3D printing of Portland cement-containing bodies

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Asif Ur Rehman ◽  
Vincenzo M. Sglavo
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Portland Cement ◽  
Pure Water ◽  
Diffusion Mechanism ◽  
Dimensional Accuracy ◽  
Portland Cement Concrete ◽  
Content Type ◽  
Polymeric Binders ◽  
Practical Implications

Purpose Recent advances in 3D printing construction elements have focused on ordinary Portland cement (OPC) concrete using polymeric binders; herein, this study aims to produce the same using pure water. Design/methodology/approach A binder jet printer prototype was used to fabricate specimens that are used to assess geometric and mechanical properties. Two distinct water-based binder formulations, compatible with OPC chemistry and piezoelectric jetting device, were used: pure water and water-polyvinyl alcohol (98:2 w/w) solution. Findings This study examines the effect of binder flow rate on dimensional accuracy. Furthermore, the changes in the mechanical properties over time with hydration have been investigated. Practical implications Results indicate that the increase in mechanical strength of Portland cement concrete with pure water was consistent; however, it was delayed by the water: PVA (98:2 w/w) solution. Post-curing by water vapor hardened the structure with the removal of layering native to 3DP and decreased infilling porosity by diffusion mechanism. Originality/value This paper has used pure water jetting for BJT of Portland cement-containing bodies.

Effect of wood particulate size on the mechanical properties of PLA biocomposite

2020 ◽  
Vol 49 (6) ◽  
pp. 465-472
Author(s):  
S. Raj Sachin ◽  
T. Kandasamy Kannan ◽  
Rathanasamy Rajasekar
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Wood Flour ◽  
Wood Particle ◽  
Poly Lactic Acid ◽  
Particle Sizes ◽  
Content Type ◽  
Particulate Size ◽  
Practical Implications

Purpose The purpose of this study is to carry out an investigation of the role of the wood particle size on the mechanical properties of poly lactic acid (PLA)-reinforced neem fiber biocomposite. Design/methodology/approach Composite test specimens were processed by reinforcing neem wood flour (NWF) in two different particle sizes, micro-sized NWF (MNWF) and nano-sized NWF (NNWF) separately into PLA. Composites were extruded at four different fiber loadings (10, 15, 20 and 25 Wt.%) into PLA matrix. The MNWF and NNWF had particle sizes varying from 5 to 15 µm and 10 to 15 nm, respectively. Findings Tensile strength, flexural strength and impact strength of PLA increased with fiber reinforcement for both the MNWF and NNWF cases. The NNWF-reinforced PLA composite at 20 Wt.% fiber loading proved to be the best composite that had outstanding mechanical properties in this research. Practical implications The developed composite can be used as a substitute for conventional plywood for furniture, building infrastructure and interior components for the automobile, aircraft and railway sectors. Originality/value A new biocomposite had been fabricated by using PLA and NWF and had been tested for its mechanical characteristics.

scholarly journals Effect of temperature on the mechanical properties of 3D-printed PLA tensile specimens

2018 ◽  
Vol 24 (8) ◽  
pp. 1337-1346 ◽  
Author(s):  
Marzio Grasso ◽  
Lyes Azzouz ◽  
Paula Ruiz-Hincapie ◽  
Mauro Zarrelli ◽  
Guogang Ren
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mechanical Test ◽  
Optical Microscope ◽  
Middle Part ◽  
Gauge Length ◽  
Effect Of Temperature ◽  
Content Type ◽  
Relevant Effect ◽  
3D Printed

Purpose Recent advancements of 3D printing technology have brought forward the interest for this technique in many engineering fields. This study aims to focus on mechanical properties of the polylactic acid (PLA) feeding material under different thermal conditions for a typical fusion deposition of 3D printer system. Design/methodology/approach Specimens were tested under static loading within the range 20ºC to 60ºC considering different infill orientations. The combined effect of temperature and filament orientation is investigated in terms of constitutive material parameters and final failure mechanisms. The difference between feeding system before and post-3D printing was also assessed by mechanical test on feeding filament to verify the thermal profile during the deposition phase. Findings The results in terms of Young’s modulus, ultimate tensile strength (UTS), strain at failure (εf) and stress at failure (σf) are presented and discussed to study the influence of process settings over the final deposited material. Fracture surfaces have been investigated using an optical microscope to link the phenomenological interpretation of the failure with the micro-mechanical behaviour. Experimental results show a strong correlation between stiffness and strength with the infill orientation and the temperature values. Moreover, a relevant effect is related to deformed geometry of the filament approaching glass transition region of the polymer according to the deposition orientation. Research limitations/implications The developed method can be applied to optimise the stiffness and strength of any 3D-printed composite according to the infill orientation. Practical implications To avoid the failure of specimens outside the gauge length, a previously proposed modification to the geometry was adopted. The geometry has a parabolic profile with a curvature of 1,000 mm tangent to the middle part of the specimen. Originality/value Several authors have reported the stiffness and strength of 3D-printed parts under static and ambient temperature for different build parameters. However, there is a lack of literature on the combination of the latter with the temperature effects on the mechanical properties which this paper covers.

