EP1871614A1

EP1871614A1 - Printing blanket for mounting on a rotating supporting cylinder of a printing machine

Info

Publication number: EP1871614A1
Application number: EP06755441A
Authority: EP
Inventors: Denis Hertzog; Lionel Cardoso; Laurent Bertapelle
Original assignee: MacDermid Printing Solutions Europe SAS
Current assignee: Trelleborg Coated Systems France SAS
Priority date: 2005-04-22
Filing date: 2006-04-21
Publication date: 2008-01-02
Anticipated expiration: 2026-04-21
Also published as: JP2008536725A; US8222168B2; EP1871614B1; JP5391441B2; FR2884753A1; US20080213530A1; ATE417743T1; FR2884753B1; ES2322199T3; WO2006111663A1; DE602006004330D1

Abstract

The invention relates to a printing blanket for mounting on a rotating supporting cylinder of a printing machine. The printing blanket is in the form of a sheet whose ends are configured as leading edges and trailing edges that are adapted for being engaged in an axial fixing gap of the supporting cylinder. The blanket is characterized in that it has a multilayer structure consisting of film and reinforcing fibers. The invention can be used in the area of the printing machines.

Description

"Printing blank intended to be mounted on a rotating support cylinder of a printing machine".

A printing blanket for mounting on a rotatable support cylinder of a sheet-like printing machine whose leading edge and trailing edge ends are configured to engage a axial fixing slot of the support cylinder.

Blankets of this type are already known which comprise a steel strip covered with an elastomer composite and folded at both ends to prepare the mounting on the support cylinder. These blankets have many drawbacks, such as their high cost due to their delicate manufacture combining a steel strip and an elastomer composite, adhesion difficulties and the fragility of the elastomer-steel connection, the delicate handling in that the Steel has a tendency to mark itself with fold formation, limitations on the size of the products due to the limitations of the widths of the rolling mills and the difficulties of disposal and recycling at the end of their life with separation of the layers. In addition, it has been found that the steel strip is mechanically aggressive towards the cylinder of the machine, which requires protection for example by a polyester film, and therefore additional handling and costs. The invention aims to provide a blanket of the type defined above, which overcomes the disadvantages just stated.

To achieve this purpose, a blanket according to the invention is characterized in that it has a multilayer structure based on films and fibrous reinforcement. According to a characteristic of the invention, the edge portion serving as fixing means in the slot of the support cylinder is a polyester or polycarbonate type film or equivalent associated with a unidirectional aramid or polyethylene type reinforcement embedded in a polymer matrix. or fiber reinforced polymers.

According to another characteristic of the invention, the part intended to be used as fixing means is formed by a polyester or polycarbonate type film associated with a reinforcement of woven or non-woven type with polyester fibers or aramid or polyamide or polyethylene or still metal embedded in a matrix of polymers.

According to yet another characteristic of the invention, the blanket fixing part is formed by a combination of two films of identical or different nature comprising a polymer intermediate layer forming a box.

According to yet another characteristic of the invention, the blanket fixing portion is formed by a combination of two films of identical or different nature comprising a polymer intermediate layer associated with unidirectional reinforcements of aramid or polyethylene type or reinforced with fibers.

According to yet another feature of the invention, the blanket attachment portion is formed by a combination of two films having a compressible intermediate layer forming a box. According to another characteristic of the invention, the blanket fixing part is formed by a combination of two films comprising a compressible intermediate layer associated with unidirectional reinforcements of aramid or polyethylene type forming a box.

The invention will be better understood, and other purposes, features, details and advantages thereof will appear more clearly in the following explanatory description made with reference to the accompanying schematic drawings given solely by way of example illustrating several embodiments of the invention and in which: Figure 1 is a sectional view, broken away a blanket mounted on a support cylinder; Figures 2 and 3 illustrate two modes of configuration of a blanket according to the invention; Figures 4 to 14 are sectional views schematically illustrating several embodiments of a blanket according to the invention.

As shown in FIG. 1, the invention relates to a blanket designated by reference numeral 1 which is mounted on a support cylinder 2, in a manner known per se by engaging its configured ends in leading edges 3 and trailing edges. 4 in an axial slot 6 formed in the cylinder 2. The leading and trailing edges are fixed in this slot 6 using a device 8 whose general structure is known and therefore does not need to to be described in more detail. It is sufficient to indicate for the understanding of the invention that this device comprises a rotating cylindrical member 9 placed in a recess 10 of complementary shape in the cylinder 2, which opens at its periphery in the slot 6 so that, in the angular position of the member 9 shown in Figure 1, a pressing member 11 which is radially movable in a radial passage 10 of the member 9 can be brought into its position shown in which its outer end 12 ensures the attachment of the edges etching and leakage of the blanket in the slot 6 by pressing its ends against the opposite inner face of the slot 6. As seen specifically in Figures 2 and 3, a blanket according to the invention has a multilayer structure which is thinned at its ends to form leading edges 3 and trailing 4, the unthinned portion then constituting the blanket printing part, which is designated by the reference 15. The blanket is obtained by cutting the desired format of a web having the multilayer structure as seen in FIG. FIGS. 2 and 13 and by appropriate machining of the ends for the formation of the leading edges 3 and leakage 4.

