EP3022058B1 - Method and device for applying adhesive tape to cylindrical bodies - Google Patents

Description

The invention relates to a device and a method for mounting adhesive tape on cylindrical bodies such as cylindrical flexographic printing plates.

In a cylindrical flexographic printing plate, the printing cylinder of the printing press is provided with a printing layer or a printing relief in the entire circumference. In principle, the actual impression cylinder of the printing press can itself be provided with a completely enveloping printing layer. However, this approach has the disadvantage that when changing the printing form under certain circumstances, the entire printing cylinder must be replaced, which can be expensive. It is therefore customary to use so-called sleeves. A sleeve is a cylindrical hollow body, also referred to as a sleeve, which has been provided on its outer cylindrical surface with a pressure layer or a pressure relief. The sleeve technology allows a very quick and easy change of the printing form. The inner diameter of the sleeves corresponds to the outer diameter of the printing cylinder, so that the sleeves can easily be pushed over the printing cylinder of the printing press. Further details of the sleeve technique are disclosed, for example, in " Technique of flexographic printing ", p. 73 ff., Coating Verlag, St. Gallen, 1999 ,

Usually, the production of a cylindrical flexographic printing plate by adhering to the outer cylindrical surface of the printing cylinder or the sleeve, a flexographic printing plate, which carries on its outwardly facing side of the printing layer or the printing relief, is glued. For this purpose, a double-sided adhesive tape is usually used whose adhesive surface is first glued to the outer cylindrical surface of the printing cylinder or the sleeve. Subsequently, the flexographic printing plate is glued to the back-side adhesive surface of the double-sided adhesive tape, in such a way that the printing layer or the printing relief is directed outwards and now forms the surface of the cylindrical flexographic printing plate.

The double-sided adhesive tape usually has compressive elastic properties in order to reduce or avoid the so-called "dot gain", an undesired effect in flexographic printing. The dot gain results from the fact that the printing surfaces of the printing layer or the printing relief are raised in flexographic printing. That is, there are generally frusto-conical pressure points, which are elastic due to the forces occurring during the printing process broaden. This leads directly to a broadening of the printed dot, ie a "dot gain". In order to avoid this undesirable effect, the printing plates are not attached directly to the printing cylinder or the sleeve, but it is provided an elastic or compressible intermediate layer which deforms elastically during printing and thus the dot gain, which leads to quality losses of the print can lead to reduced. Usually, the double-sided adhesive tape assumes the function of the elastic or compressible intermediate layer by having a certain material thickness and pressure-elastic properties. Accordingly, suitable adhesive tapes typically include a foam core. Thus, there are high demands on the process of attaching the adhesive tape to the printing cylinder or the sleeve. First, ensure that the adhesion between the inwardly facing adhesive surface of the adhesive tape and the surface of the printing cylinder or sleeve is uniform and of sufficient intensity. The contact pressure when applying the adhesive tape to the printing cylinder or sleeve must therefore be uniform and well-dosed over the entire surface. At the same time, the contact pressure must not be too strong, especially not punctiform too strong, since otherwise the foam core of the adhesive tape, in particular in individual areas, could collapse. As a result, the pressure-elastic properties of the adhesive tape, in particular in individual areas, would be impaired, which in turn would result in the unwanted dot gain.
In addition, the uniform application of the adhesive tape is made more difficult by the fact that the printing cylinder or the sleeve is usually heavy and large-area and therefore not easy to handle. When sleeve or sleeve is added that this is an axisless structure, which in turn makes holding and guiding the same complicated.
Furthermore, due to the material thickness of the adhesive tape, it is necessary to ensure that neither a larger gap remains at the abutting edges of the adhesive tape nor that the adhesive tape overlaps at the abutting edges and thus forms a protruding bead on the cylinder surface.
For the reasons mentioned, the adhesive tape is usually applied by hand or with a considerable amount of manual labor, which is both time-consuming and therefore expensive, and on the other hand error-prone.

Furthermore, from the EP2535187-A1 a device for applying adhesive tape on a cylindrical surface of a cylindrical body, wherein the device comprises a fixing roller. It is accordingly an object of the invention to provide an apparatus and a method for mounting adhesive tape on cylindrical bodies, such as, for example, cylindrical flexographic printing plates, in which the assembly takes place largely automatically in order to avoid the disadvantages mentioned largely avoid or reduce the prior art and in which the described requirements are met as far as possible.

The object is achieved according to the apparatus and the method of the independent claims 1 and 10, wherein preferred embodiments are set forth in the dependent claims.

