More than 20 years have passed since the introduction of digital printing presses for full-color printing, which was put into commercial use in the mid-1990s. In recent years, the bipolarization of small digital presses based on copiers and large and high-speed digital presses supporting up to B2/B1 sizes has progressed. There are various trends in digital printing technology, such as a shift from electrophotography to inkjet, and in Japan, B1-size sheet-fed inkjet presses and inkjet presses with a paper width of 2800 mm are starting to operate. In this article, we will explain the latest trends in digital printing presses entering a new phase.

Digital printing is established and extended as one of the packaging printing methods. It has evolved to have a cooperative relationship without competing with gravure or flexographic printing. Development and improvement of inks for OPP, PET, and OPA (ONY) have progressed, and the boil and retort types have been enhanced. Ink costs have also been reduced. Improvements in printing software and printing presses will advance, and surface printing on co-extrusion films will become widespread, reducing the delivery time of packaging materials. Digital printing platform construction will start to be utilized more frequently. Digital printing will change the way packaging business works, and individuals from other industries will enter in package business.

Labelexpo Europe is the label industry's largest exhibition, where all the technologies related to label production are displayed. At Labelexpo Europe 2019, I focused on UV inkjet label printers and peripherals, and summarized the trends on several technical topics.

Almost all major venders launched flagship printers in 2019. Most of them have two type of printers: new high-end models, and general models which are already spread in the market. The high-spec flagships have some functions for solutions to print on offset paper using aqueous pigment inks. The solutions are classified in two ways: direct jetting with primer-less inks and jetting with general inks on primer treatment, including inkjetting and a coating unit inside the machine. The popular models also had improved printability and productivity by updating print-head, inks, and so on. Inkjet papers, treated and coated, are commonly used in the widely popular machines. This report illustrates a suitable combination of inkjet devices and paper media, and introduces an optimal activity example of the digital manual print solution as a smart factory at Canon Medical Systems.

Dai Nippon Printing (DNP) has been broadening the business fields of products and services by research and development (R&D). Until the 1950s, the main business was “Ink on Paper”. We have been researching and developing new products applying printing technologies to the plastic films, glasses and metals instead of paper. Now our business fields are broadened to the fields including electronics and photo imaging services. We are targeting new business fields for the future with our strong will of “Today's Innovation is Tomorrow's Basic”.

We prepared three-dimensional functional components using multilayer-screen printing followed by removing the printed components from the silicone rubber substrate. The printings were done with four types of inks containing the functional fillers such as carbon, glass, stainless steel, and nickel. Single 0.4-mm-thick grating-shaped plates were prepared from each of the four inks. Bipolar plates for polymer electrolyte fuel cells were also prepared from the carbon and nickel inks. The functions of the printed bipolar plates—such as electroconductivity and the flow of gas through a channel—were verified by measuring the single-cell output when using the printed bipolar plates. This approach opens the way to a new low-cost process to build and prepare three-dimensional functional components.

Light diffusing ink achieving a high brightness light guide plate by printing has been required, however, dielectric particles scattering cross section is constrained by particle size and refractive index of particle and medium. Aggregated Ag nanoparticles (A-Ag-NPs) present different scattering and absorption properties from a single particle. We measured and discussed optical properties of the A-Ag-NPs in dispersion-medium water and white ink. The A-Ag-NPs showed low absorption and high scattering in the red color region. By adding the A-Ag-NPs to the white ink, side scattering light intensity at 633nm increased by 46% at the arrangement that represents the light guide plate.