Print Density Research Articles

Influence of Density of 3D Printing Using the Fdm Method on Productivity and Mechanical Properties of ABS

The economic and technical advantages of 3D printing make it a possible replacement for conventional production processes, especially for complex products and small batches. It is important to point out that technological parameters of 3D printing, such as layer thickness, print density, print speed, melting temperature, and table temperature, have a significant impact on the mechanical properties and productivity of parts obtained by 3D printing. Because of all the above, there is a great interest in research in this area. The paper presents the results of testing the tensile strength of the ABS polymer, in which two parameters were varied: the thickness of the print layer (0.39 mm) and the print density of 60–100% in steps of 10% each. The samples were obtained on a ZORTRAX M200+ 3D printer using fused filament deposition (FDM) technology. The selected thickness of the printing layer is relatively large, and with it, parts with lower accuracy and high surface roughness are obtained, although at the same time high productivity is achieved, which can satisfy some requirements. The obtained tensile strength values show that increasing the print density leads to an increase in its value, with a deviation in the sample with a print density of 100%, whereas the tensile strength values are comparable to the values obtained by other authors.

Advanced roll porous scaffold 3D bioprinting technology.

Improvements in the roll porous scaffold (RPS) 3D bioproduction technology will increase print density of 10-15µm cells by ~ 20% up to ~ 1.5 × 108 cells/mL and purity of organoid formation by > 17%. The use of 360 and 1200 dpi inkjet printheads immediately enables biomanufacturing with 10-30µm cells in a single organoid with performance > 1.8 L/h for 15µm layer thickness. The spongy bioresorbable ribbon for RPS technology is designed to solve the problems of precise placement, leakage and increasing in the number of instantly useable cell types and superior to all currently dominant 3D bioprinting methods in speed, volume, and print density without the use of expensive equipment and components. The potential of RPS for parallel testing of new substances studied was not on animals, but using generated 3D biomodels "organ on a chip". Solid organoids are more suitable for personalized medicine with simultaneous checking of several treatment methods and drugs, targeted therapy for a specific patient in vitro using the 3D composition of his personal cells, and selection of the most effective ones with the least toxicity. Overcoming the shortage of organs for implantation and personal hormone replacement therapy for everyone was achieved using printed endocrine glands based on their DNA.

A Review of 3D Printing Batteries

To stabilize the Earth’s climate, large-scale transition is needed to non-carbon-emitting renewable energy technologies like wind and solar energy. Although these renewable energy sources are now lower-cost than fossil fuels, their inherent intermittency makes them unable to supply a constant load without storage. To address these challenges, rechargeable electric batteries are currently the most promising option; however, their high capital costs limit current deployment velocities. To both reduce the cost as well as improve performance, 3D printing technology has emerged as a promising solution. This literature review provides state-of-the-art enhancements of battery properties with 3D printing, including efficiency, mechanical stability, energy and power density, customizability and sizing, production process efficiency, material conservation, and environmental sustainability as well as the progress in solid-state batteries. The principles, advantages, limitations, and recent advancements associated with the most common types of 3D printing are reviewed focusing on their contributions to the battery field. 3D printing battery components as well as full batteries offer design flexibility, geometric freedom, and material flexibility, reduce pack weight, minimize material waste, increase the range of applications, and have the potential to reduce costs. As 3D printing technologies become more accessible, the prospect of cost-effective production for customized batteries is extremely promising.

Physiological cell bioprinting density in human bone-derived cell-laden scaffolds enhances matrix mineralization rate and stiffness under dynamic loading.

