Analysis of the development and composition of inkjet technology
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I, History and development
Inkjet technology will soon become the most important scientific and technological means for graphic communication and industrial and technological materials distribution in the 21st century. As long as it is liquid ink or material, it uses air pressure, material and semiconductor electric field pressure, steam heat bubble pressure, etc. Distribute ink and materials on media or objects, high-speed printing efficiency of rotary printing machine, complex and diverse ink, material adaptability, plus the ability to face countless printed materials, and more than screen printing Developmental aspects. Some people have referred to DRUPA 08 as "DRUPA for inkjet". I believe that DRUPA 12 or later DRUPA, "Inkjet" will still be among the most valued printing and material distribution technologies.
"Inkjet" used the continuous inkjet method as the earliest, and still uses this technology, but it is used in larger and industrial production, and has nothing to do with most medium and small inkjet. The earliest in 1951, the German company Siemens patented, the principle of this type of cylinder-type pressure discharge ink, as early as the eighteenth century has been proposed, in the 1970s, most of the inkjet concentrated in the paper tube, wooden box Packing, random injection of the name, date of manufacture and box number, so you can not use the printing plate to print, can only be written by hand, and the inkjet dot word provides the convenience of automatic production line spraying. The earliest inkjet was 16dpi, which means that each ink droplet has a size of 1.5mm, and only 6-7 drops of ink per centimeter. It can't be compared with today's tiny 2pl (Picoliter, 1 trillionth of a centimeter). It can spray about 826 drops of 16dpi ink. Today, one liter of ink can spray 500 billion drops of ink, and the difference between the two exceeds 600 million times. And it is also a continuous nozzle. In the past, it was only able to spray hundreds of drops of ink per second. Today, it is as high as 160,000 drops of ink per second. Previously, only monochrome printing, in addition to color four-color printing, plus LC, LM , light blue, light red ink, RGB secondary color ink, neutral color LK and LLK light gray, light gray and other ink colors, white ink, glazing ink, fully meet the performance of most color gamut, there are also bottoming processing plus More diversified performances such as metallic color and pearl ink. Inkjet is used in paper media, plastic cloth, plastic film, acrylic, glass, ceramics, wood, stone, leather, cloth, and very extensive media, industrial labeling and industrial material distribution, in electronics, optoelectronics, In the semiconductor manufacturing process, inkjet also has room to play. If the ink-jet metal is stacked, it can be used as a 3D metal product such as a tool or a screw. Some people have envisaged that this kind of inkjet manufacturing work is necessary in the future space workstation. In the case of parts that are lacking in space maintenance, the metal inkjet manufacturing machine can be used to spray the 3D model image command nozzle onto the stack. Tool manufacturing. In the printing process, the development speed of inkjet printing, as well as the breadth of application and print quality, have far exceeded electronic imaging toner and electronic ink printing. One day, inkjet not only surpasses electronic imaging printing, but also is more traditional. In the case of plate printing, it is the most important scientific and technological method. Because inkjet is extremely useful in terms of size, it is widely used in the application of media. As long as the fluid can be sprayed by piezoelectric nozzles, including Metals and conductive materials are very easy to be industrially produced. To biotechnology applications, inkjet has a great space for development, printing and unlimited applications.
2, the four main components of inkjet technology
For the people in the printing industry, the printing plates have four major layouts: flat, convex, concave, and net, but they are all arranged by the printing lines to make the ink distribution range to the shade. The printing plate can also be slightly printed. The ink is changed and adjusted, but most of the printing results have been fixed in principle. Inkjet printing is not the case, inkjet printing nozzles should not be sprayed, or even the size of the ink droplets ejected, after the first drop of spray, do the next drop of ink to spray or spray the size of the ink droplets. There is a big difference between the way and the printing, and everyone's understanding of inkjet is also very fragmentary. There is no systematic information. The following are the four main components of the inkjet device and its role.
The main components of the inkjet system are: (1) inkjet head, (2) X and Y axis drive mechanism for driving the nozzle or media displacement and precise positioning, (3) inkjet ink and sprayed media, (4) Servo and interpret the RIP electronic mechanism of the spray page file, and perform precise displacement mechanism for the ink jet head, ink supply and command drive X-axis and Y-axis to match the movement of the inkjet head (some use a lot of nozzles to form the cross-media Material banner, there is no need for X-axis drive, only the mechanism of Y-axis displacement). Therefore, with the close cooperation of these four ink-jet components, accurate and beautiful inkjet products can be printed.
