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

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.

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

Rapid Prototyping Journal ◽

10.1108/rpj-04-2017-0055 ◽

2018 ◽

Vol 24 (8) ◽

pp. 1337-1346 ◽

Cited By ~ 12

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.

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

Rapid Prototyping Journal ◽

10.1108/rpj-04-2019-0118 ◽

2020 ◽

Vol 26 (8) ◽

pp. 1337-1344 ◽

Cited By ~ 1

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.

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

Rapid Prototyping Journal ◽

10.1108/rpj-08-2019-0214 ◽

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.

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Property Analysis of Photo-Polymerization-Type 3D-Printed Structures Based on Multi-Composite Materials

Applied Sciences ◽

10.3390/app11188545 ◽

2021 ◽

Vol 11 (18) ◽

pp. 8545

Author(s):

So-Ree Hwang ◽

Min-Soo Park

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Composite Materials ◽

3D Printing ◽

Bending Test ◽

3D Printer ◽

Complex Structures ◽

Photo Polymerization ◽

Anisotropic Structures ◽

3D Printed

Additive manufacturing, commonly called 3D printing, has been studied extensively because it can be used to fabricate complex structures; however, polymer-based 3D printing has limitations in terms of implementing certain functionalities, so it is limited in the production of conceptual prototypes. As such, polymer-based composites and multi-material 3D printing are being studied as alternatives. In this study, a DLP 3D printer capable of printing multiple composite materials was fabricated using a movable separator and structures with various properties were fabricated by selectively printing two composite materials. After the specimen was fabricated based on the ASTM, the basic mechanical properties of the structure were compared through a 3-point bending test and a ball rebound test. Through this, it was shown that structures with various mechanical properties can be fabricated using the proposed movable-separator-based DLP process. In addition, it was shown that this process can be used to fabricate anisotropic structures, whose properties vary depending on the direction of the force applied to the structure. By fabricating multi-joint grippers with varying levels of flexibility, it was shown that the proposed process can be applied in the fabrication of soft robots as well.

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Mechanical properties and water absorption behaviour of PLA and PLA/wood composites prepared by 3D printing and injection moulding

Rapid Prototyping Journal ◽

10.1108/rpj-06-2018-0149 ◽

2019 ◽

Vol 25 (4) ◽

pp. 672-678 ◽

Cited By ~ 8

Author(s):

Josef Valentin Ecker ◽

Andreas Haider ◽

Ivana Burzic ◽

Axel Huber ◽

Gerhard Eder ◽

...

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Water Absorption ◽

Tensile Properties ◽

Injection Moulding ◽

Water Storage ◽

Wood Composites ◽

Content Type ◽

Influence Of Water ◽

3D Printed

Purpose This papers aims to study the influence of water absorption on the mechanical properties of poly lactic acid (PLA) and PLA/Wood composites. Virgin PLA and PLA/Wood double-bone-shaped specimens were prepared by two methods: injection moulding and 3D printing. The results were compared to each other and showed the influence of the production method on the properties of the produced parts. Design/methodology/approach Morphology studies were done by scanning electron microscopy (SEM) from fracture surfaces of tensile and notched impact specimens of all samples. Tensile properties were analysed by the production and testing of dog-bone-shaped samples. Heat deflection temperature (HDT) was tested, as also was the crystallinity of the tested samples by differential scanning calorimetry. Findings The values for notched impact strength were higher upon water uptake in the case of injection-moulded specimens, which was not the case with 3D-printed specimens. Tensile properties of the specimens produced by both methods were reduced after water absorption tests. Values of the HDT were also lower after water absorption tests studied for both processing methods. Originality/value Morphology studies were done by SEM from fracture surfaces of tensile as well as notched impact specimens of injection-moulded and 3D-printed samples. The effect of water storage on various samples was tested. The two different production technologies were compared to each other owing to their influence of water storage. This study also dealt with NFC compounds and produced NFC composites and the influence of water storage on these samples.

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An overview on joining/welding as post-processing technique to circumvent the build volume limitation of an FDM-3D printer

Rapid Prototyping Journal ◽

10.1108/rpj-10-2020-0265 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Vivek Kumar Tiwary ◽

Arunkumar P. ◽

Vinayak R. Malik

Keyword(s):

3D Printing ◽

Literature Review ◽

Adhesive Bonding ◽

Business Leaders ◽

Future Research ◽

3D Printer ◽

Content Type ◽

Friction Stir ◽

Fused Deposition ◽

3D Printed

Purpose Three-dimensional (3D) printing, one of the important technological pillars of Industry 4.0, is changing the landscape of future manufacturing. However, the limited build volume of a commercially available 3D printer is one inherent constraint, which holds its acceptability by the manufacturing business leaders. This paper aims to address the issue by presenting a novel classification of the possible ways by which 3D-printed parts can be joined or welded to achieve a bigger-sized component. Design/methodology/approach A two-step literature review is performed. The first section deals with the past and present research studies related to adhesive bonding, mechanical interlocking, fastening and big area additive manufacturing of 3D printed thermoplastics. In the second section, the literature searches were focused on retrieving details related to the welding of 3D printed parts, specifically related to friction stir welding, friction (spin) welding, microwave and ultrasonic welding. Findings The key findings of this review study comprise the present up-to-date research developments, pros, cons, critical challenges and the future research directions related to each of the joining/welding techniques. After reading this study, a better understanding of how and which joining/welding technique to be applied to obtain a bigger volume 3D printed component will be acquired. Practical implications The study provides a realistic approach for the joining of 3D printed parts made by the fused deposition modeling (FDM) technique. Originality/value This is the first literature review related to joining or welding of FDM-3D printed parts helping the 3D printing fraternity and researchers, thus increasing the acceptability of low-cost FDM printers by the manufacturing business leaders.

