Search results

Woven and knitted polyester fabrics were pretreated with formulations containing waterborne UV curable resins and silica particles to improve inkjet print quality. The selected formulations were applied with low add-on to reduce the adverse effect on fabric hand without sacrificing the print quality. A print pattern with block areas and lines in cyan, magenta, yellow, and black colors was designed and inkjet printed on the pretreated fabrics with a wide-format inkjet printer (Encad Novajet 750) to investigate the effects of the UV curable pretreatment on the inkjet print color qualities including color depth, color gamut and color lightness.

Experimental results show that both the color depth and gamut of prints on the pretreated taffeta and knitted polyester fabrics were enhanced compared to those on untreated polyester fabrics. However, both the color depth and gamut of the prints on the pretreated satin polyester fabrics were reduced. The lightness change of the inkjet printed colors on pretreated knitted fabrics is similar to that of untreated fabrics whereas the lightness change of prints on pretreated satin and taffeta fabrics shows some differences. All colors have increased lightness on pretreated satin fabrics. However, magenta and black have decreased lightness on the pretreated taffeta fabrics.

The purpose of this study is to modify the FDM 3D printer to print with polystyrene (PS) microspheres as the printing material, thus enabling bottom-up structural color printing and evaluating structural color printing.

This study chose a range of different heated bed temperatures to determine a suitable temperature for accelerating the self-assembly of photonic crystals and printing structural colors on various substrates. In addition, this study enhanced the structural color by doping PS microspheres with different contents of Acid Black 210 dye and evaluated the color-enhanced structural color by eye and spectrophotometer under different light sources.

The results show that the modified 3D printer can be used for structural color printing, and 50°C is determined as the heated bed temperature. There are significant differences in structural colors when printing under different color backgrounds and material substrates, and corresponding suitable substrates should be selected according to the application. The doping of PS microspheres with varying contents of dye results in different color levels of structural color. As with pigment colors, the visual perception of structural color varies when viewed under different light sources.

This paper proposes to print structural colors low-costly, analyze structural colors under substrate and light source conditions, and expand the structural color gamut by enhancing structural colors, which has positive implications for further research on structural colors as printing colors.

Fused filament fabrication (FFF) is a common additive manufacturing method that is widely used owing to its low cost, environmental friendliness and safety. Colour models are needed because of their ability to express more information, but high printing quality and efficiency are difficult to achieve with the existing FFF colour printing methods because of the “inertia” of printing. Inertia refers to the feature of the former colour material remaining in the molten cavity when switching colours in colour FFF printing. The purpose of this paper is to propose a new FFF colour printing method to reduce printing material usage and printing time.

A new FFF colour printing method that uses transitioning waste to construct the part is proposed. Based on the freedom of the colour surface model’s interior space, the internal fill and support of the print model are generated using the transitioning waste to reduce printing material usage and printing time and to achieve environmentally friendly colour printing. The modified elite ant system (EAS) algorithm is used to construct and optimize this method based on the colour surface model.

A colour printing experiment is performed using a colour-mixing FFF printer platform with a special waste extrusion module. The experimental results show that this method can significantly reduce material and time consumption compared to the commonly used method. The printed part produced by this method also has high surface quality.

A new FFF colour printing method that uses transitioning waste to construct the part is proposed. Based on the freedom of the colour surface model’s interior space, the internal fill and support of the print model are generated using the transitioning waste to reduce printing material usage and printing time and to achieve environmentally friendly colour printing. The modified EAS algorithm is used to construct and optimize this method based on the colour surface model. A special waste extrusion module is developed.

The purpose of this paper is to evaluate and discuss colour properties, stability and lightfastness after accelerated exposure in xenon‐arc light apparatus, of 3D ink jet prints produced by using 3D colour printing process.

3D colour prints were produced using ZCorporation 3D printing method. The samples were divided into groups according to the finishing process applied (untreated, finished with different infiltrants). Colorimetric properties were measured using spectrophotometer. Samples were placed into xenon‐arc based weathering apparatus (Xenotest), using the preset glass filtered sunlight, standard indoor conditions. Colour stability was evaluated as change in colour after repeating the spectrophotometer measurements and comparing spectral and specific colorimetric values of initial and exposed samples.

Based on methodology used, the analysis has shown the changes in colour appearance of differently finished 3D prints, which were mostly attributed to chroma and lightness variations. The colour stability of samples studied noticeably varied and is dependent on colour, percentage of ink coverage and finishing method. Issues of colour and stability of 3D ink jet prints could become important as 3D printing emerges into new application areas, in which the object properties will need to be maintained for a certain amount of time.

