Inkjet Printing Technology Overview

With the increase in the industrial power of digital color printing systems, people began to seriously consider the future development of traditional sheetfed and web press technology. Digital color printers based on toner technology have gained a place in the field of commercial printing, but its convenient limitations such as speed and print width (as well as equipment cost) make it difficult for some industry prophets to implement toner devices. As an alternative to offset presses.

But these same experts in printing technology see the inkjet system as the most important printing equipment after the sheet-fed offset presses and web offset presses. Their attitude is very positive and there is no doubt. The stable print quality and fast print speed of the inkjet system can completely eliminate people's concerns about the origin of this practical printing technology.

The development of inkjet printing systems has been decades of history. Mead Digital is the predecessor of today's Kodak Versamark company. Since 1981, it has been dedicated to the development of inkjet printing systems.

According to IT strategy company's forecast, the worldwide income of ink jet systems, including hardware, substrates and inks - nets exceeded 57 billion U.S. dollars in 2009 - this figure will increase by 35% over 2004. Although these numbers reflect the overall state of inkjet technology, the market conditions are not the same for every specific application area - from desktop photo printers to point-of-sale display boards to proofing systems and printers. . Various markets have carried out a lot of research and development work on inkjet technology, hoping to make this technology more quickly.

Almost all inkjet application areas will show an increasing trend: In the area of ​​wide-format printing, inkjet systems will replace electrostatic printers; In the packaging field, inkjet technology will open the market for short-term promotional advertising; In the traditional printing field , Inkjet printers can complete the printing of books, or high-quality four-color printing at high speed and low speed; other areas include: variable data printing, direct mail letters, and some applications that we do not know yet. .

According to the Discovery Channel, we can see that inkjet technology has now been used to create three-dimensional solid models of product and component prototypes. Xaar, a developer of printheads, also claims that inkjet devices can also be used to make bandages for the skin surface, which can spray the transplanted skin tissue onto bandages to help a large number of burn patients.

To some extent, inkjet technology has become synonymous with faster speed, better ink and higher resolution. From the inkjet proofing technology we are currently familiar with - they have achieved excellent color fidelity and resolution - there are two kinds of inkjet printers often appear in the printing shop.

1. Additional and value-added variable data systems with a variety of ink jet print heads suitable for narrow, sheet or conventional web presses.

2, ink technology as the only imaging technology inkjet printer. The Mead Digital Systems Model 2700 monochrome inkjet printer is an inkjet system for high-volume, actual-print production. With a 12-inch high-speed printhead, this printer can print at speeds of 1,000 fpm (feet/minute), which is comparable to the speed of commercial rotary presses that printed slower in the late 1970s. The 120-dpi printer was originally used to add personalized content with variable data to the offset direct mail application form. Industries such as Webcraft (now Vertis), Standard Register, and Communicolor (now part of the Donnelley Corporation) are among the first companies to use inkjet technology for actual production. In the 1980s and 1990s, the use of ink jet printers in the bookbinding industry, especially the saddle stitching process of address and coding catalogs and catalog ordering tables (and later in the wireless glue binding process) was very common. One of the major drawbacks of inkjet technology is its ability to print in monochrome (black, black or black). It also has a low rate of separation between text and images. So inkjet printers are usually used to add independent addresses or data to preprinted color prints.

With the advent of digital four-color printers based on toner technology in the 1990s, inkjet systems also have a color printing capability. Sae Angel Digital Printing (now a Kodak Graphic and Imaging Group) has launched a true four-color (CMYK) high-speed inkjet printer Versamark that can compete with color toner printers. Some printing experts who are more predictable about the future development of the industry believe that inkjet technology will certainly be an alternative to offset printing. In fact, with the launch of a large number of new inkjet systems, 2006 seems to have become a victory year for inkjet technology.

If we want to find out what inkjet devices are suitable for use in today's commercial, variable data and packaging markets, we should have a comprehensive understanding of the product's performance and application direction.

Dahe Express

The field of application of inkjet printing systems is really varied. The biggest advances ink and printhead technology has made in recent years may be the introduction of drop-on-demand inkjet printheads and UV-curable inks.

Ink problem

The most important component of any type of inkjet printer is ink. The type of ink determines the printer's ability to handle different substrates, the reliability of the printer, and the speed it can achieve. Inkjet printer manufacturers, the ink is critical, it is the printer manufacturer's profit center, but also allows suppliers and customers to maintain long-term relationship.

