Printing Nozzle Research Articles

Parametric optimisation of 3D-printed PLA/wood dust composite for load-bearing application using grey relational analysis

This article proposes an investigation on sustainable polylactic acid/wood dust (PLA/WD) composite material for three-dimensional (3D)-printing applications. This eco-friendly material aids a remarkable reduction in thermoplastic waste, while minimising resource depletion, as a result it promotes circular economies, and mitigates environmental pollution. In order to extend the service life of manufactured components, it becomes necessary to investigate the key fused filament fabrication (FFF) processing parameters that affect the mechanical performance of PLA/WD composite parts. Taguchi-based L27 orthogonal array composite design was implemented for experimentation, and mathematical models were developed by using grey relational analysis to predict the responses for the proposed material. Moreover, the FFF input parameters with three levels of values that were considered for the experimentation are the nozzle temperature (190°C–200°C), layer height (0.12–0.28 mm), print speed (30–50 mm/min), infill density (80–100%) and raster angle (0°–90°). The results revealed that the highest grey relational grade obtained was 0.8333 for the experiment run 19 with the sample having ultimate tensile strength and shore D hardness of 20.71 ± 1.24 MPa and 74 ± 2 SHD, respectively. Moreover, raster angle, layer height and infill density were found to be the influential parameters that affect the tensile and hardness properties of the sample. Furthermore, nozzle temperature of 200°C, layer height of 0.2 mm, print speed of 30 mm/min, infill density of 100% and raster angle of 90° were obtained as optimum FFF input parameters.

Evaluating consumer 3D printing nozzles as a low cost alternative for mesophase pitch-derived carbon fiber production

Synthetic fibers, such as Kevlar fibers, SiC fibers, and carbon fibers, are essential components for constructing high performance structures. Whether for engineering, sports, energy storage (batteries and supercapacitors), or aerospace applications, fiber microstructure plays a critical role in fiber properties and functionalities. However, studying fiber nozzle configurations and spinning parameters to achieve the desired microstructure remains challenging, costly, and time consuming. Here, mesophase pitch-derived fibers were used as an example to demonstrate that low cost, commercially available 3D printer nozzles can “print” fibers. Four different nozzles were used to “print” fibers and the effects of their features on fiber properties were observed and compared to other lab spun and commercial pitch-derived CF. A longer orifice length resulted in higher modulus fiber whereas a larger draw-down ratio yielded a stronger fiber. The findings provide a new opportunity for 3D printer hardware application and open opportunities for developing low-cost fibers.

Upscaling active rheology control to cement mortar with the intervention of an inline magnetic field

Upscaling the printing ink from cement paste to mortar level is the path people must take to apply active rheology control to smart and advanced digital fabrication, which will decrease the content of binder and reduce carbon footprint. This study investigates the rheological response of cement mortars with carbonyl iron particles (CIPs) by using penetration tests and vane tests. A customized magnetorheological test setup, making use of a pipe/nozzle-like inline magnetic intervention, was developed to modify the rheological properties of responsive mortars within a few seconds. The alignment of magneto-responsive particles and the hindrance of sand on magneto-responsive particles in the mortars were visualized and determined by scanning electron microscopy (SEM). With an inline magnetic field, the yield stress determined by the slow penetration test and the torque measured by the vane test increased by a significant factor. The magneto-responsive effect and the response speed rate of the mortar can be adjusted on demand and in time. The effect of cement-to-sand (c/s) ratios and sand gradations on the magnetorheological response of cement mortars was studied. With the increase of sand content (decrease of c/s ratio), the percent increase of yield stress and torque decreased and the magneto-response speed reduced, which indicates a reduction in response efficiency. The magneto-responsive particles could more easily move in the mortar when the particle size of sand increased. Experimental proofs of concept to apply active rheology control to a 3D printing nozzle or pumping line were conducted.

