Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N10/00—Blankets or like coverings; Coverings for wipers for intaglio printing
  • B41N10/02—Blanket structure
  • B41N10/04—Blanket structure multi-layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N10/00—Blankets or like coverings; Coverings for wipers for intaglio printing
  • B41N10/02—Blanket structure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N2210/00—Location or type of the layers in multi-layer blankets or like coverings
  • B41N2210/02—Top layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N2210/00—Location or type of the layers in multi-layer blankets or like coverings
  • B41N2210/04—Intermediate layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N2210/00—Location or type of the layers in multi-layer blankets or like coverings
  • B41N2210/10—Location or type of the layers in multi-layer blankets or like coverings characterised by inorganic compounds, e.g. pigments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N2210/00—Location or type of the layers in multi-layer blankets or like coverings
  • B41N2210/14—Location or type of the layers in multi-layer blankets or like coverings characterised by macromolecular organic compounds

Definitions

• the invention relates to a method of manufacturing a multilayer printing blanket at least one outer layer of which is provided with encrusted particles and a blanket thus obtained.
• Document EP 0 511 543 describes a cylinder for a printing machine in the external oleophilic metal surface is encrusted with a hydrophilic material, for example ceramic.
• the object of the present invention is to propose a method and a blanket which overcomes the drawbacks which have just been stated.
• this method according to the invention is characterized in that the particles are embedded in the surface by pressure exerted on these particles.
• the particles are encrusted by calendering.
• the polymer layer, with the blanket carcass is passed between two calender cylinders and the calender cylinder is passed in contact with the surface in which the inlays should be made, by a container containing the particles to be encrusted, by adhering these particles to the surface of the cylinder.
• a printing blanket according to the invention is characterized in that the particles are encrusted on the surface.
• FIG. 1 is a schematic view showing a device for implementing the method according to one invention
• Figures 2 to 7 are sectional views illustrating six alternative embodiments of the structure of a blanket according to the invention ;
• the device for implementing the method according to the invention comprises, downstream of an extruder die 9 two calender cylinders 11, 12 between which pass the layer of polymer 8 produced by the extruder 9 and a blanket carcass 10.
• the temperature of the plunger cylinder 12, the roughness of the latter and the calendering pressure are parameters which control the quantity of particles deposited.
• the bin 15 can be animated by a movement of vibration to ensure regular deposition on the surface of cylinder 12.
• a device for scraping the plunger cylinder 12 can also be provided (not shown) for dosing the quantity of particles deposited and encrusted on the surface of the blanket.
• the polymer layer 8 could be the lithographic layer of the blanket or the back layer thereof or one or both of the lithographic layers of a blanket comprising a lithographic layer on the two outer faces.
• the layer on the back of the blanket is the layer on the face opposite to the face comprising the lithographic layer if the blanket has only one.
• the particles could be of any suitable type, making it possible to obtain desired transfer properties.
• the particles could be glass microbeads, polymer or ceramic powders or non-stick powders. Glass microbeads are particularly suitable for obtaining good water adhesion or affinity with fountain water.
• PTFE particles make it possible to increase the anti-adhesion of the surface and polyamide particles make it possible to improve the affinity with fatty inks.
• the encrustation on the surface of the particles can also be obtained by transfer by an electric field and then by fixing by calendering or the like with reheating.
• the inlay described here can be done on the surface of a polymer film. previously extruded and, if necessary, rectified by simple reheating of the surface thereof by means known per se, such as infrared ramps, and passage of the blanket with its layer of polymer heated on the surface between the cylinders of the calender of figure 1.
• the diameter of the particles is preferably between 1 to 50 ⁇ . If the diameter is too large, the print quality deteriorates. If the diameter is too small, the implementation of the inlay becomes difficult.