With the invention it is possible to apply an adhesive tape largely or completely automatically to cylinders or cylindrical bodies of different diameters.
A "cylinder" in the context of the invention refers to a body which is bounded by two parallel circular surfaces (top and top surfaces) and a lateral or cylindrical surface, which is formed by parallel straight lines.
A "cylindrical body" in the sense of the invention refers to a body whose shape largely corresponds to the shape of a cylinder, but in which in particular the base and the top surface can be dispensed with. The term "cylindrical body" so far not only cylinders in the above sense, but also sleeves and hollow cylinders are included.
"Adhesive tape" in the sense of the invention is a collective name for carriers coated on one or both sides with adhesives. Adhesive tapes are known in a wide variety of forms and are available in the market. Typical support materials are plastic films such as polypropylene, polyethylene, polyethylene terephthalate, polyvinyl chloride or acetate film, paper, metal foils, fabric supports such as textile fabrics and foam support materials. Preferred support materials in connection with the production of cylindrical flexographic printing plates are foam carrier materials, for example closed-cell foam made of polyethylene or an ethylene-vinyl acetate copolymer, optionally film-coated on one or both sides with a non-foamed polyethylene film which imparts pressure-elastic or compressible properties to the adhesive tape. The carrier may be coated on one or both sides with adhesive. The adhesives for making tapes can be selected from a wide variety of common materials. It can be z. B. SIS rubbers, SBS rubbers, polyisobutylenes, polyisoprenes, polyacrylates and natural rubbers, optionally with the addition of tackifying natural and / or synthetic resins act.
The device for applying adhesive tape to a cylindrical surface of a cylindrical body essentially comprises at least two fixing rollers oriented horizontally parallel to the axis, which are suitable for contacting the cylindrical surface of the cylindrical body; an adhesive tape to the Supplying adhesive tape to the cylindrical body; and means for causing the cylindrical body to rotate about its cylinder axis.
The fixing rollers are preferably continuous uniform rollers with a circular cross-section which extend in the direction of its roller axis at least over the entire length of the cylindrical body to be bonded. The fixing rollers are rotatably mounted, for example by rotatably supporting their axes. The fixing rollers are preferably at least during the bonding of the cylindrical body at a distance from each other, which is less than the cylinder diameter of the adhered cylindrical body. Two or more fixing rollers can thus form a roller bed, in which the adhered cylindrical body rest and can be held by its own weight.
Preferably, at least one of the fixing rollers is displaceably mounted in one or more directions orthogonal to its roller axis. This makes it possible to vary the spacing of the fixing rollers relative to one another, for example in order to adapt the relative position of the fixing rollers relative to one another to the respective cylinder diameter of the cylindrical body to be bonded. Further, by displacing the fixing rollers with each other, the cylindrical body to be stuck can be selectively held or released. In particular, this also makes it possible to generate a contact pressure of the fixing rollers on the cylindrical body and adjust as needed.
At least during the gluing of the cylindrical body, the fixing rollers act on the cylindrical body with a contact pressure. This can be done on the one hand by the weight of the cylindrical body by resting on at least two fixing rollers. However, the contact pressure is preferably generated and controlled in that at least three fixing rollers are used, which are arranged around the cylinder circumference of the cylindrical body around and this clamp against each other. Preferably, therefore, form the axis positions of the three or more fixing rollers in profile a triangle or polygon, in the triangular surface or polygon surface is the axis position of the cylindrical body. The cylindrical body can thus be effectively clamped between the three or more fixing rollers, with movement of the rollers toward each other increasing the pressure on the cylindrical body.
By the contact pressure exerted by the fixing rollers on the cylindrical body, it is possible due to existing friction between the surfaces of the fixing rollers and the cylindrical body, by rotating one or more of the fixing rollers, the cylindrical body in rotation to offset its cylinder axis. For this purpose, it is advantageous to provide at least one of the fixing rollers with a drive.

At the same time, the contact pressure which the fixing rollers exert on the cylindrical body fulfills the important task of bringing the adhesive surface of the adhesive tape to be applied into contact with the cylindrical surface of the cylindrical body to be bonded. The contact pressure of the fixing rollers on the cylindrical body is thus of particular importance. When applying the adhesive tape, it is important to press the adhesive tape well and evenly onto the substrate to ensure good wetting of the substrate with the adhesive, to avoid air bubbles between the adhesive tape and the cylinder surface, to maximize the contact surface between the adhesive tape and the cylinder surface and thus to achieve the resulting effect Adhesion effect between adhesive tape and cylindrical surface to make optimal. In general, the adhesive tape will reach its final strength when the maximum possible wetting of the adhesive to the substrate has been achieved, with the pressure sensitive adhesive typically taking some time to flow into the microscopic asperities. The process is favored by higher temperatures and a high contact pressure. Adhesives that achieve high final strength and high heat resistance generally take a relatively long time to perform this wetting process. On the other hand, the contact pressure or the contact time must not be too great, so that a present in the adhesive foam carrier does not collapse or lose its compressive elastic properties. The contact pressure or the pressing time must therefore be evenly distributed over the entire pressing surface and dosed well.

Preferably, therefore, at least one of the fixing rollers is provided with means for detecting or measuring the contact pressure on the cylindrical body. This can be done for example by detecting or measuring the force acting on the roller axis in the direction away from the cylinder axis. In addition or alternatively, at least one of the fixing rollers, preferably a displaceable fixing roller, is preferably equipped with means for setting or controlling the contact pressure on the cylindrical body. This can be done, for example, that the force with which the displaceable fixing roller is offset against the cylindrical body, is adjustable or controllable.

Preferably, at least one of the fixing rollers serves as a deflection roller for the supplied adhesive tape. The adhesive tape is thereby supplied to the cylindrical body to be adhered by being first guided around a partial section of the deflection roller. Viewed in profile, the adhesive tape thus runs around a circular arc of the deflection roller. Depending on the relative orientation of the direction of delivery relative to the point of contact between the guide roller and the cylindrical body, the adhesive tape around the circular arc of the guide roller in a section corresponding to a Center point angle of about 1 ° to about 270 °, preferably from about 45 ° to about 210 °, in particular from about 90 ° to about 180 °, before it is aligned at the point of contact between the pulley and cylindrical body with the cylindrical surface of the cylindrical body and on this is transmitted. A large section, for example in the range of 120 ° to 170 °, is particularly advantageous if the contact surface between the guide roller and tape should be large, for example, because the guide roller should take the tape.

As a guide roller can serve a fixing roller on which the cylindrical body rests with its own weight. This has the advantage that in the zone in which the adhesive tape comes into contact with the cylindrical surface of the cylindrical body, a contact pressure is inherently exerted by the weight of the cylindrical body. Alternatively, serve as a deflection roller a fixing roller, which is arranged substantially above the axis of the cylindrical body. Thus, it is advantageously possible to supply the adhesive tape of the deflection roller from above. Preferably, the axis of the deflection roller is arranged vertically above the axis of the cylindrical body. If the adhesive tape is fed to the deflection roller in the horizontal direction, it extends around a section of the deflection roller which corresponds in profile substantially to a semicircle (180 °) before it is aligned with the cylindrical surface of the cylindrical body at the point of contact between the deflection roller and the cylindrical body this is transmitted.

