EP1235684A1

EP1235684A1 - Sleeve comprising a layer for being fixed on a metal support roll

Info

Publication number: EP1235684A1
Application number: EP00985398A
Authority: EP
Inventors: Henri Bertoncini; Hélène BIAVA; Jerzy Kuczynski; Laurent Aubanel; Yves Lemble
Original assignee: MacDermid Graphic Arts SAS
Current assignee: MacDermid Graphics Solutions Europe SAS
Priority date: 1999-12-03
Filing date: 2000-12-04
Publication date: 2002-09-04
Anticipated expiration: 2020-12-04
Also published as: DE60021758T2; US20030031812A1; US20070051464A1; JP2003515704A; ES2246919T3; WO2001039973A1; DE60021758D1; EP1235684B1; FR2801833A1; FR2801833B1; ATE301041T1

Abstract

The invention concerns a sleeve to be mounted on a metal support cylinder and including at least one functional covering ( 20 ) forming the external surface of the sleeve, and an integration covering ( 21 ) on the cylinder ( 1 ) whose constitutive material is intended to be fixed to the metal of the cylinder by a physical link. The invention is applicable to the transformation of lap products.

Description

"A sleeve comprising a securing layer on a metal support cylinder".

The invention relates to the field of transformation of products into a sheet and more particularly, a sleeve intended to be integral with a metal support cylinder.

Such a sleeve can be used in a wide variety of techniques, including coating, embossing, calendering, doubling, spinning and printing.

The sleeves can be cylindrical, or even conical.

They can be mounted by air cushion on a particular cylinder comprising compressed air circuits or by a mechanical assembly.

Most sleeves can only be subjected to relatively low linear loads.

Indeed, the connection between the cylinder and the sleeve is not sufficient to transmit significant mechanical forces and, for very high loads, there are risks of separation between the sleeve and the cylinder.

This is why a sleeve intended to be subjected to high linear loads is generally adhered to the surface of the cylinder. The connection between the sleeve, also called cylinder lining or coating, and the cylinder is, therefore, permanent.

In addition, cylinder liners must be made directly on the cylinder.

When a printer decides to replace a worn coating, he returns the cylinder to the manufacturer. This removes the used layer and creates a new layer on the cylinder.

The embodiment of a coating therefore creates many disadvantages. First of all, it requires the transport of the support cylinders, which increases the costs and increases the downtime of the cylinders for their maintenance. In addition, the sleeve being adhered to the cylinder, it is necessary to machine the cylinder to completely remove the sleeve. The disposal of the used sleeve therefore involves risks of deterioration of the support cylinder.

In addition, the loads which stress a cylinder in a printing or processing machine cause an arrow in the support cylinder.

Compensation systems for this deflection have already been developed.

Such a compensation system consists for example in giving a domed shape to the outer surface of the sleeve which is mounted on the cylinder. During operation and under the effect of the loads which stress the cylinder, the axial variation in the thickness of the sleeve is compensated by the arrow of the cylinder.

This compensation system makes it possible to ensure a constant linear load and therefore regular processing of the print medium in the Nip, that is to say the nip area between two cylinders, in the transverse direction.

However, known compensation systems have drawbacks, since it is difficult to give the desired shape to the outer surface of the sleeve and its production is therefore a source of errors.

In addition, in the event of wear of the sleeve, it is sometimes necessary to rectify its outer surface and it is then difficult to keep the convex shape given to its outer surface, which again requires costs and machine stoppages.

The invention aims to overcome these drawbacks by providing a sleeve intended to be mounted on a cylinder metal support, without risk of separation, despite significant linear loads, this sleeve can be at least partially manufactured before being mounted on the cylinder and be easily removed to allow the mounting of another sleeve.

The object of the invention is also to propose a system for compensating deflection for such a sleeve, the production and maintenance of which are easy.

Thus, the invention relates to a sleeve intended to be mounted on a metal support cylinder and comprising at least one functional layer forming the external surface of the sleeve, as well as a fixing layer on the cylinder, the constituent material of which is intended to be fixed to the cylinder metal by a physical link.

Throughout the description, the expression “functional layer” will be understood to mean a layer which is active or which fulfills a function of printing, varnishing, embossing coating, spinning, calendering, doubling or any function imparted. , in the transformation processes, with cylinders comprising a functional coating of polymeric, composite, elastomeric or ceramic type.

