Search

The SiO 2 -Al 2 O 3 refractories and corresponding inks for 3D printing were prepared from silica glass binder suspensions and fused alumina with grain sizes of 75 and 240 μm. Phase analysis (XRD) and morphological studies (SEM) were conducted to investigate the influence of sintering temperature and Al 2 O 3 content on the strength, porosity, and density of the refractories. Rheological studies (rotational viscometry) were carried out determine the effect of polyethylene glycol (PEG) and hydroxypropyl methylcellulose (HPMC) content on the flow behavior of the inks. It was established that firing refractories based on fused silica and fused alumina at 1500 and 1600 °C led to the formation of mullite and aluminosilicate melt on the surface of Al 2 O 3 grains, enhancing the strength of the synthesized materials. Addition of PEG and HPMC to the ink composition was found to improve their rheological properties by increasing yield strength and promoting plastic flow. The ink demonstrated high printability and they are suitable for producing refractories using the Direct Ink Writing method. [ABSTRACT FROM AUTHOR]

For this research, three hydrophobically modified polyacrylamides, HPAAB, HPAAF, and HPAAS, with multiple hydrophobic monomers were designed, synthesized, and used as thickeners in aqueous ink for digital ink-jet printing. The structures were characterized by Fourier transform infrared (FTIR) analysis and nuclear magnetic resonance (NMR) spectroscopy. The viscosity–average molecular weight was determined by intrinsic viscosity determination and was adjusted according to hydrophobic content. The critical association concentration (CAC) of polymers was measured simultaneously using the apparent viscosity method and the fluorescence spectrum. The formation of a network structure and the mechanism of hydrophobic association are visualized dynamically with a scanning electron microscope (SEM) at different concentrations. Under the same conditions, HPAAB exhibited excellent thickening ability across different pH levels, temperatures, and shear rates, which is caused by the longer hydrophobic side chain and the stronger hydrophobic effect of the behenyl polyoxyethylene ether methacrylate (BEM) group. Furthermore, an aqueous ink using HPAAB as a thickener displays significant printability and stability, functioning much better than a corresponding aqueous ink that uses a commercial thickener. This is the first example of a hydrophobic associating polyacrylamide, incorporating both hydrophilic and hydrophobic units within a single hydrophobic chain, thereby serving as an efficient thickener for aqueous ink. [ABSTRACT FROM AUTHOR]

The present work aimed to study the printability and tensile behaviors of ramie yarn‐reinforced PLA‐based composites fabricated by an in situ impregnated fused filament fabrication (FFF) process. The dimensional error analysis was conducted to evaluate the printability of biocomposites with different processing variations and continuous ramie yarns. The effect of yarn volume fraction (Yf) caused by processing variations and ramie yarn characteristics on the mechanical properties was also studied. The results showed that the dimensional accuracy of the biocomposites with different ramie yarns could be adjusted by process parameter optimization. On the basis of ensuring printability, the Yf was within the range of 6.80% to 23.32% in the current study. With the increase of Yf, the tensile strength and the tensile modulus of the biocomposites significantly increased. When the Yf was 23.32%, the tensile strength and the tensile modulus increased by 60.78% and 382.35%, respectively, compared to pristine PLA. In addition, an analytical model considering the influences of Yf and microstructural characteristics such as interfacial void content (Vp) on the tensile strength of the 3D printed biocomposites was derived, and the theoretical predictions were in good agreement with experimental measurements. [ABSTRACT FROM AUTHOR]

We present a novel, systematic method for evaluating design printability in 3D food printing using a scoring system based on the Design for Additive Manufacturing (DfAM) guidelines. This study addresses a gap in the current literature by proposing a structured approach to assess and enhance the printability of 3D food designs. Our framework consists of a set of nine critical questions derived from the multi-level DfAM guidelines, focusing on key printability factors including unsupported features, geometric accuracy, and surface finish. The evaluation process converts qualitative assessments into numerical values, resulting in a comprehensive printability score that categorizes designs into high, moderate, or low printability levels. To validate the effectiveness of this method, we conducted a case study involving five different designs. The scoring system successfully explores the design space and maximizes the printability of 3D food products. This method alleviates the challenges in design evaluation compared with traditional trial-and-error approaches. The results demonstrate the practicality and efficiency of our framework's output. The proposed methodology provides a structured approach to design evaluation, offering practical insights and a valuable tool for improving the success rate of 3D printed food products. This research contributes to the field by offering a systematic framework for assessing and enhancing the printability of 3D food designs, potentially accelerating the adoption and effectiveness of 3D food printing technology in various applications. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate glycol (PETG) is a novel amorphous shape memory polymer with excellent printability for 4D printing. In this article, ethylene‐vinyl acetate (EVA) is used as a biocompatible and non‐toxic copolymer to improve plasticity and shape memory performance of PETG. PETG‐EVA blends are prepared and 3D printed using a melt mixing method and an upgraded fused deposition modeling (FDM) with a pneumatic feeding system. The results of the thermal analysis show that the blends exhibit two tan‐delta peaks, each related to their components, and morphology images confirm that they are biphasic and immiscible with good compatibility. The morphology of both EVA10 and EVA30 matrix droplets is observed, with the droplets being larger for EVA30. The use of a pneumatic feeding system, along with the ability to control the output melt flow, results in the best printing ability for EVA30, with minimal microholes between the grids and interlayer cracks. The tensile strength of PETG‐EVA blends ranged from 25.38 to 20.14 MPa, with the highest tensile strength achieved for EVA30. The shape memory performance of all three blends is similar; with shape recovery exceeding 90% in 20 s. Blends with higher EVA content exhibited faster shape recovery within the first 10 s. [ABSTRACT FROM AUTHOR]