3, the classification and principle of inkjet head
The ink jet heads can be divided into three major categories, the principle of which is also related to the position of the ink droplets of the spray cloth. The earliest development of continuous inkjet heads is complicated in principle and construction, and the spray stroke is longer than the other two. The inkjet method and DOD (Drop On Demand ink) made by the continuous inkjet head There are two biggest differences between inkjet and inkjet. Continuous inkjet uses high-speed pump or compressed air. One nozzle continuously ejects tens of thousands to fifteen to sixty thousand drops of ink per second, which can cover the entire printing surface, so these inks The droplets must be charged, and only water-based inks or environmentally-friendly water-based inks with a little alcohol can be used. Then these full-speed jets of charged droplets must pass through the magnetic field, and the ink droplets in the non-printed portion cannot naturally Sprayed onto the paper surface or the surface of the medium, so the magnetic field deflects these non-printed ink droplets into the ink droplet recovery tank, and then recycles and filters. If the ink droplets are printed, the magnetic field is biased or straight forwarded by the spray position, and the ink is sprayed in accordance with the traveling direction of the medium or the moving direction of the carton or the wooden box. The ink must be charged, whether it is printed or not printed. The ink droplets are sprayed 100%, and then the choice and distribution of the magnetic field is its characteristic. Therefore, the ink droplets must be kept the same size. The flight of the ink droplets has a magnetic pole and a biased flying space, just like the old CRT cathode ray. The screen is also an image of the electron beam distributed by the magnetic pole. The reason why the long glass tube is used for the ray deflection is the same. The continuous inkjet nozzle is generally above 150mm, and the thermal bubble type and the piezoelectric type have 15 Compared with the height of ~20mm, there is a great demand for installation space. Continuous inkjet must use water-based and chargeable ink, and the ink droplets sprayed can only be fixed in size and cannot be changed in size. Otherwise, the magnetic field is biased. There are quite a few changes in the weight of the ink drop. The larger advantage is the nozzle, because as long as the power is turned on, there will be ink ejected, and the DOD will be sprayed and stopped when needed. Ink droplets can easily clog the nozzle. Today's continuous inkjet heads are only used in a large number of black and white sprays, and the color is low resolution of about 600pdi. Some of them are only continuous inkjet heads, which are used in printing machines, processing equipment or packaging production. Continuous inkjet heads are very expensive and are generally used by less users. (Domino, Kodak is a continuous inkjet head representative manufacturer)
The thermal bubble type inkjet has two technologies: Thermal Jet or Bubble Jet. The basic principle is the same. The Chinese translation uses the term hot bubble inkjet to express both heat and bubble. Come out, as the name suggests, the hot bubble type inkjet head uses heat to instantly heat the ink in the inkjet chamber to above the boiling point, so that the water in the ink absorbs enough oxidation heat, and instantly expands into the kinetic energy of the water vapor to push, near the nozzle. The ink is ejected from the inkjet hole and directed onto the surface of the imprinted body, so heating generates vapor bubbles to eject the ink, cools the ink into the ink, and reheats. An inkjet head is like a two-stroke engine that has been performing burst-intake-exhaust compression. The action is just that the engine generates kinetic energy by the explosion. On the contrary, the inkjet head generates the ink droplet by the heat energy. It is easy to manufacture the thermal bubble type inkjet head, but it is also very precise, because the arrangement is very tight, and the heating components are very Accurate and fast response, capable of ejecting 10,000 or more 10,000 drops per second to meet the demand, is a very high frequency of heating-inkjet-cooling and ink feeding cycles. This is a very frequent heating and cooling process. The hot bubble inkjet head requires a relatively high proportion of moisture, and a lower proportion of pigments and mordants appear to be hot gas powered thermal bubble inkjet systems. Fatality. Other problems are also a tough problem with thermal bubbler systems.
(1) It is feared that the air-burning damage without ink cooling is a result of the loss of ink cooling if the nozzle is heated to 350-400 °C.
(2) The ink produces a solidified material that adheres to the heater and blocks the kinetic energy of the heating part of the heater, so that the steam thermal bubble machine can be lowered, which also affects the kinetic energy of the nozzle.
(3) The thermal bubble type inkjet head has no constant heating of the ink and the inkjet head at an early stage, so the room temperature is excessively large at a temperature of 100 ° C in a working environment of 0 ° C or 35 ° C. Therefore, the ink droplets are small, and 35?C is closer to 100?C, the kinetic energy of the vapor is easier, and the ink droplet formation is larger, so the inkjet quality cannot be stabilized. For this reason, the thermal bubble type inkjet head is mostly heated. To ensure that the incoming ink and the operating temperature of the inkjet head have a stable environment.
(4) The thermal bubble type inkjet head generally has a short working life, and in the early 1990s, the inkjet head was replaced with the ink changer.
