Enhancing textile ink-jet printing with chitosan

Following on from previous research, the possibility of using chitosan in preparing the pretreatment print paste for textile ink-jet printing was investigated but the final colour was not as good as expected. In this study, chitosan was applied separately on cotton fabric for ink-jet printing. A two-bath method was proposed and it was confirmed that a better colour yield was achieved with this method. However, the use of chitosan reduced the tensile strength of the ink-jet printed fabric slightly.     

Textile applications of photochromic dyes. Part 2: factors affecting the photocoloration of textiles screen‐printed with commercial photochromic dyes

The performance of five commercial photochromic dyes applied by screen printing on textiles was evaluated using a colour measurement methodology which has previously been established and validated. Printing as disperse dyes on polyester gives the strongest photochromic effect when the dye is located near the surface. However, the dyes are applied more effectively using an adaptation of a pigment printing method. Several factors influencing the photochromic properties of the printed textiles were evaluated. The ultraviolet reflecting properties of cotton give a higher level of photocoloration than on polyester. In the dyes studied, the spirooxazines show slightly faster colour development and fade much more rapidly than the naphthopyrans, and the latter show a residual colour after fading. The effect of the ultraviolet irradiation wavelength profile on the photochromic response may be correlated with the ultraviolet absorption spectra of the dyes.     

Optimisation of process parameters of Alpaca wool printing with Juglans regia natural dye

The aim of this research study was to optimise the process parameters of Alpaca wool hand‐knitted samples screen‐printing with Juglans regia natural dye and to set the optimal conditions regarding colour yield, colour fastness and colouristic properties of printed samples. An extensive preliminary examination of the Alpaca woollen yarn and hand‐knitted samples characteristics, the characteristics of suitable thickeners and the optimisation of the printing paste composition, was performed. A starch‐based thickener, British Gum, with a dry matter content of 4% was selected due to its rheological properties responding to properties of the Alpaca yarn and knitwear. It was determined that the fluidity increases while the viscosity and the elasticity decrease in acidic pH, so a pH of 4 was set for the thickener preparation. The thickener of lower viscosity and higher fluidity assures easier pressing of printing paste through the screen, giving uniform colour yield on the substrate, contributing to easier absorption of dyes into the fibre. A 45‐minute fixing process at 105°C by steaming delivered the best results of printing quality. Iron sulphate was used as the mordanting agent. The colour fastness to washing, dry and wet rubbing, and to light, was tested for samples with and without mordanting. The highest light and washing fastness were obtained with the iron sulphate mordanting agent printed in acid (pH 4) with paste containing 4% dry matter‐based thickener. The rubbing fastness was satisfactory for samples with iron sulphate printed with paste containing 4% dry matter thickener, fixed for 45 minutes, regardless of the pH.     

Cationic pretreatment of cotton fabric for anionic dye and pigment printing with better fastness properties

Improved printability with pigment and anionic dyes was obtained after simple cationisation of cotton fabrics with Solfix E. Different print paste formulations were used for printing cationised cotton fabrics with pigment, acid and direct dyes. Print pastes containing a synthetic thickener or a pigment emulsion showed good suitability for printing with pigment and pastes containing Meypro-gum as a thickener showed good printability with anionic dyes. The prints obtained on cationised cotton showed better overall fastness properties than prints obtained on untreated cotton. After repeated washings, the prints on cationised cotton showed a much smaller percentage colour loss than the prints on untreated cotton fabric.     

Pretreatment effects on pigment‐based textile inkjet printing – colour gamut and crockfastness properties

The application of two commercial pretreatment agents, formulated to improve the performance of a six‐colour nano‐scale pigment ink set during the textile inkjet printing of cotton and polyester (PET) fabrics, was examined. An industrial scale printer, operating at 55 linear m/h and equipped with Kyocera printheads, was used to print on commercial fabrics (180 cm wide) prepared for digital printing. The work employed an industrial scale rather than a benchtop printer to enhance the utility of the results for a commercial environment. The colorimetric attributes of printed fabrics were recorded for the individual inks as well as for spot colour combinations generated using Dr. Wirth RIPMaster v11 software. Colour table profiles were also generated and the colorimetric values of inks were compared. Colour gamuts of inks on cotton and PET, including three‐dimensional volumes in the CIELab space, were examined to assess the role of pretreatment on the colorimetric properties of the printed substrates. It was found that the pretreatments enhanced the ink receptiveness, colour intensity and colour gamut of fabrics. Pretreatment of cotton resulted in a larger gamut and more vivid colours than on PET. However, wet and dry crockfastness results were found to be low. In this regard, Time‐of‐Flight Secondary Ion Mass Spectrometry analysis of fabrics printed in the presence and absence of pretreatment indicated that the low crockfastness arises from higher pigment levels on the surface of the pretreated fabric.     