Such a functional layer may be a printing layer, an anti-wear layer, for example ceramic, a layer conferring a certain resilience, such as an elastomeric layer, or else a layer allowing the reception of ink, for example on the surface. outside of the sleeve and in particular constituted by ceramic or metal with hollow parts.

The physical connection between the sleeve and the support cylinder has advantages. It is different from a chemical bond, for example obtained by means of a permanent adhesive, because it makes it possible to remove the sleeve from the cylinder without having to machine the metal cylinder. It ensures however the same resistance to detachment as a chemical bond.

In a first embodiment, the sleeve comprises a securing layer made of a compressible material, the sleeve being intended to be force fitted on the support cylinder.

In a second embodiment, the securing layer is made of an expandable material, this material being intended to be expanded after mounting the sleeve on the support cylinder.

The expandable material is then advantageously compressible after expansion.

The bonding layer also advantageously comprises a heat-shrinkable material which, during the expansion of the bonding layer under the effect of heat, causes the sleeve to be tightened on the cylinder.

In a third embodiment, the joining layer consists of a hardenable material, which is hardened after its introduction between the cylinder and the sleeve mounted with play on the cylinder.

The sleeve according to the invention can also comprise at least one support layer, to reinforce the rigidity of the sleeve.

The support layer also makes it possible to mechanically protect the bonding layer and to modulate the mechanical behavior of said sleeve.

The sleeve according to the invention advantageously comprises a system for compensating for the deflection of the support cylinder, on which it is intended to be mounted.

In a first embodiment, this compensation system comprises a compressible layer whose compressibility is variable along the axis of the sleeve. The elastic modulus of this layer can vary in the axial direction.

The thickness of this layer can also vary in the axial direction.

In this case, this layer with variable compressibility can have a simple parabolic profile, multiple parabolic, step or frustoconical profile.

In an alternative embodiment of the sleeve, this variable compressibility layer is the layer for securing the sleeve to the support cylinder.

In this case, the sleeve can be fixed on a support cylinder having a variable thickness.

In another alternative embodiment, this variable compressibility layer is located between two layers of the sleeve.

In another embodiment of the deflection compensation system, the sleeve has at least one chamber between two of its layers, this chamber containing a pressurized fluid.

The invention also relates to a method of mounting a sleeve on a metal support cylinder, said sleeve comprising at least one functional layer forming the outer surface of the sleeve, the method consisting in:

- mount said sleeve with clearance on the support cylinder,

- introducing an expandable material under a given stress, this material being positioned between the support cylinder and the sleeve after the latter has been assembled and

- Apply said constraint to cause the expansion of the expandable material and the joining of the sleeve on the cylinder, by physical or chemical bond.

In a particular embodiment of the method, the expandable material is deposited, before mounting the sleeve on the support cylinder, on the exterior surface of the support cylinder or the interior surface of the sleeve.

Preferably, the expandable material is in the form of a ribbon, deposited by wrapping on the cylinder or the sleeve, or also in the form of a tube.

This tape or this tube advantageously comprises at least one layer of self-adhesive on one of the faces, to allow its fixing on the cylinder or the sleeve.

The invention also relates to another method of mounting a sleeve on a metal support cylinder, said sleeve comprising at least one functional layer forming the outer surface of the sleeve, the method consisting in: - mounting the sleeve with play on the cylinder support, provide a hardenable material, in particular by injection or casting, between the sleeve and the support cylinder and cause the material to harden and thus, the joining of said sleeve on the support cylinder, by physical or chemical bond.

The invention also relates to an assembly for a printing or processing machine comprising a metal support cylinder on which is fixed a sleeve comprising at least one functional layer forming the external surface of the sleeve and a securing layer, physically bonded to the metal of the cylinder. .

This bonding layer can advantageously be made of a compressible, expanded or hardened material.

Preferably, this assembly comprises a system for compensating the deflection of the cylinder.

In a first embodiment, this assembly comprises a sleeve with a compressible layer, the compressibility of which is variable along the axis of said assembly. The modulus of elasticity of this compressible layer can vary in the axial direction, the thickness of this layer can also vary in the same axial direction.

In an alternative embodiment, this variable compressibility layer is the layer for securing the sleeve to the support cylinder.

In this case, the support cylinder can have a variable thickness.

