JP2022153330A - Water-based inkjet printing method and water-based inkjet printing apparatus - Google Patents

Abstract

To provide a water-based inkjet printing method that can respond to small-lot orders, is excellent in on-demand property, and can enable speedy water-based inkjet printing on plastic film.SOLUTION: In the water-based inkjet printing method, in which a film to be printed passes through the ink head section while being given a constant tension and travels through a hot air drying path, the printing speed, drying temperature, and tension are automatically calculated according to the attribute of the film to be printed and the coverage that indicates the ink usage area, and adjustment for stable running so that the film does not flutter or meander due to the hot air during hot air drying, as well as for no shrink, is made.SELECTED DRAWING: Figure 1

Description

The present invention relates to a water-based inkjet printing method and a water-based inkjet printing apparatus, and in particular, when distributing food, a printing method that is optimal for packaging materials made of plastic film used for packaging bags for containing food and lids of food containers. and equipment.

In today's food distribution, instead of face-to-face sales where food prepared on the spot is packaged and sold, packaged foods such as processed foods, breads, and confectionery prepared in advance at food factories are sold at convenience stores. The method of selling at retail stores such as stores and supermarkets is becoming mainstream.

In the sales system described above, packaged foods are displayed on display shelves in retail stores, and customers take them in their hands and examine them before making a purchase. Therefore, the packaging itself is also required to be devised in terms of design so as to attract the customer's desire to buy and to make the packaging more noticeable to the customer.

In the above case, since the primary purpose of the packaging material itself is to package food, it is not possible to change the shape of the packaging material so as to impair its function. (referred to as "patterns, etc.") plays a very important role.

Printing is generally used as a means of applying the above-mentioned pattern to the lid of a packaging bag or a food container, and when printing on the packaging bag or the lid of a food container, printing is performed on the back side of these (reverse printing). There are two types of printing methods: printing on the front side and printing on the front side (surface printing). In this case, the Food Sanitation Law prohibits printing ink from coming into contact with food in food packaging materials. The film had to be laminated.

On the other hand, when printing on the front side of the packaging material, there are no such restrictions as described above, but since the printed layer is exposed, when the film is wound up after printing when processing it into a packaging bag or lid, it will be printed on the back side of the film. Care must be taken to prevent the printing layer from becoming unclear due to physical friction or solvents (alcohol or oil) caused by contact with other packaging materials or articles during distribution or display, or contact with human fingers. did not become.

In the above case, plastic film is a base material that does not easily absorb liquid unlike paper, etc., so gravure printing using gravure ink with high coating adhesion and flexographic printing using flexo ink were adopted for printing. (For example, Patent Document 1).

By the way, inkjet printing, which does not require platemaking and can generate images for printing from digital data, is excellent in on-demand performance, and is originally useful for food packaging materials that must be printed with various patterns at any time. but could not be adopted.

The reason for this is that water-based inkjet inks that can be used for inkjet printing do not have physical properties such as abrasion resistance, alcohol resistance, oil resistance, and water resistance, and the ink easily comes off, resulting in weak coating film adhesion. In this case, gravure ink and flexographic ink, which have high coating film adhesion, have too high a viscosity, and cannot be used in ink-jet printing, in which the ink is ejected from nozzles for adhesion, because it cannot be ejected smoothly from nozzles.

To improve the production efficiency of packaging materials for food, which are not fixed durable consumer goods with fixed types of patterns, but are consumed in a short period of time and must be printed with a wide variety of patterns according to the contents at any time. Therefore, speeding up printing is essential.

However, gravure printing and flexo printing, which require a plate to be prepared for a new design and set on the production line each time, require time to start printing, and there is a limit to speeding up. rice field.

For example, food packaging materials printed with gravure patterns require a total of 12 days for the pre-printing work (block copy submission + plate making) and printing, plus post-processing (film lamination, finishing). ) took 6 days and required a total of 18 days.

In addition, as described above, gravure printing requires color separation and plate making, so the minimum order lot is unavoidably large, and the customer has no choice but to purchase more packaging materials than necessary, resulting in waste loss.

On the other hand, it is easy to choose to use inkjet printing when printing on the back side of the bag, but this requires a process of laminating a plastic film on the printed layer side of the plastic film, which is costly and time consuming. I had a problem.

In relation to this, the inventor of the present application created the following invention.
In the first invention, patterns and/or characters are printed on the surface positioned on the front side during bag making of the plastic film that constitutes the food packaging material, and the patterns and/or characters are printed using inkjet ink. After that, the invention is characterized in that a transparent inkjet ink is overlaid on the printed area by inkjet printing.