Human organotypic bone models are an emerging technology that replicate bone physiology and mechanobiology for comprehensive in vitro experimentation over prolonged periods of time. Recently, we introduced a mineralized bone model based on 3D bioprinted cell-laden alginate-gelatin-graphene oxide hydrogels cultured under dynamic loading using commercially available human mesenchymal stem cells. In the present study, we created cell-laden scaffolds from primary human osteoblasts isolated from surgical waste material and investigated the effects of a previously reported optimal cell printing density (5 × 106 cells/mL bioink) vs. a higher physiological cell density (10 × 106 cells/mL bioink). We studied mineral formation, scaffold stiffness, and cell morphology over a 10-week period to determine culture conditions for primary human bone cells in this microenvironment. For analysis, the human bone-derived cell-laden scaffolds underwent multiscale assessment at specific timepoints. High cell viability was observed in both groups after bioprinting (>90%) and after 2 weeks of daily mechanical loading (>85%). Bioprinting at a higher cell density resulted in faster mineral formation rates, higher mineral densities and remarkably a 10-fold increase in stiffness compared to a modest 2-fold increase in the lower printing density group. In addition, physiological cell bioprinting densities positively impacted cell spreading and formation of dendritic interconnections. We conclude that our methodology of processing patient-specific human bone cells, subsequent biofabrication and dynamic culturing reliably affords mineralized cell-laden scaffolds. In the future, in vitro systems based on patient-derived cells could be applied to study the individual phenotype of bone disorders such as osteogenesis imperfecta and aid clinical decision making.

Optimizing PEEK impact strength through multi-objective FDM 3D printing

Thermoplastic materials such as Polylactic acid, Acrylonitrile Butadiene Styrene, Polyethylene terephthalate glycol, Nylon, and Thermoplastic polyurethane are favoured in Fused deposition modeling 3D printing due to their cost-effectiveness and versatile properties. However, with the introduction of high grade thermoplastic material poses compatibility challenges with existing machines and processes, impeding widespread adoption in FDM 3D printing. Incorporating new materials into 3D printing requires adjustments to hardware, software, and settings, leading to potential expenses and time investments. Maintaining quality control and consistency becomes complex as each material demands specific parameters and processing conditions. This variability hinders achieving consistent part quality in 3D printing. Moreover, achieving optimal FDM parameters for high-grade polymers (HGPs) like Polyether ether ketone (PEEK) is a challenge due to the distinctive nature of the property, requiring specialized careful considerations during its optimization process. The considerable thermal gradient and heat distribution during printing can lead to residual stresses and deformations, significantly affecting the quality and, in particular, its impact strength. This article optimizes an industry grade 3D printing PEEK based on the limited number of process parameters, namely, build orientation, in-fill density and chamber temperature. Further, the research tries to derive a predictive model for Impact Strength (IS), which is an important consideration for the 3D printed object. In this article, along with the Impact Strength, Printing Time and Material Usage are also studied to find empirical evidence of association between these output variables or response variables. The result indicates that there is a positive significant correlation or association between them. When utilizing a specific parameter setup, the resulting IS of 86.5 kJ/m², a print time of 89 minutes, and a material usage of 3.26 grams are achieved. Notably, there is a measurable reduction of 9.18% in printing time and a 11.66% decrease in material usage when the print density is set to 100% to optimize impact strength. This optimization approach proves the use of composite desirability is a better approach where multiple objectives need to be achieved. The proposed regression model predicts the impact strength with coefficient of determination value more than 50%.

Central composite disigns for optimization of the energy factor in 3D printing

This study proposes an optimization strategy to analyze the trade-off between the conflicting objectives of minimizing energy use in 3D printing by fused deposition modeling. The motivation for this work is the need to optimize natural resources, finite in nature, in a more competitive industrial reality and increasingly focused on sustainability, another important point is that energy savings generate improvement in consumption raising organizational profit. The methodologies used were a brief review of the literature and response surface methodology in a CCD experiment. The modeling of the specimen took place through the CAD Fusion 360 software, its development began with the creation of a rectangular 2D sketch, obeying the parameters of 80 mm in its length and 10 mm in width, an Ender 3 printer, yellow PLA, was used following the guidelines set out in ISO 178. Objective of the research is to optimize the manufacturing process using fused deposition modeling, reducing energy consumption (kwh). A complete factorial design was used , as factors: the printing speed (X1), the printing density (X2), layer height (X3) and the layer width (X4), as a response of the experiment were adopted for the manufacturing process, energy (Y). The residue normality tests were performed, with a p-value of 0.170 > 0.05, showing that the data are normal, the VIF below 10 and R-sq (adj) is above 87.16%, the equation has the validated model.

