Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
  • B05C5/02—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work
  • B05C5/0254—Coating heads with slot-shaped outlet
  • B05C5/0262—Coating heads with slot-shaped outlet adjustable in width, i.e. having lips movable relative to each other in order to modify the slot width, e.g. to close it
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C11/00—Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00
  • B05C11/10—Storage, supply or control of liquid or other fluent material; Recovery of excess liquid or other fluent material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C11/00—Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00
  • B05C11/10—Storage, supply or control of liquid or other fluent material; Recovery of excess liquid or other fluent material
  • B05C11/1002—Means for controlling supply, i.e. flow or pressure, of liquid or other fluent material to the applying apparatus, e.g. valves
  • B05C11/1005—Means for controlling supply, i.e. flow or pressure, of liquid or other fluent material to the applying apparatus, e.g. valves responsive to condition of liquid or other fluent material already applied to the surface, e.g. coating thickness, weight or pattern
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/02—Engraving; Heads therefor
  • B41C1/04—Engraving; Heads therefor using heads controlled by an electric information signal
  • B41C1/05—Heat-generating engraving heads, e.g. laser beam, electron beam
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
  • B05B12/08—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
  • B05B12/084—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means responsive to condition of liquid or other fluent material already sprayed on the target, e.g. coating thickness, weight or pattern

