Automatically operable aqueous inkjet printing device

Abstract

The present invention relates to an aqueous inkjet printing apparatus which can be automatically operated. The aqueous inkjet printing apparatus of the present invention includes a printing database which stores attribute data and printing data of a film to be printed; a mechanism which supplies the film to be printed; and a mechanism which executes a printing execution program in which one or more printing commands instructed by an operator are stored, the printing commands including attribute data, printing data and a printing start of the film to be printed; and according to the printing execution program, specified printing data is called from the printing database, and the film to be printed is supplied, optimal drying conditions and optimal tension conditions corresponding to the attribute data and the printing data of the film are automatically set, and an ejection position is automatically set, the ejection position being maintained in position accuracy of various colors to be printed according to stretching and shrinking of the film when the film is moved between the nozzles, and all printing is executed.

Description

TECHNICAL FIELD

[0001] The present application relates to a water-based inkjet printing device capable of automatically performing printing on a film rather than paper. BACKGROUND

[0002] Plastic films are different from paper and the like in that they are substrates that are difficult to absorb liquid, and therefore, in printing, intaglio printing using intaglio ink having high film adhesion or flexographic printing using flexographic ink has been used.

[0003] Inkjet printing, which does not require plate making and can generate a printing image using digital data, has excellent on-demand printing properties, and is useful for food packaging materials that must print various patterns and the like at any time, but has not been used. This is because water-based inkjet ink, which can perform inkjet printing, does not have various properties such as abrasion resistance, alcohol resistance, oil resistance, and water resistance, and the ink easily peels off, and the film adhesion is weak. In this case, intaglio ink or flexographic ink having high film adhesion cannot be smoothly ejected from a nozzle in inkjet printing in which ink is ejected from a nozzle and adhered, because the viscosity is too high, and therefore, has not been used.

[0004] For food packaging materials that are consumed in a short period of time and must print various patterns and the like according to the contents at any time, in order to improve production efficiency, it is inevitable to increase the printing speed. However, intaglio printing or flexographic printing must prepare a plate for a new pattern and the like, and must be set on a production line each time, and the process for starting printing takes time, and there is a limit to increasing the speed.

[0005] For example, regarding a food packaging material on which a pattern and the like is printed using intaglio printing, 12 days are required for the work (original entry + plate making) required before printing and printing, and in addition, 6 days are required for subsequent processing (film lamination, finishing), and a total of 18 days are required. In addition, as described above, in intaglio printing, color separation and plate making take time, and therefore, the minimum order quantity is inevitably large, and the customer must purchase more packaging materials than necessary, and a waste loss occurs.

[0006] On the other hand, although it is easy to adopt inkjet printing, a process in which a plastic film is laminated on the printing layer side so that the printing layer does not come into contact with food when printing is performed on the surface side of the packaging material is required, and a problem in which cost and time are required occurs.

[0007] Regarding this problem, the present inventors have created the following invention.

[0008] The first invention is characterized in that, when a pattern and / or a character are inkjet printed on a surface on a side of a plastic film to be used as a food packaging material, a transparent inkjet ink is superimposed and printed on the printed area after the pattern and / or the character are inkjet printed using an inkjet ink (Patent Document 1).

[0009] In addition, the second invention is characterized in that, when a pattern and / or a character are inkjet printed on a surface on a side of a plastic film to be used as a food packaging material, a transparent UV (Ultraviolet) ink is superimposed and printed on the printed area after the pattern and / or the character are inkjet printed using an inkjet ink (Patent Document 2).

[0010] In addition, the third invention is characterized in that, when a pattern and / or a character are inkjet printed on a surface on a side of a plastic film to be used as a food packaging material, a transparent EB (Electron Beam) ink is superimposed and printed on the printed area after the pattern and / or the character are inkjet printed using an inkjet ink (Patent Document 3).

[0011] According to the invention by the present inventor, when a pattern and the like are printed on a surface on a side of a packaging bag or a lid of a food container, even if inkjet printing is performed using an aqueous inkjet ink, a transparent inkjet ink, or a transparent UV ink, or a transparent EB ink is superimposed and printed on the printed area to protect the printed layer of the pattern and the like, so the printed layer of the pattern and the like is not exposed. Thus, contact with the back surface of the film when the film is taken up after printing is performed on the packaging bag or the lid during processing, or contact with other packaging materials or articles, or a person's fingers during distribution or display, and thus abrasion of the printed layer of the pattern and the like to become unclear or generate chipping is prevented.

[0012] On the other hand, since printing is completed by inkjet printing which is excellent in on-demand printing, unlike gravure printing or flexographic printing in which a plate for a new pattern and the like must be prepared and set on a production line, time for a process to start printing is not required, and thus speed can be improved, and thus production efficiency of food packaging materials in which various patterns and the like must be printed at any time according to contents can be dramatically improved.