In addition, the second invention is to print patterns and/or characters on the surface located on the front side of the plastic film to constitute the food packaging material. , is an invention characterized by overprinting with transparent UV ink.

In a third invention, when printing patterns and/or characters on the surface located on the front side of the plastic film to constitute the food packaging material, after inkjet printing the patterns and/or characters using inkjet ink, , is an invention characterized in that transparent EB ink is overprinted.

JP 2000-273379

According to the above-mentioned invention by the inventor of the present application, when printing a pattern or the like on the surface located on the front side of the lid of a packaging bag or a food container, even if inkjet printing is performed using a water-based inkjet ink, the printing area is transparent. Ink jet ink, transparent UV ink, or transparent EB ink is overprinted to protect the printed layer such as the pattern, so the printed layer such as the pattern is not exposed.

Therefore, contact with the back side of the film when printing and winding the film when processing it into a packaging bag or lid, or contact with other packaging materials, articles, or human fingers during distribution or exhibition. Therefore, it is possible to prevent the printed layer such as the pattern from being scraped off by friction and becoming unclear or generating shavings.

On the other hand, since printing is completed by inkjet printing, which has excellent on-demand characteristics, it is necessary to prepare a plate for new designs and set it on the production line. It eliminates the need for time required for the process of packaging, making it possible to speed up the process, and dramatically increases the production efficiency of food packaging materials that require printing of a wide variety of patterns depending on the contents at any time. be able to.

The aforementioned invention is based on the fact that water-based inkjet ink cannot be used in printing on plastic films because it does not have physical properties such as abrasion resistance, alcohol resistance, oil resistance, and water resistance, and the ink easily comes off and the coating film adhesion is weak. It breaks the conventional technical common sense.

However, the inventors of the present invention faced a new problem when they carried out water-based inkjet ink printing on plastic films, which had never been attempted before.

In water-based inkjet printing, where the ink head (printing section) is of a non-contact type, the tension of the ink head that prints and the tension of the film running in the drying path are the same, so the drying temperature and the tension in the drying path The problem is that thermal expansion and contraction of the film occurs due to the influence, and it becomes impossible to control register and dimensions.

Therefore, this water-based inkjet printing is very complicated to operate compared to the gravure press. In other words, the printing conditions are different for each printing pattern, and it is necessary to set appropriate conditions each time and perform trial printing before starting. If the film type/brand/thickness is different, it is necessary to set each time. This is a fatal flaw for a small-lot mass production machine, and although it excels in on-demand performance, there is a danger that it will impair the original purpose of speeding up printing.

The present invention has been created with the object of providing a water-based inkjet printing method and a water-based inkjet printing apparatus that solve the above problems.

That is, the water-based inkjet printing method of the present invention is water-based inkjet printing in which the film to be printed passes through the ink head section and travels in a hot air drying path while being given a certain tension,
Depending on the attributes of the film to be printed and the coverage indicating the ink usage area,
print speed,
drying temperature,
tension,
is automatically calculated, and adjustments are made so that the film can stably run so that the film does not flutter or meander due to the hot air during drying and that the film does not shrink.

Further, the invention according to claim 2 is characterized in that, in the water-based inkjet printing method, the drawing area is calculated from the printing image data, and coverage analysis is performed to automatically calculate the coverage.

Further, the water-based inkjet printing apparatus according to claim 3 is a water-based inkjet printing apparatus in which the film to be printed passes through the ink head section and travels in a hot air drying path while being given a certain tension,
By entering the coverage, which indicates the attributes of the film to be printed and the area of ink used,
print speed,
drying temperature,
tension,
By providing a printing management system that automatically calculates the , stable running is possible so that the film does not flutter or meander due to the hot air during hot air drying, and shrinkage is prevented.

According to the water-based inkjet printing method of the present invention, inkjet printing with excellent on-demand properties is realized, and even when the coverage, film type, brand, and thickness are different, the printing speed, drying temperature, and tension are automatically calculated, When drying with hot air, it is adjusted so that the film does not flutter or meander due to the hot air, so that it can run stably and it does not shrink.
print speed,
drying temperature,
tension,
By creating a database and automating the calculation, there is no need to set appropriate conditions each time and test print before starting, and the speed of printing can be increased.