Properties of UV-cured pigment prints on textile fabric

This paper studies and evaluates the UV-curing of pigment prints on textile fabric using a prototype UV scanner. A printing paste comprising synthetic thickener, emulgator, binder, pigment dispersion and photoinitiator was applied using a flat screen printing technique onto the cotton fabric, then dried and exposed to heat or UV-radiation under a mercury vapour lamp (200 W cm⁻²). The characteristics of cured prints such as paste add-on, colour properties, colour fastness to washing and dry/wet rubbing were evaluated, together with fabric stiffness. The effects of UV-curing were evaluated by Attenuated Total Reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The properties of the UV-cured pigment prints were compared with those of the thermal cured prints. Analyses of the obtained results helped to define the optimum composition of the photo reactive pigment paste, and the UV-curing conditions under which satisfactory results were obtained, comparable with those from the thermal curing method.     

Combined crease recovery finishing and pigment printing

The combined application of crease recovery finishing (using a dimethyloldihydroxyethylene urea-based finish) and pigment printing is evaluated in this study. The use of a small amount of ammonium chloride in a combined print–finish process induces significant pigment print paste viscosity losses. However, the catalyst 2-aminoethanesulphonic acid produces negligible viscosity reduction when used in the combined print–finish process, coupled with the desired levels of finish and pigment print performance. Similar dry crease recovery, breaking load, colour strength and colour fastness properties are achieved by using 2-aminoethanesulphonic acid in the combined print–finish process relative to the conventional print–finish process.     

Effect of weight reduction process on printing properties of polyester fabrics

The weight reduction process used to improve the handle and appearance of polyester fabrics is used widely in industry. In this study, polyester fabrics, which had been subjected to this process in varying degrees, were printed using three disperse dyes under controlled printing conditions. The effect of weight reduction on the print paste add-on, colour strength, wash and crock fastness, and levelness and sharpness of the print were evaluated and the results discussed.     

光固型支化聚氨酯分散剂的合成

将聚氨酯分散剂设计成超支化结构,通过在聚氨酯末端分别引入颜料锚固基团和双键基团,合成紫外光固化型支化聚氨酯分散剂（BPUs）,使分散剂具有自粘合的效果,以提高印花牢度。通过红外光谱、凝胶色谱、热重分析等分析分散剂的分子结构与性能。通过BPUs为分散剂制备颜料色浆的分散性能良好,粒径分布均匀且具有较低的粘度,并且高温储存5天粒径变化最小在20 nm以内,3000 rpm离心稳定性在92%以上。使用该色浆直接印花,其水洗牢度保持在3~4级, 比商用分散剂提高了2级左右。     

Use of a biomaterial as a thickener for textile ink‐jet printing

The feasibility of using chitosan as a thickener in the pretreatment print paste for textile ink‐jet printing was explored. An orthogonal analysis was used to determine the optimum conditions for using chitosan as a thickener in the pretreatment print paste and the effects of different process factors for achieving the best color yield in textile ink‐jet printing. With the help of the orthogonal analysis, the importance of different process factors was found to be in the order of (1) the amount of urea used, (2) the amount of chitosan used, (3) the amount of sodium bicarbonate used, and (4) the steaming time. On the basis of the results of the orthogonal analysis, the optimum conditions for using chitosan as a thickener for the pretreatment print paste were concluded to be 40 mL of chitosan, 10 g of urea, 8 g of sodium bicarbonate, and 5 min of steaming. According to an analysis of the results of different color fastness tests, chitosan could principally work as a pretreatment print paste thickener. However, the final color yield obtained from chitosan‐containing cotton fabrics depended greatly on the stage of the chitosan application. Nevertheless, the color fastness properties and the outline sharpness of the prints of cotton fabric were greatly improved by the chitosan treatment. A two‐bath chitosan treatment was developed to separate the chitosan from sodium bicarbonate and urea before it was padded onto the fabric surface to minimize the neutralization effect. On the basis of the results for the highest color yield obtained on the cotton fabric, it was confirmed that the two‐bath chitosan treatment was successfully developed. In addition, chitosan could impart higher antibacterial properties with a slight reduction in the tensile strength of the cotton fabric. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Dyeing of cationised cotton using nanoscale pigment dispersions

