Focused Inkjet Printing Technology (I)

(I. Introduction

The annual “Advertising 4 New Exhibition” held on May 9, 2006 was held at the Beijing International Exhibition Center as scheduled. In the same period, the Ink Jet Printing Branch of the China Printing and Equipment Industry Association and the First Member Congress were grandly held. The founding conference. The establishment of the Da Yin Association Inkjet Branch indicates that the ink-jet printing industry has reached a stage where it is ripe for development. In recent years, the ink-jet printing industry in China represented by inkjet photo materials has integrated the technical basis of IT printing and inkjet printing. , which has achieved rapid development, but also indicates the arrival of the era of rapid development of inkjet printing!

(II) Development history of ink jet printing

The history of ink-jet printing can be traced back to 1884. The American C.H. Richard put water in the syringe and the droplets from the end of the squeezing needle flew out of the droplets. This was inspired. If the liquid was taken out of the jet, it was electrically controlled. Its placement, you can form a portrait on paper, this is called fog ink printing. The earliest development of Ink-jet Printing (inkjet printing) was in 1878. By 1951, Siemens patented the technology for converting liquid inks into ink droplets. At that time, due to problems with needles and inks, it was not effective until 1960. It officially entered the practical stage.

In 1964, by using a special machine, it was possible to control the size of the ink droplets and the ejection rate. This was the prototype of the inkjet printer. Until 1967, Hertz developed a continuous inkjet printer, which is currently in the industry. Continuous Ink-jet Printing used on. In 1972 Siemens introduced the Piezoelectric dro-on-Demand Ink-jet Printing. In 1979, Canon introduced Thermal's dro-on-Demand Ink-jet Printing, but it was called Bubble Ink-jet Printing. In 1984, HP also Introducing Thermal dro-on-Demand Ink-jet Printing, which is the history of the development of Ink-jet Printing. Twenty years ago, this process began to be applied to the printing of barcodes and serial numbers of products, but the resolution was not satisfactory at that time. Until nearly 10 years, the quality of inkjet printing has made rapid progress.

(III) Definition of Inkjet Printing

Inkjet printing is a new non-contact, pressureless, non-printing printing technology that can be printed by inputting information stored in an electronic computer into an ink jet printer. It also has the common feature of digital printing without printing, which enables variable information printing. It shoots the ink from the fine nozzle onto the substrate at a certain speed, and then the ink image is reproduced through the interaction between the ink and the substrate.

(4) Classification of Inkjet Printing

Ink-jet Printing is broadly divided into two major categories, one is Continuous (continuous) and the other is dro-on-Demand (controllable printing); Continuous is mainly used in industry, such as labels, tickets The rough surface, metal surface, and plastic surface of cartons, etc., have the advantages of high speed, smoothness of the surface of the material is not very important, and there is a considerable distance between the nozzle and the material, so the thickness of the printed material is not affected. The disadvantage is that The resolution is not very high, and it is usually used on the surface of rough, not very resolution-oriented materials. Currently, Continuous has developed Binary Deflection and Multiple Deflection, both of which use voltage to generate skew. The principle is that the former provides ink according to the way that the ink is charged and the ink is not discharged when not energized. After the ink droplet is ejected and passes through the high pressure deflection board, the direction of the skew can be controlled, and the place where the ink is needed is more precisely reached. Uncharged ink droplets are introduced into the ink chute and can be recycled for reuse.

There are more than 20 ink-jet printing methods, but the basic principle is to generate small ink droplets first, and then guide them to the set position. It can be roughly classified into two types, continuous and on-demand. The so-called continuous inkjet, regardless of the printed or non-printed type, the ink droplets are generated in a continuous manner, and then the non-printed ink droplets are recovered or dispersed; while the on-demand ink jet is only in the printed portion. Only produce ink drops. Inkjet printing can be divided into black and white inkjet and color inkjet according to the printing color. Black and white inkjet printing uses only a single ink, so the machine structure and the ink system are relatively simple, and color inkjet printing is relatively complicated. At present, the resolution of inkjet printing can reach 40 dots/mm, and the quality is close to that of a photographic image.

Digital inkjet printers have a wide range of uses. They have general-purpose models, but their speed, resolution, and color reproduction area differ greatly depending on the purpose of use. The number of suppliers of continuous inkjet digital printers is small. There are two main types of equipment, one is high speed printing and the other is high quality color proofing. The reason why the number of suppliers of continuous inkjet printers is limited is that inkjet heads must be manufactured by companies that can provide complete solutions. On-demand ink jetting is different. There are many OEMs of ink jet heads on the market. On-demand ink jet heads can be manufactured in large quantities, and continuous ink jet heads are relatively complex and difficult to mass produce.

(5) Composition of ink jet printers

Inkjet printers consist of system controllers, inkjet controllers, print heads, substrate drive mechanisms, and the like. The ink is ejected from the nozzle of the nozzle under the control of the ink jet controller and printed on the substrate. According to the printing requirements, the drive conveys the substrate, and the system controller is responsible for the operation of the whole machine.

(6) Characteristics of inkjet printing technology

The resolution of inkjet printing is very high, and the printing quality is close to the photo. Therefore, inkjet printing can produce transparent or opaque color pictures, books, newspapers proofing and color image proofing. If the inkjet printer is connected to communication equipment, it can also transmit long-distance graphics. Since the width of the ink jet printer has become wider and wider, in recent years, a large-format print product using an ink jet printer has been widely used in advertising posters and the like. Therefore, the use of ink jet printing has become more and more widespread.