It can be seen, which is confirmed by FIGS. 4 to 12 illustrating a multitude of embodiments of a blanket according to the invention, that the portion 15 has above the layers which constitute at their ends the leading edges and a top layer and an outer printing layer 17, a fabric layer 18 and a compressible layer 19. FIGS. 2 and 3 show that a protective layer 14 may be added to the face opposite to the printer surface, below layers of the leading and trailing edges, to mechanically protect the machine cylinder and the attachment layers and to fill, if necessary, the space. The protective layer 14 may optionally be made compressible to increase the shock-absorbing capacity of the blanket 1. The protective layer 14 could be omitted at the leading edges 3 and at the trailing edge 4. The edges etching and leakage could have the same thickness and the same structure, according to Figure 2, but it could be advantageous to provide an asymmetry between the geometries of the leading edges 3 and leakage 4. Since the edge of Attack 3 is, in principle, more stressed, it could be thicker or reinforced by any means known per se with respect to the trailing edge 4 which could be thinned, which further reduces the area of the groove 13 and generating vibrations. The multilayer structure of the blanket is made according to traditional technologies based thermoréticulés or elastomers based on polymers with associated methods as described in the French patent applications No. ⁰ 2,809,667 and 2,809,665. A blanket according to the invention comprises at least one printing layer, a compressible layer and a base for fixing the blanket on the cylinder and which is formed by the combination of a film layer with at least one second film. fixed by means of a polymer layer, a reinforcement embedded in a polymer matrix for the purpose of forming a box or a foldable composite structure having a plastic behavior and a shape memory. For the manufacture of the web, it will be advantageous to use calendering or extrusion processes, and then assembly of the different layers.

Referring to Figures 4 to 14, hereinafter will be described specifically a number of exemplary embodiments of the multilayer structure of a blanket according to the invention.

In the example shown in FIG. 4, the multilayer blanket presents, successively, from the outside to the inside, an outer printing layer 17, a fabric layer 18, a compressible layer 19, a polyester-type film or polycarbonate 20, a reinforcement 21 of unidirectional aramid or polyethylene type embedded in a polymer filling matrix layer, this layer being able to be made of a material which can be rectified so that its free inner face 22 intended to come into contact with the peripheral face of the support cylinder 2 can be ground after the formation of the multilayer structure to uniform the thickness of the multilayer web, which will then be cut to the desired format.

In the exemplary embodiment according to FIG. 5, the blanket successively comprises, from the outside to the inside, as in the case of FIG. 4, an outer printing layer 17, a fabric 18 and a compressible layer 19 then a film 24 of polyester or polycarbonate type, a unidirectional reinforcement 25 of aramid or polyester type embedded in a filling layer 26 in expanded polymer and / or containing fibers, the inner face can be rectifiable.

In the example shown in FIG. 6, the blanket comprises, as in the first cases, an outer printing layer 17, a fabric 18 and a compressible layer 19 and then, embedded in a filler layer 28 made of expanded polymer or / and containing fibers, a unidirectional reinforcement 29 of aramid or polyester type, and finally a film 30 of polyester or polycarbonate type.

FIG. 7 shows an exemplary embodiment of the blanket 1, which successively comprises a printing layer 17, a fabric layer 18, a compressible layer 19, a film 32 of the N ⁰ I polyester or polycarbonate type, a unidirectional reinforcement 32 of aramid or polyester type embedded in an expanded polymer filling layer 33 and / or containing fibers, and an outer film of polyester or polycarbonate No. 2 type. The exemplary embodiment of the blanket according to the invention, illustrated in FIG. 8, comprises, following the printer layers 17, of fabric 18 and compressible 19, a film 37 of polyester or polycarbonate type No. 1, which is filled with polymer expanded or non-foamed and containing fibers and a film 9 of polyester or polycarbonate type N ⁰ 2.

In the embodiment according to FIG. 9, the blanket comprises a printer layer 17, a fabric 18, a compressible layer 19, a film 41 of polyester or polycarbonate type No. 1, a unidirectional reinforcement 42 of aramid or polyester drowned type. in a polymer filling layer 43 and a film 44 of polyester or polycarbonate No. 2 type.