The pulley may optionally be equipped with means for gripping the adhesive tape. For this purpose, the deflection roller may have at its periphery suction openings for temporarily holding the adhesive tape by means of negative pressure, wherein a Saugluftsteuerkanal is in communication with the suction openings. If the Saugluftsteuerkanal pressurized, this is communicated to the suction ports. When a portion of the adhesive tape covers such a suction opening, this portion is pressed against the surface of the guide roller due to the ambient pressure. Friction between the surfaces of the diverting pulley and the adhesive tape causes the diverting pulley to transport the adhesive tape by means of rotation about the roller axis. In order for the effect of the vacuum applied to the suction air control duct to be maximal, preferably only those suction openings are supplied with negative pressure by the suction air control duct, which are located in the section of the deflection pulley which is covered or covered by the adhesive tape.

The adhesive tape is advantageously fed to the deflection roller in the horizontal direction. The adhesive tape can rest on the deflection roller, in particular by its own weight, which can facilitate the gripping or guiding of the adhesive tape around the deflection roller. The adhesive tape is usually provided as a double-sided adhesive tape whose one adhesive surface is covered by a cover, the so-called liner. The uncovered adhesive surface is the cylindrical surface facing the sticking cylindrical body and is glued to this. If a deflection roller is used, the adhesive tape lies on top of it with its covered adhesive surface, ie with its liner.

Optionally, the adhesive tape can be provided as a double-sided adhesive tape, the two adhesive surfaces of which are exposed. In this case, the fixing rollers are advantageously provided in such a way that the adhesive tape can unfold no or only a reduced adhesive action with respect to the surface of the fixing rollers. For this purpose, the fixing rollers are siliconized on their surface, for example, or provided with an anti-adhesion coating such as polytetrafluoroethylene (PTFE, Teflon). If a deflection roller is used, its surface can be configured such that a certain adhesive effect of the adhesive tape is given, so that the deflection roller can "grasp" and transport the adhesive tape by means of its adhesive effect. Ideally, however, the adhesive effect of the adhesive tape against the surface of the deflection roller is less than with respect to the surface of the cylindrical body to be bonded, so that the adhesive tape is completely transferred to the cylindrical body at the contact surface between the deflection roller and the cylindrical body.

Optionally, as described above, the adhesive tape may be provided on a gluing surface provided with a liner, wherein the liner is peeled off before, during or after the application of the adhesive tape to the cylindrical body. Those fixing or deflection rollers, which are arranged downstream of the peeling off of the liner in such a construction, advantageously have the described reduced adhesive properties relative to the adhesive tape.

The adhesive tape is usually provided as a material web of great length (adhesive tape web). In this case, it is necessary to shorten the adhesive tape to a suitable length before, during or after the process of application to the cylindrical body. For this purpose, the device may have a separating device for separating or cutting the adhesive tape, which comprises at least one separating element. This separating element can be designed as a mechanical separating element, for example in the form of a cutting device. It can also be designed as a contactless separating element, for example as a water cutting device, comprising one or more water jet nozzles, or as a laser cutting device comprising one or more laser sources.

Preferably, the separating element over the width of the adhesive tape web along the extension of the roller axes of the fixing rollers and the cylinder axis of the cylindrical body is displaceable. For this purpose, the separating element can be mounted in a guidable manner on a bearing and guide device, wherein the guide can be effected by means of rolling or slide-mounted slide. A movable one Separating element is usually cheaper and more space-saving than a over the entire width of the adhesive tape web extending separating element. Optionally, however, the separating element can also extend over the entire width of the adhesive tape web, in particular if a non-contact separating element is used. Thus, for example, in addition to a design with one or a group of movable water jet nozzles or laser sources also conceivable that the width of the adhesive tape web is completely covered by a series of juxtaposed and individually or jointly controllable nozzles or laser sources.

As far as the separating element is designed as a mechanical separating element, it is preferably in the form of a knife, in particular a pinch diameter. In this case, the separation process takes place by direct contact of the separating element with the surface of the adhesive tape web. The back pressure of the adhesive tape web against the knife can be done in various ways, for example by a second, oppositely acting mechanical separating element, or by a cutting pad or by suitable tension of the adhesive tape web. In one embodiment, the deflection roller can serve as a cutting pad. The cylindrical body, however, preferably does not serve as a cutting pad.

The depth of cut can be adjusted by the respective cutting force. In a mechanical separating element such as a knife, the cutting depth can be varied by adjusting the pressing force of the separating element relative to the cutting pad or the tensioned adhesive tape web. If a water cutting device or a laser cutting device is used as a separating element, the cutting force can be adjusted by controlling the parameters at the water jet nozzles or laser sources. By adjusting the depth of cut can be ensured that the separating element does not act or only moderately on the cutting surface, so this does not damage. This may be particularly advantageous if the deflection roller serves as a cutting pad.

Accordingly, the separator may be configured such that the adhesive tape web of the adhesive tape is separated in various ways. On the one hand, the adhesive tape with liner, if present, can be completely severed. This is particularly advantageous if the tape together with liner is to be applied to the cylindrical body, so the sticky outer surface of the pasted cylindrical body should therefore ultimately be covered. In this case, it is advantageous to let the cutting between the guide roller and the cylindrical body or exactly on the deflection roller take place, so that a piece of the adhesive tape is available for the next bonding operation, if another cylindrical body is to be provided with adhesive tape.

On the other hand, only the tape can be severed, but the liner, if any, left intact. This has the advantage that the adhesive tape can be conveyed by advancing the liner, which can facilitate the supply of the adhesive tape to the cylindrical body to be bonded. In the course of this, the liner would have to be removed from the adhesive tape before the finished, pasted cylindrical body is removed from the device. Preferably, the liner is wound up immediately after the adhesive tape has contacted the adhered cylindrical surface of the cylindrical body and adhered thereto, for example, immediately after passing the adhesive tape around the guide roller.
Alternatively, the tape can be completely severed and the liner, if any, perforated. This type of separation preferably takes place before the deflection roller passes, so that the perforated liner can be torn off behind the deflection roller, for example. For this purpose, the deflection roller can stop while the adhering cylindrical body continues to rotate.

