more of the dependent claims, in which the mechanical cleaning organ (60) is divided into at least two parts (140) superimposed and separated along a channel (180) parallel to the roller (50) to be cleaned. 21) Apparatus according to one or more of the preceding claims, in which the mechanical cleaning member (60) has two active surfaces suitable to act on the roller (50) to be cleaned, which are inclined to each other to form a V-shaped surface with the vertex oriented towards the inside of the cleaning chamber (110). 22) A machine comprising a cylindrical roller (50) to be cleaned and an apparatus according to one or more of the preceding claims. 23) A method for cleaning a roller (50), comprising the following steps: • approach a lateral cylindrical surface of the roller (50) with a cleaning head (30) comprising a cleaning chamber (110) open towards the cylindrical surface of the roller (50) and containing inside a mechanical cleaning member (60) and feed members (70) of a detergent liquid into the cleaning chamber (110); • bring the mechanical cleaning organ (60) into contact with the cylindrical side surface of the roller (50) to be cleaned; • move the mechanical cleaning organ (60) with respect to the lateral surface of the roller (50) and in contact with it, delivering detergent liquid into the cleaning chamber (110). 24) The method of claim 23, in which the step of moving the mechanical cleaning member (60) in contact with the lateral surface of the roller (50) comprises the step of translating the mechanical cleaning member (60) in reciprocating motion. ) in a direction parallel to the axis of the roller (50). 25) The method of claim 23 or 24, comprising the step of rotating the roller (50) around its axis while the mechanical cleaning organ (60) acts on the lateral surface of the roller (50). 26) The method of claim 23, 24 or 25, also comprising the step of gradually translating the cleaning head (30) along the axis of the roller (50) to clean the entire lateral surface of the roller.