Printing Time Research Articles

Technical improvements in preparing 3D printed anatomical models for comminuted fracture preoperative planning

Preoperative planning of comminuted fracture repair using 3D printed anatomical models is enabling surgeons to visualize and simulate the fracture reduction processes before surgery. However, the preparation of such models can be challenging due to the complexity of certain fractures, particularly in preserving fine detail in bone fragments, maintaining the positioning of displaced fragments, and accurate positioning of multiple bones. This study described several key technical considerations for preparing 3D printed anatomical models for comminuted fracture preoperative planning. An optimized segmentation protocol was developed that preserves fine detail in bone fragments, resulting in a more accurate representation of the fracture. Additionally, struts were manually added to the digital model to maintain the positioning of displaced fragments after fabrication, reducing the likelihood of errors during printing or misrepresentation of fragment positioning. Magnets were also used to enable separation and visualization of accurate positioning of multiple bones, making it easier to visualize fracture components otherwise obscured by the anatomy. Finally, the infill for non-target structures was adjusted to minimize print time and material wastage. These technical optimizations improved the accuracy and efficiency of preparing 3D printed anatomical models for comminuted fracture preoperative planning, improving opportunities for surgeons to better plan surgical treatment in advance, reducing the likelihood of errors, with the goal of improving surgical outcomes.

Advancements in 3D-Printed Novel Nylon-6: A Taguchi Method for Surface Quality Sustainability and Mechanical Properties

This research aims to establish the ideal settings for Nylon-6 (PA6) three-dimensional printing utilizing the fused filament production process and examine the resultant surface roughness. ANOVA, S/N ratio, and modeling are explained, along with their application in identifying the ideal values for surface roughness, sustainability, and mechanical properties. Average-surface roughness (Ra), root-mean-squared surface roughness (Rq), print time (PT), print energy (PE), and tensile testing (T) were explored as response parameters to identify the impact of PA6 parameters (layer thickness, extrusion temperature, print speed, and infill density). Tests of validity demonstrated a significant decline in Ra, Rq, PE, PT, and T for the ideal values of the developed product of 10.58 µm and 13.3 µm, 23 min, 0.13 kWh, and 42.7 Mpa, respectively. Ra, Rq, PT, PE, and T have all been optimized using Taguchi techniques as a preliminary step towards application in future research and prototypes.

Bond properties and anisotropy performance of 3D-printed construction and demolition waste-based geopolymers: Effect of operational- and material-oriented parameters

This study investigated the bond performance of printed construction and demolition wastes (CDW)-based geopolymer, providing utilization of CDW in green materials through high tech-manufacturing methodologies. Considering the requirements of three-dimensional-additive manufacturing (3D-AM), the effects of operational and material-oriented parameters on mechanical performance were examined by conducting compressive strength, triplet shear, direct tensile, and diagonal tension tests. Anisotropy performance (perpendicular, lateral, and parallel), printing time intervals (0, 15, 30, 60-min.) between two consecutive layers, material aging time (0, 30, 60, 120-min.) of CDW-based materials, manufacturing methodologies (cast, horizontal- and vertical-printed) were evaluated on the printed specimen. The study showed that the tests conducted on masonry structures could be used on the 3D-printed structure as well. An anisotropic behavior in the compressive strength results was obtained by observing a decreasing trend in results from perpendicular to parallel and, parallel to lateral loading directions. Increasing printing time interval had a negative influence on the compressive strength of CDW-based geopolymers and anisotropy performance was mitigated in a 60-min printing time interval. Although bond strength decreased with raised printing time intervals, similar bond strength values were recorded for 30-min and 60-min printing time intervals. Similarly, increased material aging time caused decrement in bond strength, yet comparable bond strength was obtained for specimen printed with 60-min and 120-min aged mixture. According to the results, printing time intervals showed more prominent effects on bond strength compared to the material aging time. The test results indicate that vertical-printed specimens demonstrated similar mechanical performance with cast specimens, whereas horizontal-printed specimens exhibited slightly weaker performance compared to those.

PLA-based In house 3D-printed intraoperative surgical model is a time- and cost-efficient approach for mandibular reconstruction.