The research is comparative and is limited to the specific materials and procedures used.

The paper describes aspects of colour 3D printing for which the published research and literature data are still, for the most part, lacking. Colour measurements methodology and evaluation of stability described could be of value for further research and for users of the technology.

This paper aims to present a method of color three-dimensional (3D) printing based on color adherence.

First, experiments of the color effects of 3D printings using different carriers and different printing methods were performed. Second, the color of a specific point could be calculated through a theory of dimension-reducing, and the color distribution of 3D model was transformed from 3D to 1D color line corresponding with 3D print sequence. At last, the color lines, which were printed on a PE film by silk-screen printing, was carried by a filament and then printed through a fused deposition modeling 3D printer.

The printing ink and PE film are suitable as the pigment and carrier under this investigation, respectively. Based on an idea of reducing dimension, the method of 3D color printing through adhering color to a filament is realized. The color saturation of the sample was relatively high through the method.

It is hard to avoid that there may be some residual color in the nozzle through this method, and the purity of following color will be affected. As a result, continuous improvements should be made to perfect the method.

An approach of 3D color printing is described in detail, and what kind of model is more applicable is discussed particularly.

This approach is implemented to print color 3D objects with just one nozzle by means of color adherence. That is, printing the 3D objects using the filament is carried out with 1D color line, which is printed by a traditional printing method.

The purpose of this paper is to prepare anionically surface‐modified organic pigment/binder ink jet inks for printing on chitosan‐pre‐treated silk fabrics.

Anionically surface‐modified organic pigment/binder ink jet inks were prepared in four colours (cyan, magenta, yellow and black). The pigment‐to‐binder ratio was controlled at 1:6.4 for the cyan, magenta and yellow inks, and 1:3.4 for the black ink. Ink formulations (by weight) were assembled and mixed as follows: 8 per cent pigment dispersion, 10 per cent diethylene glycol, 12 per cent glycerol, 5 per cent urea, 10 per cent polyacrylate emulsion binder and 55 per cent deionised water. They were characterised in terms of their particle size, zeta‐potential, particle morphology, viscosity, surface tension and pH. The inks were printed onto silk or the chitosan pre‐treated silk fabrics using a piezo‐type ink jet printer. The fabrics were then heat cured and analysed for the effect of chitosan pre‐treatment on colour gamut, wash fastness and crock fastness.

The formulated ink jet inks yielded an acceptably good ink jetting reliability, one‐year stability and printability. The chitosan pre‐treated silk fabrics gave a wider colour gamut and colour saturation than the non‐treated one. Crock fastness and wash fastness of the chitosan pre‐treated fabrics were relatively better than those of non‐treated fabrics.

The surface‐modified pigments are transparent and thus their inks printed on the chitosan pre‐treated fabrics produced slightly low K/S values of cyan, magenta, yellow, and black colours because the limited chitosan concentration in the pre‐treatment is controlled by its solubility in acidic solution. The higher loading of chitosan pre‐treatment gave higher K/S values and a stiffer touch of the fabrics.

The water‐based pigmented inks having the sulphonate group on the pigment surface can be printed on the fabric surface pre‐treated with chitosan molecules which have the protonated amino groups to give good colour appearance. It is anticipated that this type of ink can be applied to any textile surface which has been pre‐treated with the protonated chitosan.

The modified organic pigments having the sulphonate group on their surface can be used to produce novel water‐based ink jet inks which can print on the chitosan pre‐treated silk fabric. Ionic interactions between the sulphonate group of the pigment and protonated amino groups of chitosan in conjunction with polyacrylate binder enhance colour strength, widen colour gamut and chroma, and produce good adhesion for fabric operational properties such as wash fastness and crock fastness.

The material-jetting-type (MJ) 3-D printing technology has advantages in resolution and color printing. During the printing process, a leveling technique is needed to precisely control the thickness and flatness of each layer. Roller-type leveling mechanism has been adopted in commercial MJ 3-D printers, but it is lack of research on roller leveling process parameters and establishing experimental procedures. Therefore, in this study, a roller-type leveling mechanism for a MJ color 3 D printer was developed, and experimental approaches were utilized to determine process parameters.

The roller-type leveling mechanism was chosen to provide functions of flattening and removal of excess material. The parameters studied were roller speed and rotational direction. Surface roughness, Ra, of printed single-layered specimens was measured at 15 locations for plane roughness and along five lines for line roughness to evaluate the leveling results. Adopting suitable parameters, color samples with and without leveling were printed for comparison and verification.