In another alternative embodiment, this variable compressibility layer is located between two constituent layers of the sleeve.

Finally, in another embodiment of an assembly comprising a system for compensating the deflection of the cylinder, this system consists of a chamber, located between two constituent layers of the sleeve, and containing a pressurized fluid.

The invention will be better understood and other objects, advantages and characteristics thereof will appear more clearly on reading the description which follows and which is given with reference to the appended drawings which represent nonlimiting embodiments of the invention and in which: FIG. 1 is a half-view in axial section of a printing or transformation assembly according to the invention, comprising a support cylinder and a sleeve,

- Figure 2 is a half view in axial section of a variant of a printing or processing assembly shown in Figure 1, Figure 3 is a half view in axial section of a first example of a printing or transformation assembly according to the invention comprising a system for compensating the deflection of the cylinder, FIG. 4 is a half-view in axial section showing a variant of the printing or transformation assembly shown in FIG. 3 and

FIG. 5 is also a half-view in axial section showing another variant embodiment of the printing or transformation assembly illustrated in FIG. 3.

First of all, reference is made to FIG. 1 which shows a printing or transformation assembly comprising a support cylinder 1 made of metal, on which a sleeve 2 is fixed.

In the embodiment illustrated in FIG. 1, this sleeve 2 comprises a functional layer 20 forming the external surface 2a of the sleeve and a securing layer 21 which is fixed to the cylinder 1 by means of a physical connection or chemical.

The thickness of the functional layer is typically between 8 and 25 mm, the thickness of the bonding layer is typically 0.5 to 10 mm.

The printing assembly illustrated in Figure 1 can be obtained in various ways.

First of all, the sleeve can be produced independently, then force-fitted onto the metal cylinder 1, by means known in the state of the art.

In this case, the securing layer 21 is preferably compressible. It can also include a surface relief on its internal face, facilitating the fitting of the sleeve onto the cylinder.

The securing layer 21 can also be produced at least in part, after the sleeve 2 has been mounted on the cylinder 1, a clearance then being left between the sleeve and the cylinder. It is first of all possible to deposit an expandable material on the internal face of the functional layer 20 or on the external surface of the cylinder 1.

In a first variant, this expandable material can take the form of a ribbon, a banner on the cylinder 1.

The functional layer 20 is then mounted, with play, on the banner cylinder with this tape, which is preferably provided with a layer of self-adhesive to facilitate its positioning on the cylinder 1.

Once the functional layer 20 in place around the cylinder, the banner tape is caused to expand, in particular by the action of heat if the material is expandable under the effect of heat.

For this, the whole is placed in an oven or heated by infrared or microwave or by induction.

When the ribbon expands, additional devices are used to keep the cylinder 1 and the functional layer 20 concentric.

As a variant, this expandable material can be fixed on the internal face of the functional layer, the joining between the functional layer and the cylinder taking place as described above.

Furthermore, this strip can be replaced by a tube preformed from an expandable material, positioned on the cylinder 1 or on the internal face of the functional layer 20, before it is mounted around the cylinder 1.

It is therefore here the expansion of the expandable material, previously provided under the functional layer 20 or on the support cylinder 1, which creates the connection between the functional layer 20 and the cylinder 1.

It is also possible to provide that the expandable material comprises a heat-shrinkable material, such as a heat-shrinkable fabric, which, during expansion under the effect of heat, also causes the tightening of the functional layer 20 on the support cylinder 1 at the same time.

In another alternative embodiment, the bonding layer of expandable material can be obtained by casting or injecting an expandable material between the functional layer 20 and the support cylinder 1, after assembly with clearance of the functional layer 20 on the support cylinder 1.

Means for ensuring the concentricity of the sleeve and the support cylinder can be advantageously used.

Again, the connection between the functional layer 20 and the support cylinder 1 is obtained during the expansion of the expandable material disposed between the functional layer and the support cylinder.

It may also be noted that the expandable material used to form the bonding layer can fulfill an additional sealing function, to protect the external surface of the metal support cylinder against corrosion.

Finally, the securing layer 21 can be obtained by injecting or pouring a hardenable material between the functional layer 20 and the support cylinder 1, after mounting the functional layer on the support cylinder.

The connection between the functional layer 20 and the support cylinder 1 is obtained by hardening of this material, in particular by gelation or crosslinking.