[0013] The invention breaks the conventional technical common sense that aqueous inkjet inks cannot be used because the inks easily fall off and film adhesion is weak due to lack of abrasion resistance, alcohol resistance, oil resistance, water resistance, and the like, in the printing of plastic films.

[0014] [BACKGROUND ART DOCUMENTS]

[0015] [Patent Documents]

[0016] [Patent Literature 1] Japanese Patent Publication No. 2021-88171

[0017] [Patent Literature 2] Japanese Patent Publication No. 2021-88410

[0018] [Patent Literature 3] Japanese Patent Publication No. 2021-88409 SUMMARY

[0019] The technical problem of the present application is to automatically operate water-based inkjet printing with excellent just-in-time printing, which enables small-lot and multi-variety printing as described above. In order to cope with small-lot and multi-variety production with an ultra-short delivery period, a water-based inkjet printing device must be operated at full capacity for 24 hours. In this case, it is particularly difficult to secure workers for night work. To solve this problem, it is desirable to achieve automatic operation of a water-based inkjet printing device that can operate without people.

[0020] Automatic operation of a printing device is something that can be easily thought of by those skilled in the art. However, the inventors of the present application performed water-based inkjet printing on a plastic film, which no one had ever attempted before, and faced a new problem in this regard.

[0021] The problem is that in water-based inkjet printing in which the inkjet head (printing section) is non-contact, the tension between the inkjet head performing printing and the film advancing on the drying path is under the same conditions, and therefore the film is thermally stretched and shrunk by the drying temperature and the tension of the drying path, and it is not possible to continue to control the position accuracy and size of the various colors to be printed.

[0022] Since the coverage of each printing design differs depending on the print density or range, the drying temperature and speed of the printing conditions differ each time. Printing can be performed by fixing the drying temperature and speed within a safe range, but for example, in the case of low coverage, the speed is increased in coordination with the drying capacity of the printer. In order to confirm the drying capacity of the printer, a test print must be performed each time printing is performed to confirm the drying limit. In the limit, ink adheres to the guide rollers in the drying oven, so the drying limit cannot be confirmed before printing. Therefore, even if the speed is increased, printing can only be performed at a safe speed that is low.

[0023] Furthermore, even if the optimal conditions of the drying temperature and speed are known in advance, the type of various films as a printing substrate, their thickness, and the paper width differ, which affects the position accuracy or finished size of the various colors to be printed. Therefore, it is necessary to select the optimal tension at the time of first edition printing under the predetermined drying temperature and speed conditions. Similarly, this requires multiple test prints. This test print is not suitable for printing automation because it requires multiple stops of printing for sampling to align the positions of the various colors printed.

[0024] Figure 4 is a conceptual diagram showing the flow of the film F in the water-based inkjet printing apparatus. In the water-based inkjet printing apparatus, if non-color ink such as white is printed at the same time as color ink such as KCMY, color mixing occurs, so after the color ink is printed (in the drawing, A), the ink is dried on the drying path, and then the non-color ink is printed (in the drawing, B) and dried. Here, it is clear that the film expands and contracts due to heating during movement between the nozzles that print the ink. Therefore, the position of the nozzle for the non-color ink must be set taking into account this expansion and contraction, or else the positions of the various colors printed in the printed result will be shifted.

[0025] During the movement between the nozzles, the expansion and contraction of the film varies depending on the properties of the film, the drying temperature, the travel speed, and the tension. Therefore, even if the properties of the film and the drying temperature, speed, and tension appropriate for the coverage of the print design can be obtained in advance, it is difficult to maintain the position accuracy of the various colors printed from the first time, and multiple test prints must be performed, because if only the standard position of the nozzle is used, the positions of the various colors in the printed result will be shifted.

[0026] As described above, water-based inkjet printing is very complex compared to a gravure press. That is, the printing conditions differ for each print pattern, the appropriate conditions must be set each time, and test printing is required before printing begins. If the film type, brand, and thickness differ, they must also be set each time. These factors hinder the realization of an automatic water-based inkjet printing apparatus that performs small-lot, multi-variety printing, that is, continuous printing of multiple prints with different film properties and print designs in the absence of a person.

[0027] The purpose of the creation of the invention of the present application is to provide an automatic water-based inkjet printing apparatus by solving the problems described above.