Central composite design (CCD) is a statistical experimental design technique that utilizes a combination of factorial and axial points to study the effects of multiple variables on a response. This study focused on optimizing hydrogel formulations for 3D printing using CCD. Three biopolymers were selected: sodium alginate (SA), gelatin (GEL), and carboxymethyl cellulose (CMC). The maximum and minimum concentrations of each polymer were established using a Google Scholar search, and CCD was employed to generate various combinations for hydrogel preparation. The hydrogels were characterized in accordance with their swelling degree (SD) in phosphate-buffered saline (PBS) and Dulbecco's Modified Eagle Medium (DMEM), as well as their printability in 2D and 3D assays. The formulation consisting of 7.5% SA, 7.5% GEL, and 2.5% CMC exhibited the best swelling properties and exceptional printability, surpassing all other tested formulations. This study highlights the effectiveness of design of experiment methodologies in accelerating the development of optimized hydrogel formulations for various applications in 3D printing and suggests avenues for future research to explore their performance in specific biological contexts. [ABSTRACT FROM AUTHOR]

Utilizing steel slag aggregate (SA) as a substitute for river sand in 3D concrete printing (3DCP) has emerged as a new technique as natural resources become increasingly scarce. This study investigates the feasibility of using steel slag (SS) as fine aggregate for 3DCP. Ninety mixtures with varying steel slag aggregate-to-cement ratios (SA/C), water-to-cement ratios (W/C), and silica fume (SF) contents were designed to study the workability and compressive strength of the 3D-printed concrete. Additionally, the actual components were printed to evaluate the printability of these mixtures. The experimental results indicate that it is feasible to fully employ SA in concrete for 3D printing. Mixtures with slump values ranging from 40 to 80 mm and slump flow values varying from 190 to 210 mm are recommended for 3D printing. The optimal mix is determined to have SA/C and W/C ratios of 1.0 and 0.51, respectively, and an SF content of 10% by cement weight. A statistical approach was utilized to construct the prediction models for slump and slump flow. Moreover, to predict the plastic failure of the 3D-printed concrete structure, the modified prediction model with an SA roughness coefficient of 4 was found to fit well with the experimental data. This research provides new insights into using eco-friendly materials for 3D concrete printing. [ABSTRACT FROM AUTHOR]

Direct ink writing (DIW), or robocasting, is emerging as a key additive manufacturing technique for ceramic materials. Nevertheless, controlling ink rheology, finding optimal ink properties for printability, and optimising final mechanical performance have consistently posed major challenges. This review addresses these critical aspects of ceramic DIW through a meta-analysis. It encompasses rheological data from various ceramic inks and reviews methods for tuning ink properties to improve printability. The collected rheological properties are integrated into various printability criteria and models, leading to the proposal of an empirical criterion based on two key rheological parameters. Furthermore, the mechanical properties of both dense and porous ceramic components are discussed, revealing their correlations with rheology and processing defects. The objective of this comprehensive work is to serve as a valuable toolkit and guideline, providing researchers with the necessary insights to develop superior ink formulations and enhance the mechanical performance of robocasted ceramic components. [ABSTRACT FROM AUTHOR]

Colorants used in security inks are special pigments that radiate in the UV region or IR region. Obtained pigments can be from valuable rare earth elements or they can be organic based. Organic-based pigments are generally insoluble in water, which limits their use. For this purpose, an organicbased UV-radiating pigment was synthesized and made water-soluble by forming its salt. With the obtained salt-formed pigment, inkjet ink that can be used in counterfeiting was applied and its printability and resistance properties were determined. In this study, 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was synthesized and water-based inkjet inks with hydroxy ethyl cellulose binder were produced. The prepared inks were printed on the paper surface. The color and gloss of the prints obtained were measured both in the visible region and in the UV region. Its optical properties were detected by UV spectroscopy. Strength properties such as light fastness, nitro resistance, alkali resistance, acid resistance, rub resistance, drying time, adhesion and dry film weight of the prints were determined. As a result; Inkjet ink with 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was produced and it was concluded that it has good resistance properties. [ABSTRACT FROM AUTHOR]