Print consistency evaluation on uncoated paper using various digital print engines

Print quality is most exclusively aspect which is observed mostly and corelated to different printing attributes. Various attributes like print density, color difference (ΔE value) and overprint trap are some crucial aspects to evaluate print quality. Print density refers thickness of ink film applied on any media, color difference provides significant mismatch between targeted and printed while evaluating print quality and overprint trap is ability to accept subsequent layer of ink on already printed ink. This research emphasizes on study of print quality and evaluation in terms of print consistency on uncoated paper using various digital print engines

3D printed carbon-fiber filament density effects on mechanical properties

AbstractThis study aims to select the suitable density of the material according to the mechanical properties needed by the 3D-printing application in which it will be used. 3D-printed carbon fiber filaments with different printing densities have been tensile, and a fatigue test was experimented with to find the mechanical properties. Furthermore, the modulus of elasticity, yield stress, and ultimate tensile strength of the material was determined by analyzing the stress-strain curves. The result shows that the parts printed with a high infill density give better mechanical properties, more time to build the object, more strength, and heavier weight than those printed with low infill density.

Understanding the versatile roles of cellulose nanocrystals in α-amylase immobilization, starch hydrolysis, colloidal stability and printability towards advanced starch based bio-latex performance

Recently starch based bio-latexes are facing serious bottlenecks in their preparation and applications especially at the aspects of high concentration, high colloidal stability and high rheological performance. Starch paste for bio-latex production at high concentration would be prone to retrogradation and inevitably deteriorate its performance. The excessive and uncontrollable α-amylase hydrolysis behavior of starch granules at low concentration below 30 wt% could severely affect the strengthening or binding ability of bio-latex. Herein, this study proposes a practical and effective strategy by using cationic cellulose nanocrystals (CCNC) as versatile carriers of α-amylase for the preparation of starch based bio-latex (SBL) to improve starch hydrolysis efficiency even at 50 wt% concentration. CCNC immobilized α-amylase (CCNC/E) can effectively regulate starch hydrolysis behavior with controllable amylose/ amylopectin molecular weight/ distribution for enhanced colloidal stability and viscoelasticity. Furthermore, the multifunctional roles of CCNC as excellent dispersants, nano-fillers and enhancers within starch colloids could impart SBL excellent rheological property and printability in pigmented coating and printing performance, by improving the coating surface, higher printing density/ picking velocity, and lower dot gain phenomenon, compared with the control latex samples. This study proposes a promising and practical approach for efficient production of 50 wt% starch based bio-latex with advanced performance and further valorizes the cellulose nanocrystals in the starch based biomaterials applications.

Digital printing systems and office papers interactions and the effects on print quality

Abstract In this study, electrophotographic printing and inkjet printing systems were applied to some commercial A4 office papers and their effects on print quality were determined. It is to evaluate the print quality by determining the test parameters that measure the print quality by applying electrophotographic printing and inkjet printing systems to some commercial office papers that have determined the surface properties and optical properties supplied from the market. Print quality was measured by testing with parameters such as delta gloss 60°, print lightness, print chroma, print density. As a result of the tests determined for print quality; print density values were low in A4 office papers with high roughness and porosity values, and the specular gloss values of the samples decreased in both printing applications. In electrophotographic printing; it was determined that darker colors formed with print lightness parameter, and the color scale increases in two-sided printing with print chroma values. It was determined that the color scale of print chroma values increased in two-sided prints. It was determined that mostly some commercial office papers were positively affected by printing on one side in inkjet printing and by printing on two-sided in electrophotographic printing.

