Inkjet for Industrial Continuous Web Printer and Study on Speed Enhancement

The digital printing market has been growing in spite of the shrinkage of the conventional printing market. Continuous web press printers require wide printing width, high speed color, low running cost and medium print quality, and as a result inkjet technology is considered especially suitable. This paper describes the elements and technologies used for inkjet printers in order to understand their nature in comparison with electric photography which also realizes digital printing. Items such as data processing, which enables variable data and on demand printing, paper control system and principal printing process affect the ability to achieve high speed inkjet printing. Although there are other limitations related to cost and spatial restriction, jetting from nozzle, and flying and landing of ink droplets onto the paper are recognized as the most important principal processes that enable non-contact printing at high speed. Therefore, the behavior of flying droplets was discussed experimentally and theoretically, considering the airflow generated between the printhead and paper during the feeding operation. As a result, it was clarified that the paper feeding speed limit in high speed printing is affected more by the displacement of ink dots due to a difference in drop velocity than by the airflow.