Direct ink writing (DIW) is a promising additive manufacturing technique for fabricating structural ceramics, including alumina-toughened zirconia (ATZ), heavily reliant on the rheological properties of the paste. The rheological properties of aqueous ATZ pastes with 25 wt% Pluronic® F127 hydrogel and solid loadings of 28–44 vol% were investigated, complemented by characterization of the parts, including relative density and shrinkage measurements, to assess the printability. The 42 vol% paste was identified as most suitable for producing high-density parts with minimal shrinkage. A controlled drying process gradually decreased humidity from 90% to 30% while raising temperature from 25 to 60°C over 4 days to prevent drying defects. Mechanical testing showed DIW-printed high-density (97.2±2.2%) parts with a mean flexural strength of 670±270 MPa, Vickers hardness of 13.6±2.8 GPa, and fracture resistance of 4.4±0.2 MPa, highlighting the potential for DIW to create high-density ATZ ceramic parts with favorable mechanical properties. [ABSTRACT FROM AUTHOR]

Irregular (i.e. non-spherical) morphology powder is more cost-efficient to produce than spherical shaped powder. However, its reduced levels of flowability limit the wide application ranges of laser beam powder bed fusion (LPBF). To address this issue, a novel powder sheet additive manufacturing concept (MAPS) is proposed. Herein, a pre-manufactured metal particle-polymer binder composite (i.e. powder sheet) feedstock is employed as a raw material. The printability of irregularly shaped powder particles in sheet (MAPS) format was physically investigated using a range of different process parameters. The manufacturing process was observed by high-speed imaging. Microstructural and chemical element characterisations of the irregularly shaped powder particle print were then compared against those prints which were conducted using sheet-based (MAPS) spherical powder morphologies. The results indicated that the geometric accuracy and density of irregular powder morphology sheet printing improved when using a negative defocus strategy of the laser beam. A negative defocusing strategy allowed for the melting mode of the material to be transformed from keyhole to a more favourable conduction state. High speed imaging revealed that more spatter and vapour plume were observed with the increase in the magnitude of the negative defocus. The multi-morphology 304 L stainless steel (SS304) samples were printed in a single printer using an efficient method for the first time, i.e. printing spherical SS304 material on top of irregular SS304. EDX results indicated an insignificant change of chemical elements between the spherical and irregular prints. EBSD results revealed that columnar grains could grow through the irregular-spherical transition zone and similar grain size can form between spherical and irregular prints. The results of this study provide insights into the optimum printing configurations for powder sheet additive manufacturing using a cost-effective solution of irregular morphology material. [ABSTRACT FROM AUTHOR]

Printing foods in the desired shape with minimal additives and their stability after printing are the most important points for 3D food technology. In this study, the effects of water (5%, 10%, 15%, and 20%) and salt (0.5%, 1%, 1.5%, and 2%) on the printability of meat paste were evaluated to achieve improved textural and rheological properties. The printing parameters were examined at every stage, starting from the line thickness of the printed product, until the final 3D printed product was obtained. Accordingly, meat printability determined using different ingredient flow speed (3, 3.5, 4, 4.5, and 5), fill factor (1.2%, 1.3%, 1.4%, 1.5%, and 1.6%) and distance between layers (1.2, 1.4, and 1.6 mm). Salt addition increased the firmness and consistency of the samples, while the viscosity, storage modulus, and loss modulus decreased with the addition of water. Considering the line thickness and outer length, the most appropriate shape was obtained with 10% water and 1.5% salt. The optimal ingredient flow speed, fill factor, and distance between layers at a constant printing speed (2500 mm/min) were 3, 1.2%, and 1.4 mm, respectively. Four-layer-infilled 3D-printed samples maintained their initial shape after cooking, regardless of the cooking method. However, only baked products maintained their initial shapes among full-infilled samples. Although water and salt have different functions in meat, the use of the appropriate ratio is necessary for 3D-printed meat-based products to provide printability and post-production stability. To sum up optimum parameters and road map for printing meat and meat products including leftover meats and low-value by-products were revealed. [ABSTRACT FROM AUTHOR]

Abstract Utilizing steel slag aggregate (SA) as a substitute for river sand in 3D concrete printing (3DCP) has emerged as a new technique as natural resources become increasingly scarce. This study investigates the feasibility of using steel slag (SS) as fine aggregate for 3DCP. Ninety mixtures with varying steel slag aggregate-to-cement ratios (SA/C), water-to-cement ratios (W/C), and silica fume (SF) contents were designed to study the workability and compressive strength of the 3D-printed concrete. Additionally, the actual components were printed to evaluate the printability of these mixtures. The experimental results indicate that it is feasible to fully employ SA in concrete for 3D printing. Mixtures with slump values ranging from 40 to 80 mm and slump flow values varying from 190 to 210 mm are recommended for 3D printing. The optimal mix is determined to have SA/C and W/C ratios of 1.0 and 0.51, respectively, and an SF content of 10% by cement weight. A statistical approach was utilized to construct the prediction models for slump and slump flow. Moreover, to predict the plastic failure of the 3D-printed concrete structure, the modified prediction model with an SA roughness coefficient of 4 was found to fit well with the experimental data. This research provides new insights into using eco-friendly materials for 3D concrete printing.