Effects on print quality of varying acrylic binder types in water‐based flexographic ink formulations

AbstractThe ink industry is one of the world's largest markets due to the increasing demand for printing inks for the packaging industry. Flexography printing is a well‐known promising technology for large‐area printing due to its high printing speed and roll‐to‐roll capability to print economically on a variety of surfaces and is used in nearly in all areas of packaging printing. Water‐based inks are considered non‐toxic, odourless, and more environmentally friendly options compared to solvent‐based inks. Therefore, in this article, the goal was to develop new water‐based ink formulation with different acrylic binders for flexographic printing on commercial solid bleached sulphate (SBS) board. Five inks were formulated with four different acrylic binders and compared to a commercially available ink to study their performance. The developed inks were investigated with regard to their print qualities and print characteristics. It was found that the binder type influenced some print quality while the effect was not significant for others. Using flexography printed cyan inks, the ink formulated with the highest molecular weight had the lowest print density and the largest tonal value increase (TVI) observed between 40 and 60 tone values. The same ink had the largest mottle values and variation in topography. For values of print contrast and delta gloss at 75°, although differences were observed between average values, data had inconclusive variation and spread around averages, where no conclusive trends or effects of acrylic binder type on these response factors were observed. Print chroma and dot roundness results were equally close for all printed samples.

Properties of Coated Paper Containing Cellulose Nanofibrils as an Additive

Cellulose nanofibrils (CNF) derived from wood can be used as thickening agents for suspensions or slurries because they form a gel structure by absorbing water and demonstrate an excellent shear thinning behavior. When used as a thickening agent for paper coating, CNF influences the rheological properties and water retention of the coating color, affecting the properties of the coated paper. In this study, the effects of CNF and carboxymethyl cellulose (CMC) on the properties of the coated paper were investigated. In contrast to the CMC-coating, the gloss of the CNF-coating was not improved, even when the coating weight was increased, because of the irregular shrinkage of CNF in the wet coating layer through its gel-formation characteristics. The CNF-coating exhibited a much higher ink and vehicle absorption rate than the CMC-coating. The CNF-coating showed lower variation in the printing density depending on the coat weights. Moreover, the open structure of the CNF-coating improved the absorption rate of the coated paper compared to the CMC-coating, resulting in reduced mottling.

The impact of printable interlining printing pattern on hand value of wool fabrics

The printable interlining technique directly prints the adhesive onto the garment, without needing a separate interlining. Previous research identified the optimum printing conditions concerning squeegee frequency, screen mesh, and agent viscosity, to achieve the best hand value for the wool fabrics. The selection of the printing pattern is one of the most important factors influencing the manufacturing and characteristics of the finished fabric. Therefore, theoretically printing patterns could potentially affect the most important human experiential characteristics of the fabric–hand value. In this work, utilizing both the existing and newly developed printing patterns, we systematically investigated the effect of printing pattern on the hand value of wool fabrics that are of different weights. The results showed that overall, the lightweight fabric has lower values in the categories of stiffness, smoothness, and fullness and softness given identical pattern compared with medium weight fabrics. However, lightweight fabric's THV was uniformly higher than the medium weight fabric. Lightweight fabric's primary hand values were less sensitive to variations in printing density compared to the medium weight fabric. Regardless of fabric weight, the dot-based patterns were on average the best performing wool fabrics in terms of low stiffness, high smoothness, high fullness and softness, and high THV. This indicates that to achieve the best overall hand value, the dot-based printing pattern was preferable to the solid or stripe patterns. Pattern direction, specifically the direction of stripes, had in most cases negligible effect on hand value performance. These findings imply that for future designs that achieve great overall hand value using printable interlining on wool fabrics, dot-based printing patterns should be adopted, which has the added advantage of less printing agent consumption.