Introduction. Patients with malignant mandibular reconstructive cases, commonly people often have contralateral normal side to act as a template during preoperative computer-assisted planning. Moreover, the development of Computer-Assisted Design/ Manufacturing Technology aids in the process to produce a template for cutting and/or custom fixation (pre-bending). Therefore, CAD/CAM technology has been greatly used in enhancing accuracy and reducing operation time, and minimizing possible complications due to thorough accurate planning. Method. This study displayed 5 case series incorporating In-House 3D Printed Models cases. 3D imaging was retrieved from CT scan DICOM Files, the file will then be processed to recreate a symmetrical post operative look. Furthermore, the rendered 3D File will be printed with the in-house printer using polylactic acid (PLA) Material. A sterilized 3D printed model will then be used intraoperatively to allow pre-bending of any implants for the case. Then the process, time, and cost of each case were documented. Results 100% success rate in processing all 5 cases into 3D Printed Model. The printing time consumes on average 7 hours,39 minutes (ranging from 5 hours, 59 minutes up to 9 hours, 43 minutes) and costs on average $ 1.83 on each print (ranging from $ 1.69 up to $ 2.10). Conclusion. 3D Printed reconstructed models as guidance to aid the surgeon from visualization of the post-operative look, up to intraoperative pre-bending of the implants used. Thus allowing better efficiency in reducing operation time, better post-operative look, and fewer complications. However, a bigger sample RCT will allow more detailed information.

Textile Sublimation Printing: GLCM Print Mottle Assessment of Black Printed Fabric

The white fabric was printed with different printing temperatures and pressing times using the sublimation printing process in solid-tone black color with a 100 % total ink limiting level. Non-uniformity of the print was examined through print mottle determined by grey level co-occurrence matrix (GLCM) image processing method. Color strength of print was also determined by reflectance spectrophotometry. The print with the lower print mottle was obtained at a printing temperature of 190 °C at a longer pressing time of 120 s or at an increased printing temperature of up to 210 °C at the reduced pressing time of 60 s. The print with the lower print mottle had the lowest entropy, contrast, and correlation and the highest energy and homogeneity. The print with a higher color strength was accompanied by decreased print mottle. Choosing a suitable printing temperature and pressing time for sublimation printing is helpful in achieving print with low print mottle and high color strength and balancing cost, price, and price.

The Effects of Process Parameters on Tensile Characteristics and Printing Time for Masked Stereolithography Components, Analyzed Using the Response Surface Method

The Effects of Process Parameters on Tensile Characteristics and Printing Time for Masked Stereolithography Components, Analyzed Using the Response Surface Method

High-efficiency localized electrochemical deposition based on ultrafast laser surface modification

Localized electrochemical deposition is a promising technology that allows for additive manufacturing of micro-nano structures in designated areas with high precision and controllability. However, ultra-low printing speed of current localized electrochemical deposition hinders its practical applications, especially the manufacturing of large-scale and complex devices. Here we propose a strategy combining ultrafast laser surface modification with traditional electrochemical deposition to achieve high-efficiency and large-scale printing. With using a focused ultrafast laser, arbitrary large-scale patterned structure can be efficiently scratched on substrate surface. Since the laser scratched region has formed nano-sized surface relief structures which experience local field enhancement when subjected to a voltage, the electrochemical deposition rate in the laser scratched region can be significantly improved, resulting in equivalent localized electrochemical deposition under traditional electrochemical deposition conditions. Such parallel electrochemical deposition can significantly shorten the printing time for large-scale devices. As for the processing of microstructure arrays with a size of 16 mm2, the printing time is compressed within 10 min, among which the electrochemical deposition process is compressed to 10 s. The results demonstrate the potential for improving the efficiency and scalability of localized electrochemical deposition through this combined approach.

Development of a cyber physical production system framework for 3D printing analytics