Definitions

• the present invention relates to a device for producing a printing plate, and to a method for producing such a printing plate.
• a printing plate is obtained by placing a support such as a translucent plate or a plate provided with a negative of a page to be printed, on a work surface or plate and then applying successively on the support a liquid photopolymer then a film intended to constitute the base of the printing plate. Then, the thickness of the printing plate is measured and, when this thickness differs from a predetermined thickness or setpoint thickness, the means with which the photopolymer is applied are adjusted to obtain the desired thickness of the plate printing.
• apparatuses having a reservoir from which the photopolymer is removed by gravity are preferably used.
• the reservoir is provided with an outlet in the form of a slot facing downwards and the liquid photopolymer is then applied, passing from the reservoir on the support, while the reservoir is running over the support following a scroll direction.
• a speed with which the reservoir must pass over the support The higher the speed of the tank, the thinner the deposited photopolymer layer is. Consequently, to adjust the thickness of the photopolymer layer to be obtained, the speed with which the tank scrolls is varied.
• a device comprising a reel in which a film reel is mounted.
• the apparatus for producing a printing plate having such a design has the advantage of a simple structure and the absence of complicated adjustment mechanisms.
• photopolymers although called “liquid”, are viscous and their viscosity, at equal temperature, can vary from one delivery batch to another.
• the viscosity varies according to the ambient temperature which prevails around the apparatus for producing the printing plates.
• the viscous nature of the photopolymers causes that, as opposed to the behavior of a liquid product such as water, the photopolymers leaving the tank by gravity flow from the tank with a clean speed which is not only a function of the degree of viscosity of the polymer, but also the configuration of the tank outlet slot.
• the flow rate of the photopolymer to be deposited it is generally chosen to vary the speed of travel of the tank above the support. However, when the speed of travel exceeds a limit, which is generally different from one photopolymer to another, there may be an irregular flow of the photopolymer, or even breakage of the flow of the photopolymer.
• Another disadvantage of the system described above lies in the fact that the entire thickness of the printing plate is measured. Thus, in the case of a difference between the setpoint thickness and the actual measured thickness, it is not possible to distinguish between an error in the thickness of the photopolymer layer and an error due to a problem of laying or the thickness of the film. As a result, it is impossible to make precisely targeted corrections to obtain a printing plate according to the predetermined dimensions.
• the object of the invention is to overcome the disadvantages described above.
• the object of the invention is achieved with a device for producing a printing plate comprising a support intended to receive a liquid photopolymer and then a film intended to constitute the base of the printing plate, a means of application photopolymer liquid on the support in a layer having a surface and a predetermined thickness and means for checking the thickness of the applied layer.
• the verification means comprises a detector mounted on the downstream side of the application means so as to be disposed above a portion of the photopolymer layer that has just been applied, a comparator intended to comparing the actual thickness of the portion of the polymer layer just applied with the predetermined thickness and an electrical signal generator for generating a correction signal in case of difference between the actual thickness and the predetermined thickness , the generator being connected to a device for adjusting the photopolymer flow rate of the application means.
• the device of the invention has the advantage of being able to check the thickness of the single photopolymer layer and to be able to do it continuously and especially in a part of the photopolymer layer that has just been applied. Due to the short distance between the place where the liquid photopolymer falls on the support and the part of the photopolymer layer where the thickness is verified, the reaction in case of drifting the predetermined thickness is almost immediate.
• the provisions of the invention make it possible to place the film application means close enough to the photopolymer application means. The provisions of the invention therefore do not lead to a significant enlargement of the device for producing a printing plate.
• the provisions of the invention also make it possible, according to a preferred embodiment of the invention, not to measure the actual thickness of the applied photopolymer layer, but to verify whether the surface of the deposited photopolymer layer remains at a desired temperature. constant level or not. Indeed, in the case of producing a photopolymer layer with an ideally constant thickness, the constant level of the surface of the photopolymer layer is then representative of the constancy of the thickness of the layer produced.
• This arrangement of the invention is particularly advantageous because of the transparency of liquid photopolymers.
• the support is often black.
• the thickness of the applied layer is difficult to measure with optical reflection means.
• it is easier to monitor the level of the surface of the applied layer with a reflection detector, preferably with a defined reflection working type detector.
• This type of detector uses the reflection of a beam of light on the surface of the resin in the case of a non-normal incidence.
• specular reflection on a very smooth surface (as is the case of a liquid) with an angle of incidence that is equal and opposite to the normal at the angle of reflection.
• the principle of checking the level of the surface of the applied layer also has the advantage of a simple apparatus operating over a wide range of polymer layer thicknesses. Indeed, the device of the invention, in the embodiment explained, operating only the level of the surface of the layer, the thickness of the photopolymer layer has become unimportant.
• such an apparatus may be equipped with a tray or a worktop or any other means shaped to maintain or carry the support on which the photopolymer is to be applied and to arrange this plate at a variable level relative to by means of photopolymer application.
• the plate is movably mounted so as to be remote or close to the photopolymer application means and thus to adjust a predetermined thickness or setpoint thickness.