(5) Only water-based inkjets with a high percentage of moisture can be used. Other non-aqueous inks, even environmentally friendly solvent-based inkjets containing IPA alcohols, can cause inkjet instability and fire hazard. Easy to manufacture and low cost, it is a considerable advantage of the thermal bubble type inkjet head. (Canon, HP is the representative manufacturer of thermal bubble inkjet)
The piezoelectric inkjet head uses the inkjet chamber as a jetting cylinder, and uses the pulse current of the motor and the electron to generate the hydraulic pressure in the contraction volume of the inkjet chamber, and the ink on the nozzle side is ejected from the nozzle, and the external pressure is early. The ink chamber behind the nozzle is contracted to generate ink under pressure, and as in the early days, Epson also used the power of the mechanical motor to generate ink. Later, there were also researches on glass tubes and rear motor power for inkjet. There are piezoelectric inkjet heads of the X 22r team led by the University of Cambridge in the UK. Domino is also a Cambridge system inkjet. They have continuous CIJ and thermal bubble. Three types of inkjet heads, BIJ and piezoelectric PIJ. Epson, led by the team led by President Yoshii, invented the piezoelectric Piezo inkjet method with voltage kinetic energy, and today uses semiconductor chips to manufacture piezoelectric components for inkjet heads. The technology of EP Pie's Micro Piezo Using a thin film TFT (Thin Film Technology) vibration technology to compress the kinetic energy of inkjet droplets generated by the inkjet chamber, so today's inkjet technology can be smaller and more refined, resulting in very fine ink droplets. The images and lines, on the other hand, Micro Piezo or other related semiconductor technology have also greatly improved the inkjet speed under the micro-needle point spray, and have enough inkjet speed.
Piezopie Piezo technology has the following effects:
(1) It can be sprayed according to almost all fluids (not too viscous), including water, solvent, environmentally friendly solvent, UV ink and Latex latex ink. In fact, industrial materials such as LCD color filters and conductive Silver ink, electronic circuit production materials spray, biotechnology, medical detection tools manufacturing, inkjet is no longer just related to printing, painted posters. If the food coloring is also feasible on cakes and muffins, that is, the largest amount of material sprayed.
(2) Piezoelectric inkjet heads have high stability and are extremely durable, and the output is still very stable under long-term use.
(3) The ink droplets of the piezoelectric inkjet head are large and small, and the current chord angle acting on the semiconductor can be utilized. The maximum and minimum ink droplets are about six times to eight times, so that it can be used in a single pass. For example, a small ink dot of 4 pl (1 liter of 1 liter) is in the light portion, and a large ink dot of 28 pl can be sprayed in the dark portion, but continuous inkjet is used in the dark portion to satisfy the color saturation. Slow multi-spray is enough, and the light part is too big to express the appropriate light level. The variable ink point of the piezoelectric inkjet head not only improves the print quality and speed, but also saves some ink in reasonable. The distribution of ink droplet size.
(4) Piezoelectric inkjet heads are now composed of tens of thousands of nozzle arrays, making one-time printing of banners of 520mm, 740mm or larger spans, as long as the media is shifted by Y-axis and the horizontal X-axis is used once. More than 10,000 nozzles for high resolution printing.
Therefore, the future costly Piezo piezoelectric inkjet head will continue to develop and is the most popular inkjet method.
4. X-axis and Y-axis drive mechanism for inkjet distribution
There are two kinds of situations in which the inkjet head can complete the printing job without moving. One is the number, the batch number, and the product name indicated on the wire. The inkjet head must have at least 38mm wide, and the wire moves forward. All the markings can be sprayed on it. The other is that although the printing medium is 300mm, 500mm or wider, but looking for a single-color, four-color nozzle with sufficient resolution, thousands to 10,000 nozzles per color, the same paper or media only accurate movement The Y-axis and the horizontal X-axis can swipe the entire printing frame at a time without moving. The inkjet head may wait there, waiting for the paper, and the printing medium passes through the array nozzle to make a one-time full-width high-speed jet. In addition to the large number of nozzles and high cost, the ratio of nozzle blocking will be greatly increased, because the DOD is sprayed on the ink droplets. If the ink is not ejected for several minutes to more than ten minutes, the nozzle will be sprayed with ink dry. No ink is produced, because there are blank edges or small size areas on the printing surface, which will cause blockage due to long-term non-spraying. On the other hand, the X-axis has to move the inkjet head to the left and right. It is almost impossible to find a nozzle that does not eject ink within one minute. In addition, tens of thousands of nozzle arrays have a large increase in the number of nozzle failures, and it is also difficult to replace. repair.
(1) The platform type sprayer must have the X-axis and Y-axis slide rails, the digital drive group and the optical scale positioning device. One is that the X-axis is sprayed to the left, and the Y-axis is stepped to move forward to make the ink. Heads go forward, while others require two, four to eight repeated wide shots to increase the resolution and ink density of the spray. Some inkjets are X-axis nozzles that only perform reciprocating movements on the left and right. The Y-axis is a precise displacement of the printing table on which the printing medium is placed to match the wide-format requirements of the X-axis movement. There are only a handful of high-speed machines like Inca in the UK. The X-axis nozzles are stopped and stepped again and again. In turn, the printing table of the medium is fixed and the medium is fixed on the Y-axis for high-speed displacement. The required power and high-speed movement are required. The weight of the printing table can be said to be hundreds of times more than the ink head frame, but there are also manufacturers who do this design.