Inkjet printing for smart electrochromic devices

AbstractElectrochromic technology has recently made many achievements in research and commercialization. Electrochromic devices are being developed based on various coating and printing methods for multipronged applications, and have great potential for next‐generation flexible electronics. Compared to other coating and printing techniques, inkjet printing (IJP) enables non‐contact patterning on a variety of substrates by programming the movement of the printing nozzle. IJP has great advantages in printing smart electrochromic devices because of its low cost, high resolution, high material utilization rate, and applicability to various large‐size substrates. In this review, the principles and process of IJP and the latest progress of IJP in electrochromic devices are summarized in detail. IJP of electrochromic materials, conductive contacts, and blocking layers are discussed. IJP assisted fabrication of smart electrochromic displays, flexible and stretchable electrochromic devices, electrochromic‐energy storage, smart windows, and others are also demonstrated. The problems and challenges faced by IJP electrochromic devices are emphasized, and the future development trends are prospected. This review aims at further promoting the development of IJP for smart electrochromic devices and encouraging future applications of IJP and electrochromic devices in the era of Internet of Things.

Impact behaviour of 3D printed fiber reinforced cementitious composite beams

Recent interest has grown in using 3D printing for military and civil defense engineering, particularly for infrastructure resilience against impacts. This study delves into the impact resistance of 3D printed fiber-reinforced cementitious composite (FRCC) beams. By analyzing varying fiber content, impact directions, and 3D printing nozzle sizes, the research found that the total energy dissipation of 3D printed FRCC beams was more than 40% higher and the 3D printed beams exhibited superior impact resistance compared to traditional beams, largely due to the fibers' role. The impact energy dissipation varied with different impact directions for the specimens, and the Z direction was identified as the most resistant, demonstrating anisotropic behavior in impact resistance. Smaller nozzle sizes in printing showed higher total energy dissipation, indicating increased impact resistance. X-ray analysis further revealed that the 3D printing process creates denser beams with better fiber–matrix adhesion and less porosity, improving overall impact resistance.

In situ Synthesis of Single Layered Metal-Organic Frameworks via Inkjet Printing on a Cellulose Nanofiber Film.

The inkjet printing is a simple method to develop pattern-controlled 2D metal-organic frameworks (MOFs) due to its cost-effectiveness and ease of operation. Despite the sophisticated structures of MOF crystals, the MOF surfaces are easily contaminated by the adsorption of an ink solution, and the printing nozzle can be clogged by the aggregates of MOFs during printing. Unlike the mixture inks of MOFs and a carrier medium, the surface-specific patterning by in situ synthesis provides the film surface with the controlled patterns of an MOF single layer having different morphologies of MOFs without changing the ink cartridges. It enables facile printing due to the low viscosity of inks and escapes the risk of nozzle clogging because MOFs are synthesized at the printed patterns on the substrates. The ion-exchanged cellulose nanofiber (CNF) films form strong coordination with metal ions enhancing the stability of the MOFs on the film surface. It also demonstrates the controlled coverage of the MOFs by the printing pass number and the carboxylate content of CNF and the tunable adsorption of the guest molecules for different loading capacities of the printed patterns.

Development of 3D printed k-carrageenan-based gummy candies modified by fenugreek gum: Correlating 3D printing performance with sol-gel transition

Temperature-responsive inks were formulated using k-carrageenan, fenugreek gum (FG), rose extracts, and sugar, of which the first two were used as the gelling agents. The interactions among components in these mixed ink formulations were investigated. Sol-gel transition and rheological properties of these inks were also correlated with extrusion, shape formation, and self (shape)-supporting aspects of 3D printing. Results indicated that incorporating FG increased inks' gelation temperature from 39.7 °C to 44.7–49.6 °C, affecting the selection of printing temperature (e.g., 0 % FG: 40 °C, 0.15 % FG: 45 °C, 0.3 % FG-0.6 % FG: 50 °C). Inks in solution states with lower viscosity (<5 Pa·s) were amenable to ensure their smooth extrusion through the tip of the printing nozzle. A shorter sol-gel transition time (approximately 100 s) during the shape formation stage facilitated the solidification of inks after extrusion. The addition of FG significantly (p<0.05) improved the mechanical properties (elastic modulus, hardness, etc.) of the printed models, which facilitated their self-supporting behavior. Low field nuclear magnetic resonance indicated that the inclusion of FG progressively restricted water mobility, consequently reducing the water syneresis rate of the mixed inks by 0.86 %–3.6 %. FG enhanced hydrogen bonding interactions among the components of these mixed inks, and helped to form a denser network.