3D printing technology is considered one of the emerging areas to deal with global sustainability challenges and to facilitate the Industry 4.0 adoption. However, 3D printing technology is still immature due to several limitations and negative perceptions about its quality and performance. The goal of this paper is to propose a cyber physical production system (CPPS) framework for a 3D printer to (i) monitor the process, parameters, and carbon footprint, (ii) predict the nozzle’s remaining useful life (RUL), and (iii) prescribe optimum 3D printing parameters for minimizing carbon footprint and printing time, simultaneously at the targeted surface quality. Experiments were designed based on Taguchi L-27 orthogonal array to investigate the relationship between printing parameters and performance characteristics. The usefulness of the proposed framework has been demonstrated for a 3D printer to predict the remaining useful life of the printer nozzle (prognostic model), and to find an optimal combination of printing parameters for the simultaneous optimization of sustainability and productivity at the targeted surface quality (prescriptive model). Layer height was found to have a statically significant impact on the specific carbon footprint followed by scale and bed temperature. Layer height is the only statically significant contributor to the surface roughness of 3D printed parts. The scale and layer height followed by infill have significant effect on the printing time. The significance of the present work lies in enhancing the performance of a conventional 3D printer using low-cost smart sensors, devices, and open-source software. The usefulness of the proposed CPPS framework is demonstrated as a decision support tool for a 3D printer real-time monitoring, visualization, and control. The proposed CPPS framework and its application for prognostic and prescriptive analytics is generic in nature, and is transferable and applicable to other FDM 3D printers, irrespective of brand and size.

DESIGN AND OPTIMIZATION OF THE VARIABLE-DENSITY LATTICE STRUCTURE BASED ON LOAD PATHS

Lattice structure is more and more widely used in engineering by replacing solid structure. But its mechanical performances are constrained by the external shape if the unit cells are directly filled in the design domain, and the traditional topology optimization methods are difficult to give the explicitly mechanical guidance for the distribution of internal unit cells. In this paper, a novel design and optimization method of variable-density lattice structure is proposed in order to simultaneously optimize the external shape and the internal unit cells. First of all, the envelope model of any given structure should be established, and the load paths need to be visualized by the theory of load path. Then, the design criteria of external shape are established based on the principle of smoother load paths in the structure. An index of load flow capacity is defined to indicate the load paths density and to control the density distribution of unit cells, and a detailed optimization strategy is given. Finally, three examples of a cantilever plate, an L-shaped bracket and a classical three-point bending beam are used to verify the method. The results show that the models designed by the proposed method have better mechanical performances, lower material usage and less printing time.

Investigation of the mechanical properties, surface quality, and energy efficiency of a fused filament fabrication for PA6

Abstract Practitioners in the industry are developing predictive methods for assessing key parameters and responses of engineering materials. The aim of this research is to optimize the average surface roughness (R a), flexural strength (FS), tensile strength (TS), print time (T), and print energy consumption (E) of 3D printed Nylon 6 (PA6). Quantitative parameters for infill density (ID), layer thickness (LT), and print speed (PS) were selected. Employing the central component design (CCD)-response surface methodology (RSM) for investigational design, statistical analysis, and multi-objective optimization, a total of 20 samples were produced and analyzed to develop prediction models. The implication of the selected parameters was confirmed through variance analysis (ANOVA), and the models were validated using confirmatory trial tests. It was found that LT was essential in achieving appropriate R a and T values, while ID was a crucial factor in obtaining the necessary mechanical properties. RSM optimization led to an FS of 70.8 MPa, TS of 40.8 MPa, lowest T of 53 min, lowest possible R a of 8.30 µm, and 0.203 kW·h “E” at ID = 84%, LT = 0.21 mm, and PS = 75 mm·s−1. The study also revealed weak bond strength between layers and layers debonding after bending tests, as shown in SEM micrographs. The PA6 material exhibited flexibility during tensile testing, going into plasticity before breaking. The created numerically optimized model is anticipated to benefit manufacturers and practitioners in predicting the required surface quality for various factors before conducting experiments, ultimately improving 3D printing (3DP) processes and outcomes. Despite limitations such as limited parameter selection, small sample size, and material-specific focus, this research presents valuable insights for the 3DP industry.