In addition, according to the water-based inkjet printing apparatus of the present invention, even if the coverage, film type, brand, and thickness are different, since it is equipped with a printing management system that automatically calculates the printing speed, drying temperature, and tension, the calculation can be automated. Thus, the film can be stably run so that the film does not flutter or meander due to the hot air during drying, and the film does not shrink, so that the printing method can be easily carried out at the printing site.

FIG. 2 is a conceptual diagram of the water-based inkjet printing method of the present invention. A printing example using the water-based inkjet printing method of the present invention.

Specific embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a conceptual diagram of the water-based inkjet printing method of the present invention. Reference numeral F in the drawing denotes a film to be printed, which passes through the ink head unit 10 and travels through the hot air drying path 20 while being given a constant tension. Since the ink head section 10 is of a non-contact type, the tension is the same as that in the drying path 20 . In the drying path 20, the ink surface is dried by blowing hot air from nozzles in the drying furnace.

In the present invention, the printing speed, drying temperature, and tension are automatically calculated according to the attributes of the film. Although it is an automatic adjustment, we have found the following as the optimum printing conditions for automatic adjustment.

In other words, when water-based inkjet printing is performed on a film OPP (biaxially oriented polypropylene), which generally has low heat resistance as a printing base material, the size of the print expands and contracts due to the heat of drying the water-based ink, resulting in misalignment, and the product size standard is also increased. I can't print because it comes off.

Since the ink head (printing section) is a non-contact type, the tension conditions are the same as in a drying oven. Generally, hot air drying is performed by applying hot air from a nozzle to the ink surface to dry the film, so the film flutters due to the wind. It is necessary to have a tension that allows stable running without sticking or meandering.

In other words, in water-based inkjet printing, the film to be printed passes through the ink head section and travels through the hot-air drying path while being given a certain amount of tension. It is necessary to apply tension to the film so that it can run stably so that the film does not flutter or meander, and to adjust the tension and the drying temperature so that the film to be printed does not shrink due to the tension and temperature.

With respect to the above, the inventors of the present application have found the optimum conditions for water-based inkjet printing even with a film OPP (biaxially oriented polypropylene) having low heat resistance among general-purpose films used in water-based inkjet printing. If this optimum condition is reproduced, the film OPP (biaxially oriented polypropylene) with low heat resistance can be made to run stably without fluttering or meandering due to the hot air in the drying oven, even though the water-based ink is sufficiently dried. ) does not undergo thermal expansion and contraction, and printing register control is possible, and the product dimensions are within the standard.

In this case, general-purpose film OPP (biaxially oriented polypropylene): Heat shrinkage rate 150 ° C. 5 minutes Conditions: MD (vertical) 8-30%, TD (horizontal) 5-35% Thermal expansion and contraction that is a problem when using The aim is to suppress the printing register and to reproduce the dimensions.

General general-purpose film OPP (biaxially oriented polypropylene): Heat shrinkage rate 150°C 5 minutes Condition: MD (vertical) 8-30%, TD (horizontal) 5-35% When using the specified water-based ink sufficiently dry When the drying apparatus has a furnace length of 5.5 m, the tension in the drying furnace is reduced to 20 N (10 N to 30 N at a width of 760 mm) under the conditions of a drying temperature of 85 ° C. and a speed of 80 m / min. The finished printing dimensions of the film after printing are within the standard (vertical ±0.2%, horizontal ±0.2%).

On the other hand, high heat resistant OPP (biaxially oriented polypropylene): Heat shrinkage rate 150 ° C. 5 minutes Conditions: MD (vertical) 3 to 8%, TD (horizontal) 2 to 6% When using the tension in the drying oven to 50N (40N to 60N at 760mm width).

High heat resistant OPP (biaxially oriented polypropylene) with the above water-based inkjet printer: Heat shrinkage rate 150 ° C. 5 minutes Conditions: MD (vertical) 3-8%, TD (horizontal) 2-6% When using, printing The finished dimensions are within the standard (vertical ±0.2%, horizontal ±0.2%).

As a premise for the above, the inventor of the present invention used a representative film used in water-based inkjet printing, and conducted an experiment combining temperature x tension x heating time, and found that the temperature required for drying and the temperature required for drying were stabilized in the drying oven. The optimal conditions for water-based inkjet printing were found from the tension that allows running and the heating time that corresponds to the printing speed. By reproducing this optimum condition, it is possible to design a water-based inkjet printer that can be mass-produced. The contents of the experiment are as follows.