Most people are used to pricing prints in terms of how many dollars per square foot. However, the price per square foot inkjet printing product is lower than the analog printing product price. We must analyze the benefits of inkjet printing from another perspective. This is very important.

First, inkjet technology does not offer simple one-on-one replacements like traditional analog printing, or it can be sold like traditional printing. Inkjet has brought special opportunities for people. For example, it can well meet people's need for speed, while inkjet also makes it easier to print the same pattern on different webs.

In addition, with the increasing demand of customers for short-run prints and personalized products, people are more willing to store products on CDs instead of copying or storing them on screens. The cost savings make ink-jet technology more attractive. force.

Will screen printing disappear? of course not. But its position in the market will change. With the continuous recognition of the value of digital printing by printing houses, the position of inkjet printing in the market will continue to be consolidated and strengthened.

(VII) Constraints in the Development of Inkjet Printing

Although digital printing, inkjet has a market share of about 5%. However, the development of inkjet printing is more or less constrained by some factors. At present, the following factors affect the quality of inkjet printing.

1. Color conversion. How to accurately convert the light source system's color (R, G, B) into inkjet or printed system (C, M, Y, K) is a very complicated knowledge, but only by accurately converting the color can we obtain Really high quality effect. Therefore, accurate color conversion technology is an important key to the quality of inkjet printing.

2. Resolution. In black and white ink-jet printers, the higher the resolution, the finer the resolution and the finer scale points, and the better the print quality. But for color ink jet printers, the resolution refers to how many ink dots can be printed in a width of 1 inch, regardless of whether the ink dots overlap.

3. Levels. The current ink jet printing technology can precisely control the ink droplet color scale, and the control of the color ink from the same position does not spray to spray one drop until it sprays 16 drops.

4. Print head control. The dots of ink are ejected onto the paper through nozzles. In general, the nozzle and the print head are made together, so the technology of the print head itself is very important, and the left and right print heads are the inkjet technology and the cantilever gears of the printing presses. Drive belt precision.

5. Ink. Inkjet printing inks are special inks of moderate viscosity, and should be non-toxic, stable, non-clogging, moisture-retaining, good jetting properties, and non-corrosive to the metal components of the head. At present, ink-jet inks are mostly dye-based inks, and the ink of the ink-jet printer must also have enough surface tension to prevent the ink from spattering when ejected. In addition, the ink must be fast-drying to prevent haziness on the paper. Therefore, the ink itself is also one of the factors that affect the print quality.

6. Substrate material. Inkjet printing paper requires paper with a smooth surface and a certain degree of sizing. The ink sprayed is evaporated and dried. The dots of ink are circular, and the printed letters are clear and the graphics are beautiful. Color inkjet printing paper, preferably with a very thin layer of transparent coating on the surface, can quickly absorb ink, but also to avoid light scattering, in order to get the ideal print.

(8) Current Status of the Inkjet Printing Market

At present, China's self-developed inkjet printing equipment has entered the international market, and the development prospects are good. Faced with the changes in the industrial chain within the industry and the strong demand for inkjet printing industry and market development, China

You may have heard that inkjet printing will replace analog printing in many areas. This is indeed the case. For example, the sales volume of the US wide-format inkjet printing market has reached 6 billion U.S. dollars, and this market will continue to maintain its momentum of growth in quantity and price. This growth momentum has attracted more manufacturers to participate in the competition, resulting in a continuous increase in profit pressure, and for printers, they must immediately make strategic decisions.

In many printing plants, inkjet technology does play a complementary role in the traditional printing technology. In other printing companies, the role of inkjet technology is far less than people expected. If we look at the field of screen printing, we will find that technological advances have enabled people to use inkjet technology to produce a large number of jobs, so it can now compete with screen printing companies in the short-lived field. At the same time, direct platemaking technology has effectively shortened the cycle time of offset lithography. This forces screen printers to first analyze their own business models when deciding which technologies to invest in next.

The development and progress of inkjet and other technologies does not mean that screen printing will completely disappear. For example, although the quality of UV ink jet printing products will reach or even exceed the level of UV screen printing, this does not mean that UV screen printing will completely disappear. The fact is that when mature technologies face the challenge of new technologies, their position in the market will change. For these mature technology users, maintaining a competitive advantage in the future will become very important.

The ink-jet printing industry, represented by inkjet printers in China, has shifted from relying entirely on imported equipment from abroad to transforming itself into a domestically-manufactured device. After more than ten years of development, China's inkjet industry has formed a complete industrial chain structure from inkjet printer equipment production to the development and application of ink and consumables. Both the production capacity and the production scale have also achieved great development. There is ample room for development in the domestic inkjet pictorial market.

Difficulties in the development of inkjet printing

1. The lack of a unified industry standard is not conducive to the development of the industry. The lack of industry standards in the inkjet printing market is not conducive to consumer purchases and use of products, and it is not conducive to manufacturers to improve product quality.

2. Although the inkjet printing industry in our country has developed rapidly, there is no industry association to serve the entire inkjet printing industry, and there is no statistical data on the development of the industry of a neutral nature. Therefore, there is no industry association to coordinate and coordinate.