Influence of print speed and nozzle diameter on the fiber alignment in 3D printed ultra-high-performance concrete

The limitations in the available reinforcing methods have accompanied the increasing popularity of 3D Concrete Printing (3DCP). Incorporating steel fibers as reinforcement is a promising approach to overcome these limitations. However, the impact of the printing process on the alignment of these fibers is not well understood. Therefore, the objective of this research is to quantitatively analyze the distribution of steel fiber alignment in 3D printed concrete. To achieve this, digital image analysis was employed to assess the influence of nozzle diameter, print speed, and fiber content on fiber alignment in both mold-cast and 3D-printed samples. UHPC matrix without fiber addition and fiber reinforced UHPC composites with brass-coated steel fiber contents of 1.5% and 3% by volume fraction were printed. Furthermore, Material nozzles ranging from 10 mm to 40 mm in size were employed and printing speeds of 15, 25, 35, and 45 mm/s were adjusted. Subsequently, the study examined the implications of fiber alignment on the hardened performance of printed specimens and compared them with conventionally mold-cast samples. The findings of the study demonstrated that increasing the fiber content and using smaller diameter nozzles during the printing procedure led to significant improvements in fiber orientation along the printing direction. As a result, the mechanical performance of the printed samples showed a substantial enhancement compared to the specimens produced through mold casting, primarily due to the improved fiber alignment.

Determination of fan height based on FDM nozzle temperature field analysis—an example of babbitt alloys

In this paper, the phenomenon of nozzle clogging or drooling droplets in the process of FDM metal 3D printing of tin-based Babbitt alloys was evaluated by simulation to assess the effects of different heights of cooling fans on the printer’s nozzle cooling module, and the optimal height of the fans was determined. Based on the thermal analysis results, a thermodynamic coupling analysis was carried out to analyze the thermodynamic changes of the nozzle at a given temperature. Finally, the printing trials of tin-based Babbitt alloy were carried out using self-developed forming equipment to verify the accuracy of the theory. The results show that the print quality can be effectively improved by controlling the heat dissipation module of the printer nozzle. The printed material exhibited a uniform and fine microstructure in the 3D printing trials of tin-based Babbitt alloy.

Assessing nozzle flow dynamics in fused filament fabrication through the parametric map α−λ

Polymer rheology profoundly influences the intricate dynamics of material extrusion in fused filament fabrication (FFF). This numerical study, which uses the Giesekus model fed with a full rheometric experimental dataset, meticulously examines the molten flow patterns inside the printing nozzle in FFF. Our findings reveal new insight into the interplay between elastic stresses and complex flow patterns, highlighting their substantial role in forming upstream vortices. The parametric map α–λ from the Giesekus model allowed us to sort the materials and connect the polymer rheology with the FFF nozzle flow dynamics. The identification of elastic instabilities, the characterization of flow types, and the correlation between fluid rheology and pressure drop variations mark significant advancements in understanding FFF processes. These insights pave the way for tailored nozzle designs, promising enhanced efficiency and reliability in FFF-based additive manufacturing.

Analisis dan Optimasi 3D Print Material Carbon Fiber Pla Menggunakan Metode Taguchi-Gra

Technology is evolving, and so is the manufacturing process in the industrial world. One technology that is widely used in making products with ideal dimensions is 3D printing. One of the widely used 3D printing methods is Fused Deposition Modeling (FDM). The working principle of FDM is to extrude thermoplastic filaments through a heated nozzle and print layer by layer. With the development of technology, the filaments used in 3D printing also vary. Carbon Fyber is one of the most popular materials in the industry due to its strength and durability. This study was conducted to find the optimal combination of nozzle temperature, layer height, and print speed parameters for dimensional accuracy and surface roughness on Carbon Fyber filament products. The process parameters used in this study are nozzle temperature, layer height, and print speed. The nozzle temperatures used were 195°C, 210°C, and 225°C. The layer height variations used were 0.15mm, 0.20mm, and 0.25mm. Meanwhile, the print speed is 70%, 85%, and 100%. The parameters will be arranged based on the orthogonal matrix L27(33) with interactions between parameters. Response parameters used are surface roughness and dimensional accuracy. From this study it can be concluded that the parameter that has the most influence on both responses is layer height. Parameter optimization for Carbon Fyber filament products can use the parameters of nozzle temperature 195°C, layer height 0.20mm, and print speed 85%.