(2) The drum type Y-axis drives the medium, and the nozzle performs the X-axis reciprocating spray. Most of the methods used in the roll-to-roll thin medium are the standard mode of most inkjet machines. When the X axis of the nozzle moves once, the Y-axis roller drives the medium to move forward to the opposite direction. If the drum has a precise movement, but the thickness of the medium varies with the thickness of the Y-axis, although the printing overlay accuracy is not affected, the thickness of the Y-axis printed by the thick material is longer than the thin-film printing size. The thickness of the roller formed by the thick material is relatively thick, resulting in a faster and longer moving distance, so the size of the printed image will be longer in the Y axis. However, some of these machines use a platform-type thick medium. If there is a platform to support the thick medium before and after, there is no relationship with the circumference of the driving roller, and there is no longer lengthening. In this Y-axis roller drive mode, the X-axis slide rail, digital drive and positioning are exactly the same as the first platform type, while the Y-axis drive is controlled by rotary digital stepping, using servo motor positioning and driving. After the Y-axis roller is placed once in the X-axis nozzle, the appropriate angle rotation step is taken to move the medium to be printed, basically the medium is 0.05mm~1.0mm, and the driving length of the thick medium will change. Longer. Y-axis drum type drive mode, if the drive roller and the back of the media slide, it will also affect the print length and become shorter.
(3) High-speed roll-to-roll spray, most printing papers or media have digitally controlled drive rollers, do multi-point paper or media Y-axis high-speed advancement, array nozzle spray imaging, and necessary When the sleeve is installed with the sleeve type control, since the inkjet does not have a lot of heat or the printing pressure, there is less deformation in this aspect, but the water-based inkjet has a wide width for the paper and the surface fiber absorbs and stretches. Quite affected, coupled with hot air drying, the paper will have a shrinking effect when it is released from water, but the plastic and synthetic paper materials will have elongation and elongation when exposed to heat, and the effect is different. Few machines can be like the Fujifilm Jet Press 720 machine nozzle. It is a one-color, one-color, cross-printing surface that can be printed in one straight line. There is no staggered spray time difference between the nozzles. Otherwise, when the width of the nozzle is 4 inches (101.6mm) per set, if the width of 500mm is printed, it is necessary to use five sets of inkjet heads, and the three front and the back are printed in five. If you want to spray a long parallel line along the edge of the paper, Jet Press 720's always-discharged nozzles, as long as all the sprays are good, and the three front and rear nozzles, the former will first spray the latter to make a horizontal Line, which also involves the distance between the front and rear inkjet heads and the speed of paper travel, using electronic control to do precise inkjet timing control, but also must gradually slow down due to the conditions of paper acceleration and deceleration, in simple terms, When the speed of the front surface is printed to the back and the printing surface is printed, the speed of the paper has increased a lot. Therefore, the timing changes in the size and the imaging of the ink droplets must be adjusted on the instructions of the file to the print head. On the surface, it seems to be rotating and spraying, but the changes in it are very complicated and varied. The most special place of the Epson Sure Press 4033A trademark inkjet printer is that it looks like a roll-to-roll material and a material on the surface, but the middle spray is a 300m×917mm large suction cup platform. Moving, consisting of 15 front and rear staggered nozzle groups, reciprocating and reciprocating long strips, one after another into a 300mm wide print, the paper surface label paper is 720mm × 720dpi, the plastic surface is printed at 720mm × 1440dpi, I believe Epson's design considers the accuracy of printing, but it also sacrifices print speed and print continuity, which makes it impossible to print textiles. The Surep 4033A basically has a roll-to-roll appearance, but the printing method should be classified as the first platform-based XY-axis imaging.
(4) The drum type spraying method is very special among ink jet printers. Among the Turbo Jet large-size inkjet machines belonging to the Scitex Version Printing department, there is a principle of CTF and CTP. The outer cylinder of the extremely large size is used to adsorb the printing medium, and the high-speed rotation of the drum is used to form the Y-axis inkjet image. The nozzle is made to move around the X-axis to form a precise image on the outer drum. The circumference of the drum exceeds 3.2 meters and the width is 1.8 meters. This prints less than one minute, including the upper and lower paper media. More than 50 large posters per hour can be seen, showing the high technology of Turbo Jet. Because the drum must stop when changing paper, so from the high-speed printing to stop rotating to replace the paper, and then accelerate to the drum to recognize the synchronous speed to spray, this nearly 2.5-ton roller does not only have a synchronous digital control servo drive motor, Parking should also have a more advanced butterfly brake than the car to quickly stop. If you think of it as a 2.5-ton car, the mechanism of braking immediately after the speed of 20 kilometers is less than one minute, now Turbo Jet UV-curable inks have been changed from water-based inks, and they have been sprayed and solidified. Now, UV glazing and UV repulsion have been performed to re-glaze.
