EP0955160B1 - Process for the fabrication of a sleeve , especially for the printing industrie - Google Patents

Abstract

The core roll (1) is coated with release agent and the non-elastic tube (20) is drawn over the core leaving a gap between them. After centering the tube on the roll an elastic compressible material (60,65) is injected between them and cured. Preferred Features: The gap is vented during injection through sealable vents (50) which are closed immediately the gap is filled and further material is then injected to compress the material in the gap. The vents and/or injectors (40) are located in the tube centering device (30).

Description

The invention relates to a method for producing a sleeve, in particular for the printing industry, with an essentially inelastic outer jacket and an elastic one and compressible inner jacket, in which the sleeve on a production roll core is produced as in the introductory part of claim 1 is described.

For sleeves, especially in the field of rotary printing forms in the printing industry, predominantly metallic cylinders are used, with a functional profile on the surface is produced. Steel rollers are usually galvanically coated with a copper layer coated, in which the functional profile is then introduced. Furthermore, too Known nickel sleeves, which are also produced galvanically.

The sleeves can be used, for example, as gravure, flexographic or embossing sleeves.

For the removal or re-installation of sleeves on a roll core is preferred applied a pneumatic method. For this purpose it is on the inside the sleeve an inner jacket or an expansion layer made of an elastic and compressible Material arranged. This inner jacket or the expansion layer between the roll core and the outer jacket of the sleeve is necessary because the sleeve is on the one hand when being pulled up or pulling off must not be damaged by excessive pressures and on the other the pressure of the pneumatic means, which is generally through radial passages in the roller core between the outer shell of the roller core and the inner shell of the sleeve will have to take effect on the entire surface in order to remove it easily to allow the sleeve. Furthermore, the inner jacket or the stretch layer have the Task to compensate for unevenness on the inside of a tubular sleeve.

The connection of the sleeve to the carrier core, for example made of steel or plastic can be made, can be done by means of frictional engagement or positive engagement, with the Frictional connection the sleeve is made on a core that is slightly has a smaller diameter than the later carrier core.

Methods are known in which a release agent is first applied to the roll core on which the expansion layer is then built up. After drying the Expansion layer, the surface of which must be treated and / or sanded off before in one a further step the outer jacket of the sleeve can be applied. Such one The process is very complex, especially because the expansion layer has hardened must be maintained before the further construction of the sleeve can take place. Further is the step of processing the expansion layer after it has hardened, e.g. grinding, very time consuming.

GB-A-2 051 681 used to formulate the introductory part of claim 1 discloses a method of making a roll in which, as in context with Figures 11 and 12 of GB-A-2 051 681, essentially one inelastic tube is wound on a manufacturing roll core, the tube one Has an inner diameter that is larger than the outer diameter of the production roll core, so that a space is created between them. The pipe is so on the Manufacturing roll core, centered that the distance between the pipe and the manufacturing roll core is essentially the same. Then one gets the elastic and compressible inner jacket forming mass injected into this space, which can harden there.

In this way, in a single process step, the expansion layer or the inner jacket becomes the sleeve is formed and at the same time a connection with the outer jacket of the Sleeve, an essentially inelastic tube. In addition to the significant simplification The process flow also creates problems in the connection of the inner jacket and the outer jacket avoided, since the inner jacket or the expansion layer when injecting directly with the thermoplastic or metallic tube can connect.

The expansion layer can moreover after completion of all necessary process steps cure so that there is not sufficient between the individual process steps Curing must be maintained. This speeds up the manufacturing process, In particular, the efficiency of the machines used is improved, since one The method according to the invention does not require any special machinery during curing necessary is.

It is therefore the object of the present invention to provide a method for producing a Sleeve with a substantially inelastic outer jacket and an elastic and to provide a compressible inner jacket in which the mass forming the inner jacket can be compressed as desired.

This object is achieved by a method according to claim 1, preferred embodiments are the subject of the subclaims.

According to the invention it is provided that the space between the tube and the production roll core during the injection of the mass forming the inner jacket through venting devices is vented. These venting devices can be closed and are closed as soon as the cavity between the tube and the production roll core is completely filled with the mass forming the inner jacket. For one thing a controlled and trouble-free ventilation of the space ensured, furthermore the mass forming the inner jacket is prevented from escaping from the intermediate space and created the possibility of increasing the mass in the space as desired compress in which after closing the venting devices wide mass is injected.

In a preferred embodiment, the injection forms the one forming the inner jacket Mass on one side of the space between the production roll core and the tube instead, while venting on the opposite side, in the direction of the longitudinal axis of the roller core, is carried out, which enables a particularly controlled ventilation and prevents unwanted air pockets in the expansion layer or in the inner jacket remain.