Colorants used in security inks are special pigments that radiate in the UV region or IR region. Obtained pigments can be from valuable rare earth elements or they can be organic based. Organic-based pigments are generally insoluble in water, which limits their use. For this purpose, an organic based UV-radiating pigment was synthesized and made water-soluble by forming its salt. With the obtained salt-formed pigment, inkjet ink that can be used in counterfeiting was applied and its printability and resistance properties were determined. In this study, 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was synthesized and water-based inkjet inks with hydroxy ethyl cellulose binder were produced. The prepared inks were printed on the paper surface. The color and gloss of the prints obtained were measured both in the visible region and in the UV region. Its optical properties were detected by UV spectroscopy. Strength properties such as light fastness, nitro resistance, alkali resistance, acid resistance, rub resistance, drying time, adhesion and dry film weight of the prints were determined. As a result; Inkjet ink with 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was produced and it was concluded that it has good resistance properties.

Bacterial cellulose (BC) is an exopolysaccharide with unique properties that has been applied in various fields. However, the dense and intertwined nature of BC fibers limits its use in certain applications, including 3D printing scaffolds for bone regeneration. In this work, a controllable BC-based bio-ink for 3D printing was successfully prepared by modifying the neat BC through maleic acid (MA) treatment, aiming to promote bone tissue regeneration. To achieve homogeneous BC dispersions while preserving its crystalline and chemical properties, BC was modified by MA solution (60 %, w/V) with solid-liquid ratio from 1꞉5 to 1꞉50 (w/V) to obtain MA-BC dispersions. The analysis results from microstructure, chemical group, crystallinity, and wettability indicated that the BC/MA solution with ratio of 1꞉30 demonstrated the best pre-treatment performance to obtain MA-BC. Subsequently, by combining MA-BC with gelatin, we successfully formulated MA-BC-GEL gels with favorable rheological properties and compression modulus, which can be used as promising bio-inks for 3D bioprinting applications. In vitro tests demonstrated 1꞉30 MA-BC possessed excellent biocompatibility, a significant ability to express the alkaline phosphatase gene and osteogenic-related genes, and facilitated the formation of mineralized nodules. The utilization of this novel bio-ink in scaffold preparation for bone regeneration highlights the promising application of modified BC in bone tissue engineering field.

Thermoplastic polyurethane (TPU) has emerged as extremely benign materials for next-generation manufacturing using additive manufacturing processes due to its favorable mechanical properties, durability, and as well as biocompatibility. However, the lack of stiffness of TPU affects its buckling strength and performance efficiency. Therefore, an efficient method of optimization of a 3D-printable composition of TPU-based blends is necessary. In this work, attempts were made to explore material extrusion additive manufacturing technique of acrylonitrile–butadiene–styrene (ABS)/TPU blends with particular reference to mechanical and damping behaviour. Design of experiment (DoE) was used to determine the optimum printing parameters. Rheological studies were exploited to understand the printability, and optimum 3D-printable blend composition. The damping behaviour of each blend composition was calculated and a damping ratio (ξ) between 1 ≤ ξ ≤ 2 was observed for 40 wt% ABS loading, which raised to 1 ≤ ξ ≤ 4 for 80 wt% ABS loaded blend specimen. Furthermore, for ABS incorporated TPU, a significant enhancement of stiffness over neat TPU was achieved, thereby reasonably addressing the filament stiffness issue. This work introduces an efficient method of improving TPU filament printability while parallelly identifying the printable blend composition which can be beneficial for several potential applications. [ABSTRACT FROM AUTHOR]

The sustainable use of natural resources is becoming an increasingly important issue today. Stone paper, produced as an alternative to cellulose-based paper from the forest, is rich in minerals and produced without cellulose and water. This study focuses on the behavior of screen-printing ink on two different papers, stone paper and coated sticker paper. Properties such as ink adhesion, rubbing resistance, optical printing ink density, ink consumption, and lightfastness were measured on these surfaces. Solvent- and UV-based inks were used, and printing was carried out on cellulose-based (coated sticker paper) and mineral-based (stone paper) paper layers using three different mesh counts (90, 120, and 140 tpc). The rubbing resistance and lightfastness of the papers were also measured. The present findings revealed that stone paper had the same printability properties as cellulose-based paper. The study concluded that using a 140 tpc mesh with both types of ink results in a high-lightfastness ink layer and lower ink consumption. UV-based inks exhibited high rub resistance across all mesh counts. Additionally, when printing with stone paper, there will be a reduction in ink consumption, thereby achieving cost savings. Based on the present findings, it was concluded that water- and oil-resistant stone paper can be considered an essential alternative in many fields, including the printing industry. [ABSTRACT FROM AUTHOR]