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3D printing of composites: design parameters and flexural performance

Rapid Prototyping Journal ◽

10.1108/rpj-07-2019-0188 ◽

2020 ◽

Vol 26 (4) ◽

pp. 699-706

Author(s):

Feras Korkees ◽

James Allenby ◽

Peter Dorrington

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Volume Fraction ◽

Fibre Volume Fraction ◽

Fibre Volume ◽

Design Parameters ◽

Content Type ◽

Flexural Performance ◽

3D Printed ◽

Strength And Stiffness

Purpose 3D printing of composites has a high degree of design freedom, which allows for the manufacture of complex shapes that cannot be achieved with conventional manufacturing processes. This paper aims to assess the design variables that might affect the mechanical properties of 3D-printed fibre-reinforced composites. Design/methodology/approach Markforged Mark-Two printers were used to manufacture samples using nylon 6 and carbon fibres. The effect of fibre volume fraction, fibre layer location and fibre orientation has been studied using three-point flexural testing. Findings The flexural strength and stiffness of the 3D-printed composites increased with increasing the fibre volume fraction. The flexural properties were altered by the position of the fibre layers. The highest strength and stiffness were observed with the reinforcement evenly distributed about the neutral axis of the sample. Moreover, unidirectional fibres provided the best flexural performance compared to the other orientations. 3D printed composites also showed various failure modes under bending loads. Originality/value Despite multiple studies available on 3D-printed composites, there does not seem to be a clear understanding and consensus on how the location of the fibre layers can affect the mechanical properties and printing versatility. Therefore, this study covered this design parameter and evaluated different locations in terms of mechanical properties and printing characteristics. This is to draw final conclusions on how 3D printing may be used to manufacture cost-effective, high-quality parts with excellent mechanical performance.

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3D Printing and Growth Induced Bending based on PET-RAFT Polymerization

10.26434/chemrxiv.12135801 ◽

2020 ◽

Author(s):

Chris Bainbridge ◽

Kyle Engel ◽

Jianyong Jin

Keyword(s):

3D Printing ◽

Surface Properties ◽

Raft Polymerization ◽

Advanced Manufacturing ◽

3D Printer ◽

4D Printing ◽

Printing Process ◽

Raft Agent ◽

3D Printed ◽

First Time

4D printing has steadily become an emerging area of advanced manufacturing research and has produced some truly fantastic innovations. Previously we have demonstrated the 3D printing process based on PET-RAFT polymerization, and its subsequent capability in the post-production modification of surface properties. In this work, (1) we further optimized the PET-RAFT 3D printing formulation by replacing RAFT agent CDTPA with BTPA and adjusting the monomers composition; (2) we also observed the photodegradation of the photocatalysts EB and EY under 405nm light and the effects this has on 3D printing; (3) we then did successful 3D printing using a commercial 405nm DLP 3D printer, with an improved build speed of up to 2286 µm/hr; (4) lastly, for the first time we have demonstrated a method for growth induced bending of a 3D printed strip, where the growth on one side of the strip causes stress and the strip bends accordingly to reach a more comfortable position.

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Gold nanoparticles embedded in a polymer as a 3D-printable dichroic nanocomposite material

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.10.43 ◽

2019 ◽

Vol 10 ◽

pp. 442-447 ◽

Cited By ~ 7

Author(s):

Lars Kool ◽

Anton Bunschoten ◽

Aldrik H Velders ◽

Vittorio Saggiomo

Keyword(s):

Mechanical Properties ◽

Gold Nanoparticles ◽

Optical Properties ◽

3D Printing ◽

Optical Filters ◽

Manufacturing Processes ◽

3D Printer ◽

Minute Amount ◽

3D Objects ◽

3D Printed

Background: Nanotechnology, even if unknowingly, has been used for millennia. The occurrence of shiny colors in pottery and glass made hundreds and thousand of years ago is due to the presence of nanoparticles in the fabrication of such ornaments. In the last decade, 3D printing has revolutionized fabrication and manufacturing processes, making it easier to produce, in a simple and fast way, 3D objects. Results: In this paper we show how to fabricate a 3D-printable nanocomposite composed of dichroic gold nanoparticles and a 3D-printable polymer. The minute amount of gold nanoparticles used for obtaining the dichroic effect does not influence the mechanical properties of the polymer nor its printability. Thus, the nanocomposite can be easily 3D-printed using a standard 3D printer and shows a purple color in transmission and a brownish color in reflection. Conclusion: This methodology can be used not only by artists, but also for studying the optical properties of nanoparticles or, for example, for the 3D fabrication of optical filters.

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