<Experiment content>
・Constant temperature and humidity chamber Model IG401 manufactured by Yamato Scientific Co., Ltd. Balanced temperature and humidity control system (GTHC system)
(Performance)
Temperature and humidity range: +5°C to +85°C (87°C possible)/40% to 9596
Temperature fluctuation: ±1.0°C, temperature gradient: 5°C, spatial temperature deviation: 5°C
Humidity fluctuation: ±596rh, humidity gradient: 10%rh, spatial humidity deviation: 1096rh
・Base OPP used: Tohcello (U-1, 20 μm), Futamura Chemical (FOR-AQ, 20 μm)
Special OPP: Toyobo (P2161, 20 μm)
PET: Toyobo (E5100, 12 μm)
・Jig hanging clip (width 145mm)
Weight clip (width 145mm): 350g, 950g, 1,500g
Actual water-based inkjet printing machine: Converted to a sample size of 140 mm from the experimental results at a width of 760 m
Specimen size: Vertical (film TD direction) 200 mm. Horizontal (film MD direction) 140mm
・Measurement 300mm Jls grade 1 metal rule + Tokai Sangyo loupe PEAKl0 x (scale 0.1mm)
・Temperature (each temperature setting + constant humidity of 40%) and heating time 75°C (4 seconds = 76°C, 11 seconds = 76.5°C, 18 seconds = 77°C)
80°C (4 seconds = 81°C, 11 seconds = 81.5°C, 18 seconds = 82°C)
85°C (4 seconds = 86°C, 11 seconds = 86.5°C, 18 seconds = 87°C)
Actual water-based inkjet printing machine that changes the set temperature at each heating time considering the temperature drop of the constant temperature bath: Heating time is calculated from the speed and drying oven Drying oven 5.5m, speed 80m/minute = 4 seconds, 30m/minute = 11 seconds , 0.3 m/min = 18 sec. The heating temperature is a combination of the drying conditions for water-based ink in the actual machine.

◎Experiment method Collect 3 points on both sides and the center from the horizontal direction of the film substrate (film MD direction). Measure 100mm both vertically and horizontally with a metal rule and a magnifying glass (one decimal place) and record it. Select a designated weight for the weight clip. After confirming the temperature (±1°C), hang the sample in the constant temperature bath Close the door of the constant temperature bath and heat for the specified time After the specified time, open the door and remove the sample Remove the top and bottom clips After heating, measure 100 mm both vertically and horizontally with a metal rule + magnifying glass (one decimal place) and record. Subtract the size after heating from before heating. Check thermal expansion

印刷制御範囲が０．２９６以内になる吊るしの重量を表記した
（１）ＯＰＰ：東セロ：Ｕ－１では４秒でタテ８５℃、１１秒でタテ７５℃８０℃８５℃ヨコ８５℃の場合３５０ｇにすると合格。印刷はタテ・ヨコ同時なので全て３５０ｇになる低張力が必要
（２）ＯＰＰ：フタムラ化学：ＦＯＲ－ＡＱも東セロ同様、全て３５０ｇになる低張力が必要
（３）特殊ＯＰＰ：東洋紡：Ｐ２１７１は一般ＯＰＰより耐熱があるフィルムなので１１秒でタテ８０℃８５℃の場合９５０ｇでの張力でも印刷できる
（４）ＰＥＴ：東洋紡Ｅ５１００はＯＰＰと異なり高耐熱性フィルムなので１，５００ｇの通常張力でも印刷できる <Experimental result>

(1) OPP: Tohcello: For U-1, vertical 85 ° C in 4 seconds, vertical 75 ° C, 80 ° C, 85 ° C, horizontal 85 ° C in 11 seconds, 350 g to pass. (2) OPP: Futamura Kagaku: FOR-AQ also requires a low tension of 350g like Tocello. (3) Special OPP: Toyobo: P2171 is general OPP. (4) PET: Unlike OPP, Toyobo E5100 is a highly heat-resistant film, so it can be printed at a normal tension of 1,500 g.

