engleski

Plasma Pre-treatment Influence on Color Yield of Textile Substrate

Due to its efficiency, digital InkJet printing technology, has demonstrated wider possibilities over the customary textile printing methods, such as excellent pattern quality, considerably little pollution, quick response to the frequent shifts on textile product market the reduce of the overall printing costs. However, there are still many open areas in the field of digital InkJet textile printing technology that requires intensive solution finding research in order to overcome the still existing barriers. By following an integrated approach the benefits of textile ink jet printing can maximized by improving the final printed image quality (including print definition), colour yield, colour fastness and the “handle” of the final textile ink jet printed product. Considerable research and developments are now taking place on printing inks composition, print head developments but also on the complex droplet/ substrate interaction and the droplet breakup process while interacting with printed medium, which is of key importance for reproducing digital colour [1, 2]. This paper describes the influence of textile surface pre-treatment using low-pressure plasma on colour spectral parameters of printed surface, which depends on the quantity of bounded pigments as well as on structure of the polymer layer on the surface of textile material. The pre-treatments is required to achieve the optimal benefits of textile ink jet printing by improving the final printed image quality (including print definition), colour yield, colour fastness and the “handle” of the final textile ink jet print. Pre-treatment of textile substrate (raw cotton and man-made cellulosic knitwear for clothes) were performed using low-pressure plasma type Nano LF-40 kHz using oxygen and argon as working gases under optimised plasma processes for fibre surface activation (power of 500W, pressure of 0.34 mbar, gas flow rate of 50 sccm and time duration of 2 minutes). Ink-jet (with Micro Piezo Head) digital textile printer, type Azon Tex Pro that prints directly on fabric, was used in experiments. For a better contribution and explanation of the results of surface analysis, SEM microscope analyse was carried out. For objective evaluation of colour, the Data Color Spectra flash SF+ 600 remission spectrophotometer was used, and for expression of colour differences the CIE 76 as first colour difference formula that related a measured to a known set of CIELAB coordinates, was performed. Printed image quality and colour fastness were analysed through Wash test and Abrasion test (using Martindale apparatus) according to standardized testing methods. Obtained results showed positive impact of oxygen/argon plasma pre-treatment with improving the total colour yield on the surface of substrate, because of better wettability and hydrophilicity of such pre-treated samples. The results showed significant differences in colour characteristics of pre-treaded textile samples in compare to untreated ones. One of the reasons of such results is that plasma pre-treatment allows deeper embedding of the printing ink polymer film into a structure of a fibre which further allows more firm and durable bonds of pigment with fibrous substrates and enlarges the active surface for pigment bonding.

plasma pre-treatments, surface activation, wettability, digital printing, spectral colour parameters, wear properties, cellulose knitwear

Sredstva osigurana iz Potpore istraživanju: KFPI_TP7/18: Antimikrobna svojstva tekstilnih materijala obrađenih ekološkim postupcima obrade (voditelj: doc.dr.sc. Sanja Ercegović Ražić)