If you want to talk about the driving of inkjet media, Fujifilm Turbo Jet 720 uses the most official lithographic printing machine's Feida, gauge, pre-painting, the printing cylinder with the claws, the rear section has the drying and image quality control. It is the delivery table. Here, the JP 720 prints a 740mm wide printhead, and it has a bite jaw and an adsorption device on the large-size drum. It is very close to the platform type, and four sets of online nozzles are sprayed before and after. Maintain better printing results than the platform type X-axis Y-axis drive spray, but the cost of the machine is comparable to that of the same size four-color flat print. It can print 2,700 sheets of 750×540mm size per hour, which is about flat. The printer's 16% speed, but can print different content per print.
5. Printing media and ink for inkjet
Inkjet ink must take into account the role of the nozzle and the media, even to the back of the light, water, ozone resistance to the high temperature of the IMD mold decoration, otherwise it may be defeated, and the inkjet ink and media are also not Jiaomeng Meng, Meng Without defocusing, the most relevant issues in the field of inkjet are chemical and media suitability issues, so the two must be combined.
Inkjet inks are basically based on colorants, including dye-based pigments and pigments. In addition to color, there are non-pigment materials such as white ink and metallic ink, plus some glazing and fogging to the underpass bridge. Adhesives, etc., but we only think that coloring is not acceptable, because only the coloring material can not be basically ejected by the nozzle, but there must be some mordant, not only as the liquid flowing in the ink, like the water in the hot bubble type. It is also a source of power for generating vapor propellant inks, and most liquids also serve as a source of cohesion for inkjet jets ejected from nozzles to the surface of the media, which converge in flight to form circular or teardrop-type ink droplets. Once the liquid reaches the surface of the medium, it must be removed by various means to remove the liquid to form an ink layer that does not flow and adhere, and an inkjet print is formed on the surface of the medium.
The liquid can be sprayed on the surface of the medium to form a solidified ink layer, as the printing ink is also absorbed by (1). (2) Evaporation. (3) Three ways of chemical overlap, so the curing of inkjet ink is also closely related to the surface properties of the media, especially absorption and drying, using the fibers of the paper or the pores of the coating, the water in the inkjet, high boiling point The mordant of petrochemical oil is absorbed into the paper structure, so that the ink is quickly thickened and solidified by oxygen or polymer mordant itself. In the early use of water-based inks, inkjet on smooth PET plastic sheets could not produce dry adhesion. Therefore, it is necessary to coat the PET surface with a layer of colloidal structure that produces transparent porous materials. The moisture or solvent, as well as the adsorption effect of fixed inkjet, this is also the focus of this section to emphasize the need for ink and media to have better inkjet drying and adsorption. In addition to fluid water and solvent, the resin mordant also plays the role of solidifying and coagulating concrete, sand, and stone like cement. If the resin of the mordant is not or insufficient, there is no solidified condensed color. Some of the shortcomings of inkjet early appeared immediately, that is, the water-based inkjet that is generally criticized will be printed, and the ink will be sprayed on the front side and the ink will be seen immediately on the back side. This is also a poor match between the inkjet ink and the paper material. The capillary phenomenon is too strong, and the ink is not condensed. On paper or close to the paper. Such inks are often accompanied by very easy to get wet or after water, the ink is immediately smudged or not water resistant. If we use cement paint to paint the wall surface, we can use water to adjust the viscous fluidity of the cement paint before the cement paint is painted. However, when the cement paint is dried and solidified after being painted on the wallboard, the resin is cured and combined to become insoluble. The water film layer, such as water to wipe the film layer will not fall, such a resin combined with the curing effect, in aqueous inkjet also has such characteristics, otherwise the mordant does not combine curing, then water after inkjet After evaporation, the dyes and pigments form prints on the spray surface, but they are like sand sculptures made on the sea stalls. Although there are prints and folds, there is no ability to defend against water. Once the sand sculptures or prints are washed away, Disintegration, blur, this inkjet is commonplace more than a decade ago, but today it is rare to see such an ink that does not meet the demand, this is not related to the sprayed media, but the ink itself can not be solidified after spraying And waterproof defects.
In the development of outdoor, large posters, the use of canvas, plastic PVC or other PE plastic film large size spray, often with 240dpi, 360dpi coarse inkjet, using the solvent in the ink or the rapid evaporation of alcoholic alcohol, The effect of rapid solidification of the ink is achieved, and the organic solvent not only evaporates quickly, but also slightly dissolves the surface of the plastic material, so that the solidified ink layer is not only attached to the plastic surface, but also has a melting bonding force on the surface of the plastic material. However, solvent-based VOCs contain petroleum-based solvents with too much fragrant agent, which cause great pollution to the working environment of the spray, and even the finished products will have vaporized VOCs for a long time. It is not suitable for indoor use, otherwise it will always be discharged to the human body. Harmful gas, so the new generation of outdoor and indoor large posters, the same use of volatile solvents, rather than petroleum-based aromatic solvents, is close to alcohol, petrochemicals such as alcohol, such as isopropanone, as a spray fluid And the evaporation and drying of the solvent after printing, of course, the curing effect of the solvent is not as fast as the aromatic solvent and high adhesion, but the environmental pollution is only one tenth of the aromatic solvent.