• the tray is mounted in a fixed position and it is the photopolymer application means and the film reel that are movably mounted so that they can be moved closer to or away from the tray.
• the application means comprises dosing means.
• This arrangement of the invention makes it possible to scroll the photopolymer application means with respect to the support with a constant speed of movement or application. More particularly, this arrangement of the invention makes it possible to use a motor with a constant speed, which simplifies the device of the invention thanks to the absence of a variable speed drive.
• the application means comprises a reservoir for the photopolymer and, at the end of the reservoir, dosing means.
• the dosing means can be arranged immediately after the outlet of the tank.
• the outlet of the tank which is generally in the form of a slot, is formed at least partially by dosing means.
• the reservoir is shaped so that the photopolymer can exit through a slot with variable opening, this slot being formed between a doctor blade and a cylindrical body of non-circular cross section.
• the doctor blade and the cylindrical body being mounted on the tank, they form an integral part.
• the variation of the opening of the slot is obtained by rotating the cylindrical body about its longitudinal axis according to an electrical correction signal generated by the detector verifying the constancy of the level of the surface of the deposited polymer layer.
• the cylindrical body is provided with a flat part extending in a plane parallel to its longitudinal axis.
• This flat surface gives the cross section of the cylindrical body the non-circular shape. Since the non-circular side of the cross-section is oriented towards the doctor blade and the outlet slot of the reservoir is thus delimited between the non-circular side of the cylindrical body and the doctor blade, the opening of the slot can be varied by rotating the cylindrical body around of its longitudinal axis.
• the doctor blade is disposed above the support for receiving a layer of a photopolymer at a height which is greater than the predetermined thickness of the photopolymer layer to be applied.
• the height at which the doctor blade is arranged relative to the support about 2 mm larger than the thickness of the photopolymer layer to be produced.
• the object of the invention is also achieved with a method of producing a printing plate by means of a device comprising a support intended to receive a liquid photopolymer and then a film intended to constitute the base of the printing plate, a means applying the photopolymer liquid on the support in a layer having a surface and a predetermined thickness and means for checking the thickness of the applied layer.
• the method comprises at least the following steps:
• This method is advantageously implemented using the device described above.
• FIG. 1 very schematically represents a device of the invention and Figure 2 shows the arrangement of the various elements of the application means of the device of the invention in a side view.
• FIG. 1 represents a device for producing a printing plate according to the invention.
• This device comprises a support 1 intended to receive a liquid photopolymer and then a film intended to constitute the base of the printing plate, as well as an application means 3 of the liquid photopolymer on the support 1 in a layer 2 and a means check 5 the thickness of the layer 2 applied.
• the application means 3 moves relative to the support 1 in the direction D.
• the support 1 rests on a plate 30.
• the verification means 5 comprises a detector mounted on the downstream side of the application means 3.
• the detector 5 is thus disposed above a portion of the photopolymer layer 2, which has just been applied.
• the detector 5 is connected to a comparator (not shown) for comparing the actual thickness of the portion of the previously applied polymer layer 2 with the predetermined thickness.
• the comparator comprises, or is connected to, an electrical signal generator for generating a correction signal in case of a difference between the actual thickness and the predetermined thickness of the photopolymer layer.
• the electrical signal generator is connected to a device for adjusting the photopolymer flow rate of the application means 3.
• the plate 30 and the application device 3 are advantageously mounted so that one can be moved in elevation relative to the other. Generally, it will be easier to mount the plate 30 movable relative to the application means 3 fixedly mounted.
• FIG. 2 represents the different elements of the application means 3 and the position relative to the support 1.
• the application means 3 comprises a reservoir 4 for the photopolymer and, at the end of the reservoir 4, dosing means 7, 8.
• the metering means 7, 8 comprise a doctor blade 7 and a cylindrical body 8 having an axis longitudinal 9 and a non-circular cross section.
• the non-circular shape of the section of the body 8 is obtained by a flat part 10 which extends in a plane parallel to the longitudinal axis 9 of the cylindrical body 8.
• the flat part 10 is oriented towards the doctor blade 7 so as to define a slot 6 to opening L variable between the doctor blade 7 and the cylindrical body 8.
• the variation of the opening L of the slot 6 is obtained by rotating the cylindrical body 8 about its longitudinal axis 9 according to an electrical correction signal generated by the detector 5.
• the orientation of the flat part 10 with respect to a vertical plane is indicated in the figure by an opening angle ⁇ .
• FIG. 2 also represents the thickness g of the photopolymer layer 2 and the height h at which the doctor blade 7 is disposed. Without this being indicated numerically, FIG. 2 clearly shows that the height h is greater than the thickness g of the photopolymer layer 2.
• the thickness g of the deposited photopolymer layer 2 can be varied while keeping a constant rate of application.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Plasma & Fusion (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Coating Apparatus (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=36972846

Family Applications (1)

Country Status (7)

Families Citing this family (12)

Family Cites Families (10)

• 2006
  • 2006-05-29 FR FR0651933A patent/FR2901506B1/fr not_active Expired - Fee Related
• 2007
  • 2007-05-24 WO PCT/FR2007/051325 patent/WO2007138218A1/fr active Application Filing
  • 2007-05-24 ES ES07766096T patent/ES2376914T3/es active Active
  • 2007-05-24 CN CNA2007800187711A patent/CN101448643A/zh active Pending
  • 2007-05-24 EP EP07766096A patent/EP2021180B1/de not_active Expired - Fee Related
  • 2007-05-24 US US12/301,804 patent/US20100233354A1/en not_active Abandoned
  • 2007-05-24 JP JP2009512648A patent/JP5043101B2/ja active Active

Non-Patent Citations (1)

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