Investigation of a Spreading Model for a High Speed Spot Color Printer using Hot Melt Ink Jet Inks

摘要

This paper presents the major findings of a comprehensive thesis research project conducted by the author. Capillary flow porometry and mercury intrusion porosimetry techniques were utilized to evaluate key paper properties of the modified spreading model for a porous medium with transverse and radial capillaries. A novel technique known as transverse capillary flow porometry, useful in the evaluation of in-planar (x-,y-directional) pores, was also incorporated. Accent Color Sciences' Truecolor 400 web-fed printer with Spectra CCP-256 printheads and Sabre hot melt inks were used to generate print samples. 75 nanogram ink drops were jetted onto three different plain papers at a printing speed of 160 FPM. The resultant drop radius (R_p) was determined and used in the spreading model in relation to the radius of the ejected ink drop (R_f). An initial drop radius (R_d) at the time of impacting the paper was calculated based on the evaluated paper and printing properties. The spreading model has been compared to the Spectra "Splat Model", developed specifically for hot melt inks. The two spreading models were further simplified into three components: (1) Final Drop Spreading Coefficient [FDSC], (2) Drop Impact Spreading Coefficient [DISC], and (3) Characteristic Paper Spreading Coefficient [CPSC]. The analysis proved that the two models had very comparable CPSCs, but different DISCs and FDSCs.