It is particularly preferred that the above-mentioned ventilation devices and / or injection devices are arranged in a centering device that the tube in one maintains predetermined, uniform distance from the manufacturing roll core. By the the compact construction provided thereby simplifies the method, furthermore can largely avoid errors caused by the interaction of several components become.

The finished sleeve is preferably removed pneumatically by a liquid or gaseous medium is pressed into the roll core and by radial Bores in the outer surface of the production roll core exerts pressure on the sleeve. As a result, the finished sleeve can be pulled off the production roll core, without higher pressures or frictional forces occurring which damage the inner jacket or the expansion layer.

In a further embodiment, the inside of the inner jacket is covered by a structured surface of the production roll core formed with a structure. Thereby is a positive connection between the finished sleeve and a Carrier core ensured. Such a positive connection can be used in particular high forces to be expected to be desirable compared to the frictional Connection to provide increased holding force.

The production roll core preferably consists of metallic materials, in particular Aluminum or steel. Depending on the requirements, other materials can also be used the manufacturing roll core are used, these are especially after their durability or durability, but also according to their weight.

Closed-cell cells are particularly suitable as an elastic and compressible mass for the inner jacket Foams in which there are additional air bubbles and / or expanded polystyrene beads can be introduced. Such a material shows excellent elasticity and Compression values, while a secure connection between the inner jacket and the outer casing of the sleeve remains ensured. Even processing this Foaming is very unproblematic.

Furthermore, particles can be introduced into the mass forming the inner jacket in order to to make the inner jacket electrically conductive.

In a further embodiment, the inner jacket consists of two or more layers. Such a multilayer structure leads to a higher flexibility of adaptation Sleeve to the desired task, so that the more complex manufacturing process is accepted becomes.

A functional profile for later use, in particular, is preferred on the outer jacket in rotary printing, introduced, further can also on the outer jacket further coatings are applied. These other coatings are particularly effective preferably made of polyurethane (PU), polytetra fluorethylene (PTFE) or copper and allow a problem-free incorporation of a functional profile and also fulfill a protective function for the underlying layers of the sleeve.

Both the materials for the outer jacket, preferably metallic or thermoplastic Material, as well as the materials of any other coatings, in particular with regard to the desired method for applying a functional profile, such as direct structuring using a laser beam or ablation an ionized state, selected and adapted.

In a further embodiment it is provided that an additional functional layer is glued on, whereby the usual manufacturing step of attaching a functional profile, for example by direct structuring using a laser beam or by ablation from the ionized state, is significantly simplified.

The functional layer can also be a wear protection layer, for example.

Breakthroughs, bores and the like through the sleeve are also intended under the functional profile be understood. It is also possible to retrofit the sleeve with Arteines perforations To provide sieves. Then such a sleeve can be used, for example, as a rotary screen Screening of bulk goods or as a suction cylinder, for example to suck films or to Pulling water out of paper can be used.

Due to the flexible design of the surface, it can also be used as a textile printing template possible.

In a further embodiment, the production roll core has a conical Course on, which in particular the pneumatic pulling or removing the sleeve is simplified by the roll core. Such a conical course can also ever depending on the field of application for later use.

In a further preferred embodiment, the production roll core is directly as Carrier core used for the use of the manufactured sleeve. This will take the step of Removal of the sleeve is unnecessary, which also leads to a simplified processing process and for an immediate introduction of the manufactured sleeve into the manufacturing process leads.

Basically, you can apply a wide variety of surfaces or layers all known methods can be used on the sleeve. These include in particular Spraying process, thermal spraying, fluidized bed sintering, vulcanizing rubber, pouring on or the application of shrink sleeves etc.

All known methods can also be used for structuring the sleeve. These include in particular the laser direct structuring already mentioned, both of which can be variable in area as well as depth, also the abovementioned removal from the ionized state or a mechanical engraving etc.

The method according to the invention is illustrated in the accompanying FIG. 1, which shows a cross section by an embodiment of a system showing a sleeve according to the invention Manufactures method, explained in more detail.

In Figure 1, a roll core 1 is shown, the compressed air connection 2, through the compressed air pressed as one of the possible liquid or gaseous media in the roll core and has a radial bore 3 in the outer jacket of the roll core 1, through which the compressed air between the inner jacket or the expansion layer 60, 65 and the production roll core 1 for pneumatic removal or mounting of the sleeve is pressed.

A thermoplastic tube 20 is used here as the inelastic tube, which means Centering devices 30 at a uniform distance from the production roll core 1 is held.