Using UV or LED UV-curable inkjet, this inkjet will not solidify for a long time under normal temperature and no ultraviolet light environment, and this UV ink composition is a mordant mainly composed of optically sensitive resin. The sensitizer and the photosensitive starter will produce a molecular bridging combination of the photosensitive polymer resin under UV ultraviolet light irradiation, which is completed in less than one second or less, because of the action of photochemistry, the inkjet Curing adhesion occurs immediately on the surface of the media. After UV, there is LED UV inkjet. At present, it replaces traditional UV ink in many places, becoming the mainstream of this photographic chemistry. The wavelength of LED UV is concentrated in 365~405mm LED, and the wavelength is singular, unlike UV. The lamp is made of 300-400mm ultraviolet light and 400-700mm visible light, even 50% 700mm or more IR infrared light, so only 28~30% of the output of the UV usable light spectrum, plus a large amount of IR infrared heat energy Removal, and the UVC part of 300-320mm will make O2 in the air become O3. Ozone is intrusive to the environment, and it is very harmful to human eyes and skin. The life of the lamp is 1,000-1,500 hours, and its energy declines. quickly. LED UV can last up to 10,000 hours of life, without preheating, so the real life is more than one time, without too much cooling, do not worry about ozone. It is also lighter and easier to install near the inkjet head or at both ends of the mobile nozzle. The only thing that LED UV should pay attention to is that its "near violet spectrum" has weak light energy and the LED UV light output has a low wattage. Therefore, it is necessary to use LED UV ink with high optical sensitivity, and the spectrum of the photosensitive light should also be Re-improvement, the ultraviolet light UVA (near violet), UVB (medium ultraviolet light) and UVC (strong ultraviolet light) can be sensitive to the sensitization of the three-spectrum sensitization. The function characteristics are sensitive to the characteristics of the LED UV light-emitting spectrum. Otherwise, some people take the original UV inkjet to spray, and use LED UV to illuminate, but the curing effect is 15-20%. The reason is that the LED UV is too narrow. Can only produce a very limited curing effect. This is also the reason why LED UV lamps can only be cured with exclusive LED UV inkjet. In addition to solvent and environmentally friendly solvent inkjet, UV and LED UV are also the main spray and curing combination of plastic inkjet. The new generation of Latex latex inkjet, although developed in the past two years, is a new type of multi-purpose inkjet. Latex is also dissolved in aqueous emulsion, but its properties are more like the early melted wax. Inkjet, has good adhesion to most media. If the candle oil is dissolved in the surface of the glass that many materials cannot adhere to, the wax droplets under cold solidity have good adhesion, and the latex inkjet is The moisture in the emulsion is heated and evaporated at a temperature of 60 to 80 ° C. The latex adheres the pigment to the surface of the substrate to be printed, which is also a new type of inkjet that replaces solvent or UV, LED UV inkjet.
There are also many ways to improve the adhesion of inkjet printing surfaces. For example, plastic surfaces are added with some plasticizers during molding. Plasticizers produce some plastic surface properties with low dyne values during the manufacture of plastics. It is difficult to attach, like some self-adhesive label paper, the back paper is coated with a silicon coating layer, which can make the self-adhesive trademark back and this silicon coated release paper easy to tear, and the plasticizer also acts like The effect, so whether it is necessary to remove this low cause value regardless of inkjet or UV printing, all of which have a plastic surface layer of plasticizer, so use a direct flame spray to burn the plastic surface to remove the plasticized rubber to maintain the plastic surface adhesion. . In addition, the high-voltage discharge Corona's arc action causes the plastic surface to produce roughness or raise the surface cause value, which is a treatment method, but one month after the surface treatment, the plasticizer will return to the plastic surface layer, so that the treated The surface of the plastic is poorly affected by ink, so some people use Permer, which is a base layer. This method is not only effective but also long-lasting. Mimaki's inkjet machine can now be used on the inkjet machine. The scope is bottomed out. These methods are different from the ink-based anti-smudge layer coating of the aqueous ink, because the water-based ink and the medium have a part that is afraid of the surface capillary pores to absorb too much anti-blocking, so that the ink is attached to the coating layer. Make up the ink. In addition to the transparent primer coating, many transparent and metal materials must also have a white ink base. As a shielding layer that requires the appearance of ink color, today, the shielding rate is extremely high and there is a very fine white powder granular titanium dioxide. Forming an easy-to-use primer pattern, usually cured with UV, but Epson has an SP 7900W inkjet machine that can be used as an aqueous inkjet for plastic film surfaces. Basically, these materials are coated with a primer. Have better adhesion. Today, inkjet is also required to be improved into direct printing of general printing paper, which can save a lot of trouble, that is, it is not necessary to use special surface treated coated paper when proofing, for coated paper, light coated paper, non-coated Unprocessed paper such as cloth paper, printing paper, cardboard, copper stencil, corrugated paper, etc., directly sprayed with an inkjet machine, which can be very close to the printed product after proofing, which is very beneficial in the communication of proofing and printing finished products. Even a few or ten sample books can be directly printed and produced without the need for plate making and printing on the machine. In particular, the possibility of not applying two-sided inkjet printing is also increased. It is not necessary for today's Fuji Film Company's Jet. Press 720 still needs to do paper processing before inkjet printing generally coating paper. It is believed that water-based inkjet will gradually move toward this research and development direction, not only proofing and finished products are consistent, but also the types of papers that can be selected are very wide. .