The device has a loading mechanism for introducing the adhered cylindrical body in an adhesive position, that is, a position in which the sticking of the adhesive tape to the cylindrical surface of the adhered cylindrical body can take place. The insertion mechanism also serves as an ejector mechanism, with which the pasted cylindrical body is moved from the adhesive position, for example, to a packaging or Abtransporteinheit.
The adhesive position is essentially determined by the relative displacement of the cylindrical body relative to the adhesive tape web. The cylindrical body is then in the adhesive position when application of the adhesive tape to the cylindrical surface of the cylindrical body leads to the desired result with respect to the position of the adhesive tape on the cylindrical body. The adhesive position is generally given when the adhered cylindrical body extends beyond the width of the adhesive tape web in the direction of the cylinder axis at equal ends at both ends.

The insertion and ejection mechanism is configured to allow the cylindrical body to be displaced along the extension of the roller axes of the fixing rollers and the cylinder axis of the cylindrical body, respectively. Thus, it is possible to adjust or control the relative position of the adhered cylindrical body to the position of the adhesive tape. Locating the correct adhesive position can be facilitated by positioning means, for example by one or more contact elements or light barriers along the extension of the roller axes of the fixing rollers and the cylinder axis of the cylindrical body. Such positioning means can during the introduction and / or ejection process, the position of the Feedback cylindrical body and cause, for example, a control of the introduction and ejection mechanism.

Preferably, the insertion and ejection mechanism carries the cylindrical body, for example, by the cylindrical body rests on the insertion and ejection mechanism by its own weight. In this case, the introduction and ejection mechanism can be designed such that it acts on the cylindrical body so that the cylindrical body can be moved into or out of the adhesive position with little or no additional effort. Particularly preferably, the introduction and ejection mechanism causes the displacement of the cylindrical body automatically.

In one embodiment, the loading and ejection mechanism may be provided by one or more conveyor belts extending along the extension of the roller axes of the fixing rollers and the cylinder axis of the cylindrical body, respectively. On the one or more conveyor belts, the cylindrical body can rest with its own weight during the loading and unloading operation. Preferably, two or more conveyor belts are provided in parallel spaced relationship, wherein the distance between the two outermost conveyor belts is smaller than the cylinder diameter of the adhered cylindrical body. The two or more conveyor belts can thus form a transport bed, in which rest the adhering cylindrical body and can be held by its own weight. In this case, the two or more conveyor belts may be inclined or be designed tiltable so that their transport surfaces facing in the direction of the cylinder axis of the cylindrical body or can be aligned. In order to be able to effect a feed in the direction of the extent of the roller axes of the fixing rollers or the cylinder axis of the cylindrical body, the one or more conveyor belts may be provided with corresponding drive means.
Optionally, a magazine may be provided in which a plurality of cylindrical bodies to be adhered are kept. This magazine can have an output unit with which a cylindrical body to be bonded is transferred to the insertion mechanism. For example, the magazine can hold the adhered cylindrical body axially parallel to the fixing rollers stacked, so that when releasing a sticking cylindrical body on the output unit of the cylindrical body passes by gravity due to its own weight to the insertion mechanism. The tracking further reproached Cylindrical body can also be done by their gravity accordingly, by the remaining stack after release of the lowermost cylindrical body moves.

1. (a) Kontaktieren der Zylinderfläche des zylindrischen Körpers durch zumindest zwei achsparallel ausgerichtete Fixierrollen;
2. (b) Anbringen des Klebebands an der Zylinderfläche des zylindrischen Körpers; und
3. (c) Wickeln des Klebebands auf den zylindrischen Körper durch Drehen des zylindrischen Körpers um seine Zylinderachse.

The method for applying adhesive tape to a cylindrical surface of a cylindrical body essentially comprises the steps

1. (A) contacting the cylindrical surface of the cylindrical body by at least two axially parallel fixing rollers;
2. (b) attaching the adhesive tape to the cylindrical surface of the cylindrical body; and
3. (c) wrapping the adhesive tape on the cylindrical body by rotating the cylindrical body about its cylinder axis.

The process of applying the adhesive tape to the cylindrical surface of the cylindrical body essentially begins with bringing the cylindrical body first into the adhesive position, that is, the position in which the adhesive tape can be stuck to the cylindrical surface of the cylindrical body to be bonded. This can be done, for example, by displacing the cylindrical body along the extension of the roller axes of the fixing rollers or the cylinder axis of the cylindrical body with the aid of the described insertion mechanism. For this purpose, the insertion mechanism, for example, act on the cylindrical body in such a way that it is guided into the adhesive position with little or no additional effort. Particularly preferably, the introduction mechanism causes the displacement of the cylindrical body automatically.

If the introduction mechanism is provided by one or more conveyor belts, the introduction process can take place in that the one or more conveyor belts cause an advance in the direction of the extent of the roller axes of the fixing rollers or the cylinder axis of the cylindrical body.

The introduction process is terminated as soon as the cylindrical body has reached the adhesive position. The identification of the adhesive position can be facilitated by the fact that positioning means during the Einbringvorgangs the position of the cylindrical body feedback and cause or enable, for example, a control of the introduction mechanism. As long as the positioning confirm that the adhesive position has not yet been reached, so the cylindrical body has not yet sufficiently offset in the axial direction, the introduction process is continued. If the insertion mechanism automatically causes the displacement of the cylindrical body, the insertion mechanism continues to feed in this case. If the positioning confirm that the adhesive position has been reached, the insertion process ends or the feed is interrupted. If the positioning means confirm that the adhesive position has been exceeded, the Inserting slowly or gradually undone until the adhesive position is reached. For this purpose, the introduction mechanism can make a backward feed.

