The use of plasma pre-treatment for enhancing the performance of textile ink-jet printing

In this study the effect of low temperature plasma (LTP) treatment of cotton fabric for ink-jet printing was investigated. Owing to the specific printing and conductivity requirements for ink-jet printing, none of the conventional printing chemicals used for cotton fabric can be directly incorporated into the ink formulation. As a result, the cotton fabric requires treatment with the printing chemicals prior to the stage of ink-jet printing. The printing chemicals as a treatment to cotton fabric are applied by the coating method. The aim of this study was to investigate the possibility and effectiveness of applying LTP pre-treatment to enhance the performance of treatment paste containing sodium alginate, to improve the properties of the ink-jet printed cotton fabric. Experimental results revealed that the LTP pre-treatment in conjunction with the ink-jet printing technique could improve the final properties of printed cotton fabric.     

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.     

Effect of cotton fabric pretreatment on drop spreading and colour performance of reactive dye inks

Ink dot distribution on cotton fabrics determines the colour performance of reactive dye inkjet printing, and ink drop spreading is one of the important factors influencing the ink dot distribution. In order to reveal the relationship between fabric pretreatment and ink drop spreading, two pieces of cotton fabric were pretreated respectively with sodium alginate and sodium alginate plus high fatty acid derivative solutions. Results indicate that the surface energy of the cotton fabrics was reduced from 73.79 to 69.45 and 58.49 mJ m^?2 after the pretreatment with sodium alginate and sodium alginate plus high fatty acid derivative respectively. Correspondingly, the spreading area of cyan ink drops on these fabrics was reduced from 104.9 to 92.5 and 72.3 mm². Furthermore, on the fabric treated with sodium alginate plus high fatty acid derivative, the strip‐like ink dots were narrow and short, which means the dye was concentrated in an area on the fabric surface. Colorimetric values of the inkjet‐printed fabrics demonstrated that the high fatty acid derivative would enhance the ability of sodium alginate to control ink droplet spreading, thereby improving the colour performance.     

Study of the factors influencing colour yield of an ink-jet printed cotton fabric

In this study, the factors influencing the final colour yield of an ink-jet printed cotton fabric were investigated. The factors included the content of the pretreatment paste (the amounts of sodium alginate, sodium bicarbonate and urea) and the steaming time. Four different inks – cyan, magenta, yellow and black – were used in this study and the influences of these factors on the four different colours were studied through experimental design. The results showed that apart from the influence of individual factors, the final colour yield also depended on the interaction effect of the factors.     

Modified guar gum: An alternative source for printing of cotton fabric with reactive dye

The alginate thickener is the thickener frequently used for reactive printing of textile. The thickener responds with reactive pigments and thus does not lead to the fabric composition becoming stiffer. In this study, we prepared oxidised natural guar gum with hydrogen peroxide, sodium hypochlorite and sodium hydroxide. All other polysaccharides comprise reactive hydroxyl units with a stronger reactivity that must be replaced if they are to be used in reactive printing. Guar derivatives were synthesised and verified using Fourier-transform infrared (FTIR) spectroscopy. Natural thickeners, synthetic guar gum derivatives, have been employed in textile printing technique. In comparison to other synthetic thickeners, modified environmental guar gum polymer has been shown to be an ecologically friendly and low-cost thickener. Cotton fabric printed with modified guar thickening with hydrogen peroxide has even stronger colour strength than fabric printed with sodium alginate thickener, which is highly favourable. Penetration properties, colour value, colour strength, colour fastness to washing, light and rubbing was compared with alginate thickener (readily available on the market). Guar gum thickeners showed enhanced features versus sodium alginate for reactive printing. Partially replaced guar gum is an appropriate option due to the colour and physical properties.     