The example shown in FIG. 10 comprises, as the examples above, an outer printing layer 17, a fabric 18 and a compressible layer

19 and then, specific to this example, a film 46 of polyester or polycarbonate type No. 1, a unidirectional reinforcement 47 of aramid or polyester type, embedded in a filling layer 48 of expanded or unexpanded polymer, and / or containing fibers, a film 49 of polyester or polycarbonate type No. 2 and a filler layer 50 of expanded or unexpanded polymer.

FIG. 11 shows an example which comprises, like those mentioned above, on the outside a printing layer 17, a fabric 18 and a compressible layer 19 and, subsequently, a film 52 of polyester or polycarbonate type No. 1 , a filler layer 53 made of expanded or non-foamed polymer and containing fibers, a film 54 of polyester or polycarbonate type No. 2 and a filler layer 55 made of expanded or unexpanded polymer, this polymer being able to be rectified so that its face The inner part can be ground to ensure a uniform thickness of the blanket.

FIG. 12 shows yet another embodiment of a blanket according to the invention, which comprises an outer printing layer 17, a fabric 18, a compressible layer 19, a layer 57 of unidirectional reinforcement N ° 1 in aramid or polyester, etc., arranged perpendicularly to the unidirectional reinforcement No. 2, a unidirectional reinforcement 58 No. 2 aramid or polyester, a filling layer 59 of expanded or unexpanded polymer, and / or containing fibers, a film 60 of the type polyester or polycarbonate and a filler layer 61 expanded or unexpanded polymer and whose free face is rectified, optionally. FIG. 13 shows yet another embodiment of a blanket according to the invention, which comprises, specifically, following the three outer printing layers 17, of fabric 18 and compressible 19, a reinforcement 63 unidirectional N ⁰ I aramid or polyester, etc., arranged perpendicular to the unidirectional reinforcement No. 2, a film 64 of the polyester or polycarbonate type, a unidirectional reinforcement 65 aramid or polyester and a filler layer 66 of expanded or unexpanded polymer and / or containing fibers, whose free face can be rectifiable.

Finally, FIG. 14 illustrates an exemplary embodiment of a blanket according to the invention, which comprises, beneath the printing portion formed by the printer layer 17, the fabric 18 and the compressible layer 19, a unidirectional reinforcement N ⁰ I in aramid or polyester, with the reference 68, integrated in a filler layer 69 of expanded or unexpanded polymer and / or containing fibers, a non-directional reinforcement 70 No. 2 aramid or polyester embedded in a filler layer 71 in expanded or unexpanded polymer and / or fiber-containing, the free face of the latter layer being optionally rectified.

It is apparent from the descriptions of the numerous examples of embodiment of a blanket according to the invention, that the function filled, in the case of known blankets, by a single strip, is accomplished in the case of the invention by a multilayer structure based on of films and fibrous reinforcements, which eliminates the problems inherent in the blankets used until now. With regard to the multilayer structure, it has furthermore been found that a simple film known per se of thickness similar to the known metal strip would not constitute a satisfactory solution to the problem which is at the basis of the invention. on the one hand because of the insufficient mechanical strength, and on the other hand, because of the absence of shape memory making assembly difficult, if not impossible in practice. Regarding the mechanical strength, a blanket must work for months without risk of loss of integrity to ensure the safe operation of the presses. However, a thin film alone, of thickness similar to steel, that is to say from 0.2 to 0.3 mm, is not strong enough in itself and a Thicker film would become brittle in the crease zone with cracking and fracture initiation.

On the other hand, the multi-layer blankets proposed by the invention make it possible to retain the capacity to be folded by a thin strip, to provide an increased mechanical safety by adding material and to retain its shape memory without generating structural weaknesses in the fold zone.

It can be seen from the various examples of implementation of the invention that the part of the blanket intended to be used as a fixing means to replace the known steel strip, that is to say the leading and trailing edges can to include:

a polyester or polycarbonate type film or equivalent associated with a unidirectional aramid or polyethylene type reinforcement embedded in a matrix of polymer or of polymer reinforced with fibers; a polyester or polycarbonate type film associated with a reinforcement of woven or non-woven type with polyester or aramid fibers or polyamide or polyethylene or metal embedded in a polymer matrix;

a combination of two films of identical or different nature comprising a polymer intermediate layer forming a box; a combination of two films of identical or different nature comprising a polymer intermediate layer associated with unidirectional reinforcements of aramid or polyethylene type or reinforced with fibers; an association of two films comprising a compressible intermediate layer forming a box; a combination of two films comprising a compressible intermediate layer associated with unidirectional reinforcements aramid type or polyethylene forming a box.

The order of the layers is irrelevant and could be the subject of an optimization choice. A layer of protection on the opposite side to the printer side can be added to mechanically protect the machine cylinder and the fixing layers and fill the space if necessary. It should be noted that the reinforcement is, preferably, embedded between two films and embedded in a polymer matrix.