Effect of Application of Vinyl Acetate Ethylene Emulsion Binder and Type of Pigment on the Quality of Inkjet Paper

Zeolites and precipitated calcium carbonate (PCC) were applied together with a vinyl acetate ethylene (VAE) emulsion to identify an alternative pigment for silica to improve runnability and develop the application technology for the VAE emulsion. The low shear and high shear viscosity of the coating color were decreased when zeolites were mixed with PCC. The coating color exhibited lower shear and higher shear viscosity when the emulsion contained VAE than when it containing poly(vinyl) alcohol. Silica with a large specific surface area and pore volume exhibited a small surface contact angle, and the coating color also showed a smaller contact angle with zeolites having a porous structure than with PCC. Silica with a large specific surface area and pore volume showed high print density. For each type of pigment, the print density of coated paper was higher when using zeolites than when using PCC. When the VAE emulsion binder was applied, the ink density decreased.

Assessing the stab resistive performance of material extruded body armour specimens

This paper investigates the effect of material extruded body armour specimen size on stab penetration depth and back-face signature (BFS) and establishes the minimum thickness required for a series of material extrusion materials to provide protection against the UK Home Office Scientific Development Branch (HOSDB) body armour KR1-E1 requirements. In stage one, material extruded planar test specimens ranging from 40 × 40 mm to 80 × 80 mm in length and width with 10 mm increments at three different thicknesses, 6, 8 and 10 mm, were stab tested under 24 joules of impact energy using a gravity driven drop test apparatus. In stage two, 50 × 50 mm specimens in six material categories, PC, ABS, PLA, TPLA, PA and TPU, were manufactured at different thicknesses via material extrusion and impacted in accordance with the UK HOSDB KR1-E1 stab impact energy level as they were the optimum size when considering overall stab and BFS performance. The study established the fundamental steps towards the use of material extrusion in future personal protection solutions. Results demonstrated that stab penetration and BFS were dependent on specimen size, thickness and material type, and there was an inverse relationship between stab penetration depth and BFS. Also, a minimum thickness of 5 mm for PC and TPLA, 6 mm for ABS, 7 mm for PLA, 11 mm for PA and 12 mm for TPU, with 100% print density, was required in order to provide protection against the HOSDB KR1-E1 level of 24 J stab impact energy.

A SURVEY ON THE EFFECTS OF ENVIRONMENTALLY FRIENDLY SOY PROTEIN INKS ON FLEXOGRAPHY PRINT PARAMETERS IN THE PACKAGING INDUSTRY

"The synthetic resins in printing inks are harmful to the environment because they are not biodegradable and emit volatile organic compounds. The printing industry has sought alternative printing inks to solve these issues. The aim of the work is to explore sustainable and environmentally friendly inks, without scarifying ink performance. To determine their performance and effect on print quality, soy proteins were investigated. Also, commercial and formulated acrylic inks were used as reference inks. From the results, the print density of soy protein water-based inks is higher than that of the reference inks. Moreover, they obtained a higher print gloss than the reference inks. The printing contrast values of soy protein water-based inks are relatively low. There was no considerable difference found in TVI values. Overall, the soy protein water-based inks produced a very competitive result in printability and presented high potential for replace synthetic components in current commercial inks."

The recyclability and printability of electrophotographic printed paper

Abstract Paper is the most successful recycled material from commercial and municipal wastes. Part of recycled paper requires deinking to meet the product requirement, such as tissue, printing grade and newspaper. The original print method plays a major role in deinking performance. The digital print methods, such as electrophotographic (or laser) print, have been rapidly adapted in the commercial printing. Paper mills need to modify their procedure to deink these types of recycled paper, which contain fine toner particles. In this study, the recyclability of electrophotographic printed paper has been evaluated extensively, or three repeats with an industrial standard. Meanwhile, recycled fiber from each repeat underwent printability analysis. Except the influence from papermaking method and pulp furnish, the strength of the recycled fiber slightly declines after each repeat because of fiber deterioration, which also affected the paper surface properties. However, the recycled fiber presented good printability on each recycling, especially on print density and fine details. It suggested that the electrophotographic substrate can tolerate a high recycled fiber content.