Printability and interlayer adhesion are the most critical issues in 3D printing of immiscible polymer blends. It can affect structural integrity and mechanical performance of the printed parts. In this work, an effective strategy to improve the printability and interlayer adhesion of immiscible acrylonitrile‐butadiene‐styrene/polypropylene (ABS/PP) blends was implemented by introducing styrene–ethylene/butylene–styrene copolymer grafted with maleic anhydride (SEBS‐g‐MA) as a compatibilizer. The printability of the developed blends was investigated using rheological properties such as absolute value of complex viscosity, loss tangent and die‐swell ratio. Interestingly, it was found that the additive manufactured blends with 20 wt% SEBS‐g‐MA loading showed improved interlaminar shear strength, impact strength, Young's modulus and toughness as compared with the pure blend. Fractography analysis revealed that two different possible failure mechanisms, interface and matrix failure were apparent in the 3D printed samples with and without SEBS‐g‐MA content. This work provides a promising pathway to fabricate the complex structures from polymer blends with improved mechanical properties and surface finish. Highlights: This study demonstrated improved interlayer adhesion at the printed interface of immiscible ABS/PP blends in presence of SEBS‐g‐MA.The printability of the developed blends was predicted from rheological properties.Additive manufactured blends with SEBS‐g‐MA loading showed improved mechanical performance. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to determine the ink removal efficiency of papers with different recycling numbers and to examine some electrophotographic printing properties. Design/methodology/approach: The base papers prepared according to the INGEDE 11p standard are subjected to six recycling stages (RS) under equal conditions. The physical-optical properties of the papers obtained at the end of each RS are measured and CMYK (cyan, magenta, yellow, key) color measurement scales are printed on each paper with electrophotographic printing. Color measurements of the printed papers are measured using the X-Rite eXact spectrophotometer, adhering to the ISO 13655:2017 standard. According to the measurement results of the optical properties, the ink removal efficiency of each recycling step is determined as a percentage (%) using some formulas. Findings: As general, according to DEMLab and IERIC data, it is determined that the ink removal efficiency increased as the recycling repetition increased. In DEMf factor values, the highest deinking efficiency is obtained after the fourth RS. There is no significant difference between the printing properties of the samples. Originality/value: It has been a matter of curiosity that papers lose their properties after how many RS. Many studies have been carried out on this subject and it has been presented by experimental methods that the printability properties of papers increase or decrease after which RS. This study can be a pioneer for future studies. [ABSTRACT FROM AUTHOR]

Polyolefins and polyolefin elastomers (POEs) are widely used in various applications due to their unique properties. However, their use in 3D printing has been limited due to challenges such as excessive softness, shrinkage, warpage, and poor mechanical properties. In this study, two strategies were employed to enhance the performance of POEs in 3D printing. First, POE was blended with 10%, 30%, and 50% percentages of linear low‐density polyethylene (LLDPE) to improve the material's mechanical properties and printability. Second, a specialized printer called a pneumatic feeding fused granule fabrication (FGF) printer was used. This printer allows for the direct printing of material granules, eliminating the need for filaments and resolving filament‐related problems. To evaluate the quality of the printed parts, tensile tests, dynamic mechanical thermal analysis (DMTA), and scanning electron microscopy (SEM) imaging were conducted. The printed parts showed desirable tensile properties (with approximately 3000% elongation at break and approximately 12 MPa tensile strength). Compression tests were also conducted on cubic structures with varied composition ratios and printing patterns such as grid, triangle, and honeycomb. The main purpose of this research was to explore the energy absorption capabilities of the printed blends. The results of our study showed that blending POE with LLDPE improved printability, tensile strength, energy absorption, and compressive properties. The blend with 50% LLDPE and honeycomb structure exhibited the best compressive and energy absorption properties. Highlights: Blending of POE and LLDPE using melt mixing with three different blending ratios.Successful 3D printing with the fused granule fabrication technique.Investigating mechanical properties, microstructure, and thermal analysis.125% increase in ultimate tensile strength by increasing LLDPE.Achieving the highest energy absorption for the 3D printed honeycomb structure. [ABSTRACT FROM AUTHOR]

For the 3D STAR project and 3D printing purposes, a special finegrained cement mixture from locally available raw materials was developed. The reason for the development of the custom mixture was the possibility of arbitrary optimization of the developed mixture at any stage of the project and for any type of application. Mix design, printing head and the entire system from mixing to extrusion was the subject of research and development for this project. It was therefore necessary to address both issues in parallel and to respond in both sectors to the realities arising from the partial results of the different groups involved in the development. [ABSTRACT FROM AUTHOR]

Sustainability and limitations in embedded reinforcement are the main obstacles in digital fabrication with concrete. This study proposed a 3D printable fiber-reinforced calcined clay-limestone-based cementitious material (FR-LC3). The binder systems incorporating calcined clay (CC) and limestone filler (LF) were optimized by determining the flow characteristics and water retention ability of the paste. The effect of fiber volume on the key fresh and mechanical properties of the fiber-reinforced mortars made with the optimized binder was evaluated. A combination of offline assessments and inline printing were employed to investigate the printability of the FR-LC3 with various binder systems and viscosity-modifying admixture (VMA) dosages. The results revealed that the binary system with 20% CC and the ternary system containing 30% CC and 15% LF were highly advantageous, with enhanced packing density, robustness, and water retention ability. Incorporating 2% 6-mm steel fiber contributed to the highest 28-day compressive and flexural strengths and toughness without significantly compromising the fluidity. Finally, the developed FR-LC3 mixtures were successfully printed using an extrusion-based 3D printer. The LF addition in the ternary system decreased the maximum buildable height of a single-wall printed object while reducing the SP/VMA ratio significantly increased the height due to enhanced yield stress and thixotropy. [ABSTRACT FROM AUTHOR]