It is advantageous to bend the blanket in the hot state to help shape and keep shape memory thereof after bending and cooling. The bending can be performed by machines known per se already used to bend the offset plates. In these machines, the leading and trailing edge blankets are successively introduced into a slot adapted to a mechanical stop. The machine automatically bends the blanket held in position by the operator. Two types of bending are considered depending on whether it is the leading edge or the trailing edge.

It should also be noted that the filling polymer or the polymer matrix to be used in the context of the invention could usefully have a glass transition temperature greater than ambient temperature to help shape memory in case of bending of the ends. hot. As shown in FIG. 2, it could be advantageous to provide an asymmetry between the geometries of the leading and trailing edges. The leading edge which is more stressed could be thicker and reinforced by any known means in relation to the trailing edge which could be thinner, the aim being to further reduce the area of the non-printer groove and generating vibrations .

By way of example, the total thickness of a blanket according to the invention could be between 1.00 mm and 3.30 mm, the thicknesses of the films envisaged between 50 microns and 250 microns, the thicknesses of the polymer layers of connection between 0, 10 and 0.5 mm and the thicknesses of the fixing zones according to the invention between 0.25 and 0.70 mm. Regarding the nature of the materials, the films could be polyester, polybutylene terephthalate (PBT), polycarbonate, and polypropylene. As a polymer, it would be advantageous to use thermoplastic material such as polyurethane

(TPU), polyesters, polyethylene, extruded elastomers, extruded and short fiber reinforced elastomers or polyamides. With regard to fibers, it is advantageous to use polyester, aramid, polyamide, polyethylene, glass, carbon or steel fibers. As an associated blanket, it is advantageous to use traditional rubber with a compressible layer of fabric reinforcement and polymer technology.

Claims

REVENDI CATIONS

A printing blank intended to be mounted on a rotary support cylinder of a printing machine, having a multilayer film-based and fibrous reinforcement structure defining a sheet shape whose ends configured at the edges of a etching and leakage are adapted to be engaged in an axial fixing slot of the support cylinder, the trailing and attacking edges having a lower thickness than the blanket in its printing part

(15), the multilayer structure of the blanket (1) having, from the outside to the inside, successively, a multilayer portion having an outer printing layer (17) and which is removed at the leading edges ( 3) and leakage (4) and an underlying fixing portion whose ends constitute at least the leading edges (4) and trailing

(3), characterized in that the underlying fixing part has a multilayer structure.

2. blanket according to claim 1, characterized in that it comprises below the multilayer portion whose ends constitute the leading edges (3) and leakage (4) a protective layer (14) in contact with the outer surface of the support cylinder (2).

3. blanket according to claim 2, characterized in that the protective layer (14) is removed at the leading edges (3) and leakage (4).

4. Blanket according to one of claims 1 to 3, characterized in that the leading edges (3) and trailing

(4) have the same multilayer structure.

5. Blanket according to one of claims 1 to 3, characterized in that the trailing edge (4) is thinned with respect to the leading edge (3).

6. Blanket according to one of claims 1 to 5, characterized in that the multilayer portion constituting the leading edges (4) and leakage (3) comprises a film such as polyester or polycarbonate type associated with a unidirectional aramid or polyethylene type reinforcement embedded in a matrix of polymer or fiber-reinforced polymer.

7. blanket according to one of claims 1 to 5, characterized in that the multilouch.es part of constitution of the trailing edges (4) and etching (3) comprises a film such as polyester or polycarbonate associated with a reinforcement of woven or non-woven type with polyester or aramid fibers or polyamide or polyethylene or metal embedded in a polymer matrix.

8. blanket according to one of claims 1 to 5, characterized in that the multilayer forming portion of the leading and trailing edges comprises a combination of two films, where appropriate identical, comprising a polymer intermediate layer forming a caisson.

9. blanket according to one of claims 1 to 5, characterized in that the multilayer portion constituting the leading edges (3) and leakage (4) comprises a combination of two films, where appropriate identical, comprising a polyester interlayer associated with unidirectional reinforcements of aramid or polyethylene type or reinforced with fibers.

10. blanket according to one of claims 1 to 5, characterized in that the multilayer portion constituting the leading edges (3) and leakage (4) comprises a combination of two films having a compressible intermediate layer forming a box .

11. blanket according to one of claims 1 to 5, characterized in that the multilayer portion constituting the leading edges (3) and leakage (4) comprises a combination of two films and, between the two films, a compressible intermediate layer associated with unidirectional reinforcements type aramid or polyethylene forming a box.

12. blanket according to one of claims 1 to 11, characterized in that its multilouch.es structure is made in the form of a web and cut to the desired format and the leading edges and trailing edges are obtained by appropriate machining of ends of the blanket cut into the format.

13. blanket according to one of claims 1 to 11, characterized in that it comprises a back layer made of a rectifiable polymeric material and in that this back layer has been ground to uniform the thickness of the blanket.