According to plane roughness results, forward rotation achieved better leveling. Plane roughness was the major criteria to determine roller speed with the assistance of standard deviation of line roughness. The best parameters of the self-developed MJ color 3-D printer were found to be rolling forward at 1,100 rpm. In addition, printed color samples showed great improvement in surface roughness with leveling and no obvious color mixing after leveling.

Leveling is important to achieve desired layer thickness, smooth surface and good color quality in color 3-D printing. For MJ 3-D printing, only patents were revealed regarding roller design, but paper publications have not been presented. This research practically proposed to use experimental approach to understand the effects of roller operating parameters and to find the suitable ones based on surface roughness results.

This research established the experimental procedures and also suggested guidelines of experimentally obtaining suitable roller leveling process parameters. Developers can refer to this study results to design and adjust leveling mechanism in a new MJ 3-D printer.

The experimental approach can be applied to similar MJ 3-D printing systems if different materials are introduced or the platform speed is changed. The observed trends suggested several guidelines to plan limited experiments only to obtain suitable roller process parameters.

The purpose of this paper is provide a broad view for the standardization efforts of color quality evaluation of color 3D printing techniques. Further, this review paper demonstrates the processes and color properties of most color 3D printing techniques with specific devices and applications to extend the range of possible memberships of standardization group.

Six color 3D printing techniques including plastic-based, paper-based, powder-based, organism-based, food-based and metal-based color 3D printing have been introduced and illustrated with colorization principles and forming features in detail. Moreover, for printed 3D color objects, literature about color measurement, color specification and color reproduction are described and analyzed, respectively.

Four color 3D printing techniques including plastic-based, paper-based, powder-based and food-based color 3D printing show great affinity toward standardization of color quality evaluation, while their colorization principles indicate that it is difficult with a single standard frame. It is possible to develop a completed color quality evaluation standard for color 3D printing based on approaches in color 2D printing when color measurement method and devices are standardized together.

The paper provides an important guide focusing on the efforts to standardize the colorization processes and color quality evaluation of the color 3D printing techniques.

In this present study, electrophotographic printing is made on papers which are subjected to different recycling numbers, and this paper aims to examine the colour changes of this printing type.

Four-colour electrophotographic printing is carried out on adhering to the INGEDE 11p standard recycled papers four times under the same conditions. Colour measurements are made by means of electrophotographic printed colour scales printed on these recycled papers. Colour measurements are made with the X-Rite eXact spectrophotometer according to the ISO 13655:2017 standard. As a result of colour measurements, colour differences (ΔL′, ΔH′, ΔC′, ΔE₀₀) of recycled papers are determined using some formulas.

According to the values obtained after four recycling, the highest ΔL′ value is found to be 4.80 yellow and the lowest 1.92 black. Again, according to the measurement results, it is determined that the highest ΔE00 is yellow colour with a value of 5.66, and lowest ΔE₀₀ is black colour with a value of 1.98. In ΔH′, black colour is the highest value of 12.61, the lowest value with −2.05 is obtained in magenta colour. It was observed that the highest ΔC′ value is 2.98 in yellow, and the lowest value is −0.28 in black.

In the printing industry, sometimes customers want to monitor the colour differences in the printing by taking the L′a′b′ obtained values as a result of printing from the printing houses. If the colour differences exceed the tolerance values, then they can interfere with the printing. As a result of the calculations, colour changes in electrophotographic printing are observed with many parameters. This study can be a pioneer for the studies that can be done on this subject.

The purpose of this paper is to study a feasible visualization of large-size three-dimension (3D) color models which are beyond the maximum print size of newest paper-based 3D printer used 3D cutting-bonding frame (3D-CBF) and evaluate the effects of cutting angle and layout method on printing time of designed models.

Sixteen models, including cuboid model, cylinder model, hole model and sphere model with different shape features, were divided into two symmetric parts and printed by the Mcor IRIS HD 3D printer. Before printing, two sub-parts were rearranged in one of three layout methods. Nine scaled sizes of original models were printed to find the quantitative relationship between printing time and scale values in each type. For the 0.3 times of original models, six cutting angles were evaluated in detail.

The correlation function about colorization time and printed pages was proposed. Based on 3D-CBF, the correlation between printing time and scale size is statistically defined. Optimization parameters of designed parts visualization about cutting angel and layout method were found, even if their statistical results were difficult to model their effects on printing time of specimens.

The research is comparative and limited to the special models and used procedures.

The paper provides a feasible visualization and printing speed optimization methods for the further industrialization of 3D paper-based printing technology in cultural creative field.