Use and analysis of UV varnish printed braille information on commercial packaging products

This paper investigates the possibility of reproducing Braille by UV ink-jet printing on self-adhesive labels, previously printed by flexo printing technol- ogy. The aim was to determine whether it is possible to reproduce Braille, the degree of quality of created Braille dots (cells), the legibility of Braille text, and how many layers of varnish are necessary for quality reproduc- tion. The Braille letter was applied to the previously printed label (design) using 8, 10, 12, 14 and 16 layers of varnish. It has been found that it is possible to reproduce a quality and legible Braille. With the increase in the number of layers, the assessment of legibility and quality of reproduction by the respondents also increased. Samples reproduced with 12 layers of varnish received a very good grade of legibility and good grade for quality of Braille. Samples reproduced with 8 and 10 layers received bad grades for legibility, and even worse for quality, while samples with a higher number of layers of varnish, 14 and 16, received even better grades. The threshold for quality reproduction would therefore be the use of 12 layers of varnish, where a good ratio of workmanship and economy is obtained.

Enhancing digital ink-jet printing patterns quality through controlling the crystallinity of cotton fibers

Cotton fibers have a high crystallinity, which makes a large number of reactive hydroxyl groups blocked and therefore affects the ink-jet printing performance of reactive dyes on cotton fabrics. In this work, the alkali treatment was employed to adjust the structure of cotton fibers. The crystallinity of treated cotton fibers reduced from 73.9–58.5%, and the breaking strength did not decrease compared with original cotton fiber. Thus, the accessible reactive hydroxyl groups and the wettability were enhanced for treated cotton fibers, which promoted the penetration of inks into the fibers. The optimal K/S value of 23.47 was achieved for treated cotton fabrics which was higher than that of untreated cotton fabrics (17.15). Meanwhile, the printed fabrics displayed good washing fastness, rubbing fastness and glossiness. This work provides an effective way for improving the utilization of dye solution and producing high-quality cotton fabric digital printing products.