十二烷基硫酸钠对亚麻织物喷墨印花性能的影响

为提高亚麻织物的喷墨印花颜色效果,将十二烷基硫酸钠（SDS）与海藻酸钠（SA）协同作用于亚麻织物的预处理工艺,对处理后织物表面墨滴的铺展面积、喷墨印花色块的颜色参数进行了测试,使用接触角测量仪、扫描电子显微镜（SEM）、固体表面zeta电位仪、X射线光电子能谱仪（XPS）和傅里叶变换红外光谱仪（FTIR）对预处理前后亚麻织物表面物理和化学性能进行了表征。结果表明：与SA预处理织物相比,表面活性剂的引入可使亚麻织物表面墨滴铺展面积减小14%,墨滴渗化程度也明显减小;青色和黑色印花色块的表观颜色深度增加,摩擦色牢度略有降低,断裂强力和耐日晒色牢度无明显改变。同时从SEM图看出,经预处理后,SDS+SA预处理剂在亚麻织物表面上形成了薄膜,纤维间以锯齿状的膜结构堵塞了孔隙,促使更多的活性染料在滴落的位置与纤维发生共价结合;此外,预处理处理后织物的亲水性增加,有利于染料对亚麻纤维的上染。     

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.     

Polymerization products of acrylic acid with Gleditsia triacanthos gum as thickeners for reactive printing

Glactomannan gum was isolated from Gleditsia triacanthos seeds. It was then subjected to polymerization with acrylic acid using potassium persulfate initiation system. Products of the polymerization reactions are referred to as composites. Technical evaluation of the latter as thickening agent in reactive printing using cotton fabric was studied. The use of composite in printing cotton fabric with natural dye was also studied. It was found that the composite pastes are characterized by a non‐Newtonian pseudoplastic behavior, and their apparent viscosity increases on increasing the concentration of acrylic acid. The composite can be diluted by water and its viscosity increases by neutralization. Printing pastes of the composite are very stable for storing, in contrast with those of natural gum which exhibit no stability for storing. It was also found that reactive prints thickened with the composite display relatively higher K/S than those thickened with native gum do. Meanwhile, K/S values of prints thickened with the composite are comparable with the values of those thickened with sodium alginate. Printed fabrics using the composite as a thickener exhibit soft handle, and their overall fastness properties are almost equal to, if not higher than, the properties of those printed using sodium alginate. On the other hand, printing of cotton fabric with a natural dye using the composite as a thickener results in prints with K/S values lower than those obtained using commercial synthetic thickener; but the overall fastness properties are nearly the same. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 931–943, 2006     

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     

Enhancing the outline sharpness of crosslinked printed cotton fabrics using ethylene glycol diglycidyl ether

In the current study, to obtain environmentally friendly printed cotton fabrics with a clear contour edge, ethylene glycol diglycidyl ether (EGDE) as a crosslinking agent and guar gum as a thickener were used with natural madder dye. The solid content of the thickener was assessed to determine the optimal viscosity of the printing paste. Scanning electron microscopy images and colour depth (K/S) values were used to analyse the surface morphology and printing properties. The pattern outline of the printed cotton fabric was assessed with an optical microscope. Also, the overall fastness properties of the printed fabrics were evaluated. The results showed that when the solid content of guar gum was 2.5%, the viscosity of the printing paste was close to 10 000 mPa.s, which was suitable for printing cotton fabrics. Scanning electron microscopy analysis showed that most of the printing paste was removed during the washing process, and did not affect the microstructure of the cotton fabric. Compared with direct printed cotton fabrics, the K/S values of mordant and crosslinked printed cotton fabrics increased by 3.12 and 4.01, respectively. In the optical microscopy photographs, the mordant and crosslinked printed cotton fabrics displayed a clear outline sharpness of the printed pattern, and excellent printed products were obtained. The colour fastness to washing, rubbing and light of the crosslinked printed cotton fabric were significantly improved, reaching levels of 4-5.     

