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Item type:Publication, Biocomposites of bio-polyethylene reinforced with a hydrothermal-alkaline sugarcane bagasse pulp and coupled with a bio-based compatibilizer(MDPI, 2020-05-01)Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Physical, thermal and tensile behaviour of 3D printed kenaf/PLA to suggest its usability for ankle–foot orthosis – a preliminary study(Emerald Group Holdings Ltd., 2022-08-02)This paper aims to discuss the physical and thermal properties of the three-dimensional (3D) printing natural composite filament, as well as the tensile behaviour of the printed composites to get an insight of its possibility to be used as an ankle–foot orthosis (AFO) material. Design/methodology/approach: Physical test that was conducted includes scanning electron microscopy analysis, thermogravimetric/differential scanning calorimetry analysis as well as the effect of fibre load after extrusion on the filament morphology. Tensile test was conducted with different amounts of fibre loads (0, 3, 5 and 7 Wt.%) on the printed specimens. Findings: There is an increment of strength as the fibre load is increased to 3 Wt.%; however, it decreases significantly as it is increased to 5 and 7 Wt.% because of the presence of voids. It also shows that the extrusion temperature severely affects the structure of the filaments, which will then affect the strength of the printed composites. Based on the results, it is possible to use kenaf/polylactic acid (PLA) filament to print out AFO as long as the filament production and printing process are being controlled properly. Originality/value: The unique aspect of this paper is the investigation of kenaf/PLA filament as a material for 3D printing, as well as its material consideration for AFO manufacturing. This paper also studies the effect of extrusion temperature on the morphological structure of the filament and its effect on the tensile properties of the printed kenaf/PLA specimen. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Copper Tannate (CuTn) based coating on 3D printed face masks(Trans Tech Publications Ltd, 2022-01-01)The impact of COVID-19 crisis on global supply chains caused a critical shortage of essential goods like medical devices. Additionally, massive consumption increased mask contamination and waste. 3D printing has become a fast and versatile manufacturing alternative that prevents a single use of masks. However, SARS-CoV-2 virus can persist on plastic surfaces for days. This study proposes the optimization of 3D printed masks, by applying a coating rich in hydrolyzable tannins and copper, in order to diminish the virus presence. Different paints were formulated with copper tannate and applied on thermoplastic polyurethane 3D panels to test bacterial stability. Results showed a significant reduction of colony-forming units on coated polymeric surfaces. Paints pigmented with copper tannates could improve the protection provided by printed masks, even against the COVID-19 virus. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Development and characterization of a printable concrete made with construction and demolition waste aggregates(Springer Science and Business Media B.V., 2024-01-01)To address the environmental challenges associated with Construction and Demolition Wastes (CDW) disposal and the depletion of natural sand resources by the construction industry, this paper investigates the potential use of fine aggregates from CDW as a complete replacement for natural sand in concrete formulations tailored for 3D printing applications. The study begins by physically characterizing fine aggregates produced by crushing and sieving CDW from concrete and fired clay brick residues. This stage includes water content and water absorption capacity tests, specific gravity tests and unit weight tests, and particle size analysis. Then, a 3D printable concrete mix formulated entirely with CDW fine aggregates, replacing 100% of natural sand, is developed using mortar flow and rotational rheology tests. This formulation is validated by printing a medium-sized wall using a 3D printing system developed in-house. Finally, compression tests are performed on printed filaments to examine mechanical properties such as compressive strength and modulus of elasticity. Fresh-state and hardened-state properties are compared with control concrete samples made with natural sand (0% of CDW fine aggregates). The study demonstrates the feasibility of formulating printable concretes with a total replacement of sand by CDW for real-size applications. However, special attention must be given in large-scale projects to the rate of workability loss caused by the high water absorption capacity of CDW fine aggregates. The research findings offer valuable insights into the potential and performance of CDW aggregates in 3D-printed concrete applications within the context of a circular economy. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Comprehensive investigation into the influence of soil composition and water content on cracking due to drying shrinkage in 3D-printed earthen structures(Springer Science and Business Media B.V., 2024-01-01)As a raw material for additive construction, earth offers a multitude of benefits, from environmental and economic to social points of view. However, the fresh-state properties of printable materials and the curing conditions of additively manufactured elements make large-scale 3D-printed earthen structures susceptible to suffering severe cracking from shrinkage during drying. This project investigates the effect of soil composition and water content on the development of drying shrinkage cracking in 3D-printed earthen structures. This article presents two strategies for minimizing those cracks: decreasing the clay content of the soil by adding fine sand and decreasing the required water content for printability by using a clay dispersant agent. Earth-based mix designs with different soil/fine-sand ratios and sodium hexametaphosphate (SHMP) contents were subjected to flow table, rotational rheology, and shrinkage cracking tests. The results indicate that the clay and water content are determining factors that minimize the appearance of cracks due to drying shrinkage. Two earthen-based formulations with zero cracks due to shrinkage resulted from replacing 50% wt. of the soil with fine sand and the addition of 0.55 and 2.20% wt. of SHMP. Further research is needed to confirm the validity of these findings across diverse soil types and curing conditions. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Soil-Cement Matrices for Additive Construction: 3D Printing System Validation and Printing Tests(Trans Tech Publications Ltd, 2023-01-01)Soil as a building material is gaining renewed interest from academia, and the constructionsector, mainly for fabricating low-environmental impact homes. The fabrication of houses with soilusing traditional methods such as adobe, cob, and rammed earth dates back to ancient times. However, emerging construction technologies, such as 3D printing, can be compatible with this material for building purposes. The article presents the validation of a 3D printing system for construction applications and the evaluation of soil-cement matrices' printability. First, the paper defines the printing parameters through experimental testing on soil matrices. Then, the article evaluates the printability of soil-cement matrices through filament printing and stacking tests. The results show that the 3D printing system prototype can fabricate small and medium-sized elements with soil matrices after correctly defining the pumping speed, printing speed, and layer height. Furthermore, experimental printing test results demonstrate that soil-cement matrices can be easily extruded and stacked; however, their printability capacity is strongly affected by the total water content and printing speed. This research highlights the suitability of soil-cement mixtures for additive manufacturing, a promising outcome that can facilitate the construction of homes in remote areas using 3D printing systems. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preliminary Experimental Evaluation of Buildability Improvement Methods for Concrete for 3D Printing(Trans Tech Publications Ltd, 2023-01-01)3D concrete printing is an innovative construction process based on fully auto nomousmaterial deposition. One of the challenges of implementing this technology is the development of printable concrete formulations, as this material must exhibit particular fresh-state properties. Among these, buildability is one of the most important. This property describes the material's ability to support weight at very early ages, allowing a layer-by-layer construction. Therefore, this paper aims to evaluate two approaches for improving concrete buildability: the optimization of the super plasticizer dosage and the external application of quick-setting admixture. The results showed that reducing super plasticizer content improved buildability by increasing the static yield strength.However, this approach has a collateral disadvantage as concretes presented problems duringextrusion. On the other hand, the results of cylinder stability and Vicat tests indicate that the external application of quick-setting admixture leads to concretes with improved buildability without affecting the initial workability and a faster hardening process. According to these results, the latter approachcan potentially be applied in small and large-scale 3D printing. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Evaluation of Chitosan and Potato Starch as Stabilizers to Improve the Mechanical and Water Durability Properties of Printable Earth-Based Matrices Reinforced with Sisal Fibers(Trans Tech Publications Ltd, 2023-01-01)Due to economic, sustainable, and aesthetic benefits, academia and the construction industry are exploring the use of earth in modern construction is being widely studied. Unfortunately, earth as a construction material has low mechanical, poor water durability resistance, and the potential to swell and crack. Therefore, this paper evaluates chitosan and potato starch, natural biodegradable polymers, as stabilizers to improve mechanical strength and water durability resistance of printable earth-based matrix reinforced with sisal fibers. Although the test results indicated that the chitosan had a better performance as an earth stabilizer than potato starch, adding both stabilizers resulted in earthen composites with higher compressive strength and lower water permeability. These results demonstrate the feasibility of using natural stabilizers to improve the performance of earth-based materials for 3D printing without affecting their printability capacities. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Rapid and cost-effective fabrication of microfluidic chips with resin 3D printing(Springer Science+Business Media, 2026-01-01)The fabrication of microfluidic chips has traditionally relied on photolithographic techniques. Although highly precise, these methods require specialized cleanroom facilities and involve multiple complex steps. In recent years, additive manufacturing—particularly resin-based 3D printing—has emerged as a promising alternative, offering more accessible, cost-effective, and rapid prototyping. In this study, we present a protocol for fabricating high-resolution microfluidic templates using an LCD-based resin 3D printer, followed by replication of microchannels in polydimethylsiloxane (PDMS). Our results show that while LCD 3D printing enables fast prototyping, it has limitations in accurately reproducing fine features (especially channel widths below 100 μm) due to overexpansion of cured resin. Morphological and dimensional analyses by scanning electron microscopy (SEM) revealed discrepancies between the designed and actual channel dimensions, primarily attributed to the printer’s pixel size constraints and light diffusion during polymerization. Despite these challenges, the ability to reuse a printed template for multiple PDMS replications significantly enhances fabrication scalability and cost efficiency. This study underscores the potential of resin-based 3D printing for microfluidic applications and provides optimization strategies to improve dimensional accuracy in future development.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Experimental investigation of seawater exposure and specimen geometry effects on the mechanical performance of 3D-printed ABS and ABS/CF(Springer Science+Business Media, 2026-06-01)In this work, the effects of seawater exposure and specimen geometry on the mechanical performance of 3D-printed Acrylonitrile Butadiene Styrene (ABS) and carbon fiber-reinforced ABS (ABS/CF) were investigated. Enclosed 3D printers were used to avoid shrinkage and warping of ABS and ABS/CF. The standard specimen types in this research work were ASTM D638 type IV, ISO 527-2 type 1BA, and ASTM D3039 full-section specimens. The tensile tests were strain-controlled tests with a strain rate of 0.1 min− 1. Firstly, the effects of the different specimen types on the tensile strength and Young’s modulus of unaged (as-printed) ABS and ABS/CF were analyzed. Secondly, the three types of specimens were immersed in seawater for 1, 2, and 3 weeks to evaluate moisture absorption and the degradation of the mechanical properties. The results indicated that the test specimen type had a statistically significant effect on the mechanical properties of ABS and ABS/CF, with the ISO 527 specimen exhibiting the lowest tensile strength and Young’s modulus. Moreover, all ABS and ABS/CF specimens showed moisture uptake of less than 1%. After three weeks of exposure, the ABS and ABS/CF retained over 90% of their mechanical properties. The good retention of mechanical properties and moisture resistance makes these materials suitable for short-term marine applications.