A 2D numerical model of 3D concrete printing including thixotropy

Additive Manufacturing (AM) techniques are increasingly drawing interest in the construction sector since they can offer new architectural possibilities while improving the accuracy and the sustainability of the construction process. Among these techniques, 3D Concrete Printing (3DCP) is probably the most established and its future role in lowering the environmental impact of the building industry is under deep investigation. 3DCP main advantages, which are linked to the capacity of building optimized structural shapes, without the need for formworks and in very short times, are however still limited by the lack of knowledge and regulation. It is therefore necessary to provide designers with more advanced design tools to fully unlock the potential of 3DCP. This work presents a numerical model of 3DCP, which realistically simulates the extrusion and layer deposition phases. The model assumes that fresh concrete can be treated as a homogeneous viscous fluid. The problem is then governed by the Navier-Stokes equations, which are solved in a Lagrangian framework with the Particle Finite Element Method (PFEM). A Bingham law, modified to include thixotropic effects, is employed to accurately reproduce the material rheological behaviour at the early ages. The model is then applied to simulate a simple printing scenario, for which the fundamental experimental data is available in the literature, to assess the role of thixotropy in the printing process. The results show how thixotropy has a crucial effect in limiting the overall shape deformation and in avoiding the early compression failure of the bottom layers. In this view, the developed model can be applied to optimize the printing parameters with respect to the rheological properties and could also suggest how to improve the toolpath and the printing times for a given structure.

Three-Dimensional Printed Plate Template Versus Hemipelvis Model in Patient-Specific Plate Preparation for Posterior Wall Acetabular Fractures.

The application of three-dimensional (3D) printing technology in the management of posterior wall acetabular fractures can greatly reduce surgical invasiveness and operative time and simplify the procedure of reconstruction plate contouring, but the cost and time of patient-specific plate preparation on the basis of traditional 3D-printed pelvis model should not be neglected. We described a new method for patient-specific plate preparation by using 3D-printed plate template. The study aimed to assess the effectiveness and feasibility of the 3D-printed plate template in patient-specific plate preparation for posterior wall acetabular fractures. A total of 65 cases of posterior wall acetabular fractures with surgical treatment from December 2012 to December 2020 were chosen. According to the different plate contouring methods, the 65 cases were divided into three groups, which were group A (21 cases), group B (20 cases), and group C (24 cases). In group A, the 3D-printed plate template was used to contour the patient-specific reconstruction plate before surgery, whereas the 3D-printed hemipelvis model was adopted for group B. In group C, the reconstruction plate was contoured intraoperatively. Among the three groups, the instrumentation time, surgical time, blood loss, patient-specific plate preparation time, complications, reduction quality, and hip function were compared. The Kruskal-Wallis test was used to analyze the reduction quality and hip function among three groups. In comparison with group C, patients in groups A and B were featured by obviously shorter instrumentation time (-22, -23 min), shorter surgical time (-46, -44 min), and less intraoperative blood loss (-110, -122 mL). Compared to the hemipelvis model in group B (2.29 ± 0.56 vs. 12.70 ± 3.79 days), the 3D printing time for plate templates in group A was significantly shorter. The reduction quality and hip function had no obvious statistical difference among the three groups. The complication rate within group A (3/21) and group B (3/20) were both slightly lower than group C (5/24), with no obvious difference. Both the patient-specific pre-contoured plate fixation methods based on the 3D-printed hemipelvis model and plate template can achieve satisfactory clinical efficacy, with the advantage of shorter instrumentation and surgical time, and less intraoperative blood loss. However, 3D printing of plate template is easier and less time-consuming, considering the shorter time and less cost for 3D printing of physical model.

Operational Performance and Energy Efficiency of MEX 3D Printing with Polyamide 6 (PA6): Multi-Objective Optimization of Seven Control Settings Supported by L27 Robust Design

Both energy efficiency and robustness are popular demands for 3D-printed components nowadays. These opposing factors require compromises. This study examines the effects of seven general control variables on the energy demands and the compressive responses of polyamide (PA6) material extrusion (MEX) 3D printed samples. Nozzle Temperature, Layer Thickness, Orientation Angle, Raster Deposition Angle, Printing Speed, Bed Temperature, and Infill Density were studied. An L27 orthogonal array was compiled with five replicas. A total of 135 trials were conducted, following the ASTM D695-02a specifications. The stopwatch method was used to assess the construction time and energy usage. The compressive strength, toughness, and elasticity modulus were experimentally determined. The Taguchi technique ranks each control parameter’s impact on each response measure. The control parameter that had the greatest impact on both energy use and printing time was layer thickness. Additionally, the infill density had the greatest influence on the compressive strength. Quadratic regression model equations were formed for each of the response measures. The ideal compromise between mechanical strength and energy efficiency is now reported, with merit related to technological and economic benefits.

