An assessment of thermosetting infiltrate in powder-based composites made by additive manufacturing

2018 ◽  
Vol 53 (7) ◽  
pp. 873-882 ◽  
Author(s):  
Breno Ferreira Lizardo ◽  
Luciano Machado Gomes Vieira ◽  
Juan Carlos Campos Rubio ◽  
Tulio Hallak Panzera ◽  
João Paulo Davim
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Porous Structure ◽  
Epoxy Polymer ◽  
Complex Geometry ◽  
Microstructural Analysis ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Small Series ◽  
Dimensional Printing

Rapid prototyping for material deposition or additive manufacturing has been widely used for short time production of parts with complex geometry in small series. The three-dimensional printing process needs post-processing to improve the strength, stiffness and/or surface finish of the parts. Printed parts in pristine condition are generally very brittle with a porous structure, so infiltrates have been introduced to improve their mechanical and physical characteristics. This work investigates the effect of two infiltrates, epoxy polymer and cyanoacrylate, under a vacuum pressure system on the mechanical properties of powder-based composites made by three-dimensional printing. Samples printed under pristine and infiltrated conditions were tested under tensile, flexural, compressive and impact loadings. The infiltrated samples achieved superior mechanical properties, especially when the epoxy polymer was applied via a vacuum system. The microstructural analysis showed that the infiltrates were not able to penetrate the entire sample, revealing a porous structure in the centre, mainly when the cyanoacrylate was used. The epoxy polymer infiltrate was able to substantially increase the mechanical performance of three-dimensional samples, being a promising material when higher structural requirements are required.

Facing the challenges of the food industry: Might additive manufacturing be the answer?

2018 ◽  
Vol 233 (8) ◽  
pp. 1902-1906 ◽  
Author(s):  
Antonio Sartal ◽  
Diego Carou ◽  
Rubén Dorado-Vicente ◽  
Lorenzo Mandayo
Keyword(s):  
Additive Manufacturing ◽  
Industry 4.0 ◽  
Food Industry ◽  
Information Technologies ◽  
Three Dimensional ◽  
Sustainable Competitive Advantage ◽  
Three Dimensional Printing ◽  
Main Driver ◽  
The One ◽  
Dimensional Printing

Our research explores how additive manufacturing can support the food industry in facing its current global challenges. Although information technologies are usually highlighted as the main driver of the Industry 4.0 concept, which was first introduced during the Hannover Fair event in 2011, we posit that additive manufacturing can be the true generator of a sustainable competitive advantage in this sector. This evidence stems from a case study in a plant of one of the world’s largest fishing multinational companies. Our results show how, through robotic claw optimization using three-dimensional printing, we not only reduce the manufacturing costs but also increase the flexibility of the line and reduce time to market. On the one hand, our findings should encourage managers to test this technology at their facilities; on the other hand, policymakers should promote the adoption of additive manufacturing, highlighting the potential of this technology within the Industry 4.0 context.

scholarly journals Main Clinical Use of Additive Manufacturing (Three-Dimensional Printing) in Finland Restricted to the Head and Neck Area in 2016–2017

2019 ◽  
Vol 109 (2) ◽  
pp. 166-173 ◽  
Author(s):  
A.B.V. Pettersson ◽  
M. Salmi ◽  
P. Vallittu ◽  
W. Serlo ◽  
J. Tuomi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Patient Specific ◽  
Future Research ◽  
Imaging Data ◽  
University Hospitals ◽  
Three Dimensional Printing ◽  
Dimensional Printing ◽  
Head Area

Background and Aims: Additive manufacturing or three-dimensional printing is a novel production methodology for producing patient-specific models, medical aids, tools, and implants. However, the clinical impact of this technology is unknown. In this study, we sought to characterize the clinical adoption of medical additive manufacturing in Finland in 2016–2017. We focused on non-dental usage at university hospitals. Materials and Methods: A questionnaire containing five questions was sent by email to all operative, radiologic, and oncologic departments of all university hospitals in Finland. Respondents who reported extensive use of medical additive manufacturing were contacted with additional, personalized questions. Results: Of the 115 questionnaires sent, 58 received answers. Of the responders, 41% identified as non-users, including all general/gastrointestinal (GI) and vascular surgeons, urologists, and gynecologists; 23% identified as experimenters or previous users; and 36% identified as heavy users. Usage was concentrated around the head area by various specialties (neurosurgical, craniomaxillofacial, ear, nose and throat diseases (ENT), plastic surgery). Applications included repair of cranial vault defects and malformations, surgical oncology, trauma, and cleft palate reconstruction. Some routine usage was also reported in orthopedics. In addition to these patient-specific uses, we identified several off-the-shelf medical components that were produced by additive manufacturing, while some important patient-specific components were produced by traditional methodologies such as milling. Conclusion: During 2016–2017, medical additive manufacturing in Finland was routinely used at university hospitals for several applications in the head area. Outside of this area, usage was much less common. Future research should include all patient-specific products created by a computer-aided design/manufacture workflow from imaging data, instead of concentrating on the production methodology.