If the cylindrical body to be bonded is in the adhesive position, the cylindrical body can be removed from the insertion mechanism. The removal from the introduction mechanism can be effected, for example, by holding the cylindrical body now by fixing rollers, in particular by the cylindrical body resting on fixing rollers. For this purpose, one or more fixing rollers can be moved up to the cylindrical body. Alternatively, if two or more fixing rollers are already in relative positions to the cylindrical body which allow the cylindrical body to rest, the insertion mechanism can be moved away from the cylindrical body so as to deposit the cylindrical body on the fixing rollers. A combination of both measures is possible. In particular, the insertion mechanism may optionally be actively removed from the cylindrical body to be adhered as soon as it is supported or lifted by the fixing rollers.

Preferably, one or more fuser rollers will approach them from below the cylinder axis of the cylindrical body to be adhered until they contact the cylindrical surface of the cylindrical body and lift or lift the cylindrical body in succession. The displacement or approach of the fixing rollers can be done in particular by offsetting their axle bearings, for example by the axle bearings are mounted on a pivotable arm, or by the axle bearings are slidably mounted on rails. The displacement of the axle bearings may be basically provided along any direction suitable for bringing the fixing roller (s) into contact with the cylindrical body. Preferably, the displacement of the axle bearings takes place substantially in the direction of the cylinder axis of the cylindrical body to be bonded. Particularly preferably, two or more fixing rollers are mounted such that they can be offset symmetrically with respect to a vertical through the cylinder axis of the cylindrical body. Particularly preferred is a symmetrical movement of the fixing rollers obliquely upward in the direction of the cylinder axis of the cylindrical body.

In one embodiment, the cylindrical body is fixed by three or more fixing rollers. For this, three or more fixing rollers contact the cylindrical surface of the cylindrical body from different directions so as to effectively pinch the cylindrical body therebetween. For example, three fixing rollers in profile form a triangle around the cylindrical body such that the cylinder axis of the cylindrical body comes to rest in the triangular area. By displacing one or more fixing rollers in the direction of the cylinder axis of the cylindrical body, a fixing of the same is effected.

The contact pressure, which cause the fixing rollers in this embodiment on the cylindrical surface of the cylindrical body, can be adjusted so that it is possible to set by rotating one of the fixing rollers, the cylindrical body in rotation. At the same time, the contact pressure can be adjusted so that the subsequently applied adhesive tape is pressed in a suitable manner on the cylindrical surface of the cylindrical body. For this purpose, the contact pressure can be detected or measured and controlled by controlling the movement of one or more fixing rollers in the direction of the cylinder axis of the cylindrical body.

When the cylindrical body is held or fixed by the fixing rollers, the gluing step may begin. For this purpose, the adhesive tape is first contacted with an adhesive surface with the cylindrical surface of the cylindrical body. Subsequently, the cylindrical body is rotated about its cylinder axis, so that the adhesive tape is wound on the cylindrical surface. The rotation of the cylindrical body can be done by rotating one or more fixing rollers.

During the wrapping of the adhesive tape on the cylindrical body, the adhesive tape passes one or more fixing rollers. By the contact pressure, which cause the fixing rollers on the cylindrical surface of the cylindrical body, the adhesive tape is pressed against the cylinder surface in a suitable manner.

The supply of the adhesive tape to the cylindrical body preferably takes place via at least one deflection roller, which is formed by at least one of the fixing rollers. That is, the adhesive tape is passed around a portion of the respective fixing roller (s) before coming into contact with the cylindrical surface of the cylindrical body. Viewed in profile, the adhesive tape runs around a circular arc of the deflection roller. Depending on the relative orientation of the direction of delivery relative to the point of contact between the guide roller and cylindrical body, the adhesive tape around the arc of the guide roller in a section corresponding to a center angle of about 1 ° to about 270 °, preferably from about 45 ° to about 210 °, in particular from about 90 ° to about 180 °, before it is aligned at the point of contact between the guide roller and the cylindrical body with the cylindrical surface of the cylindrical body and is transmitted to this. A large portion, for example in the range of 120 ° to 170 °, is especially advantageous if the contact surface between the guide roller and the adhesive tape should be large, e.g. because the pulley should take the tape. This can be done for example by means of negative pressure.

The winding of the adhesive tape on the cylindrical body is ideally interrupted before a second layer of adhesive tape is formed on the cylindrical surface. For this, the rotation of the cylindrical body before it has performed a complete revolution since contact with the tape.

Now, the separation of the adhesive tape can be done. Preferably, the adhesive tape is to be cut off so that the beginning and end of the adhesive tape strip applied to the cylindrical body lie against one another with a minimum gap. It should therefore preferably no gap between the butt ends of the tape strip arise and the butt ends of the tape strip should not overlap. The length of the tape strip thus ideally corresponds to the circumference of the cylindrical body.

To cut the adhesive tape accurately, a separation or perforation can be carried out parallel to the cylinder axis of the cylindrical body. This can be done by means of a mechanical separating element such as a cutting device, or by means of a non-contact separating element such as a water cutting device or a laser cutting device. Preferably, the separation or perforation is carried out by moving the separating element along the extension of the roller axes of the fixing rollers or the cylinder axis of the cylindrical body.

As far as the separating element is designed as a mechanical separating element, the separation process can be carried out by direct contact of the separating element with the surface of the adhesive tape web. The back pressure of the adhesive tape web against the knife can be provided in various ways, for example by a second, oppositely acting mechanical separating element, or by a cutting pad or by suitable tension of the adhesive tape web. In one embodiment, the deflection roller can serve as a cutting pad. The cylindrical body, however, preferably does not serve as a cutting pad.

The cutting depth can be varied by the respective cutting force, for example, by adjusting the pressing force of the separating element relative to the cutting pad or the tensioned adhesive tape web. If a water cutting device or a laser cutting device is used as a separating element, the cutting force can be adjusted by controlling the parameters at the water jet nozzles or laser sources. By adjusting the depth of cut can be ensured that the separating element does not act or only moderately on the cutting surface, so this does not damage. This may be particularly advantageous if the deflection roller serves as a cutting pad.