Effect of infill pattern scaling on mechanical properties of FDM-printed PLA specimens

3D printing offers a significant advantage in the production of hollow parts through the use of infill patterns. However, these patterns are typically generated by slicer software with a primary focus on providing basic structural rigidity, while neglecting other important criteria. This paper presents a simplified infill scaling technique for fused deposition modeling (FDM) and evaluates its effectiveness through tensile tests. The research question addressed in this study is whether adjusting the size of the pattern can reduce print time while maintaining the same stiffness at a given infill ratio. The methodology involves analyzing the results obtained from the tensile tests. The findings reveal that the print time can be reduced to some extent by properly adjusting the size of the infill pattern. However, it is observed that the mechanical resistance is influenced by the layer formation process. In conclusion, this research contributes to understanding the relationship between infill scaling, print time reduction, and mechanical resistance in FDM 3D printing.

Deconvolution volumetric additive manufacturing

Volumetric additive manufacturing techniques are a promising pathway to ultra-rapid light-based 3D fabrication. Their widespread adoption, however, demands significant improvement in print fidelity. Currently, volumetric additive manufacturing prints suffer from systematic undercuring of fine features, making it impossible to print objects containing a wide range of feature sizes, precluding effective adoption in many applications. Here, we uncover the reason for this limitation: light dose spread in the resin due to chemical diffusion and optical blurring, which becomes significant for features ⪅0.5 mm. We develop a model that quantitatively predicts the variation of print time with feature size and demonstrate a deconvolution method to correct for this error. This enables prints previously beyond the capabilities of volumetric additive manufacturing, such as a complex gyroid structure with variable thickness and a fine-toothed gear. These results position volumetric additive manufacturing as a mature 3D printing method, all but eliminating the gap to industry-standard print fidelity.

Issues of the Research of The Little Traveller's Book. Polemic Discourse

A polemical article reacts to the plenary part of the conference Francysk Skaryna and the Renaissance book culture. Skaryna’s Little Travel Book turns 500, held in Vilnius on 22–23 September 2022. After a review of the history of Little Traveler’s Book studies since 1971, five problems in the study of the first printed book of the GDL, touched on in S. Temchin’s plenary speech The Place of Printing of Francysk Skaryna’s “Little Traveller’s Book”: New Assumptions are discussed. In addition, two other aspects related to the study of place and time of printing: genre predetermination and application of modern methods to the study of Little Traveler’s Book are investigated.

The effect of layer thıckness on the accuracy of the dıfferent ın-house clear alıgner attachments.

The accuracy of the attachments, one of the key components of clear aligner therapy, is important for obtaining more precise tooth movement. The aim of this study was to evaluate the accuracy of the ovoid, hemi-ellipsoid, and vertical rectangular attachments produced by the digital light-processing(DLP) 3-dimensional printing technologies with 25µm, 75µm, and 125µm layer thickness. The ovoid, hemi-ellipsoid, and vertical rectangular attachments were positioned onto the convex surface of the central incisor by the software. The printing process was carried out by a DLP printer using a commercially printed resin with 25µm, 75µm, and 125µm layer thickness (n = 30, for each group). All test models' digital data was exported into the reverse engineering software for the superimposition. After selecting the 5 comparison points for the ovoid and vertical rectangular attachments, and 6 comparison points for the hemi-ellipsoid attachment, the Root Mean Square (RMS) was evaluated for each group. There is a statistically significant difference between the 25µm and 125µm layer thickness of total RMS values in the ovoid, hemi-ellipsoid, and vertical rectangular attachment groups (p = 0.001, p = 0.03, and p = 0.00 respectively). The printing time with the 25µm layer thickness was 4 times longer than with the 125µm layer thickness. This study revealed that the accuracy of the attachments used for in-house clear aligner therapy is affected by the layer thickness of the 3D printer. The layer thickness of the 3D printer is a crucial factor in determining attachment accuracy, but its clinical significance is minimal. Clinicians should make informed decisions about the appropriate layer thickness, taking into account their workflow preferences, time constraints, and other practical considerations specific to their clinical practice.

The Effects of Polyaniline Nanofibers and Graphene Flakes on the Electrical Properties and Mechanical Properties of ABS-like Resin Composites Obtained by DLP 3D Printing.