As for dyes and pigments for inkjet, dyes are the most important color materials in the 1980s and 1990s. Because the price of dyes is suitable and the particle size is 2 to 3 nm, the aperture of any inkjet device can be very smooth. Squirting. However, the biggest disadvantage of dyes is that they are not durable and are easily faded by the action of ultraviolet light. Moreover, the color gamut of dyes is relatively wide, and it is easier to smudge than pigments. Therefore, after 2000, the particle size of the new generation of nano-synthetic pigments is not as small as that of dyes, but the particle size maintained at 50-100 nm is also easy to flow out in the nozzle if the nozzle aperture is 10 nm ( 0.01mm) is also a hundred times of 100nm without blocking concerns, and the color gamut of the pigment is also expanded under nanocrystallization. Although not as wide as the dye, it is also very easy to reconcile the mordant spray. In the early 1990s, the diameter of the nozzle was probably 20 to 30 mm. At the time, the particle size of the coarse-grained synthetic material was 3 to 4 mm, and some of it was about 8 to 10 mm, so the nozzle was subjected to some unusual coarse particles. As long as two or three pigments are stuck in the ink chamber to the nozzle hole, a blocking condition may occur. At the time, some researchers tried to use the bead milling method to grind the existing coarse pigments to the nanometer size, and claimed that the average particle size is close to the nanometer (100 nm), but it takes time and labor, the most important The average value is close to nanometer, but some coarse particles that are not ground will be three or five times larger, which will result in poor blocking of the ink nozzle when used in inkjet. Today, because of the popularity of synthetic nano-pigment, it is very suitable for inkjet, and with the improvement of some mordant resins, in the description of the inkjet manufacturer, each pigment is like a pearl of pearl milk tea. The transparent resin with pigment as the core, and after the inkjet, forms a smooth transparent resin sealing layer on the printing surface to prevent the contact between the pigment and the air, and it can be more durable and does not fade. At the same time, it can also slightly delay the irradiation of ultraviolet rays, and extend the finished product of the sprayed products to be light-resistant and weather-resistant for more than 50 years (not direct sunlight).
In addition to pigments, everyone is also thinking about spraying gold ink and silver ink. This problem also involves gold powder (copper powder-based, real gold powder is too expensive for only a few occasions can be used). The spray of silver powder (calcium powder) and pearl powder. At present, Roland DG Lelan inkjet has metal powder inkjet, which forms a silver spray and yellow, which can replace gold powder, or add other colors to form metal ink. Spraying, but the color can't flash brightly, and there is still a big gap in expectation. Inkjet is also spray-coated, and it is also useful to reject ink and UV glazing to form a localized bright and hairy matte effect. Some of these inkjets are also chasing some surface finishes, so there is a lot of material support.
6. Operation of control and servo interpretation software
The title of "Control and Servo Interpretation Software" is not easy to understand. The difference between the two softwares is exactly where, if we change the role of inkjet, think of the inkjet machine as a color knitting machine. There must be a lot of colored silk yarns. In the past, we had to manually control the warp and weft yarns to show the color image we need. Now the control program formed by the screen is no longer the memory of the operator, nor is it Using a lot of holes in the hole machine, the pulling control line is used to make the moving image of the warp and weft yarns, but the moving warp and weft yarns are controlled by the computer's map, so the system for controlling the warp and weft shifting up and down, and the command control are controlled. The system, like the inkjet control system of the inkjet machine, must separate the nozzles according to how many nozzles the inkjet head can separate, respectively, to remove four or six colors or more to eleven or two colors, each orifice The distance dpi number and the completed dpi number are sprayed once or multiple times to complete the required resolution, and more related to the ink droplets of some inkjet heads, the ink droplets from large to small are divided into fourth order, Order instruction, as a control pulse current suitable droplet formation. The sensing speed and position of the inkjet head, the response and the return of the stroke, and the spray instructions are naturally the elements of the inkjet quality relationship. With a Piezo piezoelectric inkjet head, it has to spray more than 20,000 ink drops per second, and more than 10,000 nozzles to more than 50,000 arrays of inkjet nozzles, reaching one billion instructions per second. The nozzles in different positions are appropriately sprayed with ink droplets of different colors and different orientations in the range of 600 to 2880 dpi. In addition to the computer, the calculation of the gap of many fixed positions, as well as the X-axis, Y-axis moving position, and even the perception of the Z-axis three-dimensional object spray in the future, are all good image quality.