[0028] That is, the automatic water-based inkjet printing apparatus of the invention of the present application, which causes a film to be printed to pass through an ink nozzle portion while applying a fixed tension to the film to be printed and travel on a hot air drying path, includes:

[0029] a print database that stores attribute data of the film to be printed and print data;

[0030] a mechanism that feeds the film to be printed; and

[0031] a mechanism that executes a print execution program in which one or more print commands instructed by an operator are stored, the print commands including the attribute data of the film to be printed, the print data, and a print start;

[0032] According to the printing execution program, specified printing data is called from the printing database, and a specified printed film is supplied, optimal drying conditions and optimal tension conditions corresponding to the attribute data of the film and the printing data are automatically set, and an ejection position is automatically set, which maintains the position accuracy of various colors to be printed according to the stretch and shrink of the film when moving between the nozzles, and all printing is executed.

[0033] In addition, the automatic water-based inkjet printing device further comprises:

[0034] An initial preset database is provided, taking the attribute of the film to be printed and the coverage related to the printing design as elements,

[0035] The optimal drying conditions and the optimal tension conditions considering the thermal shrinkage of the film under the drying conditions can be obtained, the optimal drying conditions include drying temperature and running speed, the drying temperature refers to the temperature at which the film can stably run without shaking or bending due to hot air, and the shrinkage is controlled within a predetermined minimum limit,

[0036] Under the optimal drying conditions and the optimal tension conditions including drying temperature and running speed obtained according to the attribute of the film to be printed and the coverage related to the printing design, the ejection position information can be obtained, which maintains the position accuracy of various colors to be printed according to the stretch and shrink of the film when moving between the nozzles;

[0037] A mechanism for calculating the coverage related to the printing design according to the printing data; and

[0038] A printing control mechanism, for the attribute of the film to be printed and the coverage related to the printing design, respectively refers to the initial preset database, and automatically calculates

[0039] The printing speed,

[0040] The drying temperature,

[0041] The tension,

[0042] The ejection position,

[0043] Based on the above parameters, printing is performed.

[0044] In addition, the automatic water-based inkjet printing device takes the film type, brand, thickness, and paper width as the attribute of the film to be printed.

[0045] The water-based inkjet printing apparatus of this application, by assigning the properties of the film to be printed and the coverage information related to the printing design during the printing execution process, can automatically calculate and adjust the printing speed, drying temperature, and tension even if the coverage, film type, brand, or thickness is different. This ensures that the film can move stably during hot air drying without shaking or bending due to the hot air and without shrinking. Furthermore, based on the expansion and contraction of the film as it moves between the printheads, it maintains the positional accuracy of the various colors to be printed and automatically adjusts the ejection position. Therefore, it can automatically perform various printings with different film properties and printing designs without human intervention. Attached Figure Description

[0046] Figure 1 This is a block diagram of the water-based inkjet printing apparatus of the invention of this application.

[0047] Figure 2 This is a conceptual diagram of the film supply device of the water-based inkjet printing apparatus of the present application.

[0048] Figure 3 This is a concept diagram of a water-based inkjet printing device.

[0049] Figure 4 This is a concept diagram of a water-based inkjet printing device.

[0050] Figure 5 It is a chart related to the top and bottom dimensions after printing.

[0051] Figure 6 It is a chart relating to the left and right dimensions after printing.

[0052] [Symbol Explanation]

[0053] F: Membrane

[0054] 1: Printing control device

[0055] 2: Storage device

[0056] 3: Control Panel

[0057] 4: Initial Preset Database

[0058] 5: Print Database

[0059] 6: Membrane supply device

[0060] 7: Sprayer head

[0061] 8: Printing Original Creation Device

[0062] 9: Terminal

[0063] 10: Inkjet printing equipment

[0064] 11: Turning Tower

[0065] 12: automatic conveyer

[0066] 13: turret

[0067] 14: automatic conveyer

[0068] 20: inkjet head

[0069] 30: hot air drying path DETAILED DESCRIPTION

[0070] Hereinafter, a specific embodiment of the application of the present application will be described based on the drawings. Figure 3 is a conceptual diagram of an aqueous inkjet printing device that is a premise of the application of the present application. Symbol F in the figure is a film to be printed that is passed through an inkjet head 20 while being given a fixed tension and travels on a hot air drying path 30. The inkjet head 20 is non-contact, so it is under the same conditions as the tension in the drying path 30. In the drying path 30, hot air is blown from a nozzle in a drying furnace to the surface of the ink to dry it.

[0071] In the application of the present application, first, the printing speed, the drying temperature, and the tension are automatically calculated according to the properties of the film, and automatic adjustment is performed so that the film can stably travel without shaking or bending due to the hot air at the time of hot air drying, and the film does not shrink, and it is considered that the following is the optimum printing condition at the time of automatic adjustment.

[0072] That is, when aqueous inkjet printing is performed using an OPP (Oriented polypropylene) film, which generally has low heat resistance, as a printing substrate, heat generated by drying of the aqueous ink causes the printed size to expand and contract, the positions of various colors printed do not align, and there is a large deviation in the product size from the reference, and it is not possible to print. The inkjet head (printing section) is non-contact, so it is under the same conditions as the tension in the drying furnace, but hot air drying is generally performed by blowing hot air from a nozzle to the surface of the ink to dry it, so it is necessary to have a tension so that the film can stably travel without shaking or bending due to the wind.