Abstract Polyethylene terephthalate glycol (PETG) is a novel amorphous shape memory polymer with excellent printability for 4D printing. In this article, ethylene‐vinyl acetate (EVA) is used as a biocompatible and non‐toxic copolymer to improve plasticity and shape memory performance of PETG. PETG‐EVA blends are prepared and 3D printed using a melt mixing method and an upgraded fused deposition modeling (FDM) with a pneumatic feeding system. The results of the thermal analysis show that the blends exhibit two tan‐delta peaks, each related to their components, and morphology images confirm that they are biphasic and immiscible with good compatibility. The morphology of both EVA10 and EVA30 matrix droplets is observed, with the droplets being larger for EVA30. The use of a pneumatic feeding system, along with the ability to control the output melt flow, results in the best printing ability for EVA30, with minimal microholes between the grids and interlayer cracks. The tensile strength of PETG‐EVA blends ranged from 25.38 to 20.14 MPa, with the highest tensile strength achieved for EVA30. The shape memory performance of all three blends is similar; with shape recovery exceeding 90% in 20 s. Blends with higher EVA content exhibited faster shape recovery within the first 10 s.

Additive manufacturing (AM), especially Laser Powder-Bed Fusion (L-PBF), provides alloys with unique properties, but faces printability challenges like porosity and cracks. To address these issues, a co-design strategy integrates chemistry and process indicators to efficiently screen the design space for defect-free combinations. Physics-based models and visualization tools explore the process space, and KGT models guide microstructural design. The approach combines experiments, databases, deep learning models, and Bayesian optimization to streamline AM alloy co-design. By merging computational tools and data-driven techniques with experiments, this integrated approach addresses AM alloy challenges and drives future advancements.

Three-dimensional extrusion bioprinting technology aims to become a fundamental tool for tissue regeneration using cell-loaded hydrogels. These biomaterials must have highly specific mechanical and biological properties that allow them to generate biosimilar structures by successive layering of material while maintaining cell viability. The rheological properties of hydrogels used as bioinks are critical to their printability. Correct printability of hydrogels allows the replication of biomimetic structures, which are of great use in medicine, tissue engineering and other fields of study that require the three-dimensional replication of different tissues. When bioprinting cell-loaded hydrogels, a small amount of culture medium can be added to ensure adequate survival, which can modify the rheological properties of the hydrogels. GelMA is a hydrogel used in bioprinting, with very interesting properties and rheological parameters that have been studied and defined for its basic formulation. However, the changes that occur in its rheological parameters and therefore in its printability, when it is mixed with the culture medium necessary to house the cells inside, are unknown. Therefore, in this work, a comparative study of GelMA 100% and GelMA in the proportions 3:1 (GelMA 75%) and 1:1 (GelMA 50%) with culture medium was carried out to determine the printability of the gel (using a device of our own invention), its main rheological parameters and its toxicity after the addition of the medium and to observe whether significant differences in cell viability occur. This raises the possibility of its use in regenerative medicine using a 3D extrusion bioprinter. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

3D printing is an additive manufacturing technology that locates constructed models with computer-controlled printing equipment. To achieve high-quality printing, the requirements on rheological properties of raw materials are extremely restrictive. Given the special structure and high modifiability under external physicochemical factors, the rheological properties of proteins can be easily adjusted to suitable properties for 3D printing. Although protein has great potential as a printing material, there are many challenges in the actual printing process. This review summarizes the technical considerations for protein-based ink 3Dprinting. The physicochemical factors used to enhance the printing adaptability of protein inks are discussed. The post-processing methods for improving the quality of 3D structures are described, and the application and problems of fourth dimension (4D) printing are illustrated. The prospects of 3D printing in protein manufacturing are presented to support its application in food and cultured meat. The native structure and physicochemical factors of proteins are closely related to their rheological properties, which directly link with their adaptability for 3D printing. Printing parameters include extrusion pressure, printing speed, printing temperature, nozzle diameter, filling mode, and density, which significantly affect the precision and stability of the 3D structure. Post-processing can improve the stability and quality of 3D structures. 4D design can enrich the sensory quality of the structure. 3D-printed protein products can meet consumer needs for nutritional or cultured meat alternatives. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM), especially Laser Powder-Bed Fusion (L-PBF), provides alloys with unique properties, but faces printability challenges like porosity and cracks. To address these issues, a co-design strategy integrates chemistry and process indicators to efficiently screen the design space for defect-free combinations. Physics-based models and visualization tools explore the process space, and KGT models guide microstructural design. The approach combines experiments, databases, deep learning models, and Bayesian optimization to streamline AM alloy co-design. By merging computational tools and data-driven techniques with experiments, this integrated approach addresses AM alloy challenges and drives future advancements. [ABSTRACT FROM AUTHOR]

This review provides a comprehensive overview of additive manufacturing (AM) or 3D-printing (3DP) applications in the pharmaceutical industry, with a particular focus on the critical role of polymer selection. By providing insights into how material properties influence the 3DP process and the quality of the final product, this review aims to contribute to a better understanding of the interplay between polymers and pharmaceutical 3DP. As 3DP technologies are increasingly integrated into pharmaceutical sciences, this review contributes insights into the nuanced process of polymer selection, serving mainly as a foundational guide for researchers and formulators new to the subject seeking to harness the full potential of pharmaceutical 3DP by understanding the physicochemical properties, roles, and functions of used polymers in 3D-printed dosage forms and medical devices. [ABSTRACT FROM AUTHOR]