If there is no computer with high-speed calculation ability, and the relative position of the inkjet head and the medium can be measured very accurately, the plane spray is absolutely non-relative, and the ink head is moved by the X-axis. Moving in the Y-axis is the relative position. If the Y-axis is moving in a platform type, the accuracy of the fine guide and the measuring position electronic scale, and the real-time return movement becomes very important. If the Y-axis is a tool for driving the medium with the drive shaft or the printing rotary drum, then the rotation angle of the drive shaft or the printing rotary drum, and the return work caused by the relative movement of the medium are very important, these mechanical and high precision The movement of the motor and the determination of the position are all within the control range of the inkjet machine. In the inkjet head of the inkjet machine, the spray command is to accept and execute the map to be printed, and the partial and partial instructions are formed to piece together the large surface of the whole surface. This instruction is only the execution of the loyalty of the person, and all the preparations of the inkjet machine do not have a little autonomy. Instead, they follow the "servo interpreter" and the "map file" handed down. At the most, the inkjet machine with Lc light blue and Lm light red is added. How to transfer the part of the CMYK four-color map from the blue ink and red ink to make Lc, Lm The shallow ink spray fills the subtle and thick layers of the light part, and allows the low-resolution inkjet to have a light color to complement the light part size. Some divide black into black and gray Lk, or even completely change to neutral color replacement, with K black, Lk gray, Llk light gray as the gray component of the main body of the picture and the suppressed color, all CMY and Lc, Lm, and even Adding RGB three colors is only in the color of the colored place, and does not participate in the neutral and suppressed colors of the ink. This kind of color-coded spray method using K3 neutral color, its dominance is in the back-end spray machine itself, not on the front-end servo interpreter, this is just like the side dish of the restaurant, today the food has fish as to how to cook The chef decides, but if the chef wants the braised fish, the chef can't change, so many small systems need to change the output file, while the big system is that the previous Rip understands the full status and characteristics of the inkjet. The six-color or CMYK+RGB spray can be interpreted without changing to the inkjet control system. The K3 neutral color rendering method can reduce the difference of the color of the spray line, save the inkjet, and also reduce the metamerism phenomenon of the sprayed picture under different light sources, because the neutral color is the main color tone. Under different spectral light sources, it can still maintain black and gray, and does not produce different color sensations under the light source with different spectrums. Therefore, the software of the inkjet machine outside the hardware is also improved a lot. And an ICC Profile (ICC characteristic curve) adjustment using the Lab gamut space to control the color reproduction of the inkjet machine is like the speed and direction of the aircraft when flying, but the airflow is smooth, windy, crosswind, It will change the heading and height of the aircraft, so the ICC Profile not only compensates for the changes in the ink head and ink, but also the color, ink receptivity and color rendering of the different media surfaces, resulting in comprehensive color effects and changes, and the ICC Profile is also Do this work. Therefore, each nozzle of the nozzle not only accepts the jetting machine to change the printing file into the dot matrix of each color of the inkjet machine, but also receives the characteristic instruction of the color deviation trimming of the ICC Profile, so the process is also complicated.
The front-end servo interpreting software is like the pre-press part of the previous printing process. It must have the ability to download and download the web page. When processing the page file to be printed, store it, use a reasonable editing file software to interpret the page. Use RIP to interpret each color dot matrix file. If it is a general inkjet machine, give RGB file or CMYK file. As for inkjet, how to change the three-color and four-color dot matrix files into six colors or more that you want to output. The color dot matrix is self-care by the ink jet machine as described above. Conversely, this server is only used by a high-end inkjet machine, so the role of RIP interpretation depends on the inkjet machine's several colors of spray arrangement to interpret, inkjet inkjet head According to the "bit map" sent by the interpreter, it is not necessary to change it to a new spray file suitable for the inkjet machine. These files are smaller than the 2400dpi lithograph, but the print size is larger. If the color number of each color spray is large, and if the inkjet head has 4th order and 8th order, the whole file size is much larger, so the server also needs a considerable capacity and capacity.
7, the comprehensive conclusion
Inkjet technology combines an "inkjet head" that ejects ink droplets at a high-speed pressure. Some people say that it is necessary to maintain extremely high-efficiency jets, and the pressure on the inkjet head is also large, and "inkjet ink" The diversity, the spray and the drying suitability, and the suitability of the use must be well matched with the nozzle and the medium. It is a chemical test and is advancing with the times. The X-axis and Y-axis mechanisms that drive the nozzles, with today's digital control technology, plus precision rails and display reward mechanisms, are the least problematic parts that are easy to match. The functions of the control and servo interpreter are now gradually developing perfectly. But one day if it is changed to 3D spray manufacturing, the entire RIP interpretation is naturally different, and the spray ink will also be changed into conductive material. The insulating material tool is used to make metal liquid to biomedical technology, but the possibility is developing. In the future, the printable area of "Print abe" will definitely go beyond the scope of screen printing because of the diversified application of inkjet technology.