Single‐phase ink‐jet printing onto cotton fabric

The current commercial application of ink‐jet reactive inks to cotton fabrics requires pretreating with pad liquor containing a thickener, urea and alkali prior to printing. In this study, attempts have been made to develop a reactive ink‐jet print in a single‐phase process by adding an organic salt to the ink formulation and hence removing the need to pretreat fabrics. This approach utilises inks containing both a reactive dye, in this case Procion Red H‐E3B, and an organic salt such as sodium formate, sodium acetate, sodium propionate or tri‐sodium citrate. The behaviour of a novel reactive ink formulation for ink‐jet printing on to cotton fabric was evaluated at different pH vlaues. The results at optimum pH indicated that printed non‐pretreated fabrics with ink containing organic salts exhibited a higher level of reactive dye fixation than printed pretreated fabric containing no organic salt ink. The yielded prints demonstrate excellent colour fastness to washing and dry/wet crocking properties. The light fastness of the printed fabrics was improved by adding an organic salt to the ink formulation.     

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.     

Digital and conventional printing and dyeing with the natural dye annatto: optimisation and standardisation processes to meet future demands

The plant colorant annatto was investigated to determine its potential use as a natural dye for conventional and novel textile applications. Alum was selected as a mordant. Different techniques of mordanting and a broad set of variations in the dyeing recipes were applied to achieve optimisation and an improvement in colour fastness properties. Quality control of all dyeings was performed using standard fastness tests and colour measurements. Printing of cotton fabrics was also achieved with annatto using the flatbed screen‐printing technique. Measurement of the rheological and physical properties of the annatto printing paste confirmed its stability and suitability for conventional printing. Fastness properties of the conventionally printed annatto fabric were also measured. A novel water‐based digital printing ink using annatto was prepared and applied to cotton fabric using a digital printing application. The physical properties of the annatto ink‐jet ink were also measured. Wash, light and rub fastness properties of the annatto digitally printed fabric were determined and compared with those of conventional printing methods. The results were promising for annatto as a natural colorant, which possibly paves the way for the development of a new range of natural environmentally friendly dyes.     

The use of carbon nanotubes in textile printing

The characteristic properties of carbon nanotubes (CNTs), particularly their heat conduction, electrical conductivity, high modulus of elasticity, high strength, and resistance to chemicals, have resulted in widespread application of CNTs in nanotechnologies. In this study, CNTs were used to impart specific functionality to textiles by printing techniques. To this aim, modified commercial aqueous dispersions of multiwalled CNTs from Nanocyl^® were used for preparing special compositions as paste for printing by conventional techniques (screen printing) and as inks for ink‐jet printing to bestow the fabric antistatic and antibacterial properties. Taking into account the importance of the dispersion level of CNT in the printing composition from the point of view of antistatic properties, the quality of the CNT dispersion was assessed on the basis of particle size distribution by means of a DLS PSS Nicomp device. Printings were done on two types of woven fabrics: 100% cotton and 30/70% cotton/polyester blend. The CNTs used in printing were found to impart antistatic and antibacterial properties to the printed fabrics. These imparted properties were resistant to repeated washing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Resistance variation of conductive ink applied by the screen printing technique on different substrates

This research study focuses on the application of conductive ink by the screen printing technique to evaluate the potential of creating printed electrodes and to investigate the effect of washing upon electrical resistance and flexibility. Two conductive inks were applied by a conventional screen printing method on four different textile substrates, 100% cotton, 50%/50% cotton/polyester, 100% polyester and 100% polyamide. The inks were also applied on a multifibre fabric. Atmospheric plasma treatment was applied to improve the adhesion to the samples, and the resistance values were compared with those of non‐treated samples. The values were measured before and after cleaning and washing tests, which were performed to simulate domestic treatment for garments to predict the behaviour of the inks after normal usage of the fabrics. Comfort properties like stiffness of the fabrics were also evaluated after five and 10 washing cycles. It was observed that PE 825 ink forms a thicker film on the fabric surface, contributing to the loss of flexibility of the textile. However, PE 825 ink also produced the best results in terms of durability and lower values of resistance. Polyamide fabrics lost their conductive property after five washing cycles due to weak bonding between the ink and the fibres, whereas cotton fibres provided the best results.     