Additional devices are also used in this case to ensure concentricity between the support cylinder and the sleeve.

The diameter of the support cylinder / sleeve assembly obtained is between approximately 60 and 500 mm, while its length can be up to 7 m.

The thickness of the bonding layer is typically between 0.5 and 10 mm. In the case where the bonding layer is obtained from an expandable or hardenable material, the manufacturing tolerances of the cylinder 1 and of the functional layer 20 are not very strict, since the bonding layer can compensate for certain defects, in the extent that the concentricity between the support cylinder and the sleeve is well ensured.

In the above description, it has been considered that the sleeve consists only of a functional layer 20 and a securing layer 21.

Of course, the invention is not limited to this embodiment and the sleeve could include other layers, in particular one or more support layers, other functional layers or even layers not fulfilling any particular function during the 'impression but allowing to adjust the diameter of the sleeve.

In this regard, reference can be made to FIG. 2 which illustrates a support cylinder 1 on which is fixed a sleeve 3 comprising a functional layer 30 forming the outer surface of the sleeve, a reinforcing layer 31, another functional layer 32 which is here a compressible layer and a securing layer 34.

This layer 34 will not be described in detail since it can be produced like the layer 21 described with reference to FIG. 1.

The support layer 31 can in particular be made of a composite material obtained with a sheet of glass fibers impregnated with resin. Other fibers than glass fibers can be used, with any resin known for this type of application.

The support layer can also be made of a hard and thick material to compensate, with a thickness total fixed, a reduced thickness of functional layer in order to harden the Nip.

We will now give two examples illustrating the method of mounting a sleeve according to the invention.

In these two examples, the connection layer of the sleeve is obtained by expansion of an expandable material and the sleeve comprises a functional layer, a support layer and a connection layer (embodiment not illustrated in FIGS. 1 and 2).

Example 1

The sleeve consisting of a support layer of glass-epoxy composite 2 mm thick and an elastomer layer having a hardness of 95 Shore A (of CSM family) and 15 mm thick, is manufactured on a mandrel with a diameter of 74.4 mm and a width of 1000 mm.

The inner surface of the sleeve has a slight relief to facilitate mechanical attachment with the bonding layer described below.

A ribbon of a thermoplastic mixture of the family of polyolefins having a hardness of 75 ShA and containing 5% of a swelling agent (of the microsphere type expandable in temperature of brand Expancell) is extruded separately in the form of a ribbon with a thickness of 1 mm. The extrusion takes place at a temperature such that the microspheres do not expand during the extrusion.

The ribbon described above is wound on a metal core (support cylinder) with a diameter of 68 mm helically and edge to edge with a single layer.

The metal core has a simply machined, unpolished outer surface.

The sleeve described above is fitted onto the assembly consisting of the metal core of diameter 68 mm with its ribbon. The inside diameter of the sleeve being greater by 3.2 mm to that of the metal core, this operation is easy because there is a considerable clearance.

The assembly is mechanically blocked at the edges and brought to temperature in an oven. The cycle was 2 hours at 80 ° C followed by 2 hours at 120 ° C. The expansion of the tape fills the space between the metal core and the sleeve and creates a mechanical tightening stress.

After cooling, the assembly is machined concentrically and cylindrically before being subjected to an endurance test.

The linear load continuously supported by the joined sleeve at a linear speed of 50 m / min. was 49 N / mm. The result obtained is sufficient for a sleeve of the size tested with a functional coating having a hardness of 95 ShA.

Simple means, known per se, exist to increase the admissible load if necessary:

Higher containment of the bonding layer with lower expansion;

Reduction in thickness of the bonding layer;

Increase in the hardness of the matrix of the bonding layer (from 75 ShA used in the example described here up to 96 ShA).

Example 2

The sleeve consisting of a support layer and an elastomer layer is obtained as described in Example 1.

The ribbon wound on the metal core is a heat-shrinkable woven ribbon which is impregnated with a flowable and crosslinkable polyurethane of hardness 75 ShA and containing 8% of swelling agent. The pouring being done at room temperature, the microspheres do not expand at this stage. This ribbon is such that it has the possibility of expanding during a post-baking at 120 ° C.

The other steps of the assembly process are identical to those described for example 1.

Whatever the type of securing layer and its embodiment, its main characteristic is that it allows a physical connection to be made between the sleeve and the metal support cylinder.