Accordingly, the adhesive tape web of the adhesive tape can be separated in various ways. On the one hand, the adhesive tape with liner, if present, can be completely severed. This is particularly advantageous if the tape together with liner is to be applied to the cylindrical body, so the sticky outer surface of the pasted cylindrical body should therefore ultimately be covered. In this case, it is advantageous to let the cutting between the guide roller and the cylindrical body or exactly on the deflection roller take place, so that a piece of the adhesive tape is available for the next gluing process if an additional cylindrical body is to be provided with adhesive tape.
On the other hand, only the tape can be severed, but the liner, if any, left intact. This has the advantage that the adhesive tape can be conveyed by advancing the liner, which can facilitate the supply of the adhesive tape to the cylindrical body to be bonded. In the course of this, the liner would have to be removed from the adhesive tape before the finished, pasted cylindrical body is removed from the device. Preferably, the liner is wound up immediately after the adhesive tape has contacted the adhered cylindrical surface of the cylindrical body and adhered thereto, for example, immediately after passing the adhesive tape around the guide roller.
Alternatively, the tape can be completely severed and the liner, if any, perforated. This type of separation preferably takes place before the deflection roller passes, so that the perforated liner can be torn off behind the deflection roller, for example. For this purpose, the deflection roller can stop while the adhering cylindrical body continues to rotate.
After the adhesive tape has been cut to length, the cylindrical body is preferably further rotated so that the remainder of the cut-to-length adhesive tape strip comes into contact with the cylindrical surface of the cylindrical body and at least one of the contact points, that is the contact points between the fixing rollers and cylinder surface, passes.
Finally, the pasted cylindrical body is released from the fixing rollers, preferably by performing the steps of holding or fixing in reverse order. In this case, the pasted cylindrical body can finally be returned to the insertion mechanism, which now serves as an ejection mechanism by supporting or effecting a movement of the pasted cylindrical body out of the adhesive position. If the introduction mechanism has been provided by one or more conveyor belts, the ejection process can take place in that the one or more conveyor belts cause an advance in the direction of the extension of the roller axes of the fixing rollers or the cylinder axis of the cylindrical body, the sticky cylindrical body of the Device out. Preferably, the direction of the ejection corresponds to the direction of insertion.

The invention will be described below with reference to preferred embodiments in conjunction with the accompanying drawings.

The FIGS. 1A to 1F Fig. 3 are schematic sectional views of an embodiment of the invention illustrating the apparatus for applying adhesive tape to a cylindrical surface of a cylindrical body.

The FIG. 2 is a schematic sectional view of another embodiment of the invention, in which the cylindrical body rests on the pulley with its own weight.

The FIG. 3 is a schematic sectional view of another embodiment of the invention, in which the liner of the adhesive tape is removed from the adhesive tape and wound up after the adhesive tape has been guided around the deflection roller.

The Fig. 1A shows a schematic sectional view of an apparatus 10 for applying adhesive tape 40 on a cylindrical surface 21 of a cylindrical body 20. The device 10 comprises fixing rollers 30, one of which is designed in the form of a deflection roller 30c. the deflection roller 30c has a negative pressure region 32, in which the adhesive tape 40 is held on the deflection roller 30c by means of negative pressure. The adhesive tape 40 is provided as an adhesive tape web by an adhesive tape roll 45. In the exemplary embodiment shown, this is a double-sided adhesive tape whose adhesive surface is covered by a cover or a liner 41. The adhesive tape 40 is thereby unwound from the adhesive tape roll 45 such that the liner 41 is interposed between the adhesive tape 40 and the lateral surface of the deflection roll 30c. For separating the adhesive tape into individual adhesive tape strips, a separating device 50 is provided.

In Fig. 1A the cylindrical body 20 rests on conveyor belts 61 of an insertion mechanism 60. With the help of the conveyor belts 61 and the introduction mechanism 60, the cylindrical body 20 can be displaced along its cylinder axis until it is in an adhesive position within the apparatus 10 shown, ie a position in which the adhesive tape 40 is stuck to the cylindrical surface 21 the cylindrical body 20 can be made. In a first step of an exemplary method for applying the adhesive tape 40 on the cylindrical surface 21 of the cylindrical body 20 so the cylindrical body 20 is initially outside the plane of the Fig. 1A put on the conveyor belts 61 of the introduction mechanism 60 and with the aid of the conveyor belts 61 in the plane of the Fig. 1A transported into it. Upon reaching the adhesive position, the feed of the conveyor belts 61 stops and the phase of fixing the cylindrical body 20 by means of the fixing rollers 30 begins. For this purpose the lower two fixing rollers 30a, 30b are moved orthogonally to the extent of their roller axes and symmetrically to each other in the direction of the cylinder axis of the cylindrical body 20.

After a certain time, the fixing rollers 30a, 30b contact the cylindrical surface 21 of the cylindrical body 20 with their respective peripheral surface and begin to lift it from the conveyor belts 61 of the introduction mechanism 60, as in FIG Fig. 1B shown. The fixing rollers 30a, 30b are moved in the direction of the cylinder axis of the cylindrical body 20 until the cylindrical body 20 is completely lifted off the conveyor belts 61 of the introduction mechanism 60 and contacts the lateral surface of the deflection roller 30c. Means for detecting the contact pressure (not shown) ensure that the movement of the fixing rollers 30a, 30b is interrupted as soon as the desired contact pressure of one or more fixing rollers 30a, 30b on the cylindrical surface 21 of the cylindrical body 20 has reached a desired value.

In the next step, the in Fig. 1C is illustrated, the adhesive tape 40 is attached to the cylindrical surface 21 of the cylindrical body 20. For this purpose, in the exemplary embodiment shown, one of the fixing rollers 30a, 30b is rotated counterclockwise by means of a drive (not shown) in rotation about its roller axis. The friction existing between the circumferential surface of the driven fixing roller 30a / 30b and the cylindrical surface 21 of the cylindrical body 20 results in a rotation of the cylindrical body 20 about its cylinder axis in a clockwise direction. The rotation of the cylindrical body 20 is in turn transmitted to the guide roller 30c, which accordingly rotates counterclockwise and the adhesive tape 40 unwinds from the adhesive tape roll 45 and the cylindrical surface 21 of the cylindrical body 20 feeds.

