Printing method
By using partially cured ink printing methods on the aircraft panel, the problem of ink transfer before curing is solved, and the finish and quality of printing is improved. The method includes steps such as partial curing of the ink, image capture and analysis, and repair, ensuring that the ink has solidified before applying the varnish.
Patent Information
- Application Number
- CN202411490985.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-10-26
- Filing Date
- 2024-10-24
- Publication Date
- 2025-04-29
AI Technical Summary
In the prior art, when printing on the panel of an aircraft using UV cured ink, problems may occur in the transfer of ink before curing, resulting in defects in the design and logo.
A printing method is used in which the ink is partially cured before applying the varnish and the defect is detected by image capture and analysis steps, and if the defect is found, repair is performed. The method includes the application step, the nailing step, the image capture and analysis step, the deposition step, the curing step, the erase step, the repair step, and the return step.
By partially curing the ink, ensuring that the ink has solidified before applying the varnish, reducing the possibility of ink transfer and improving the finish and quality of the printing.
Smart Images
Figure CN119898133A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a printing method for producing coated supports, in particular panels of aircraft, using inks that cure when exposed to ultraviolet (UV) radiation. Prior art
[0002] In aircraft, the fuselage comprises supporting parts, such as metal or composite materials, and the supporting parts are usually covered with paint and / or ink in order to protect the supporting parts and to decorate the aircraft, for example with the logo of the airline company.
[0003] The ink used is typically an ink that cures by exposure to UV radiation.
[0004] Thus, the method comprises: the steps of applying an ink curable by UV on the support; the step of applying a varnish on the ink; and the step of applying UV so as to cause the ink and the varnish to cure.
[0005] While this method produces good results, it can happen that the ink transfers before curing, thereby creating defects in the design and logo.
[0006] Therefore, there is a need to find a printing method that further improves the finish of the ink applied to the support. Summary of the invention
[0007] The subject of the invention is a printing method for printing a decoration on a support, in which the ink is partially cured and corrected before the varnish is applied and before the component is completely cured.
[0008] For this purpose, a printing method is proposed for printing a decoration on a support using an ink that cures under ultraviolet radiation, said printing method comprising:
[0009] - an application step during which said ink is deposited on a support so as to form a decoration,
[0010] - a pinning step during which the ink thus applied is subjected to low-intensity UV radiation,
[0011] - a first image capturing step, during which at least one first image of the decoration is captured,
[0012] - a first analysis step during which the first image thus captured of the decoration is analyzed in order to detect any defects,
[0013] If no defects are found, the printing process continues:
[0014] - a deposition step during which the varnish is deposited on the ink, and
[0015] - a curing step during which the ink and varnish are subjected to high-intensity UV radiation,
[0016] If defects are found, the printing process continues:
[0017] - an erasing step during which the ink is removed in the removal area surrounding the defect,
[0018] - a second image capturing step during which at least one second image of said removal area is captured,
[0019] - a second analysis step during which said second image is analyzed in order to determine the portion of the decoration to be redone,
[0020] - a repairing step during which said ink is deposited on the support so as to form said portion of the decoration to be redone, and
[0021] - A return step during which the printing method loops back to the first analysis step.
[0022] In this way, the ink forming the decoration is partially cured so that it can be set and corrected before the varnish is applied.
[0023] Advantageously, the curing step is carried out just before the step of depositing the varnish on the ink.
[0024] Advantageously, the applying step, the first image capturing step and the second image capturing step are performed by a machine controlled by a control unit.
[0025] Advantageously, the repairing step is performed by a machine controlled by a control unit and comprises the sub-steps of programming the machine according to the portion of the decoration to be redone and of depositing ink on the support by the machine thus programmed.
[0026] Advantageously, the erasing step is performed by a machine controlled by a control unit. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above-mentioned features and other features of the present invention will become more apparent upon reading the following description of embodiments, which is set forth with reference to the accompanying drawings, in which:
[0028] Figure 1 shows an algorithm of the printing method according to the present invention, and
[0029] Figure 2A support element which has been coated by means of the method according to the invention is schematically depicted. DETAILED DESCRIPTION
[0030] Figure 1 shows an algorithm of the printing method 100 according to the present invention, and Figure 2 An assembly 200 is shown comprising a support 202 on which an ink 204 and a varnish 206 have been deposited by applying a printing method 100 according to the invention.
[0031] In the context of the present invention, the printing method 100 ensures that a decoration is printed on the support 202. When the support 202 constitutes a panel of an aircraft fuselage, the decoration is, for example, the logo of an airline.