[0073] That is, in aqueous inkjet printing in which a film to be printed is passed through an inkjet head while being given a fixed tension and travels on a hot air drying path, considering the properties such as heat resistance of the film, it is necessary to give a tension to the film, and the tension and the drying temperature are adjusted to a range in which the film to be printed does not shrink due to the tension and the temperature, and the tension is such that the film can stably travel without shaking or bending due to the hot air at the time of hot air drying.

[0074] With respect to the above, the inventors of the present application found the optimum conditions under which water-based inkjet printing can be performed even with an OPP film, which is less heat resistant than general-purpose films commonly used in water-based inkjet printing. If the optimum conditions are reproduced, the less heat resistant OPP film can become a stable traveling state under temperature conditions in which the water-based ink is sufficiently dried, does not cause shaking or bending due to hot air in a drying oven, and does not thermally shrink, thereby enabling control of the position accuracy of various colors to be printed, and thus enabling the product size to be within a reference range.

[0075] In this case, the goal is to suppress thermal shrinkage, which becomes problematic when a general-purpose OPP film is used, which has a thermal shrinkage of MD (machine direction) 8-30% and TD (transverse direction) 5-35% at 150°C for 5 minutes.

[0076] In the case of using a general-purpose OPP film, which has a thermal shrinkage of MD (machine direction) 8-30% and TD (transverse direction) 5-35% at 150°C for 5 minutes, the tension in the drying oven was reduced to 20 N (to 10 N-30 N when the width is 760 mm) under conditions in which a drying device using a designated water-based ink is sufficiently dried, the oven length is 5.5 m, the drying temperature is 85°C, and the speed is 80 m / minute, whereby the printed film had a printing completion size within a reference range (±0.2% in the machine direction and ±0.2% in the transverse direction).

[0077] On the other hand, in the case of using a high-heat-resistant OPP film, which has a thermal shrinkage of MD (machine direction) 3-8% and TD (transverse direction) 2-6% at 150°C for 5 minutes, the tension in the drying oven was reduced to 50 N (to 40 N-60 N when the width is 760 mm).

[0078] In the water-based inkjet printer, in the case of using a high-heat-resistant OPP film, which has a thermal shrinkage of MD (machine direction) 3-8% and TD (transverse direction) 2-6% at 150°C for 5 minutes, the printing completion size was within a reference range (±0.2% in the machine direction and ±0.2% in the transverse direction).

[0079] Under the above premise, the inventors of the present application performed a combination experiment of temperature x tension x heating time using representative films used in water-based inkjet printing, and found the optimum conditions under which water-based inkjet printing can be performed, based on the temperature required for drying, the tension under which the film can travel stably in the drying oven, and the heating time corresponding to the printing speed. If the optimum conditions can be reproduced, a water-based inkjet printer capable of automatic operation can be designed. The contents of the experiment are as follows.

[0080] <Contents of Experiment>

[0081] • Constant temperature and high humidity machine

[0082] Model IG401, balance temperature and humidity control system (GTHC system) manufactured by Yamato Scientific Co., Ltd.

[0083] (Properties)

[0084] Temperature and humidity range: +5°C to +85°C (87°C is possible) / 40% to 95%

[0085] Temperature variation: ±1.0°C, temperature gradient: 5°C, spatial temperature deviation: 5°C

[0086] Humidity variation: ±5%rh, humidity gradient: 10%rh, spatial humidity deviation: 10%rh

[0087] • Substrate used

[0088] OPP: Mitsui Chemicals Tohcello Inc. (U-1, 20 μm), FUTAMURA CHEMICAL CO., LTD. (FOR-AQ, 20 μm)

[0089] Special OPP: TOYOBO CO., LTD. (P2161, 20 μm)

[0090] PET: TOYOBO CO., LTD. (E5100, 12 μm)

[0091] • Auxiliary tool

[0092] Hanging clip (width 145 mm)

[0093] Weight clip (width 145 mm): 350 g, 950 g, 1,500 g

[0094] Water-based inkjet printer: converted to sample size 140 mm based on the experimental results for a width of 760 mm

[0095] *Printer 20N = 350 g, printer 50N = 950 g, printer 80N = 1,500 g

[0096] Sample

[0097] Size: 200 mm in the longitudinal direction (film TD direction), 140 mm in the lateral direction (film MD direction)

[0098] • Measurement

[0099] 300 mm Jis 1st class ruler + magnifying glass PEAK 10 x (scale 0.1 mm) manufactured by Tohkai Sangyo Co., Ltd.