Due to the increasing demands of consumers from the food packaging, it enabled the improve of active packaging practices. Antimicrobial and antifungal coatings or films are an active packaging application. In such packaging materials, natural or synthetic antimicrobial material is added to the film or coating to help the packaging protect food. The use of biofilms produced from biopolymers in food packaging is more suitable than polymers with many damages such as PET, PE. Film production of many biopolymers such as cellulose derivatives, chitosan, PVA, starch PLA can be realized. Pelargonium graveolens plant is a natural source with strong antifungal and antimicrobial properties. For the reasons explained above, the experimental study aims to manufacture printable film with antimicrobial properties which is used in active packaging, using cellulose butyrate acetate and Pelargonium graveolens essential oil. For this purpose, cellulose butyrate acetate bio films, having variative ratios (0.1, 2.5, 5, 10 %) of Pelargonium graveolens oil, were produced with spin coating method. The transparency of prepared five different films were defined by UV–vis. spectroscopy. The antimicrobial properties of the produced films were measured against gram positive and negative bacteria. All produced biofilms were printed. The printability parameters of biofilms, (color, gloss) were determined. Consequently, cellulose butyrate acetate films loaded with Pelargonium graveolens oil were successfully produced. It is concluded that obtained all biofilms are with no color, transparent and printable with oil based inks. It was determined that the quantity Pelargonium graveolens oil raised in the biofilms had a strong inhibitory effect against gram positive and negative bacteria. With these features; produced films are considered to be suitable for active packaging applications. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Six printing mixtures with variations in cement:sand ratios (in mass) were analyzed, keeping the water/dry material ratio constant, evaluating their printability, considering visual aspects, pumpability and filament integrity. The mixtures were subjected to mini-slump tests, spread on a consistency table, squeeze-flow, and deformation under load of the printed filaments at printing intervals of 0 min, 15 min and 30 min, and then the proportions of the compatible mixtures were determined. with the print. The properties in the hardened state, resistance to bending and compression, adhesion between layers, specific mass and voids index were determined for specimens extracted from printed parts. It was possible to observe that for the printing system used there is an ideal range for these constitutive relationships, and that the mixtures, even with different viscosities, measured according to the squeeze flow, can be printable, provided they meet the ideal ranges for the determined relationships. Regarding the interface of the printed layers, these are critical points of fragility, due to factors such as the formation of regions with voids and loss of surface moisture, which favors the reduction of the mechanical performance of the parts, with the increase in the deposition time.

This study investigates the effects of steel fiber shape (straight and hooked-end) and content (0, 0.5, 1.0, and 1.5 vol%) on rheological properties, printability, mechanical performance and microstructure of 3D printable steel fiber reinforced high strength concrete (3DP-SFHSC). The results indicate that the increase of fiber content improves the mechanical behaviors of 3DP-SFHSC, but the extrudability suffers from reduction when the fiber content exceeded 1.0 vol% due to the significant increase in yield stress. The addition of 1.5 vol% hooked-end fibers enhances the compressive strength of 3DP-SFHSC by 8%, 25.7%, and 40.4% in the X, Y, and Z directions, respectively. Additionally, it also improves the tensile strength in the X direction by 37.67%. The printed specimens exhibit weaker mechanical properties compared to the cast specimens. On the one hand, the lower fiber-matrix compactness resulting from the absence of vibration during printing leads to increased porosity and weak bonding between the steel fibers and matrix. On the other hand, the inconsistent movement between fibers and mortar matrix during extrusion process may also cause the formation of gaps around fibers. Straight fibers show pronounced enhancements in buildability, compressive strength and tensile strength compared to hooked-end fibers at the same fiber volume fraction. Straight fibers align easily during the extrusion process, contributing to a matrix with lower porosity and smaller average pore size.

3D concrete printing (3DCP) presents unique challenges in optimizing rheological properties of concrete mixture, while tailoring the rheology of Engineered Cementitious Composites (ECC) for 3D printing (3DP-ECC) is more intricate due to the added complexity of fiber dispersion. This study proposes an innovative printability evaluation method specifically designed for 3DP-ECC, which takes into account the impact of fiber dispersion while also emphasizing cost-effectiveness and efficiency. Additionally, the proposed method enables the calculation of the printable open time, thus adjusting the mixing time of the ECC paste. The feasibility of the proposed method was verified through actual printing test and rheological test, and experimental results showed good agreement with theoretical results. The tensile performance of 3DP-ECC was also investigated, providing further validation for the proposed methodology.