[0032] Thus, the printing method 100 makes it possible to print a decoration on a support 202 using ink 204, and more particularly using an ink that cures when it is subjected to ultraviolet (UV) radiation. In the embodiment of the assembly 200, the ink 204 completely covers the support 202, but depending on the decoration to be produced, the ink 204 may cover only a portion of the support 202.
[0033] Therefore, the printing method 100 according to the present invention comprises:
[0034] an application step 102 during which ink 204 is deposited on the support 202 in order to form the decoration, and
[0035] - a pinning step 104 during which the ink 204 thus applied is subjected to low-intensity UV radiation.
[0036] The applying step 102 is performed by a printing device comprising a print head and preferably a machine having at least one driven axis, the printing module being attached at the end of the machine. The print head is, for example, a print head of an inkjet printer, which uses the nozzles of the print head to simultaneously eject droplets of ink of different colors according to the color desired to be obtained. The machine may be any type of machine having at least one axis that can be controlled in position, such as an automatic machine equipped with an arm.
[0037] The pinning step 104 includes exposing the ink 204 to UV radiation of an intensity sufficient to partially cure the ink 204 but insufficient to completely cure the ink. The wavelength of the UV radiation is suitable for the photochemical properties of the ink 204, and the droplets of the ink 204 increase in viscosity but are not completely cured. In this state, the droplets of the ink 204 are solidified to prevent flow, but remain sensitive and can be erased by contact and / or chemical attack.
[0038] The printing method 100 then continues with a first image capturing step 106 during which at least one image of the decoration, referred to as the first image, is captured using an image capturing device such as a scanner or a camera. Thus, a plurality of images with different contrast levels can be acquired.
[0039] The thus captured first image of the decoration is analyzed during a first analysis step 108. The first analysis step 108 comprises processing the first image for automatically detecting defects such as drops, areas without ink, misaligned nozzles of the print head, color defects, presence of dust, etc., for example using image analysis software.
[0040] Of course, the first analysis step 108 may be performed directly by a technician through a visual analysis of the first image of the decoration.
[0041] If no defects are found during the first analysis step 108, the printing method 100 continues with a deposition step 110 during which a varnish 206 is deposited on the ink 204. This varnish 206 is transparent and adapted to the ink 204 used and it ensures protection of the ink 204, for example from impacts.
[0042] Once the varnish 206 is in place, the printing method 100 continues with a curing step 112 during which the ink 204 and the varnish 206 are subjected to high-intensity UV radiation, which ensures, among other things, that the ink 204 is cured by the varnish 206. In this case, the intensity of the UV radiation must be higher than that used during the pinning step 104, and the intensity of the UV radiation must be sufficient to completely cure the ink 204. As previously described, the wavelength of the UV radiation is adapted to the photochemical properties of the ink 204, and the pinned droplets of the ink 204 are converted into a solid state.
[0043] The curing of the ink 204 is performed without contact with oxygen in the air, which inhibits the curing reaction, and therefore the final degree of curing is higher than that in the case where curing occurs in contact with air.
[0044] According to another embodiment of the present invention, the curing step 112 is performed just before the step 110 of depositing the varnish 206 on the ink 204, but in this embodiment the curing of the ink 204 occurs in contact with oxygen in the air.
[0045] If a defect is found during the first analysis step 108, the printing method 100 continues with an erasing step 114 during which the ink 204 is removed in a removal area surrounding the defect. This erasing step 114 is performed manually or mechanically, for example, using laser blasting, using a solvent suitable for the ink 204. If the defect consists of a drip on the edge of the decoration, the removal area consists of an area containing the edge and the drip.
[0046] Then, the printing method 100 continues with a second image capturing step 116 during which at least one image, referred to as second image, of the removed area is captured using an image capturing device such as used for the first image capturing step 106 , such as a scanner or a camera.
[0047] Once the second image has been captured, it is analyzed during a second analysis step 118 to determine the portion of the decoration to be redone in order to replace the erased decoration in the removed area. This analysis makes it possible to determine, for example, the contours to be redone, the colors to be used, etc.
[0048] After this analysis, the printing method 100 continues with a repair step 120 during which ink 204 is deposited on the support 202 in order to form the portion of the decoration that is to be redone.
[0049] The printing method then loops back to the first analysis step 108 during a return step 122 in order to continue analyzing the decoration and verifying the printing while this analysis is taking place.
[0050] With this printing method 100, the ink 204 forming the decoration is partially cured to solidify the ink 204 so as to allow the decoration to be analyzed and, if necessary, corrected before applying the varnish 206 and before final curing.