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.     

Digital ink-jet printing of regenerated cellulose nanofibrous mats with reactive inks

The versatility of nanofibres enables them to be used for various technological applications such as filtration, biomedicine and healthcare, composites, protective and functional textiles. Recently, in addition to the functional properties of electrospun nanofibrous mats, their aesthetic properties have been explored. Herein, attempts have been made to develop digital ink-jet printing of regenerated cellulose nanofibrous mats with reactive inks. First, a cellulose acetate polymer was created to fabricate electrospun cellulose acetate nanofibrous mats, which were then converted into regenerated cellulose nanofibrous mats through deacetylation. Next, the cellulose nanofibrous mats were treated with an alkaline solution then coloured with four (cyan, magenta, yellow and black) commercially available reactive inks by a digital ink-jet printing method using a piezoelectric digital ink-jet printer. Various parameters were investigated, including the optimal concentration of the pretreatment agents, fixation temperature and time, colour yield and the absorbency of the electrospun nanofibrous mats. The digital ink-jet printed cellulose nanofibrous mats exhibited excellent colour yield and colour fastness properties. Morphological analysis through scanning electron microscopy and chemical analysis through Fourier Transform–infrared were also carried out.     

石墨烯/棉织物制备及其电热性能研究

采用丝网印刷方式将氧化石墨烯浆料印制在棉织物表面,再经还原方法得到了电热性能优良的石墨烯棉织物。综合分析织物表面形貌、表面电阻及发热性能,探究了印制次数、还原浓度、还原时间及还原剂种类对石墨烯棉织物发热性能影响。结果表明,印制次数为10次,还原浓度为5 mg/mL,时间6 h,施加在两端电压为24 V时,织物的表面电阻为4.0 kΩ/cm,表面温度为46.8℃,电热性能达到最佳。     

Properties of ink‐jet printed,ultraviolet‐cured pigment prints in comparison with screen‐printed,thermo‐cured pigment prints

A collection of printed fabrics for men’s shirts was designed and prepared using computer‐aided design/computer‐aided manufacturing technology. The colours for designs were ink‐jet printed on cotton fabrics with pigments and ultraviolet‐cured. These prints represented the target colours for subsequent flat‐screen printing, which was performed using pigment printing pastes and thermal curing. For an exact transfer of colours of the ink‐jet‐printed standard into the screen‐printing process, a computer recipe prediction method was used. A comparison of colorimetric parameters of fabrics printed with both printing techniques shows minimal and acceptable differences in the CIELab colour values. A comparison of colour fastness properties proves that very good colour fastness is achieved on the pigment‐printed fabrics produced with both printing techniques. The flat‐screen‐printed fabrics show better colour fastness to washing, perspiration and rubbing, while ink‐jet‐printed fabrics show better colour fastness to dry‐cleaning and light. The fabrics printed with both printing techniques have high rigidity and non‐elastic properties. The mechanical and physical parameters are strongly dependent upon the amount of the dry substance of the printing media applied on the cotton fabric surface, which is higher on screen‐printed fabrics. The ink‐jet‐printed fabrics show better air permeability than flat‐screen‐printed fabrics.     

Printing of antimicrobial microcapsules on textiles

One of the processes for the application of functional compounds that alter textile properties is encapsulation. In our research, a microencapsulated biocide was used to produce an antimicrobial textile product. Melamine–formaldehyde polymer wall microcapsules with a triclosan core were applied to a cotton fabric by screen printing. Printed samples were dried and cured. The fabric hand properties of washed and unwashed samples were tested and the antibacterial activity against Staphylococcus aureus and Escherichia coli was evaluated. The quantity of free formaldehyde on the printed and washed samples was monitored for 2 months. The results show that microcapsules with triclosan can be successfully applied to a cotton fabric by printing, where they provide good antibacterial protection without substantially changing the fabric properties. The quantity of formaldehyde on the unwashed samples is high and it changes with time; however, it significantly decreases with washing.