Peningkatan Kuat bentur Produk 3D Printing Fused Deposition Modeling menggunakan Filamen Polypropylene

In the world of manufacturing technology there is the latest breakthrough called 3D Printing which is based on layer manufacturing. In making products, a method of adding material in layers is used, usually called additive manufacturing. The principle used in this manufacturing process technology is layered modeling, by converting 3D data directly from computer-aided design (CAD) into a physical model. Many manufacturing technologies have been developed to make prototypes according to needs, for example FDM (Fused Deposition Modeling). Setting factors and experimental levels is an important step in maximizing the quality of research level products referring to transparent materials formed from polypropylene filaments. The factors that vary are Nozzle Temperature, Bed Temperature, Print Speed, and Layer Height. This research design uses the Taguchi method. This research uses an L9 orthogonal matrix with 3 levels. Based on the results of the research carried out, we can conclude that in the impact strength test there is an increase in the results of the impact strength test with the most influential process parameters, respectively, namely Print Speed (35mm/s), Layer Height (0.3mm), Bed Temperature (97 °C) and Nozzle Temperature (215°C) using Polypropylene filament. So the strongest impact strength test value is in experiment no. 2 with an average value of 0.03370 Joules and the weakest is in experiment no. 1 with an average value of 0.02959 Joules.

Problems and Handling Methods of Laser Printers

A laser printer is a common office and personal printing equipment widely welcomed for high-speed, high-quality print output. The high temperature usually causes the printer nozzle temperature to be too high, affecting the printing quality and even damaging the printer. This is because the laser printer works by attaching the toner to the paper through high-temperature sintering, hence the print head’s temperature. Maintaining a suitable temperature environment is crucial for the normal operation and life of the laser printer. In addition, If the position and thickness of the black and white tendons change, it may affect the uneven distribution of the ink when printing, resulting in patches or blur of the printed image. In the printer’s cartridges, the black and white bars are separated, ensuring that the ink in the cartridge is evenly distributed when printing. If the position and thickness of the black and white tendons change, it may affect the uneven distribution of the ink when printing, resulting in patches or blur of the printed image. Therefore, when replacing ink cartridges or resetting or modifying some settings of the printer, be careful to be sure not to damage the printer. This study aims to solve the technical defects of laser printers, improve the level of printing technology, and improve the user experience.

Extraction of volatile organic compounds liberated upon filament extrusion by 3D pen and its comparison with a desktop 3D printer using solid-phase microextraction fiber and Arrow

Desktop 3D printers that operate by the fused deposition modeling (FDM) mechanism are known to release numerous hazardous volatile organic compounds (VOCs) during printing, including some with potential carcinogenic effects. Operating in a similar manner to FDM 3D printers, 3D pens have gained popularity recently from their ability to allow users to effortlessly draw in the air or create various 3D printed shapes while handling the device like a pen. In contrast to numerous modern 3D printers, 3D pens lack their own ventilation systems and are often used in settings with minimum airflow. Their operation makes users more vulnerable to VOC emissions, as the released VOCs are likely to be in the breathing zone. Consequently, monitoring VOCs released during the use of 3D pens is crucial. In this study, VOCs liberated while extruding acrylonitrile butadiene styrene (ABS) filaments from a 3D pen were measured by solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS). SPME was investigated using the traditional fiber and Arrow geometries with the DVB/Carbon WR/PDMS sorbent while four different brands of ABS filaments—Amazon Basics, Gizmodork, Mynt 3D, and Novamaker—were used with the 3D pen. Heatmap analysis showed differentiation among these brands based on the liberated VOCs. The nozzle temperature and printing speed were found to affect the number and amount of released VOCs. This study goes a step further and presents for the first time a comparison between 3D pen and a desktop 3D printer based on liberated VOCs. Interestingly, the findings reveal that the 3D pen releases a greater number and amount of VOCs compared to the printer. The amounts of liberated VOCs, as indicated by the corresponding chromatographic peak areas, were found to be 1.4 to 62.6 times higher for the 3D pen compared to the 3D printer when using SPME Arrow.