As already mentioned, the lateral surface of the deflection roller 30c facing away from the adhesive tape 40 is free and is sticky. Thus, as soon as the adhesive tape 40 is supplied due to the rotation of the guide roller 30 c of the cylindrical surface 21 of the cylindrical body 20, it begins to adhere to the cylindrical surface 21 of the cylindrical body 20. Continued rotation of the cylindrical body 20 and the guide roller 30c causes the adhesive tape 40 to be gradually wound on the cylindrical surface 21 of the cylindrical body 20. The desired adhesion of the adhesive tape 40 to the cylindrical surface 21 of the cylindrical body 20 is provided by the contact pressure exerted by the deflection roller 30c with its lateral surface opposite the cylindrical surface 21 of the cylindrical body 20.

Before the cylindrical body 20 has made a complete revolution about its cylinder axis, the drive of the fixing roller 30a / 30b is interrupted and the adhesive tape 40 together with liner 41 becomes severed by means of the separator 50, as in Fig. 1D illustrated. This operation is carried out when the length of the adhesive tape 40 already wound on the cylindrical body 20 together with the length of the uncoated adhesive tape 40 located between the cylindrical body 20 and the separator 50 corresponds to the cylinder circumference of the cylindrical body 20. This ensures that the length of the separated tape strip is equal to the cylinder circumference of the cylindrical body 20, thus can cover this in exactly one position.

After the adhesive tape 40 has been cut to length by the separating device 50, the drive of the fixing roller 30a / 30b is reactivated, so that the cylindrical body 20 continues to rotate and the remaining portion of the adhesive tape strip is glued to the cylindrical surface 21 of the cylindrical body 20, as in FIG Fig. 1E shown. When this process is completed, the adhered tape strip surrounds the cylindrical surface 21 of the cylindrical body 20 in one layer, without overlap, and ideally without any significant gap between the abutting edges of the tape strip.

Adhesion of the subsequent adhesive tape 40, which is supplied by the deflection roller 30c of the already pasted cylindrical surface 21 of the cylindrical body 20, is prevented by the fact that the adhesive strip located on the cylindrical surface 21 of the cylindrical body 20 on its outwardly facing surface continues to be the one already mentioned Liner 41 wears.

After the entire cylindrical surface 21 of the cylindrical body 20 is covered with adhesive tape, the drive of the fixing roller 30a / 30b is again interrupted, and the cylindrical body 20 is again put on the conveyor belts 61 of the loading mechanism 60 as shown in FIG Fig. 1F shown. To this end, the fixing rollers 30a, 30b in turn orthogonal to their roller axes and symmetrically to each other obliquely down to their original position. The pasted cylindrical body 20 is finally brought out of the adhesive position by the conveyor belts 61, which now serve as the ejection mechanism. In the embodiment shown this is done by further transporting the pasted cylindrical body 21 into the drawing plane, where it is transferred to a packaging and removal unit (not shown).

Fig. 2 shows a further embodiment of the device 10, comprising a cylindrical body 20, fixing rollers 30, one of which serves as a deflection roller 30c, adhesive tape 40 and a separator 50. The adhesive tape 40 is again provided as a double-sided adhesive tape, one surface, in the example shown the down-facing surface, covered with a liner 41.

In the embodiment shown, the cylindrical body 20 rests with its own weight on the deflection roller 30c. This has the advantage that at the contact surface between the lateral surface of the guide roller 30c and the cylindrical surface 21 of the cylindrical body 20, the maximum contact pressure is provided. If it allows the weight of the cylindrical body 20, in this embodiment, moreover, if necessary, the provision of only two fixing rollers 30, one of which forms the deflection roller 30c, suffice.

In this embodiment, the cylindrical body 20 is again fed by conveyor belts 61 of an insertion mechanism 60 in the adhesive position. Subsequently, the introduction mechanism 60 is removed from the cylindrical body 20 downward, so that the cylindrical body 20 is deposited on the fixing roller 30a and the guide roller 30c. A drive of the fixing roller 30a about its roller axis causes the cylindrical body 20 to rotate about its cylinder axis, which in turn causes the guide roller 30c to rotate and causes the adhesive tape 40 to be fed to the cylindrical surface 21 of the cylindrical body 20. By further rotation, the adhesive tape 40 is wound on the cylindrical surface 21 of the cylindrical body 20 and adhered to the cylindrical surface 21 of the cylindrical body 20 by the contact pressure, which is present between the lateral surface of the guide roller 30c and the cylindrical surface 21 of the cylindrical body 20. Before the cylindrical body 20 has completed a complete revolution about its cylinder axis, the drive of the fixing roller 30a is interrupted and the separator 50 cuts through the adhesive tape 40 and the liner 41. Thereafter, the drive of the fixing roller 30a is restarted and the cylindrical body 20 is further circulated rotated its cylinder axis until the cylindrical surface 21 is completely covered by a single layer of the adhesive tape as already described. Lastly, the loading mechanism 60 is again moved from below to the cylindrical body 20 until the cylindrical body 20 rests on the conveyor belts 61 of the loading mechanism 60 and lifted off the fixing roller 30a and the guide roller 30c, and the pasted cylindrical body 20 by means of the conveyor belts 61 transported out of the adhesive position.

In the Fig. 3 The embodiment shown differs from that in FIG Fig. 2 In the embodiment shown, essentially, the liner 41 located on the double-sided adhesive tape is pulled off the adhesive tape 40 during winding of the adhesive tape 40 onto the cylindrical surface 21 of the cylindrical body 20 and wound up on a liner winder 42. Consequently, in this embodiment, the outer surface of the pasted cylindrical body 20 is tacky, so that the fixing rollers 30 as well as the conveyor belts 61 of the introduction mechanism 60 are designed adhesive-repellent (eg siliconized).