[0100] • Temperature (each temperature setting + humidity 40% fixed) and heating time

[0101] 75°C (4 seconds = 76°C, 11 seconds = 76.5°C, 18 seconds = 77°C)

[0102] 80°C (4 seconds = 81°C, 11 seconds = 81.5°C, 18 seconds = 82°C)

[0103] 85°C (4 seconds = 86°C, 11 seconds = 86.5°C, 18 seconds = 87°C)

[0104] Considering the temperature drop of the constant temperature tank, change the setting temperature in each heating time

[0105] Water-based inkjet printing actual machine: calculate the heating time according to the speed and drying oven

[0106] Drying oven 5.5 m, speed 80 m / min = 4 seconds, 30 m / min = 11 seconds, 0.3 m / min = 18 seconds

[0107] Combination of heating temperature conditions for water-based ink to dry in the actual machine

[0108] * Actual machine 30 m / min = 75°C, 80 m / min = 85°C, 0.3 m / min does not need to be tested in the actual machine

[0109] ◎ Experimental method

[0110] Take 3 places from both sides, the center of the film substrate, in the transverse direction (film MD direction)

[0111] Cut with dimensions of 200 mm in the longitudinal direction and 140 mm in the transverse direction

[0112] Punch holes with a needle at intervals of 100 mm in the longitudinal and transverse directions of the central part of the sample

[0113] Before heating, actually measure (accurate to one decimal place) 100 mm in the longitudinal and transverse directions using a ruler + magnifying glass and record

[0114] Regarding the weight clamp, select the specified weight

[0115] Install a hanging clamp on the upper part of the sample and a weight clamp on the lower part

[0116] Confirm that the constant temperature tank is at the specified temperature (± 1°C) and hang the sample in the constant temperature tank

[0117] Close the door of the constant temperature tank and heat for the specified time

[0118] After the specified time has elapsed, open the door and remove the sample

[0119] Remove the clamps from the upper and lower portions

[0120] After heating, measure (to one decimal place) 100 mm in both the longitudinal and transverse directions using a ruler + magnifying glass and record

[0121] Subtract the size after heating from the size before heating and record

[0122] Plot the subtracted size in the graph (+ indicates extension, - indicates contraction)

[0123] Confirm the thermal expansion of each sample

[0124] <Experiment Results>

[0125] The experiment results are shown in Table 1 below.

[0126] Table 1

[0127]

[0128] The hanging weight at which the printing control range is within 0.2% is indicated.

[0129] (1) OPP: Mitsui Chemicals Tosoh Silica Co., Ltd.: In the case of using U-1, 4 seconds are required at 85°C in the longitudinal direction, and 11 seconds are required at 75°C, 80°C, 85°C in the longitudinal direction and at 85°C in the transverse direction, at which time the tension is 350 g, and this is considered to be acceptable. Printing is performed simultaneously in the longitudinal and transverse directions, and therefore a low tension of 350 g is required for all printing

[0130] (2) OPP: Nikka Chemical Co., Ltd.: FOR-AQ is the same as Mitsui Chemicals Tosoh Silica Co., Ltd., and a low tension of 350 g is required for all printing

[0131] (3) Special OPP: Toyobo Co., Ltd.: P2171 is a film that is more heat resistant than ordinary OPP, and therefore 11 seconds are required at 80°C, 85°C in the longitudinal direction, at which time printing can also be performed with a tension of 950 g

[0132] (4) PET: E5100 of Toyobo Co., Ltd. is different from OPP, and is a high heat resistant film, and therefore printing can also be performed with a tension of 1500 g, which is the usual tension

[0133] One of the features of the present application is that initial preset functions are provided as a prerequisite for automatic operation, and if the properties of the film to be used (film type, brand, thickness, paper width) and the design-related coverage are input just before printing, the optimal drying conditions (drying temperature and speed) for water-based ink and the optimal tension conditions (traction rate of each drive roller under various conditions) for the substrate to be used can be automatically set at one time, thereby facilitating the setting of optimal printing conditions.

[0134] That is, an initial preset database of optimal drying conditions (drying temperature, speed) and optimal tension conditions (traction rate of each drive roller under various conditions) is created in advance, the optimal drying conditions being obtained based on drying condition elements (film type, brand, thickness, paper width, design-related coverage) obtained in advance through testing, and the optimal tension conditions taking into account the thermal shrinkage of the film under the drying conditions. When printing, if the film type, brand, thickness, and paper width are selected from the initial preset setting screen, and the % value of the design-related coverage is input, the drying temperature, speed, and optimal tension conditions (traction rate of each drive roller under various conditions) taking into account the thermal shrinkage of the film under the drying conditions under the optimal printing conditions can be automatically set at one time from the first edition without trial printing.