• the invention makes it possible to produce a blanket which may include other advantageous features in addition to these which have just been mentioned.
• a blanket comprising on the back a layer of polymer material can be rectified to make the thickness of the blanket more uniform, while preserving or even improving the properties and printing qualities.
• the rectification of the polymer layer on the back makes it possible in particular to regularize the thickness of blankets with rectified and sanded lithographic layer and blankets with a smoother surface obtained by molding and therefore exhibiting excellent printing quality.
• the rectification is applicable to all blankets whose thickness must be uniform, regardless of the means used to produce a lithographic surface ensuring good print quality.
• the invention thus makes it possible to obtain, compared to the blanket without rectification, a gain in precision by a factor of 2, namely an overall thickness tolerance of
• the invention also makes it possible to obtain a reduction in the total thickness of the blanket. Indeed, by separating the different functions to be performed by the blanket, and by conferring these functions on specific layers, one can establish an optimal blanket structure by assembling layers of fabric, compressible layers and the lithographic layer. It has been found that the use of a beam or a woven wire or grid makes it possible to replace several fabrics and thus provides a reduction in thickness.
• the use of a bundle of aramid-type fibers saves the relative thickness of at least one ply of fabric.
• the gain is at least 0.5 mm.
• the beam replaces reinforcing fabrics which contribute to the compressibility of the blanket, this compressibility is maintained despite the removal of the fabrics by rendering the polymer layer on the back, compressible accordingly.
• the invention makes it possible to produce a blanket with a practically uniform thickness of 1.00 to 1.30 mm while retaining the breaking strength of known blankets.
• the invention allows the production of a blanket comprising, from inside to outside the following layers: a layer of slightly compressible polymer, an aramid beam or the equivalent in warp direction, a main compressible layer, a stabilization fabric with , for example, monofilaments in the weft and flexible warp direction and a lithographic layer.
• the stabilization fabric can be replaced by a layer of hard polymer optionally reinforced with fibers and, in a second variant, the compressible layer or layers can be made anisotropic by incorporating fibers oriented in the plane of the blanket. In this case, the stabilization layer can be omitted with additional thickness reduction.
• Figures 2 to 7 show the structure of six advantageous embodiments of a blanket according to the invention, having a reduced thickness.
• the blanket shown in FIG. 2 comprises, from the inside to the outside a layer of slightly compressible polymer 1, a compressible layer 3 in which the beam 2 is integrated, a stabilization fabric or reinforced hard layer 4, and a lithographic layer 5.
• the blanket has a thickness of approximately 1.2 mm.
• the compact polymer layer 6 is removed with respect to the blanket of FIG. 2, which makes it possible to reduce the thickness of the blanket to approximately 1.1 mm.
• FIG. 4 shows a blanket in which the beam 2 is integrated into the polymer layer 1 on the back of the blanket, the compact polymer layer 6 also being removed.
• the thickness of the blanket is approximately 1.2 mm.
• the blanket of Figure 5 corresponds to that of Figure 4, with the difference however that the beam 2 is integrated in the compressible layer in the upper part thereof.
• the thickness of the blanket is 1.1 mm.
• the blanket shown in FIG. 6 has an even smaller thickness of approximately 1 mm thanks to the fact that the layers 1 of compressible polymer and the layer 6 of compact polymer have been omitted, the assembly 2 being integrated into the compressible layer 3 in the upper part thereof.
• FIG. 7 shows a blanket comprising on the back a compressible layer 3 with the beam integrated in the upper part thereof, an anisotropic compressible layer 7 and a lithographic layer 5. The thickness of this blanket is also about 1 mm.
• the layers by using materials and means for assembling the layers, which do not involve the use of solvents, for constituting the different layers, it is possible to obtain blankets which do not constitute any danger for man and the environment.
• the different layers of the blankets can be made to adhere to each other by treatment of the corona or ionization or flame type.
• the elastomers used in the context of the invention have the particularities that they do not contain thermal crosslinking agents. They are of a thermoplastic nature with a suitable rheology and the different layers can be crosslinked by radiation after assembly of all or part of the blanket.