The supply of the cylindrical body 20 in the adhesive position in the manner described by means of the conveyor belts 61 of the introduction mechanism 60. Once the adhesive position is reached, the cylindrical body 20 is lifted in this embodiment of the conveyor belts 61 of the introduction mechanism 60 by the left lower fixing roller 30a is moved up to the cylindrical body 20. Feeding of the adhesive tape 40 can be done in this embodiment by driving the liner winder 42, while winding the adhesive tape on the cylindrical surface 21 of the cylindrical body 20 again by driving one of the fixing rollers 30a, 30b proceeds. For cutting the adhesive tape 40, a separating device 50 is again used, but in this embodiment only the adhesive tape 40, but not the liner 41, is severed.

The adhering of the pasted cylindrical body 20 is carried out last in the manner already described, wherein in this embodiment, the pasted cylindrical body 20 leaves the device with a sticky surface, which allows an immediate further processing thereof.

The apparatus and method have been described by way of exemplary embodiments, which serve to illustrate the invention but are not intended to limit the scope of protection defined by the claims. Where applicable, all individual features illustrated in the individual embodiments may be combined and / or interchanged without departing from the scope of the invention.

LIST OF REFERENCE NUMBERS

10

Device for applying adhesive tape

20

Cylindrical body

21

cylindrical surface

30

fuser rollers

30a, 30b

Movable / driven fixing rollers

30c

idler pulley

32

Under pressure range

40

duct tape

41

liner

42

Line Up winding

45

tape roll

50

separator

60

introducing mechanism

61

conveyor belts

Claims (15)

1. Device (10) for applying adhesive tape (40) to a cylindrical surface (21) of a cylindrical body (20), comprising:

   at least two horizontal axially parallel securing rolls (30a, 30b), disposed in order to make contact with the cylindrical surface (21) of the cylindrical body (20) with their respective lateral surfaces;

   an adhesive tape feed for feeding adhesive tape to the cylindrical body (20);

   means for setting the cylindrical body (20) into rotation about its cylindrical axis; and

   an insertion and ejection mechanism (60) that allows a displacing of the cylindrical body (20) along the extent of the roll axes of the securing rolls (30) or the cylindrical axis of the cylindrical body (20),

   wherein the cylindrical body (20) can be moved away from the insertion and ejection mechanism (60).
2. The Device (10) according to claim 1, wherein at least one of the securing rolls serves as guide roll (30c) for the adhesive tape (40) that is fed in, wherein the adhesive tape (40) covers the guide roll (30c) in a section corresponding to a central angle from about 1° to about 270°, preferably from about 45° to about 210°, especially from about 90° to about 180°.
3. The Device (10) according to one of the preceding claims, wherein the movement of the cylindrical body (20) away from the insertion and ejection mechanism (60) is brought about by one or more securing rolls moving up against the cylindrical body (20) and by the cylindrical body (20) lying on at least one securing roll (30).
4. The Device (10) according to claim 3, wherein the movement of the cylindrical body (20) away from the insertion and ejection mechanism (60) is brought about by a movement of the insertion and ejection mechanism (60) away from the cylindrical body (20), so the cylindrical body (20) lies on one or more securing rolls (30).
5. The Device (10) according to one of the preceding claims, further comprising a sectioning facility (50) for cutting at least partially through the adhesive tape (40).
6. The Device (10) according to one of the preceding claims, comprising at least three axially parallel securing rolls (30), which are disposed around the cylindrical body (20) in such a way that they can pinch said cylindrical body (20) between themselves.
7. The Device (10) according to one of the preceding claims, wherein at least one of the securing rolls (30) is mounted moveably in one or more directions orthogonally to its roll axis.
8. The Device (10) according to claim 7, further comprising means for recording and controlling the pressure of the at least one movable securing roll (30) on the cylindrical body (20).
9. The Device (10) according to one of the preceding claims, wherein at least one of the securing rolls (30) is equipped with a drive that is suitable for setting the securing roll (30) into rotation about its roll axis.
10. Method for applying adhesive tape (40) to a cylindrical surface (21) of a cylindrical body (20), by means of a device according to one of the claims 1-9, comprising:

    (a) inserting the cylindrical body (20) by means of the insertion and ejection mechanism (60);

    (b) contacting the cylindrical surface (21) of the cylindrical body (20) with the respective lateral surface of at least two horizontal axially parallel securing rolls (30a, 30b);

    (c) moving the cylindrical body (20) away from the insertion and extraction mechanism (60);

    (d) applying the adhesive tape (40) to the cylindrical surface (21) of the cylindrical body (20); and

    (e) winding the adhesive tape (40) onto the cylindrical body (20) by means of rotation of the cylindrical body (20) about its cylindrical axis.
11. The method according to claim 10, wherein at least one of the securing rolls (30) serves as guide roll (30c) for the adhesive tape (40) that is fed in, wherein the adhesive tape (40) is passed around the guide roll (30c) in a section corresponding to a central angle from about 1° to about 270°, preferably from about 45° to about 210°, especially from about 90° to about 180°.
12. The method according to one of the claims 10-11, wherein, in step (c), the insertion and extraction mechanism (60) can be moved away from the cylindrical body (20).
13. The method according to one of the claims 10-12, further comprising at least partially cutting-through the adhesive tape (40) by means of a sectioning facility (50).
14. The method according to one of the claims 10-13, further comprising - before the contacting step and/or after the winding step - the displacing of the cylindrical body (20) along the extent of the roll axes of the securing rolls (30) or the cylindrical axis of the cylindrical body (20) by means of a insertion and ejection mechanism (60).
15. The method according to one of the claims 10-14, wherein contact with the cylindrical surface (21) of the cylindrical body (20) is made by at least three axially parallel securing rolls (30), which are disposed around the cylindrical circumference of the cylindrical body (20) in such a way that they pinch this cylindrical body (20) between themselves.

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