Effect of UV-Curable Inkjet Printing Parameters on Physical, Low-Stress Mechanical, and Aesthetic Properties of Polypropylene Knitted Fabrics

Abstract

As the use of textile polypropylene (PP) fibers becomes more common in commercial textiles and sportswear, the investigation of the effects of UV-curable ink on the heat-sensitive PP knitted fabrics is crucial to optimize functional clothing design. This study investigated the effects of UV-curable ink on the heat-sensitive PP knitted fabrics when the ink was cured using UV light at room temperature, to avoid degradation of the PP fabric by high temperature, and provided an alternative coloring method for PP fabric used in sportswear. The influences of printing parameters such as the printing distance, number of overprints, and color of ink on fabrics as well as aesthetic, physical, and low-stress mechanical properties in terms of tensile, bending, shearing, surface, and compression were systematically investigated. The results indicated that the physical properties and low-stress mechanical properties of PP fabrics printed with UV-curable ink were significantly affected by the number of overprints and the color of the prints, whereas the color appearance was affected mainly by the number of overprints and the printing distance. In terms of the fabric's hand value, only 2HB and 2HG5 were significantly affected by the number of overprints and the color of the prints, with the prediction rate exceeding 40% among the low-stress mechanical properties. The fabric's hand value was not significantly affected by the thin UV-cured ink film when compared with the fabric itself. Fabric printed in a color with the greatest lightness and the fewest overprints had the lowest fabric weight, thickness, and color difference (∆E) towards the reference color, in addition to better bending recovery and resilience properties. The new knowledge from this study can provide an alternative coloring method for PP knitted fabric to increase the design variety available to textile designers who use PP fabric. The results from this study contribute to the textile and knitwear design industry.

Modern printing techniques for enhancing the printability performance of synthetic textile materials via different treatment methods

“…Inkjet printing is paired with UV-curable ink in UVcurable inkjet printing. [18,19] The photopolymerization of the binder, which is the chemical process that causes curing, is started when UV radiation of a certain wavelength from the UV light source installed on the inkjet printer's print head is absorbed. After being exposed to UV light, the binder, which contains pigment particles, creates a thin film that is placed on the printing substrate.…”

“…The system provides an objective evaluation of hand characteristics, including bending, surface, shearing, tensile, and compression analyses. [19]…”

“…The printed fabric's colors were measured using an X-Rite ColorEye 7000A spectrophotometer. [19] The Leica M165C stereomicroscope and Adobe Photoshop CC software were used to examine the visual quality of prints on textiles at varied printing distances in terms of resolution. [19]…”

“…[19] The Leica M165C stereomicroscope and Adobe Photoshop CC software were used to examine the visual quality of prints on textiles at varied printing distances in terms of resolution. [19]…”

“…The outcome of the stepwise multiple regression analysis demonstrated that the fabric's mass per unit area and thickness rise as the number of overprints grows and are also influenced by the color of the print fig 4. [19] In general, as the lightness of the printed color dropped, the mass per unit area and thickness of the cloth grew.…”