[0135] As for the registration of the various colors to be printed next, the positions of the four colors of the color and the white of the non-color are aligned under the optimal printing conditions automatically set at the time of first edition printing. In this case, the initial preset automatically sets the optimal drying conditions and the optimal tension conditions, so the positions of the various colors aligned under the condition of thermal shrinkage of the film can be grasped in advance through testing and additionally saved in the initial preset database.

[0136] That is, the ejection position information of the nozzle is additionally stored in the initial preset database, and when the nozzle is at the ejection position, the various colors printed under the conditions of the optimal drying conditions (drying temperature, speed) and the optimal tension conditions (traction rate of each drive roller under various conditions) and further the positions of the various colors have been aligned under the conditions, the optimal drying conditions being obtained based on drying condition elements (film type, brand, thickness, paper width, design-related coverage) obtained in advance through testing, and the optimal tension conditions taking into account the thermal shrinkage of the film under the drying conditions. Thus, even at the time of first edition printing, trial printing is not required, and the positions of the various colors to be printed can be aligned from the first time. Since the positions of the various colors to be printed can be aligned from the first time at the time of first edition, the loss so far is almost eliminated, and mass production printing can be implemented. The following is a specific example.

[0137] The initial preset function first inputs the elements of the substrate to be used (film type, brand, thickness, paper width = Example: OPP, Mitsui Chemicals Tosoh Silica Co., Ltd., U-1, #20, 760mm) and the coverage related to the design (Example: Coverage of 4 colors = 100%, Coverage of 2 whites = 140%) just before printing, while automatically setting the optimal drying conditions of the water-based ink (drying temperature 88°C, speed 80m / minute) and the optimal tension conditions suitable for the substrate to be used (traction rate of each drive roller in each condition: ultra-weak mode = tension 20-25N), thereby facilitating the setting of the optimal printing conditions.

[0138] Figure 5 and Figure 6 are diagrams related to the finished printing size and printing accuracy. The finished printing size is obtained from the initial preset database that has been debugged in advance through testing, for example, under the conditions shown in Figure 5 , as shown in Figure 5 : up and down 0.00±0.1%, as shown in Figure 5 : left and right 0.30±0.1%, if the left and right sizes are not within the reference range, the design size is enlarged before printing, and the finished product is within the reference range. That is, the problem can be addressed in advance by adjusting the job, so that the printing can be completed from the first time.

[0139] Regarding the printing accuracy, for example, under the conditions shown in Figure 5 , 6 , under the optimal drying conditions (drying temperature 88°C, speed 80m / minute) and the optimal tension conditions suitable for the substrate to be used (traction rate of each drive roller in each condition: ultra-weak mode = tension 20-25N), thermal shrinkage of 45 lum occurs during drying, so the positions of the 4 colors CMYK and the 2 whites to be printed later are shifted. An initial preset database related to the positional accuracy of the various colors to be printed, which has been debugged in advance through testing, is required. In the state where the positional accuracy of the various colors to be printed is consistent (for example: the difference (up and down and left and right) in the positions of the CMY various colors and the white x 2 degrees from K (black) is within the reference ±0.2mm), the database is the position information data of the total 4 colors and 2 whites of the nozzles (for example: position information of CMYK 4 colors x total 7 nozzles, white x 2 = total 7 nozzles).

[0140] Figure 1Fig. 1 is a block diagram of an automatic water-based inkjet printing apparatus of the present application. Symbol 1 in the figure is a printing control apparatus that creates and executes a printing execution program in which one or more printing commands instructed by an operator are stored, the printing commands including attribute data of a film to be printed, printing data, and a printing start, the printing execution program being stored in a storage apparatus 2.

[0141] Symbol 3 in the figure is an operation panel through which the operator issues a printing command to the printing control apparatus. A printing command can also be issued from an external terminal 9 via the Internet N. The terminal 9 also serves as a mechanism that receives an abnormality notification when a failure or an error occurs during unattended automatic operation.

[0142] Symbol 5 in the figure is a printing database in which printing data called up in accordance with the printing execution program is stored in advance. Here, the printing data refers to printing original data created by an operator based on printing design received from a printing orderer and specification information of attributes of a film to be printed, such as a film type, a brand, a thickness, a paper width, and the like, and data created by a printing original creation apparatus 8 connected in a wired or wireless manner is stored in the printing database 5 via the printing control apparatus of the printing apparatus.