[0051] Depending on the material of the support 202 and the type of ink 204 used, it can be expected that the support 202 includes: a plate 202a, the plate 202a is made of metal or a synthetic material; a base primer layer 202b deposited on the plate 202a; an outer primer layer 202c deposited on the base primer layer 202b; and a white layer 202d deposited on the outer primer layer 202c, and the ink 204 is deposited on the white layer 202d.
[0052] Although the printing method 100 can be implemented manually by a technician, as explained above, it is preferred that the printing method 100 is implemented using a machine equipped with at least one driven axis, which carries the printing head and the image capture device and possible mechanical sandblasting device. The machine and therefore the printing head and the image capture device and possible mechanical sandblasting device are controlled by a control unit.
[0053] According to a particular embodiment, the applying step 102, the first image capturing step 106 and the second image capturing step 116 are performed by a machine controlled by a control unit, wherein the image capturing device transmits the images directly to the control unit which can analyze these images. The machine then carries the image capturing device.
[0054] According to a particular embodiment, the repairing step 120 is performed by a machine controlled by a control unit and comprises the sub-steps of programming the machine according to the portion of the decoration to be redone and of depositing, by the machine thus programmed, ink 204 on the support 202. The control unit determines in particular the position that the printing head must occupy in order to repair the portion of the decoration to be redone, the path that the printing head must follow, the colors that must be used and the positions where these colors must be deposited, etc.
[0055] According to a particular embodiment, the erasing step 114 is performed by a machine controlled by a control unit.
[0056] According to a particular embodiment, the control unit comprises the following connected via a communication bus: a processor or CPU (Central Processing Unit); a RAM (Random Access Memory); a ROM (Read Only Memory), for example a flash memory; a data storage device, such as an HDD (Hard Disk Drive), or a storage medium reader, such as an SD (Secure Digital) card reader; at least one communication interface COM and / or an I / O (Input / Output) component.
[0057] The communication interface COM and / or I / O components allow the control unit to interact with the machine, the print head, the image capture device, etc.
[0058] The processor can execute instructions loaded into the RAM from the following: ROM; external memory; storage media, such as SD card; or communication network. When the control unit is turned on, the processor can read the instructions in the RAM and execute them. These instructions form a computer program that generates the implementation of the behaviors, steps and algorithms described in this article through the processor.
[0059] Therefore, all or some of the behaviors, steps and algorithms described herein may be implemented via software by executing a set of instructions by a programmable machine, such as a DSP (digital signal processor) or a microcontroller, or may be implemented via hardware by a machine or a dedicated component (chip) or a dedicated component group (chip set), such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). More generally, the control unit constitutes a system in the form of an electronic circuit that is designed and configured to implement the behaviors, steps and algorithms described herein.
Claims
1. A printing method (100) for printing a decoration on a support (202) using an ink (204) that cures under ultraviolet (UV) radiation, the printing method (100) comprising: - an application step (102), during which said ink (204) is deposited on said support (202) in order to form said decoration, - a pinning step (104), during which the ink (204) thus applied is subjected to low-intensity ultraviolet radiation, - a first image capturing step (106), during which at least one first image of the decoration is captured, - a first analysis step (108) during which said first image of said decoration thus captured is analyzed in order to detect any defects, If no defects are found, the printing method (100) continues by: - a deposition step (110), during which a varnish (206) is deposited on the ink (204), and - a curing step (112), during which the ink (204) and the varnish (206) are subjected to high-intensity ultraviolet radiation, If a defect is found, the printing method (100) continues by: - an erasing step (114), during which the ink (204) is removed in a removal area surrounding the defect, - a second image capturing step (116), during which at least one second image of the removed area is captured, - a second analysis step (118) during which the second image is analyzed in order to determine the portion of the decoration to be redone, - a repairing step (120) during which said ink (204) is deposited on said support (202) so as to form said portion of said decoration to be redone, and - a return step (122), during which the printing method (100) loops back to the first analysis step (108).
2. The printing method (100) according to claim 1, wherein: The curing step (112) is performed just before the step of depositing (110) the varnish (206) on the ink (204).
3. The printing method (100) according to claim 1, wherein: The applying step (102), the first image capturing step (106) and the second image capturing step (116) are performed by a machine controlled by a control unit.
4. The printing method (100) according to claim 1, wherein: The repairing step (120) is performed by a machine controlled by a control unit and comprises the sub-steps of programming the machine according to the portion of the decoration to be redone and of depositing the ink (204) on the support (202) by the machine thus programmed.
5. The printing method (100) according to claim 1, wherein: The erasing step (114) is performed by a machine controlled by a control unit.