<Detailed graph of experimental results>
(1) 75°C: OPP vertical thermal expansion <Tohcello U-1 #20>

（１）７５℃の場合、実機で水性インクは速度３０ｍ／分＝１１秒で乾燥するので印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
１１秒の張力９５０ｇではタテで限度少し超え、３５０ｇであれば合格 (1) 75°C: OPP horizontal thermal expansion <Tohcello U-1 #20>

(1) At 75°C, the water-based ink dries at a speed of 30 m/min = 11 seconds on the actual machine, so the print controllable range: Vertical and horizontal expansion and contraction is 0.2% or less for 11 seconds, and a tension of 950 g is vertical. A little over the limit, if it is 350g, it will pass

(1) 80 ° C: OPP vertical thermal expansion <Tohcello U-1 #20>

（１）８０℃の場合、実機で水性インクは速度８０ｍ／分＝４秒で乾燥限界だが
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
４秒の張力９５０ｇでタテ・ヨコ共合格 (1) 80°C: OPP horizontal thermal expansion <Tohcello U-1 #20>

(1) At 80 ° C, water-based ink is dried at a speed of 80 m / min = 4 seconds on the actual machine, but the print controllable range: Vertical and horizontal expansion and contraction is 0.2% or less with a tension of 950 g for 4 seconds. Horizontal pass

(1) 85°C: OPP vertical thermal expansion <Tohcello U-1 #20>

（１）８５℃の場合、実機で水性インクは速度８０ｍ／分＝４秒で乾燥する
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
４秒の張力９５０ｇはタテで限度少し超え、３５０ｇであれば合格 (1) 85°C: OPP horizontal thermal expansion <Tohcello U-1 #20>

(1) At 85°C, water-based ink dries at a speed of 80 m/min = 4 seconds on the actual machine. Print controllable range: Vertical and horizontal expansion and contraction is 0.2% or less for 4 seconds. Tension 950 g is the vertical limit. If it exceeds a little and is 350g, it passes.

(2) 75 ° C: OPP vertical thermal expansion <Futamura Chemical FOR-AQ # 20>

（２）７５℃の場合、実機で水性インクは速度３０ｍ／分＝１１秒で乾燥するので
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
１１秒の張力９５０ｇではタテが限度超え、３５０ｇであれば合格 (2) 75 ° C: OPP horizontal thermal expansion <Futamura Chemical FOR-AQ # 20>

(2) At 75°C, water-based ink dries at a speed of 30 m/min = 11 seconds on the actual machine, so the print controllable range: Vertical and horizontal expansion and contraction is 0.2% or less for 11 seconds. Exceeding the limit, pass if 350g

(2) 80 ° C: OPP vertical thermal expansion <Futamura Chemical: FOR-AQ # 20>

（２）８０℃の場合、実機で水性インクは速度８０ｍ／分＝４秒で乾燥限界だが
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
４秒の張力９５０ｇではタテで限度少し超え、３５０ｇであれば合格 (2) 80 ° C: OPP horizontal thermal expansion <Futamura Chemical: FOR-AQ # 20>

(2) At 80°C, water-based ink is dried at a speed of 80m/min = 4 seconds on the actual machine, but the print controllable range: Vertical and horizontal expansion and contraction is 0.2% or less, and tension 950g is vertical for 4 seconds. A little over the limit, if it is 350g, it will pass

(2) 85 ° C: OPP vertical thermal expansion <Futamura Chemical: FOR-AQ # 20>

（２）８５℃の場合、実機で水性インクは速度８０ｍ／分＝４秒で乾燥する
印刷制御可能な範囲：タテ・ヨコの伸縮が０，２９６以下は
４秒の張力９５０ｇではタテで限度少し超え、３５０ｇであれば合格 (2) 85 ° C: OPP horizontal thermal expansion <Futamura Chemical: FOR-AQ # 20>

(2) At 85°C, water-based ink dries at a speed of 80 m/min = 4 seconds on the actual machine. Print controllable range: Vertical and horizontal expansion and contraction is 0,296 or less, and tension of 950 g for 4 seconds is slightly limited in vertical direction. Pass if it exceeds 350g

(3) 75°C: Special OPP vertical thermal expansion <Toyobo P2171 20μ>

（３）７５℃の場合、実機で水性インクは速度３０ｍ／分＝１１秒で乾燥するので
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２９６以下は
耐熱性があるタイプなので１１秒の張力１，５００ｇでもタテ・ヨコ共に合格 (3) 75°C: Special OPP horizontal thermal expansion <Toyobo P2171 20μ >

(3) At 75°C, water-based ink dries at a speed of 30 m/min = 11 seconds on the actual machine, so the print controllable range: Vertical and horizontal expansion and contraction of 0.296 or less is a heat-resistant type, so it takes 11 seconds. Even with a tension of 1,500 g, both vertical and horizontal pass