Optimization of the color fastness and mechanical properties of pigment dyed PC fabric

2018 ◽  
Vol 47 (5) ◽  
pp. 396-405
Author(s):  
Abdul Azeem ◽  
Sharjeel Abid ◽  
Noman Sarwar ◽  
Shahzaib Ali ◽  
Ahsan Maqsood ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Design Methodology ◽  
Industrial Process ◽  
Color Fastness ◽  
Content Type ◽  
Washing Fastness ◽  
Market Values ◽  
Dyed Fabrics ◽  
Bending Length ◽  
Practical Implications

Purpose The purpose of this study is to improve the mechanical properties and reduce the stiffness/harshness of fabric associated with the pigment dyeing of textiles. Design/methodology/approach The fabric was pigment dyed with the addition of three different softeners and binders. The fabric was then analyzed to have improved textile properties by measuring tear strength, bending length, crocking and washing fastness tests. Findings The conventional route of pigment dyeing (without any softener) imparted poor mechanical and rubbing fastness. The softener-added recipe provided better mechanical, rubbing and washing fastness, and the stiffness values were oppressed as well. Practical implications Because of reduced stiffness, increased fastness and mechanical properties, the use of softener with pigment dyeing can improve the market values and satisfaction of the dyed fabrics. The finished product would also have better life and endurance. The process can be modified easily to have a better end-product with a negligible cost addition in industrial process, as softeners are cheap and used in low (10-20 g/l) in industrial settings without affecting the required shades. Originality/value This is the first report, to the best of the author’s knowledge, on the optimization of pigment dyeing of PC fabric with the addition of Helizarin and perapret softeners in dyeing bath.

A physical investigation of dimensional and mechanical characteristics of 3D printed nut and bolt for industrial applications

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ramesh Chand ◽  
Vishal S. Sharma ◽  
Rajeev Trehan ◽  
Munish Kumar Gupta
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
3D Printing ◽  
Surface Properties ◽  
3D Printer ◽  
Content Type ◽  
Safety Issues ◽  
Machine Failure ◽  
Sharp Edges ◽  
3D Printed

Purpose A nut bolt joint is a primary device that connects mechanical components. The vibrations cause bolted joints to self-loosen. Created by motors and engines, leading to machine failure, and there may be severe safety issues. All the safety issues and self-loosen are directly and indirectly the functions of the accuracy and precision of the fabricated nut and bolt. Recent advancements in three-dimensional (3D) printing technologies now allow for the production of intricate components. These may be used technologies such as 3D printed bolts to create fasteners. This paper aims to investigate dimensional precision, surface properties, mechanical properties and scanning electron microscope (SEM) of the component fabricated using a multi-jet 3D printer. Design/methodology/approach Multi-jet-based 3D printed nut-bolt is evaluated in this paper. More specifically, liquid polymer-based nut-bolt is fabricated in sections 1, 2 and 3 of the base plate. Five nuts and bolts are fabricated in these three sections. Findings Dimensional inquiry (bolt dimension, general dimensions’ density and surface roughness) and mechanical testing (shear strength of nut and bolt) were carried out throughout the study. According to the ISO 2768 requirements for the General Tolerances Grade, the nut and bolt’s dimensional examination (variation in bolt dimension, general dimensions) is within the tolerance grades. As a result, the multi-jet 3D printing (MJP)-based 3D printer described above may be used for commercial production. In terms of mechanical qualities, when the component placement moves from Sections 1 to 3, the density of the manufactured part decreases by 0.292% (percent) and the shear strength of the nut and bolt decreases by 30%. According to the SEM examination, the density of the River markings, sharp edges, holes and sharp edges increased from Sections 1 to 3, which supports the findings mentioned above. Originality/value Hence, this work enlightens the aspects causing time lag during the 3D printing in MJP. It causes variation in the dimensional deviation, surface properties and mechanical properties of the fabricated part, which needs to be explored.