Three-dimensional printing is regarded as a future-oriented additive manufacturing technology that is making significant contributions to the field of polymer processing. Among the 3D printing methods, the DLP (digital light processing) technique has attracted great interest because it requires a short printing time and enables high-quality printing through selective light curing of polymeric materials. In this study, we report a fabrication method for ABS-like resin composites containing polyaniline (PANI) nanofibers and graphene flakes suitable for DLP 3D printing. As-prepared ABS-like resin composite inks employing PANI nanofibers and graphene flakes as co-fillers were successfully printed, obtaining highly conductive and mechanically robust products with the desired shapes and different sizes through DLP 3D printing. The sheet resistance of the 3D-printed composites was reduced from 2.50 × 1015 ohm/sq (sheet resistance of pristine ABS-like resin) to 1.61 × 106 ohm/sq by adding 3.0 wt.% of PANI nanofibers and 1.5 wt.% of graphene flakes. Furthermore, the AP3.0G1.5 sample (the 3D-printed composite containing 3.0 wt.% of PANI nanofibers and 1.5 wt.% of graphene flakes) exhibited 2.63 times (22.23 MPa) higher tensile strength, 1.47 times (553.8 MPa) higher Young's modulus, and 5.07 times (25.83%) higher elongation at break values compared to the pristine ABS-like resin with a tensile strength of 8.46 MPa, a Young's modulus of 376.6 MPa, and an elongation at break of 5.09%. Our work suggests the potential use of highly conductive and mechanically robust ABS-like resin composites in the 3D printing industry. This article not only provides optimized DLP 3D printing conditions for the ABS-like resin, which has both the advantages of the ABS resin and the advantages of a thermoplastic elastomer (TPE), but also presents the effective manufacturing process of ABS-like resin composites with significantly improved conductivity and mechanical properties.

Modeling of Energy Consumption and Print Time for FDM 3D Printing Using Multilayer Perceptron Network

Given the recognized advantages of additive manufacturing (AM) printing systems in comparison with conventional subtractive manufacturing systems, AM technology has become increasingly adopted in 3D manufacturing, with usage rates increasing dramatically. This strong growth has had a significant and direct impact not only on energy consumption but also on manufacturing time, which in turn has generated significant costs. As a result, this problem has attracted the attention of industry actors and the research community, and several studies have focused on predicting and reducing energy consumption and additive manufacturing time, which has become one of the main objectives of research in this field. However, there is no effective model yet for predicting and optimizing energy consumption and printing time in a fused deposition modeling (FDM) process while taking into account the correct part orientation that minimizes both of these costs. In this paper, a neural-network-based model has been proposed to solve this problem using experimental data from isovolumetrically shaped mechanical parts. The data will serve as the basis for proposing the appropriate model using a specific methodology based on five performance criteria with the following statistical values: R2-squared > 99%, explained variance > 99%, MAE < 0.99%, MSE < 0.02% and RMSE < 1.36%. These values show just how effective the proposed model will be in estimating energy consumption and FDM printing time, taking into account the best choice of part orientation for the lowest cost. This model provides a global understanding of the primary energy and time requirements for manufacturing while also improving the system’s cost efficiency. The results of this work can be extended and applied to other additive manufacturing processes in future work.

A multiobjective optimization parameters applied to additive manufacturing: DOE-based approach to 3D printing

The performance and quality of 3D printing, as well as the mechanical properties of the final part, depend on its printing parameters, such as layer thickness, printing speed, infill density, filling pattern, printing material, and many others. In this study, the influence of printing parameters on the mechanical properties of the final printed part is investigated, and at the end, a multi-objective optimization was performed on the experimental responses. To study the effects of printing parameters, the Design of Experiments methodology was used, where five parameters considered essential were evaluated: layer thickness, printing speed, infill density, filling pattern, and printing material. Once everything was printed, mechanical tests of traction, compression, and bending were used to obtain the experimental curves. After obtaining the experimental responses by extracting the test curves, the ANOVA method was applied, through which it was possible to obtain a behavior equation, a relation of the main effects, and Pareto graphs of each experimental result on the studied parameters. Finally, the multi-objective optimization allowed obtaining printing parameters that allowed improvements in several mechanical properties in addition to the minimization of time and total mass. Results indicated a reduction of 72.39% in the average time of printing and an increase of 9.06% in the mass after the optimization where the mechanical properties were substantially optimized.