An additional chemical bond should not be excluded, in particular between the bonding layer and the functional layer or the support layer if it is present.

A support cylinder equipped with a sleeve according to the invention can support linear loads up to 350 N / mm and linear operating speeds of up to 2000 meters / minute, without risk of separation between the cylinder and the muff.

The sleeve according to the invention therefore makes it possible to combine the advantages of a coating which cannot be separated from the support cylinder, even under heavy loads, and those linked to the presence of a compressible layer.

In addition, when the sleeve is used, it is easy to remove it from the support cylinder since it can be detached from it under the effect of an appropriate force.

This considerably simplifies the removal of the sleeve, compared to the coatings known in the prior art, which are adhered to the support cylinder, an irreversible connection being thus formed between the coating and the support cylinder.

In particular, it suffices to clean and possibly degrease the external surface of the cylinder 1 after the complete removal of the sleeve, and it is not necessary machine the outside surface of the cylinder to completely remove the sleeve.

This therefore eliminates the drawbacks mentioned above since the risks of deterioration of the support cylinder are eliminated. On the other hand, the cylinders no longer have to be sent back to the manufacturer to replace the sleeve.

The removal of the used sleeve and the fixing of a new sleeve can be carried out directly at the printer.

This therefore considerably reduces the duration and maintenance costs of these cylinders.

This also makes it possible to reduce the number of support cylinders held by the user to ensure the operation of these machines, despite the necessary maintenance. Printers or users can therefore reduce their investments. Users can also reduce production losses associated with long changes.

It may also be noted that, when the securing layer is obtained from a compressible or hardenable material, its thickness can be modulated for a sleeve comprising, moreover, the same constituent layers. This therefore makes it possible to fill support cylinders having different external diameters, with the same sleeve, by varying the thickness of the securing layer.

These sleeves can typically be adapted to cylinders whose diameter can vary between 1 and 10 mm.

It should also be noted that the sleeves can, at least in part, be produced before they are mounted on the support cylinder. This makes it possible to reduce the duration of the maintenance since only the fixing layer must, if necessary, be produced after mounting of the sleeve on the cylinder. Reference is now made to FIGS. 3 to 5 which illustrate an assembly according to the invention comprising a system for compensating the deflection of the cylinder.

Referring firstly to FIG. 3, the printing assembly according to the invention comprises the support cylinder 1 of cylindrical shape, of constant diameter and a sleeve 4 fixed on the cylinder.

This sleeve 4 comprises a functional layer 40 forming the outer surface 4a of the sleeve, an intermediate layer 41, in particular a support layer such as the layer 31 described with reference to FIG. 2, and a securing layer 42.

This joining layer 42 can in particular be made of an expanded or hardened material, such as layers 21 and 34 which have been previously described with reference to FIGS. 1 and 2.

This securing layer 42 here has a parabolic profile. This profile could also be conical or tapered stage. This profile is obtained by giving the internal surface of the layer 41 a complementary shape, curved towards the axis of the sleeve.

After mounting the sleeve, initially consisting of layers 40 and 41, around the support cylinder 1, the expandable or hardenable material placed between the internal surface of the layer 41 and the exterior surface of the support cylinder 1 is expanded or hardened, as this has been described previously with reference to FIG. 1.

This expanded or hardened material thus fills the space between the sleeve and the cylinder, which ensures the fixing of the sleeve on the support cylinder with a securing layer having this parabolic profile which makes it possible to compensate for the deflection of the cylinder during its use in a printing machine. It can be seen that with such a compensation system, the outer surface of the sleeve is cylindrical and has a constant thickness. Compensation of the deflection is therefore obtained for a given load, without having to give a particular shape to the external surface of the sleeve, which eliminates the drawbacks of the compensation systems known up to now.

Furthermore, when the compensation system is formed by the securing layer, it is obtained very simply, by securing the sleeve to the support cylinder.

In this case, the deflection of the deflection is of course obtained first of all by varying the thickness of the securing layer along the axis of the support cylinder 1. In addition, the variable thickness between the internal surface of the layer 41 and the external surface of the cylinder 1, during the formation of the joining layer 42, itself generates a variation of the compression module in the layer 42.

In general, the thickness variation profile of the layer 42 is chosen to obtain appropriate compensation for the deflection of the cylinder, for given dimensions of the cylinder and a given linear operating load.