On the manufacturability of Inconel 718 thin-walled honeycomb structures by laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
José M. Zea Pérez ◽  
Jorge Corona-Castuera ◽  
Carlos Poblano-Salas ◽  
John Henao ◽  
Arturo Hernández Hernández
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Dimensional Accuracy ◽  
Honeycomb Lattice ◽  
Lattice Structures ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Content Type ◽  
Powder Bed ◽  
Thin Walled

Purpose The purpose of this paper is to study the effects of printing strategies and processing parameters on wall thickness, microhardness and compression strength of Inconel 718 superalloy thin-walled honeycomb lattice structures manufactured by laser powder bed fusion (L-PBF). Design/methodology/approach Two printing contour strategies were applied for producing thin-walled honeycomb lattice structures in which the laser power, contour path, scanning speed and beam offset were systematically modified. The specimens were analyzed by optical microscopy for dimensional accuracy. Vickers hardness and quasi-static uniaxial compression tests were performed on the specimens with the least difference between the design wall thickness and the as built one to evaluate their mechanical properties and compare them with the counterparts obtained by using standard print strategies. Findings The contour printing strategies and process parameters have a significant influence on reducing the fabrication time of thin-walled honeycomb lattice structures (up to 50%) and can lead to improve the manufacturability and dimensional accuracy. Also, an increase in the young modulus up to 0.8 times and improvement in the energy absorption up to 48% with respect to those produced by following a standard strategy was observed. Originality/value This study showed that printing contour strategies can be used for faster fabrication of thin-walled lattice honeycomb structures with similar mechanical properties than those obtained by using a default printing strategy.

Effects of post-curing conditions on mechanical properties of 3D printed clear dental aligners

2020 ◽  
Vol 26 (8) ◽  
pp. 1337-1344 ◽  
Author(s):  
Prashant Jindal ◽  
Mamta Juneja ◽  
Divya Bajaj ◽  
Francesco Luke Siena ◽  
Philip Breedon
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mechanical Strength ◽  
Financial Burden ◽  
Experimental Studies ◽  
Cost Savings ◽  
Time Duration ◽  
Content Type ◽  
Curing Conditions ◽  
3D Printed

Purpose 3D printing techniques have been widely used for manufacturing complex parts for various dental applications. For achieving suitable mechanical strength, post-cure processing is necessary, where the relative time duration and temperature specification also needs to be defined. The purpose of this study/paper is to assess the effects of post curing conditions and mechanical properties of 3D printed clear dental aligners Design/methodology/approach Dental long-term clear resin material has been used for 3D printing of dental aligners using a Formlabs 3D printer for direct usage on patients. Post-curing conditions have been varied, all of which have been subjected to mechanical compression loading of 1,000 N to evaluate the curing effects on the mechanical strength of the aligners. Findings The experimental studies provide significant insight into both temperatures and time durations that could provide sufficient compressive mechanical strength to the 3D printed clear dental aligners. It was observed that uncured aligners deformed plastically with large deformations under the loading conditions, whereas aligners cured between 400°C–800°C for 15–20 min deformed elastically before fragmenting into pieces after safely sustaining higher compressive loads between 495 N and 666 N. The compressive modulus ratio for cured aligners ranged between 4.46 and 5.90 as compared to uncured aligners. For shorter cure time durations and lower temperature conditions, an appropriate elevated compressive strength was also achieved. Originality/value Based on initial assessments by dental surgeons, suitable customised clear aligners can be designed, printed and cured to the desired levels based on patient’s requirements. This could result in time, energy and unit production cost savings, which ultimately would help to alleviate the financial burden placed on both the health service and their patients.

3D printing of biofiber-reinforced composites and their mechanical properties: a review

2020 ◽  
Vol 26 (6) ◽  
pp. 1113-1129
Author(s):  
Lai Jiang ◽  
Xiaobo Peng ◽  
Daniel Walczyk
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Reinforced Composites ◽  
Research Directions ◽  
Content Type ◽  
Reinforced Composite ◽  
3D Printed ◽  
Materials Used ◽  
Printing Processes ◽  
Pure Resin