Cotton modified with a cationic reagent has been dyed by an exhaustion process using nanoscale pigment dispersions. Pigment uptake, colour yield and fastness properties on cotton were measured. Uptake of pigment was found to be closely related to the concentration of cationic reagent, pH of the pretreatment bath, pretreatment temperature and time of cationisation. These factors also influenced the fastness properties of the fabric. Nanoscale pigment dispersions gave a much higher colour yield than conventional pigment dispersions on cotton. Fastness properties were acceptable for wash-down effects. It is clear that exhaust dyeing using nanoscale pigment dispersions offers a number of advantages in terms of pigment requirement, improved handle and appearance, and also in environmental protection.     

Aloe vera gel: a new thickening agent for pigment printing

An attempt was made to print cotton fabric with pigments using a new thickening agent based on Aloe vera gel in combination with sodium alginate. The results were compared with the standard conventional printing recipe containing synthetic thickener, and a favourable effect of Aloe vera introduction was achieved. The results show that the properties of the printed fabric (sharpness, colour yield, overall fastness properties, softness, and water vapour transmission) are dependent on the percentage of Aloe vera gel in the thickener combination, the concentration of printing auxiliaries, and the curing conditions. Optimal printing properties were achieved by using a printing paste containing 80% Aloe vera/20% sodium alginate (700 g kg^?1), pigment (50 g kg^?1), binder (145 g kg^?1), fixer (10 g kg^?1), and ammonium sulfate (5 g kg^?1), followed by drying at 85 °C for 5 min and curing at 150 °C for 3 min. The sample printed with the new recipe showed superior rubbing fastness and handle properties, with a slightly lower colour yield, when compared with the sample printed with synthetic thickener. Finally, economic issues arising from synthetic thickener substitution are highlighted.     

A Study into the Influence of Paper Coatings on Paper Properties and Print Quality of Dye Sublimation Thermal Prints

The need for good quality paper for dye sublimation transfer printing has been reported previously as a principal requirement for the process. Pigmented coated papers have gained acceptance in the traditional paper printing industry, but, despite their importance, have inspired very few reports in literature about their application in heat transfer printing.

In the current work, we studied the influence of both clay and ground calcium carbonate (GCC) pigments and the incorporation of plastic pigment on the surface structure and mechanical properties of the coated paper used for transfer printing. The results showed that paper coating significantly reduced the surface roughness of the paper. The mechanical properties of the prepared coated paper, including tensile strength, stretch, tensile energy absorption (TEA), and burst index, were improved when coated compared to those of uncoated paper. The addition of plastic pigment to the coating mixture helped improve the paper's properties.

The optical density of the transfer-printed polyester fabric using the prepared coated paper was also compared with that of uncoated paper. It was shown that a slight increase in optical density was evident in the coated paper.

The possibility of producing a second polyester print from the exhaust paper was also investigated. Coated paper incorporating plastic pigment, in particular, showed higher optical density than did uncoated paper.

We found that coated paper based on clay, GCC, clay/plastic pigment, or GCC/plastic pigment consumed less dye paste than uncoated paper though producing printed fabric with higher optical density—especially in the second print.     

The effect of different radiation sources for the UV curing of a screen‐printed,water‐based polyurethane acrylate binder

In this paper, titanium‐dioxide‐pigmented printing pastes of water‐borne, UV‐curable polyurethane acrylate binder with two different UV‐curing photoinitiator combinations were prepared and screen printed on a black t‐shirt fabric. The effects of mercury and gallium radiation sources employed either singly or in combination for UV curing and the total energy level on the printing performance were investigated. The cured textile samples were subjected to colour measurements before and after five cycles of washing, and hiding power and changes in chromacity, hue, and colour were determined. Single‐lamp applications of mercury and gallium were not satisfactory, and opaque pigment hindered deep curing, especially at thicker coating levels. It was found that employment of a mercury–gallium lamp system applying an irradiation at medium level can provide pigment printing of opaque white inks with excellent coverage, washing resistance, and medium hardness.     