[0143] Symbol 4 in the figure is an initial preset database. Here, the initial preset database stores the following data: with the attributes of the film to be printed and a coverage rate related to a printing design as factors, an optimum drying condition including a drying temperature and a traveling speed, the drying temperature being a temperature at which the film can travel stably without causing a shift or a bend due to a hot air and with a shrinkage controlled to a minimum, and an optimum tension condition considering a thermal shrinkage of the film under the drying condition, and an ejection position information that maintains a position accuracy of various colors to be printed according to an expansion and a contraction of the film when moving between heads, can be obtained under the optimum drying condition including the drying temperature and the traveling speed and the optimum tension condition obtained in accordance with the attributes of the film to be printed and the coverage rate related to the printing design; for information of the attributes of the film to be printed and the coverage rate related to the printing design, the initial preset database is referred to respectively, and an automatic calculation is performed of:

[0144] a printing speed,

[0145] a drying temperature,

[0146] a tension,

[0147] an ejection position.

[0148] Symbol 7 in the figure is a head that is driven by a control command from the printing execution program, and likewise, symbol 6 in the figure is a film supply apparatus that supplies a film and travels at a specified speed, a tension, a drying apparatus.

[0149] In the film supply device 6, a plurality of films F need to be selected and supplied according to control commands from a print execution program, and although it is possible to use an automatic conveyer to convey the material roll used in printing to the printing device side, the preparation work in the unwinding section and the winding section must all be completed by the operator. That is, the following operations are difficult to automate: the work of setting the material roll to be used next in the unwinding section and taping it to the connection on the film of the previous material roll; the work of removing the wound roll on which printing is completed from the winding section, installing a new paper tube, cutting the film and connecting it to the new paper tube.

[0150] In addition, the work of connecting the material roll being used to the new material roll and passing it through the printer is difficult to automate when the material roll being used is almost finished.

[0151] Incidentally, it is necessary to ensure the print quality when a print order is received, but it is necessary to take samples for quality inspection, confirm the print quality and ensure the quality when printing is completed, which makes it difficult to automate.

[0152] In addition, an appearance inspection machine needs to be set up each time printing is performed, but this must be set by the operator, because it is difficult to automate the appearance inspection machine in conjunction with the inkjet machine for automatic inspection.

[0153] Figure 2 is a conceptual diagram of an embodiment of a film supply device for realizing the automation, in which symbol 10 represents an inkjet printing device in which a film F advances. Symbol 12 is an automatic conveyer 12 that conveys the material roll on which the film F before printing is wound to a designated position, and similarly, 14 is an automatic conveyer 14 that conveys the printed roll on which the film F after printing is wound to a designated position, and in this embodiment, the automatic conveyers are made to operate in conjunction with the unwinding section and the winding section of the inkjet printing device 10 and automatically.

[0154] In this embodiment, the unwinding section and the winding section are turret type. When the raw material roll used by the A shaft is about to be used up, the next raw material roll to be used (the raw material roll indicated by the print execution program) is brought to the setting position by the automatic conveyer 12 and is automatically gripped on the inkjet printer side. The raw material roll is set with the tape adhered by the operator beforehand, in a state in which the tape adhered portion is facing upward. After the inkjet printer is stopped, the turret 11 is rotated to the tape position of the raw material roll of the next B shaft, so that the film F of the raw material roll of the A shaft is automatically attached to the appropriate position, and then the film F of the A shaft is automatically cut. The raw material roll of the A shaft after the cutting automatically winds the excess film F. At this time, the automatic conveyer 12 waits below the A shaft, and the turret 11 is automatically moved to place the remaining raw material roll of the A shaft on the automatic conveyer. The inkjet printer automatically rotates the turret 11 to return it to the fixed position when the raw material roll is detached. The automatic conveyer on which the remaining raw material roll of the A shaft is placed transports it to the designated position. The inkjet printer automatically feeds the substrate to the winding section at the tape splicing portion of the raw material, winds it, and then stops. After the operation up to this point is completed without error, the automatic print start mode is entered.

[0155] The winding operation after the automatic operation of the unwinding section is completed and the printing is completed will be described. The winding section is also turret type. The printed film F is wound on the A shaft. The new paper tube to be used next (which is wound with tape beforehand by the operator) is brought to the B shaft by the automatic conveyer which approaches the setting position of the B shaft, and is automatically gripped on the inkjet printer side. The inkjet printer automatically rotates the turret 13, and by rotating the turret, the printed wound film of the A shaft is automatically attached to the tape of the B shaft to which the new paper tube is adhered. Then, the film F of the printed side of the A shaft is automatically cut. The excess film F of the printed side of the A shaft after the cutting is automatically wound. At this time, the automatic conveyer 14 waits below the A shaft, and the turret 13 is automatically moved to place the printed wound roll of the A shaft on the automatic conveyer. The inkjet printer automatically rotates the turret 13 to return it to the fixed position when the printed wound roll is detached. The automatic conveyer on which the printed roll of the A shaft is placed transports it to the designated position.