Purpose This paper aims to summarize the up-to-date research performed on combinations of various biofibers and resin systems used in different three-dimensional (3D) printing technologies, including powder-based, material extrusion, solid-sheet and liquid-based systems. Detailed information about each process, including materials used and process design, are described, with the resultant products’ mechanical properties compared with those of 3D-printed parts produced from pure resin or different material combinations. In most processes introduced in this paper, biofibers are beneficial in improving the mechanical properties of 3D-printed parts and the biodegradability of the parts made using these green materials is also greatly improved. However, research on 3D printing of biofiber-reinforced composites is still far from complete, and there are still many further studies and research areas that could be explored in the future. Design/methodology/approach The paper starts with an overview of the current scenario of the composite manufacturing industry and then the problems of advanced composite materials are pointed out, followed by an introduction of biocomposites. The main body of the paper covers literature reviews of recently emerged 3D printing technologies that were applied to biofiber-reinforced composite materials. This part is classified into subsections based on the form of the starting materials used in the 3D printing process. A comprehensive conclusion is drawn at the end of the paper summarizing the findings by the authors. Findings Most of the biofiber-reinforced 3D-printed products exhibited improved mechanical properties than products printed using pure resin, indicating that biofibers are good replacements for synthetic ones. However, synthetic fibers are far from being completely replaced by biofibers due to several of their disadvantages including higher moisture absorbance, lower thermal stability and mechanical properties. Many studies are being performed to solve these problems, yet there are still some 3D printing technologies in which research concerning biofiber-reinforced composite parts is quite limited. This paper unveils potential research directions that would further develop 3D printing in a sustainable manner. Originality/value This paper is a summary of attempts to use biofibers as reinforcements together with different resin systems as the starting material for 3D printing processes, and most of the currently available 3D printing techniques are included herein. All of these attempts are solutions to some principal problems with current 3D printing processes such as the limit in the variety of materials and the poor mechanical performance of 3D printed parts. Various types of biofibers are involved in these studies. This paper unveils potential research directions that would further widen the use of biofibers in 3D printing in a sustainable manner.

Effect of print orientation on microstructural features and mechanical properties of 3D porous structures printed with continuous digital light processing

2019 ◽  
Vol 25 (6) ◽  
pp. 1017-1029
Author(s):  
Javier Navarro ◽  
Matthew Din ◽  
Morgan Elizabeth Janes ◽  
Jay Swayambunathan ◽  
John P. Fisher ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Biaxial Loading ◽  
Digital Light Processing ◽  
Printing Process ◽  
Content Type ◽  
Simple Compression ◽  
Microct Imaging ◽  
Microporous Scaffolds ◽  
Part Orientation

Purpose This paper aims to study the effects of part orientation during the 3D printing process, particularly to the case of using continuous digital light processing (cDLP) technology. Design/methodology/approach The effects of print orientation on the print accuracy of microstructural features were assessed using microCT imaging and mechanical properties of cDLP microporous scaffolds were characterized under simple compression and complex biaxial loading. Resin viscosity was also quantified to incorporate this factor in the printing discussion. Findings The combined effect of print resin viscosity and the orientation and spacing of pores within the structure alters how uncrosslinked resin flows within the construct during cDLP printing. Microstructural features in horizontally printed structures exhibited greater agreement to the design dimensions than vertically printed constructs. While cDLP technologies have the potential to produce mechanically isotropic solid constructs because of bond homogeneity, the effect of print orientation on microstructural feature sizes can result in structurally anisotropic porous constructs. Originality/value This work is useful to elucidate on the specific capabilities of 3D printing cDLP technology. The orientation of the part can be used to optimize the printing process, directly altering parameters such as the supporting structures required, print time, layering, shrinkage or surface roughness. This study further detailed the effects on the mechanical properties and the print accuracy of the printed scaffolds.

Printing the way to success

2017 ◽  
Vol 33 (6) ◽  
pp. 4-6
Keyword(s):  
3D Printing ◽  
Competitive Advantage ◽  
Design Methodology ◽  
Reading Time ◽  
Business Models ◽  
Content Type ◽  
Customer Base ◽  
Pertinent Information ◽  
User Entrepreneurs ◽  
Practical Implications

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings 3D printing is big business, and it is growing fast. While there is some adoption of the technology in industry, the vast majority is occurring at home, with users. These user entrepreneurs are carving their own path into business, providing products and services to a growing customer base in a way that large incumbent organizations cannot. The innovative and adaptable nature of these user entrepreneurs perfectly fits the 3D printing market, but with such a diverse marketplace and large number of competitors, a competitive advantage is being sought. Holzmann et al. (2017) look at the use of business models to ascertain whether they can provide this desired advantage in the 3D printing user market. Practical implications The paper provides strategic insights and practical thinking that have influenced some of the world’s leading organizations. Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

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