(3) 80°C: Special OPP vertical thermal expansion <Toyobo P2171 20μ>

(3) 80°C: Special OPP horizontal thermal expansion <Toyobo P2171 20μ>

(3) At 80°C, water-based ink is dried at a speed of 80 m/min = 4 seconds on the actual machine, but the print controllable range: Vertical and horizontal expansion and contraction of 0.2% or less is a heat resistant type, so 4 seconds. Passed both vertically and horizontally even with a tension of 1,500g

(3) 85°C: Special OPP vertical thermal expansion <Toyobo P2171 20μ>

（３）８５℃の場合、実機で水性インクは速度８０ｍ／分＝４秒で乾燥する
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
耐熱性があるタイプなので４秒の張力１，５００ｇでもタテ・ヨコ共に合格 (3) 85°C: Special OPP horizontal thermal expansion <Toyobo P2171 20μ>

(3) At 85°C, water-based ink dries at a speed of 80 m/min = 4 seconds on the actual machine. Print controllable range: Vertical and horizontal expansion and contraction of 0.2% or less is a heat resistant type, so it takes 4 seconds. Even with a tension of 1,500 g, both vertical and horizontal pass

(4) 75 ° C: PET vertical thermal expansion <Toyobo E5100 12μ>

(4) 75°C: PET horizontal thermal expansion <Toyobo E5100 12μ>

(4) At 75°C, water-based ink dries at a speed of 30m/min = 11 seconds on the actual machine, so print controllable range: Vertical and horizontal expansion and contraction of 0.2% or less is a heat resistant type, so 11 seconds Passed both vertically and horizontally even with a tension of 1,500g

(4) 80 ° C: PET vertical thermal expansion <Toyobo E5100 12μ>

（４）８０℃の場合、実機で水性インクは速度８０ｍ／分＝４秒で乾燥限界だが
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
耐熱性があるタイプなので４秒の張力１，５００ｇでもタテ・ヨコ共に合格 (4) 80 ° C: PET horizontal thermal expansion <Toyobo E5100 12μ>

(4) At 80°C, water-based ink is dried at a speed of 80 m/min = 4 seconds on the actual machine, but the print controllable range: Vertical and horizontal expansion and contraction of 0.2% or less is a heat-resistant type, so 4 seconds. Passed both vertically and horizontally even with a tension of 1,500g

(4) 85 ° C: PET vertical thermal expansion <Toyobo E510012μ>

（４）８５℃の場合、実機で水性インクは速度８０ｍ／分＝４秒で乾燥する
印刷制御可能な範囲：タテ・ヨコの伸縮が０．２％以下は
耐熱性があるタイプなので４秒の張力１，５００ｇでもタテ・ヨコ共に合格 (4) 85 ° C: PET horizontal thermal expansion <Toyobo E510012μ>

(4) At 85°C, water-based ink dries at a speed of 80 m/min = 4 seconds on the actual machine. Print controllable range: Vertical and horizontal expansion and contraction of 0.2% or less is a heat resistant type, so it takes 4 seconds. Even with a tension of 1,500 g, both vertical and horizontal pass

FIG. 2 shows the outline of the prior invention by the inventor of the present application as described above. First, a pattern and/or characters 1 are printed on a film F using water-based inkjet ink, and then inkjet ink or UV ink is applied thereon. Alternatively, the transparent printing layer 2 is overprinted using EB ink.

F film 1 pattern and/or letter 2 transparent printing layer 10 ink head section 20 hot air drying path

Claims (4)

In water-based inkjet printing, the film to be printed passes through the ink head section and travels in a hot air drying path while being given a constant tension,
Depending on the attributes of the film to be printed and the coverage indicating the ink usage area,
print speed,
drying temperature,
tension,
is automatically calculated, and adjustments are made so that the film can stably run so that the film does not flutter or meander due to the hot air during drying and that the film does not shrink. 2. The water-based inkjet printing method according to claim 1, wherein the coverage is automatically calculated by calculating the drawing area from the printing image data and performing coverage analysis. In a water-based inkjet printing apparatus in which a film to be printed passes through an ink head section and travels in a hot air drying path while being given a constant tension,
By entering the coverage, which indicates the attributes of the film to be printed and the area of ink used,
print speed,
drying temperature,
tension,
A water-based inkjet printing device characterized by being equipped with a printing management system that automatically calculates the film so that it can stably run so that the film does not flutter or meander due to the hot air during drying, and it does not shrink. 4. A water-based inkjet printing apparatus according to claim 3, wherein the coverage is automatically calculated by calculating the drawing area from the printing image data and performing coverage analysis.

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