[0156] In this embodiment, when the raw material roll being used at the front is about to be used up, it is connected to a new raw material roll and is automatically passed through the printer. That is, the tape adhered position of the remaining portion of the raw material roll and the tape connection portion of the next new raw material roll is detected by the unwinding section, the inkjet printer automatically travels at low speed, the position at which the tape connection portion is wound into the winding drum is detected, and the inkjet printer is automatically stopped. The inkjet printer body enters the automatic print mode after receiving the signal that the automatic operation is completed.

[0157] In this embodiment, samples are taken for quality inspection at the time of printing completion, and the print quality is confirmed to ensure the quality. In order to reasonably perform this operation, the following mechanism is adopted: by using a digital color matching method with a two-dimensional colorimeter, when the color difference ΔE = 3 or less is obtained after printing, the quality can be ensured. Thus, the print samples produced by automatic operation without people at night are collected in the subsequent process the next day. This is done to store and manage the samples retained during the quality assurance period.

[0158] In addition, although the appearance inspection machine needs to be set up each time of printing, in this embodiment, the appearance inspection machine is linked with the inkjet printing device to perform automatic inspection without people. That is, during the operation of the inkjet printing device, the appearance inspection machine inspects all products. In the application, the automatic operation of the inkjet printing device is performed by the print execution program, and the appearance inspection machine also performs actions in linkage with this function.

[0159] In addition, the initial preset database and the print control device for automatic operation described above can of course be integrated with the printing device, and can also be integrated with a printing original creation device for creating print original data and attribute designation data of the film to be printed by the print order receiver, and can exchange data with the independent printing device through wired or wireless means.

[0160] The automatically operable water-based inkjet printing device according to the application determines the print schedule for the night, i.e., the print reservation, during the day shift. The print reservation can be performed by having the person in charge create the print execution program in advance according to the order of printing at night. In the reservation screen, first, the type or brand of the film, the thickness, the width, and the coverage (10% to 150%) are selected as the print design information under the initial preset function, and the input is completed. The direct switching screen associates the image data. When the image data prepared in advance is selected and clicked on the screen, the image data name is written on the reservation screen. When these operations are completed and the reservation button is finally pressed, all information can be set in advance according to the reservation order. Occasionally, there is a jump in the reservation, and once the reservation for the night is completed or even if it is being reserved, there is an interrupt function, and when all the inputs are completed in the same way and the "interrupt" button is pressed, the first reservation can be made.

[0161] If the day shift operator completes all the print operations of the day shift manual operation, presses the "reservation start" button, and then presses the "OK" button, the reservation part of the subsequent printing is all converted to the automatic operation mode without people, and the automatic operation starts. When a fault or error occurs in the middle, information is sent remotely to notify the abnormality. The machine remains in a stopped state and waits for recovery. The fault removal is performed by the operator. After all the errors are removed, the remaining reservation operation is restarted. Alternatively, all the remaining parts can be reset at one time.

Claims

1. An automatically operating water-based inkjet printing apparatus, characterized in that, while applying a fixed tension to the film to be printed, the film passes through an ink nozzle and travels along a hot air drying path, This automatically operating water-based inkjet printing device includes: A printing database that stores the property data of the film to be printed and the printing data; An organization that supplies the film to be printed; and An organization that executes a printing process, wherein the printing process stores one or more printing commands instructed by an operator, the printing commands including property data of the film to be printed, printing data, and printing start; According to the printing execution procedure, the specified printing data is retrieved from the printing database and supplied to the specified film to be printed. The drying conditions and tension conditions corresponding to the film's property data and the printing data are automatically set, and the ejection position is automatically set to execute all printing. The ejection position is based on the expansion and contraction of the film as it moves between the printheads, maintaining the positional accuracy of the various colors to be printed.

2. The automatically operating water-based inkjet printing apparatus according to claim 1, characterized in that, Also includes: The initial database is pre-set, using the properties of the film to be printed and the coverage related to the printing design as factors. The drying conditions and tension conditions that take into account the thermal shrinkage of the film under these drying conditions can be determined. These drying conditions include drying temperature and travel speed. The drying temperature refers to the temperature at which the film can travel stably during hot air drying without swaying or bending due to the hot air, and where shrinkage is controlled to a minimum. Based on the properties of the film to be printed and the coverage related to the printing design, the optimal drying conditions, including drying temperature and travel speed, and the optimal tension conditions, can be obtained. The ejection position information is based on the expansion and contraction of the film as it moves between the nozzles, which maintains the positional accuracy of the various colors to be printed. An organization that calculates coverage related to print design based on print data; as well as The printing control mechanism automatically calculates the following information based on the properties of the film to be printed and the coverage related to the printing design, referring to the initial preset database: Printing speed Drying temperature tension, Spray position, Printing is performed based on these parameters.

3. The automatically operating water-based inkjet printing apparatus according to claim 1 or 2, characterized in that, The film type, brand, thickness, and paper width are used as attributes of the film to be printed.

Images