砂磨制备荧光涂料印花色浆效果的评价

本文对砂磨法制备的荧光涂料印花色浆用于印花后试样的牢度、荧光效果等实际应用性能进行了评价；其中用测配色仪测量印花试样的荧光效果，准确快捷，应予推广。     

Surface treatment of cotton fabrics with chitosan

Antibacterial activities of cotton and polyester/cotton fabrics treated with chitosan or chitosan/DMDHEU have been investigated. The washing durability properties of the aforementioned fabrics were also studied. Another group of fabric samples produced from mature and immature cotton fibres were dyed with reactive dyes and the colour yields and colour differences of the dyed fabrics assessed. The surfaces of the treated and untreated cotton fabrics were observed by scanning electron microscopy to compare the morphology.     

Improving transfer printing and ultraviolet‐blocking properties of polyester‐based textiles using MCT‐β‐CD,chitosan and ethylenediamine

This study demonstrates the possibility of improving the transfer printability and fastness properties, as well as the ultraviolet‐protecting functionality, of polyester, polyester/wool, polyester/cotton and polyester/viscose woven fabrics via pretreatment with monochlorotriazinyl β‐cyclodextrin (MCT‐β‐CD), chitosan or ethylenediamine, followed by subsequent transfer printing with sublimable disperse dyes. The modification variables as well as the transfer printing conditions were optimised. The experimental results reveal that generating hydrophobic cavities (via grafting of β‐CD) at the fabric surface, fixing of chitosan, with its amino groups, onto the finish/fabric matrix, or introducing amine functional groups, via aminolysis of the polyester component, results in obtaining transfer printed fabric samples with darker depth of shades and better fastness properties, as well as with higher ultraviolet‐protecting functions. It was further noted that, in all cases, the enhancement in the imparted properties is governed by type of substrate, kind and extent of chemical modification, affinity for the sublimable disperse dyes, accessibility of generated hosting and fixing sites, as well as the ultraviolet‐blocking capacities of the modified/post‐printed substrates against damaging ultraviolet rays. The mode of interaction, as well as the surface morphology of some non‐treated and treated fabric samples, was also investigated.     

Influence of additives on the fabric stiffness and colour depth of viscose printed with a guar gum thickener and a reactive dye

The effect of additives in a printing paste containing guar gum thickener and bireactive dye for cellulose printing was studied. The efficiency of the additives with respect to their chemical structure and concentration and the efficiency in combination with thickeners of different types (nonsubstituted, different degrees of carboxymethylation) and different concentrations (solid content) was investigated by assessing the fabric stiffness, colour depth, dye penetration, the viscosity and viscoelasticity of the printing paste and the printing paste add-on. Some additives caused a decrease in the fabric stiffness to an acceptable degree with little effect on the colour depth. Dye penetration was found to be exclusively additive-dependent. Spectroscopic and rheological investigations confirmed the reduction of dye/guar gum interactions due to the occurrence of additive/guar gum and additive/dye interactions. The best quality prints were obtained using a printing past containing a nonionic surfactant and a highly carboxymethylated guar gum thickener.     

氧化铁红颜料对白水泥基3D打印材料流变及可打印性能的影响

目前3D打印技术在建筑材料领域的研究主要集中在大型结构的建立和力学性能上,而对异形装饰及景观构件的研究还很少.本文采用白色硅酸盐水泥作为胶凝材料,并引入亚微米级粒度氧化铁红颜料来制备彩色水泥基3D打印材料,并研究氧化铁红颜料对白水泥基3D打印材料流变性能、可打印性能及力学性能的影响.结果表明,低掺量的颜料可以降低白水泥...     

Printability of Sized Kenaf (Hibiscus cannabinus) Papers

This article reviews the effect of chitosan, cationic starch and polyvinyl alcohol as sizing agents to improve printability properties of kenaf handsheets. The polymers were incorporated into the sheets by spray application. This study clearly demonstrated that the use of chitosan could improve the printability and print quality of kenaf paper in terms of water and oil absorption, ink penetration, print density and gloss for offset printing. Both PVA-sizing and cationic starch sizing gave print densities and ink penetrations than were intermediate between chitosan and the unsized control sheet, which gave the lowest values for these properties. Kenaf paper sized with chitosan gave the best mix of desirable printing paper properties and was superior to kenaf papers sized with either cationic starch or PVA.