FIG. 4 illustrates another embodiment of the compensation system.

The reference 1 always designates a support cylinder of constant diameter along the axis of the cylinder.

The sleeve 5 according to the invention comprises a functional layer 50 forming the outer surface 5a of the cylinder / sleeve assembly, a support layer 51, a layer 52 allowing compensation for the deflection of the cylinder, another support layer 53 and a layer solidarity 54. The joining layer 54 is obtained as described above for the layers 21 of the sleeve 2 and 34 of the sleeve 3.

The layer 52 has, on its outer face 52a, a parabolic profile, the inner surface of the layer 51 having a complementary shape. The profile could also be conical.

This layer 52 therefore has a variable thickness along the axis of the cylinder 1 and, where appropriate, a modulus of elasticity also variable along the axis of the sleeve 5.

This variation in modulus and / or thickness makes it possible to compensate for the deflection of the cylinder, while retaining a sleeve of constant diameter.

Finally, reference is made to FIG. 5 which illustrates another embodiment of a support cylinder / sleeve assembly according to the invention, with a deflection compensation system. This assembly consists of a support cylinder 10 and a sleeve 6.

The cylinder 10 has a curved outer surface 10a, with a parabolic profile. This profile could also be conical. The sleeve 6 comprises a functional layer 60 forming the outer surface 6a of the assembly, a support layer 61 and a securing layer 62.

This joining layer 62 is obtained from an expandable or hardenable material, like the layers 21 and 34 illustrated in FIGS. 1 and 2.

The layers 60 and 61 have a constant thickness. The joining layer 62 has on its outer surface 62a a cylindrical shape and on its inner face a conical profile complementary to the conical profile of the outer surface 10a of the support cylinder 10. Thanks to the particular profile of the support cylinder 10, there again is obtained a system for compensating for the deflection of the cylinder, by virtue of a variation in the thickness of the bonding layer in the axial direction and possibly a variation of the modulus of elasticity in this same axial direction.

Of course, the invention is not limited to the embodiments which have just been described and, in particular, the layer of the sleeve which serves to compensate for the deflection of the cylinder could only have a modulus of elasticity variable in the direction axial, having a constant thickness.

In addition, the embodiments described with reference to Figures 3 and 4, on the one hand and 5, on the other hand could be combined. Thus, the sleeve could comprise a securing layer of variable thickness thanks to a support cylinder of variable diameter and also another layer inside the sleeve comprising a particular profile like the layer 52 described with reference to FIG. 4.

One could also provide a profiled cylinder as well as a support layer also profiled, as illustrated in FIG. 3, the profile of the cylinder and that of the support layer being adapted to impart a desired thickness variation to the securing layer.

In operation, the compressible layer 42, 52 or 62 is deformed in compression under the effect of the charges in the nip. This compressible layer is deformed more significantly at the ends of the sleeve than at its center, which compensates for the deflection of the cylinder by generating a uniform linear load.

The assembly according to the invention could also include a deflection compensation system constituted by a chamber placed inside the sleeve, containing a pressurized fluid and having a suitable geometry.

In general, the assemblies according to the invention make it possible to compensate for arrows up to 4 mm.

The main advantage of the compensation system provided in the sleeve according to the invention is that it makes the convex profile given to the sleeves known in the prior art unnecessary to obtain this deflection compensation. This results in a considerable simplification of the manufacture of the sleeve and therefore a reduction in cost. In addition, the sleeves are generally corrected several times to regenerate the work surface. These successive adjustments can lead to errors in the definition of the outer surface of the sleeve, which leads to inappropriate deflection compensation. This drawback is completely avoided with the invention since it is sufficient for the diameter of the sleeve to be constant.

The incorporation of a compressible or simply expanded layer also makes it possible, if necessary, to compensate in a simple manner for the possibility of local overloads at the edge of the width of the product passing through the Nip or to protect the functional coating against accidental overloads. This layer acts in a way like a mechanical fuse which mechanically protects the machine on which the cylinder is mounted in case of passage of a foreign body in the Nip.

It can also be noted that the presence of a securing layer and, where appropriate, of a compressible polymer layer, which can be made damping by means known per se, contributes to damping vibrations or the dynamic response in the event shock, the assembly consisting of the cylinder and the sleeve. The effectiveness of the cushioning polymer layer is greatly increased by the confinement of the latter between the rigid layers consisting respectively of the cylinder and of a support layer.