Micrometer-thick and porous nanocomposite coating for electrochemical sensors with exceptional antifouling and electroconducting properties

Development of coating technologies for electrochemical sensors that consistently exhibit antifouling activities in diverse and complex biological environments over extended time is vital for effective medical devices and diagnostics. Here, we describe a micrometer-thick, porous nanocomposite coating with both antifouling and electroconducting properties that enhances the sensitivity of electrochemical sensors. Nozzle printing of oil-in-water emulsion is used to create a 1 micrometer thick coating composed of cross-linked albumin with interconnected pores and gold nanowires. The layer resists biofouling and maintains rapid electron transfer kinetics for over one month when exposed directly to complex biological fluids, including serum and nasopharyngeal secretions. Compared to a thinner (nanometer thick) antifouling coating made with drop casting or a spin coating of the same thickness, the thick porous nanocomposite sensor exhibits sensitivities that are enhanced by 3.75- to 17-fold when three different target biomolecules are tested. As a result, emulsion-coated, multiplexed electrochemical sensors can carry out simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid, antigen, and host antibody in clinical specimens with high sensitivity and specificity. This thick porous emulsion coating technology holds promise in addressing hurdles currently restricting the application of electrochemical sensors for point-of-care diagnostics, implantable devices, and other healthcare monitoring systems.

System and Method for One or More Extruders Using a Robotic Arms to Print a 3D Model

The need for creating realistic body parts and anatomical models using additive printing was long ago recognised. The paper "Rapid prototyping approaches for anatomical modelling in medicine" by M. McGurk et al. in Ann. R. Coll. Surg. Engl. 1997; 79; 169-174, which discussed 3-D printing of models, summarised the state of the art in this subject some years ago. Models were made by sprinkling liquid over a layer of precursor powder using inkjet printer nozzles to form a solid, thin slice. For each additional slice, the printing procedure was repeated until the item was finished as a "green state" component, which was then burned in a furnace to sinter it. The product was then subjected to further processing to create a full density portion. Large item 3D printing has been simpler than in previous years because to the development of software for computer controlled robotic XY motion systems used in the semiconductor and optical sectors. Layered building of 3D things is now a comparatively cheap and quick operation for 3D printing equipment thanks to software applications like SolidWorks, AutoCAD 360, and similar software products. Larger things may be 3D printed by either attaching rails above the print nozzles for X-Y motion directed from above the nozzles, or by positioning the object to be created on an X-Y table with motion supplied below the nozzles. The current work attempts to construct a 3D printing setup that utilises two robotic arms to print a single component. Here, the bed will be swivelled to a specific angle to prevent the robotic arms from becoming entangled, and the robotic arms will also move 180 degrees from their mean positions. Additionally, the related software will be developed locally in our lab, resulting in a shorter printing time and higher level of accuracy.

In-flight imaging of aerosol jet printer droplets to enable spatially resolved flow rate measurements

The effect of process drift in aerosol jet (AJ) printing has been a hindering factor in its large-scale adoption in printed electronics. In this study, we developed an in situ droplet imaging system using a double-pulse laser to quantify the distribution and velocity of sparse droplets between the AJ printer nozzle and the substrate. The droplet velocity and distribution were then used to evaluate a spatially resolved droplet flow rate that was capable of detecting and quantifying process drift over time. Using the droplet imaging system, the effect of different focus ratios was analyzed. The droplet flow rate was shown to be indicative of the deposited line morphology for low to moderate focus ratios. At a high focus ratio, the tool was able to identify non-idealities in the fluid properties which are explained in a detailed analysis. AJ printing demonstrates significant promise for the additive manufacturing of electronics, and this work represents a step toward non-invasive, in-flight monitoring in real time.