Robocasting stands as a pertinent additive manufacturing technique for producing intricate ceramic parts. Amidst stricter environmental regulations, the adoption of natural additives becomes imperative. This study investigates the influence of plant-based additives on the rheology and printability of eco-friendly pastes.Various 50 vol%-alumina pastes were formulated using natural binders, plasticizers and dispersants (e.g., lignosulfonate, polysaccharides, glycerol) and then assessed through oscillation and flow rheological analyses. Paste viscosity and rigidity often deviated from printability maps reported in the literature, showing the complexity of defining universal printability criteria. A comprehensive investigation was conducted on the water retention capabilities of additives, liquid phase migration and paste drying kinetics.This paper highlights the critical importance of constraining liquid phase migration within eco-friendly ceramic pastes and the crucial role of polymer chain reorientation under shear. Consequently, this research lays diversifying formulations, offering sustainable solutions for industrial ceramic applications.

In recent years, 3D hydrogels based on alginate (Alg) have undergone substantial advancements, holding transformative potential for biomedicine and regenerative medicine. Nevertheless, the viscosity of Alg needs to be further increased, in order to print complex 3D structures. Attempts to adjust printability often employ rheological modifiers like methylcellulose (MC), but these still lack mechanical integrity for broader biomedical applications. Our study sought to chemically modify Alg/MC to create a photopolymerizable hydrogel by incorporating acrylate-based monomers, which would enhance the curing ability of the base hydrogel, leading to better mechanical properties of Alg/MC, such as stretchability and stability with shape recovery. Comprehensive mechanical assessments unveiled remarkable tensile properties, achieving a notable specific strength benchmark of 44.72 kPa/(g.cm-3) before reaching the point of fracture. This represents a substantial 250 % improvement compared to samples lacking the acrylate monomer. Biomedical assessments confirmed the hydrogel's promising potential, especially with the MG-63 cell line, underscoring its suitability for advanced applications like tissue engineering.

3D bioprinting uses biomaterials combined with cells to develop living constructs. This study explores the optimization of natural polymers, including silk fibroin, gelatin, and alginate, as bioink for 3D bioprinting in bone tissue engineering. The physicochemical properties of the bioink were thoroughly examined, revealing high water uptake and reduced degradation rate due to the addition of silk fibroin. The compressive modulus increased with higher alginate concentration. Rheological analysis confirmed shear-thinning properties and viscoelasticity of the ink. Through meticulous parameter optimization, the ink achieved the highest print accuracy with 4 % w/v alginate content. The printed scaffolds exhibited both macro and micro porosity, making them suitable for bone tissue regeneration. Furthermore, the scaffolds remained stable in culture medium for 36 days. The optimal composition for the hydrogel was determined to be a blend of 5 % fibroin, 7 % gelatin, and 4 % alginate in equal ratios. The bioink demonstrated excellent biocompatibility and, when supplemented with alendronate, enhanced alkaline phosphatase activity in MG-63 osteoblast-like cells. This finding indicates the commitment of cells toward the osteoblastic phenotype. Overall, this study successfully optimized the bioink and bioprinting process for bone tissue engineering applications, highlighting its promising potential for future advancements in the field.

For this research, three hydrophobically modified polyacrylamides, HPAAB, HPAAF, and HPAAS, with multiple hydrophobic monomers were designed, synthesized, and used as thickeners in aqueous ink for digital ink-jet printing. The structures were characterized by Fourier transform infrared (FTIR) analysis and nuclear magnetic resonance (NMR) spectroscopy. The viscosity–average molecular weight was determined by intrinsic viscosity determination and was adjusted according to hydrophobic content. The critical association concentration (CAC) of polymers was measured simultaneously using the apparent viscosity method and the fluorescence spectrum. The formation of a network structure and the mechanism of hydrophobic association are visualized dynamically with a scanning electron microscope (SEM) at different concentrations. Under the same conditions, HPAAB exhibited excellent thickening ability across different pH levels, temperatures, and shear rates, which is caused by the longer hydrophobic side chain and the stronger hydrophobic effect of the behenyl polyoxyethylene ether methacrylate (BEM) group. Furthermore, an aqueous ink using HPAAB as a thickener displays significant printability and stability, functioning much better than a corresponding aqueous ink that uses a commercial thickener. This is the first example of a hydrophobic associating polyacrylamide, incorporating both hydrophilic and hydrophobic units within a single hydrophobic chain, thereby serving as an efficient thickener for aqueous ink.

We present a novel, systematic method for evaluating design printability in 3D food printing using a scoring system based on the Design for Additive Manufacturing (DfAM) guidelines. This study addresses a gap in the current literature by proposing a structured approach to assess and enhance the printability of 3D food designs. Our framework consists of a set of nine critical questions derived from the multi-level DfAM guidelines, focusing on key printability factors including unsupported features, geometric accuracy, and surface finish. The evaluation process converts qualitative assessments into numerical values, resulting in a comprehensive printability score that categorizes designs into high, moderate, or low printability levels. To validate the effectiveness of this method, we conducted a case study involving five different designs. The scoring system successfully explores the design space and maximizes the printability of 3D food products. This method alleviates the challenges in design evaluation compared with traditional trial-and-error approaches. The results demonstrate the practicality and efficiency of our framework’s output. The proposed methodology provides a structured approach to design evaluation, offering practical insights and a valuable tool for improving the success rate of 3D printed food products. This research contributes to the field by offering a systematic framework for assessing and enhancing the printability of 3D food designs, potentially accelerating the adoption and effectiveness of 3D food printing technology in various applications.