The methods for applying the surfaces or layers can vary depending on the application arbitrarily selected or used in combination.

On the one hand, injection nozzles 40 are formed in the centering devices 30, which are direct in connection with the space between the thermoplastic tube 20 and the Roll core 1 stand, on the other hand vent nozzles 50 on the opposite side of the space so that a controlled ventilation of the space during the injection of the material forming the inner jacket 60, 65 is ensured.

In Figure 1, the inner jacket or the expansion layer 60, 65 has already been injected, the Expansion layer is an elastomeric matrix 60, into which expanded polystyrene beads 65 are introduced have been.

Those disclosed in the above description, in the drawing and in the claims Features of the invention can be used individually or in any combination be essential for the implementation of the invention.

Claims (20)

1. A method of making a cylindrical shell, particularly for the printing industry, comprising a substantially inelastic outer surface (20) and an elastic and compressible inner surface (60, 65), wherein the cylindrical shell is made on a production roller core (1), comprising the following steps:

   mounting a substantially inelastic tube (20) on the production roller core (1), the tube (20) having an inside diameter larger than the outside diameter of the production roller core (1), so that a gap forms between them;

   centring the tube (20) on the production roller core (1) so that there is a substantially equal spacing between the tube (20) and the production roller core (1);

   injection of a material (60, 65) forming the elastic and compressible inner surface, into the gap between the tube (20) and the production roller core (1) and

   curing of the injected material (60, 65),

   characterised in that the production roller core (1) is coated with a release agent, and in that the gap between the tube (20) and the production roller core (1) is vented by means of closable venting devices (50) during the injection of the material (60, 65) forming the inner surface, the venting devices (50) being closed as soon as the gap between the tube (20) and the production roller core (1) has been completely filled with the material (60, 65) forming the inner surface, and after the closure of the venting devices (50) injection of material (60, 65) forming the inner surface is continued in order to compress the material (60, 65) in the gap.
2. A method according to claim 1, characterised in that the injection is effected at one side of the gap between the production roller core (1) and the tube (20), while venting is carried out at the opposite side.
3. A method according to claim 1 or 2, characterised in that the venting devices (50) and/or the injection devices (40) are disposed in a centring device (30) for the tube (20).
4. A method according to any one of claims 1 to 3, characterised in that the removal of the completed cylindrical shell is carried out pneumatically, preferably by means of compressed air.
5. A method according to any one of claims 1 to 4, characterised in that in order to remove the cylindrical shell a liquid or gaseous medium is forced through a connection (2) into the roller core (1) and exerts pressure on the cylindrical shell through radial bores (3) in the outer surface of the production roller core (1).
6. A method according to any one of the preceding claims, characterised in that the inside of the inner surface is formed with a structure by means of a structured surface of the production roller core (1).
7. A method according to any one of the preceding claims, characterised in that the production roller core (1) consists of metallic materials, particularly aluminium or steel.
8. A method according to any one of the preceding claims, characterised in that closed-cell foams are used as material (60, 65) for the inner surface.
9. A method according to any one of the preceding claims, characterised in that air bubbles and/or expanded polystyrene beads (65) are introduced additionally into the material (60) forming the inner surface.
10. A method according to any one of the preceding claims, characterised in that particles which make the inner surface conductive are additionally introduced into the material (60, 65) forming the inner surface.
11. A method according to any one of the preceding claims, characterised in that the inner surface consists of two or more layers.
12. A method according to any one of the preceding claims, characterised in that the substantially inelastic tube (20) consists of a metallic or a thermoplastic material.
13. A method according to any one of the preceding claims, characterised in that a function profile is applied to the outer surface (20).
14. A method according to claim 13, characterised in that the function profile is applied by a surface-variable and/or depth-variable direct structuring with a laser beam and/or by an erosion from an ionised state and/or by a mechanical engraving.
15. A method according to any one of the preceding claims, characterised in that further coatings are additionally applied to the outer surface (20).
16. A method according to claim 15, characterised in that the additional coatings consist of polyurethane (PU), polytetrafluoroethylene (PTFE) or copper.
17. A method according to claim 15 or 16, characterised in that the coatings are applied by a spraying process, thermal spraying, fluidised-bed sintering, pouring on, or by the use of shrink sleeves.
18. A method according to claim 15, characterised in that a function layer is additionally stuck on.
19. A method according to any one of the preceding claims, characterised in that the production roller core (1) has a conical configuration.
20. A method according to any one of the preceding claims, characterised in that the production roller core (1) is used as a support core for the use of the finished cylindrical shell.

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