The reference signs inserted after the technical characteristics appearing in the claims are intended only to simplify the understanding of the latter and should not limit their scope.

Claims

1. Sleeve intended to be mounted on a metal support cylinder and comprising at least one functional layer (20, 30, 40, 50) forming the external surface of the sleeve, as well as a securing layer (21, 34, 42, 54) on the cylinder, the constituent material of which is intended to be fixed to the metal of the cylinder by a physical connection, characterized in that the securing layer is made of an expandable material, this material being intended to be expanded after mounting the sleeve with play on the support cylinder.

2. Sleeve according to claim 1, wherein the expandable material is compressible after expansion.

3. Sleeve according to claim 1 or 2, wherein the securing layer also comprises a heat-shrinkable material which, during the expansion of the securing layer under the effect of heat, causes the tightening of the sleeve on the cylinder.

4. Sleeve according to one of claims 1 to 3, comprising at least one support layer (31, 41, 51, 53).

5. A sleeve according ^'to one of Claims 1 to 4, comprising a clearing system of the arrow of the support cylinder.

6. Sleeve according to claim 5, comprising a compressible layer (42, 52, 62) whose compressibility is variable along the axis of the sleeve.

7. Sleeve according to claim 6, wherein the modulus of elasticity of this compressible layer varies in the axial direction.

8. Sleeve according to claim 6 or 7, wherein the thickness of this compressible layer (42, 52, 62) varies in the axial direction.

9. A sleeve according to claim 8, in which this compressible layer has a simple parabolic profile, multiple parabolic, step or frustoconical profile.

10. Sleeve according to claims 6 to 9, wherein this variable compressibility layer is the securing layer (42, 62) of the sleeve (4, 6) on the support cylinder (1, 10).

11. Sleeve according to claim 9 or 10, intended to be fixed on a support cylinder (10) having a variable thickness.

12. Sleeve according to one of claims 6 to 9, wherein the variable compressibility layer (52) is located between two layers (51, 52) of the sleeve (5).

13. Sleeve according to claim 5, comprising at least one chamber between two layers of the sleeve, this chamber containing a pressurized fluid.

14. Method for mounting a sleeve on a metal support cylinder, said sleeve comprising at least one functional layer forming the external surface of the sleeve, the method consisting in:

- mount said sleeve with clearance on the support cylinder,

- Apply said constraint to cause the expansion of the expandable material and 'the joining of the sleeve on the cylinder, by physical or chemical bond.

15. The method of claim 14, wherein the expandable material is deposited, before mounting the sleeve on the cylinder, on the outer surface of the support cylinder or on the inner surface of the sleeve.

16. The method of claim 15, wherein the expandable material is in the form of a ribbon deposited by wrapping on the cylinder or the sleeve or in the form of a tube.

17. The method of claim 16, characterized in that the tape or the tube comprises at least one layer of self-adhesive on one of the faces.

18. Assembly for a printing or processing machine comprising a metal support cylinder (1, 10) on which is fixed a sleeve (2, 3, 4, 5) comprising at least one functional layer (20, 30, 40, 50) forming the external surface of the sleeve and a securing layer (21, 34, 42, 54), physically linked to the metal of the cylinder, the securing layer being made of a compressible, expanded or hardened material.

19. The assembly of claim 18, comprising a system for compensating the deflection of a cylinder.

20. The assembly of claim 18 or 19, the sleeve (4, 5, 6) comprises a compressible layer (42, 52, 62) whose compressibility is variable along the axis of said assembly.

21. The assembly of claim 20, wherein the modulus of elasticity of this compressible layer varies in the axial direction.

22. The assembly of claim 19 or 20, wherein the thickness of the compressible layer varies in the axial direction.

23. Assembly according to one of claims 19 to 22, in which the layer with variable compressibility is the securing layer (42, 62).

24. The assembly of claim 23, wherein the support cylinder (10) has a variable thickness.

25. Assembly according to one of claims 18 to 22, wherein the variable compressibility layer (52) is located between two layers (51, 53) of the sleeve (5).

26. The assembly of claim 19, the sleeve of which comprises at least one chamber, situated between two constituent layers of the sleeve and containing a pressurized fluid.