Accuracy of 3D printed dental casts for protective dental splints during general anesthesia

PurposeThe purpose of this study is to obtain the optimal three-dimensional (3D) printing condition through the accuracy evaluation of the protective dental splints (PDSs) produced using 3D printed dental casts under various conditions.Design/methodology/approachThe dental casts of dentiform were made using the conventional method and three digital methods. The three 3D printers used one or two materials for each, and the density of the material was varied to find the appropriate printing condition. PDSs were fabricated by the same method using vacuum former on conventional dental casts, and 3D printed dental casts. PDSs were mounted on a dentiform, and the accuracy was measured according to the criteria.FindingsAll of the PDSs fabricated using the traditional method showed the highest accuracy, whereas the PDSs made using 3D printed casts showed accuracies that varied with the type of printer, material characteristics and printing density. Achieving the accuracy required for 3D printed dental casts to be used as protective dental devices made with a vacuum former requires appropriate materials and 3D printing density. The findings of this study can be used when making 3D printed models and individual PDSs through intraoral scanning for patients in whom it is difficult to take impressions using traditional methods.Originality/valueWhen a digital device is applied to the fabrication of PDSs, it has the advantage of saving time and materials and preventing damage to teeth and periodontal tissue that may occur during the conventional method.

Improving local stability of aluminium profile with low-modulus stiffeners: Experimental and numerical web buckling analysis

Facades of modern buildings are the frequent objects of application of aluminium profiles. Reduction of the self-weight governs the development of those structures—a decrease of the web thickness and an increase of the profile height ensure the required flexural resistance of the building components. However, such an optimisation process makes these structural elements vulnerable to web crippling. The findings reported in the literature linked the solution of the buckling problem to the application of low-modulus filler material to stabilise the web’s deformations and increase the load-bearing capacity and the deformation energy absorption of thin-walled composite elements. This study experimentally illustrates the above solution, developing an efficient hybrid cross-section. A hollow section aluminium profile (mullion) available on the market was the subject of the three-point bending and compression tests. Low-modulus polymer stiffeners produced using a 3D printing technique strengthened the composite samples developed in this study. The infill density of the printed polymer was the variable of the research. A 10% printing density was the minimum value used in the tests. The adhesively bonded stiffeners, even of the minimum infill density, doubled the flexural resistance of the profiles. A local buckling caused the failure of the reference specimens, having no internal infill. On the contrary, the aluminium breakage resulting from the strengthened samples’ tests indicates an efficient use of materials. A simplified numerical linear buckling analysis helps to explain the stiffeners’ effect.

Methodology to Create Reproducible Validation/Reference Materials for Comparison of Filter-Based Measurements of Carbonaceous Aerosols That Measure BC, BrC, EC, OC, and TC

A simple method that reproducibly creates validation/reference materials for comparison of methods that measure the carbonaceous content of atmospheric particulate matter deposited on filter media at concentrations relevant to atmospheric levels has been developed and evaluated. Commonly used methods to determine the major carbonaceous components of particles collected on filters include optical attenuation for “Black” (BC) and “Brown” (BrC) carbon, thermal-optical analysis (TOA) for “Elemental” (EC) and “Organic” (OC) carbon, and total combustion for “Total” carbon (TC). The new method uses a commercial inkjet printer to deposit ink containing both organic and inorganic components onto filter substrates at programmable print densities (print levels, as specified by the printer–software combination). A variety of filter media were evaluated. The optical attenuation (ATN) of the deposited sample was determined at 880 nm and 370 nm. Reproducibility or precision (as standard deviation or in percent as coefficient of variation) in ATN for Teflon-coated glass-fiber, Teflon, and cellulose substrates was better than 5%. Reproducibility for other substrates was better than 15%. EC and OC measured on quartz-fiber filters (QFF) compared to ATN measured at 880 nm and 370 nm on either QFF or Teflon-coated glass-fiber yielded R2 > 0.92 and >0.97, respectively. Four independent laboratories participated in a round robin study together with the reference laboratory. The propagated standard deviation among the five groups across all print levels was <2.2 ATN at 880 nm and <2.7 ATN at 370 nm with a coefficient of variation of <2% at ~100 ATN.