• the materials used have the ability to become fluid at high temperature and therefore allow the creation of good quality thin films, in particular by extrusion.
• PP polystyrenic
• elastomers of the styrenic family formulations of elastomers of the olefin family, copolymers of olefins and functionalized olefins, elastomers of the acrylonitrile family, EPDM or CSM, reinforcements with fibers or threads of aramid type, reinforcements with fibers or threads of polyethylene or polypropylene type, reinforcements with polyester fibers or yarns or mixtures of such fibers or yarns.
• a tubular lithographic layer can be produced from a lithographic layer obtained by extrusion and cut to the appropriate length and after having bevelled the ends, by winding this layer on a support sleeve, by superimposing the bevelled ends. and heating them.
• This layer could be cross-linked by radiation, if necessary, then rectified and sanded. It could be encrusted with particles on the surface.
• the support sleeve in this case could be the blanket layer on which the lithographic layer rests.
• a compressible layer could be produced in a similar manner with the additional possibility of ensuring the expansion of this layer during the assembly of the ends by means of expandable microspheres previously incorporated into the materials forming the layer.
• the extruded film intended to become a compressible layer could advantageously include fibers which will be oriented in the plane during extrusion to give the layer anisotropic properties.
• An extruded film comprising oriented fibers may also act as a reinforcement or stabilization or control paper flow layer.
• the invention provides many advantages. Thanks to the rectification of the polymer layer on the back of the blanket, the thickness of the blanket is more precise and uniform. This has a direct impact on the performance of the blankets. Indeed, a controlled thickness improves the pressure quality and longevity of the blankets.
• the excellent print quality provided by a smooth and even very smooth printing surface can be maintained. Such a smooth surface makes it possible to print the details precisely and generate a so-called “sharp" impression or even a "high fidelity” impression. It allows the use of a stochastic frame.
• the smooth surface can be characterized by a very low roughness (Ra: average roughness measured with the profilometer) of less than 0.4 ⁇ against values of 0.8 to 1.5 ⁇ for blankets of the state of the art.
• the deterioration of the regularity of the thickness when it is desired to obtain a very smooth printing surface, for example by sanding this surface and the compromise made for known blankets which are content with a less efficient sanding and therefore a less smooth surface can be eliminated thanks to the rectification of the layer on the back, as proposed by the invention.
• the reduction in the thickness of the blankets provides a reduction in vibrations by making it possible to design cylinders with a narrow groove for fixing the blanket and therefore to minimize rebounds during high-speed rolling.
• the invention also ensures a reduction in cost insofar as a thin blanket requires for its production a lesser quantity of material which is the most important item in the cost price.
• the invention allows a further reduction in the quantities of waste.
• a thin blanket according to the invention also has the following advantages: reduction of paper waste by rotary; possibility of implementing innovative tension systems; increased folding flexibility facilitating the winding of the blanket at the fixing groove and possible printing as close as possible to said groove.

Landscapes

• Printing Plates And Materials Therefor (AREA)
• Laminated Bodies (AREA)
• Reinforced Plastic Materials (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Production Of Multi-Layered Print Wiring Board (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=8850892

Family Applications (1)

Country Status (8)

Families Citing this family (4)

Family Cites Families (36)

• 2000
  • 2000-05-31 FR FR0007065A patent/FR2809666B1/fr not_active Expired - Fee Related
• 2001
  • 2001-05-30 EP EP01940641A patent/EP1313622B1/de not_active Expired - Lifetime
  • 2001-05-30 AT AT01940641T patent/ATE353058T1/de not_active IP Right Cessation
  • 2001-05-30 AU AU2001274158A patent/AU2001274158A1/en not_active Abandoned
  • 2001-05-30 DE DE60126414T patent/DE60126414T2/de not_active Expired - Lifetime
  • 2001-05-30 JP JP2001588018A patent/JP2003534950A/ja active Pending
  • 2001-05-30 WO PCT/FR2001/001679 patent/WO2001092027A1/fr active IP Right Grant
• 2002
  • 2002-11-27 US US10/305,156 patent/US7357078B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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