Ink is mainly divided into water-based inks, and solvent-based inks are UV-cured (it can also be water-based) inks. The structure of the printer also shows the type of ink it can use. Continuous inkjet printers can use aqueous and solvent-based inks, and dyes often make the ink incredibly agglomerate. The sublimation of the ink is a problem, and the bubbles generated by the vibrating piezoelectric crystal are also factors that prevent the printer from producing a good printing effect. The ink formulator's job is not so good.

Kodak Versamark created a series of printhead aperture plates using electrolithography (electronic lithography) technology. Years of practical experience show that this type of orifice plate is very suitable for aqueous inks. Solvent-based inks can easily corrode tiny holes, but this problem can be solved with new design structures. In fact, the use of solvent-based inks on some printheads works very well because the solvent it contains keeps the orifices clean. One of the main problems with inkjet technology is to keep the hole in the well plate clean and to remove any obstacles left on it. Dry ink, dust particles, or any slight impurities can cause the printhead to shut down. One potential problem with using UV-curing inks is to keep the UV light source density consistent with the actual print-out of the ink as it comes out of the printed hair, otherwise it will ruin the entire production process.

In general, the application direction controls the type of ink. In the bookbinding industry, UV-coated covers are very common. The printheads are at least 3/8 inches above the substrate at work, and solvent-based inks are often used with continuous inkjet printheads. Although water-based inks are also used in this area, people need to take some high-temperature drying measures to reduce the moisture in the ink (usually infrared drying). In drop-on-demand inkjet UV printheads, the cost of the ink can vary greatly depending on the substrate.

Substrate challenges

Due to the need to use aqueous and solvent-based inks, ink-jet printing technology usually faces the challenges of substrates. Water-based inks tend to fade, and if the mail gets damp, the colors will fall faster. Although solvent-based inks can be used on coated substrates, people have developed a series of strict environmental penalties for their use. UV curable inks can now be used on a variety of substrates, including coated paper and plastic. The images printed with these inks are more durable and fade-free, and the reliability and stability of the print head have also been improved. In addition, the characteristics of the rapid transfer of UV-curing inks have also expanded their potential application fields, finding a better substitute for previous ink-jet printers using solvent-based inks.

New printheads that use drop-on-demand inkjet technology have also substantially changed the game specifications for the inkjet printing market. Some of the major equipment suppliers - HP, Spectra and Sai Angel - have equipped their inkjet printheads with this core technology. Although there are many integrated products in the inkjet printing system on the market, customers still only believe that these few suppliers produce inkjet printing systems. Because they know that the print head is the core of all inkjet printing systems.

Drop-on-demand printheads use an intermittent ink jet method that applies discontinuous pressure to the liquid ink during ink ejection. The liquid ink is only pressurized when the print data signal is applied, and ejection occurs where needed. This type of print head is suitable for printing on a variety of substrates and can also be used with a variety of inks.

Fundamentally speaking, ink jet technology is also a binding technology, so we can also find print heads with 128 nozzles or 256 nozzles (1 inch or 2 inches wide). Companies like Xaar and Spectra are designing and manufacturing print heads themselves, and they will design different models based on their use and operating environment. Print heads are usually sold through OEMs (original equipment manufacturers) to the rest of the world, and print head project teams from the private sector will also work with OEMs to jointly commit to the application and promotion of inkjet technology.

Connect the print head

People have succeeded in increasing the horizontal print width of inkjet printers/printers to 16 inches thanks to a great deal of experience gained in the installation of inkjet printheads and the integration of printheads using electronic technology. Improved droplet generation technology enables the printer to achieve higher print speeds while maintaining higher print quality. Xaar and Spectra have a large number of OEM partners: Mutoh, SunJet, casting Technology International, VUTEk (EFI), Heidelberg, Xennia, Buskro, Kodak Versamark and others. Advances in printhead and ink technology have also enabled the printing of high-resolution wide images on metal and optical materials.

In the commercial and specialty printing fields, labels, bills, trademarks, coupons, and other products commonly used in narrow web presses have gradually begun to be manufactured using inkjet devices.

A special application area of ​​inkjet technology is the printing of bar codes. Ordered or unique barcodes are labels, coupons