The impact of nozzle diameter and printing speed on geopolymer-based 3D-Printed concrete structures: Numerical modeling and experimental validation

3D Concrete Printing (3DCP) is a promising technology with significant advantages for the construction industry, encompassing reduced labor costs, diminished carbon dioxide emissions, enhanced time efficiency, improved user convenience, and design flexibility. To ensure optimal structural outcomes and resource efficiency, integrating numerical modeling and simulation is imperative for predicting structural behavior and identifying potential premature failures in 3DCP. Despite the recognized importance of this integration, the impact of different printing parameters on numerical models, particularly with variations in printing speed and printing layer, remains an unexplored area. This research delves into the influence of crucial printing parameters, specifically printing speed and nozzle diameter, on the buildability of 3D-printed structures within the built environment. A comprehensive experimental analysis is conducted on geopolymer-based 3D-printed structures, encompassing diverse process parameters associated with 3D printing (3DP) technology. A numerical model is deployed to predict the buildability of these structures, and its results are compared with experimental findings, assessing the efficacy of numerical modeling under varying printing parameter conditions. Rigorous characterization of input material properties is undertaken to ensure the accuracy of numerical simulations. Experimental results showcase favorable processability and buildability of geopolymer materials derived from novel Construction and Demolition Waste (CDW). Findings indicate that an increased nozzle size, reflected in greater layer height and width, positively influences buildability, whereas higher printing speeds correlate with reduced buildability. The numerical model successfully captures these buildability trends, though with an error ranging from 32 % to 45 % in predicting failure in 3D-printed structures. Nevertheless, the overall performance of the numerical model remains reliable in predicting the influence of printing parameters on buildability.

Boron‐polymer composites engineered for compression molding, foaming, and additive manufacturing

AbstractBoron (specifically 10B) is the element of choice to shield thermal neutrons due to its large (n, α) cross‐section; however, very few polymer composites containing high boron concentrations are available. This study aimed to determine the maximum possible amount of boron that could be introduced into a polymer matrix. Diverse manufacturing techniques, ranging from additive manufacturing to compression molding, were employed to fabricate inks and filaments for 3D printing, foams, and flexible pads. Composites using siloxanes, poly(lactic acid), and acrylonitrile butadiene styrene containing up to 80 wt% boron were sucessufully fabricated. The addition of known plasticizers (polyethylene glycol) and reinforcing agents (carbon nanofibers and fumed silica) helped to overcome fabrication problems such as clogging of the printing nozzle or crumbling of compression molded parts. In addition, the thermal‐mechanical properties of these novel boron composites were determined and shown to vary according to boron concentration, presence of additives, and fabrication techniques utilized.

Semi-crystalline materials for pharmaceutical fused filament fabrication: Dissolution and porosity

A better understanding of crystallization kinetics and the effect on drug product quality characteristics is needed to exploit the use of semi-crystalline polymers in pharmaceutical fused filament fabrication. Filaments were prepared from polycaprolactone or polyethylene oxide loaded with a crystallization inhibitor or inducer, which was either 10% (w/w) ibuprofen or theophylline. A design-of-experiments approach was conducted to investigate the effect of nozzle temperature, bed temperature and print speed on the printed tablets’ microstructure and dissolution kinetics. Helium pycnometry derived porosity proved an ideal technique to capture significant distortions in the tablets’ microstructure. On the other hand, terahertz time domain spectroscopy (THz-TDS) analysis proved valuable to investigate additional enclosed pores of the tablets’ microstructure. The surface roughness was analyzed using optical coherence tomography, showing the importance of extensional viscosity for printed drug products. Drug release occurred via erosion for tablets consisting of polyethylene oxide, which partly reduced the effect of the inner microstructure on the drug release kinetics. An initial burst release effect was noted for polycaprolactone tablets, after which drug release continued via diffusion. Both the pore and crystalline microstructure were deemed essential to steer drug release. In conclusion, this research provided guidelines for material and process choice when a specific microstructure has to be constructed from semi-crystalline materials. In addition, non-destructive tests for the characterization of printed products were evaluated.