scholarly journals Three-dimensional printing, muscles, and skeleton: mechanical functions of living wood

2019 ◽  
Vol 70 (14) ◽  
pp. 3453-3466 ◽  
Author(s):  
Bernard Thibaut
Keyword(s):  
Additive Manufacturing ◽  
Field Experiments ◽  
Secondary Growth ◽  
Three Dimensional ◽  
Wood Properties ◽  
Force Generation ◽  
Three Dimensional Printing ◽  
Pipe System ◽  
External Forces ◽  
Dimensional Printing

AbstractWood is well defined as an engineering material. However, living wood in the tree is often regarded only as a passive skeleton consisting of a sophisticated pipe system for the ascent of sap and a tree-like structure made of a complex material to resist external forces. There are two other active key roles of living wood in the field of biomechanics: (i) additive manufacturing of the whole structure by cell division and expansion, and (ii) a ‘muscle’ function of living fibres or tracheids generating forces at the sapwood periphery. The living skeleton representing most of the sapwood is a mere accumulation of dead tracheids and libriform fibres after their programmed cell death. It keeps a record of the two active roles of living wood in its structure, chemical composition, and state of residual stresses. Models and field experiments define four biomechanical traits based on stem geometry and parameters of wood properties resulting from additive manufacturing and force generation. Geometric parameters resulting from primary and secondary growth play the larger role. Passive wood properties are only secondary parameters, while dissymmetric force generation is key for movement, posture control, and tree reshaping after accidents.

scholarly journals Effect of Three-dimensional Printing with Nanotubes on Impact Resistance

2019 ◽  
Author(s):  
Anne Schmitz
Keyword(s):  
Mechanical Properties ◽  
Lower Limb ◽  
Impact Resistance ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Impact Tester ◽  
The Impact ◽  
Dimensional Printing ◽  
Pendulum Impact ◽  
Pendulum Impact Tester

Abstract The types of biomedical devices that can be three-dimensional printed (3DP) is limited by the mechanical properties of the resulting materials. As a result, much research has focused on adding carbon nanotubes (CNT) to these photocurable polymers to make them stronger. However, there is little to no data on how CNTs affect the impact resistance of these polymers, an important property when designing and manufacturing lower limb prosthetics. The objective of this study was to expand the use of 3DP to prosthetics by testing the hypothesis that adding CNTs to a stereolithographic (SLA) photocurable resin will result in a cured polymer with increased impact resistance. Twenty-six total specimens: 13 with nanotubes and 13 without nanotubes, were printed on a Form2 SLA printer. Once all the specimens were printed, washed, and cured, the impact resistance was quantified using a pendulum impact tester in a notched Izod configuration. Contrary to the hypothesis, the specimens with SWCNTs (0.312 ± 0.036 ft*lb/in) had a significantly lower impact resistance compared to the non-SWCNT specimens (0.364 ± 0.055 ft*lb/in), U = 34.0, p = 0.004. This decreased impact resistance may be due to voids in the printed polymer around the aggregated nanotubes. Thus, SLA polymers still do not have the impact strength needed to be used for a full lower limb prosthetic.

scholarly journals Bone Printing Methods

2018 ◽  
Vol 3 (2) ◽  
pp. 24-33
Author(s):  
Filipa Pinto de Oliveira
Keyword(s):  
Additive Manufacturing ◽  
Bone Tissue ◽  
Bone Structure ◽  
Three Dimensional ◽  
Special Focus ◽  
Medical Field ◽  
Three Dimensional Printing ◽  
Work Done ◽  
Dimensional Printing

consider to be a synonymous of additive manufacturing has made its way into the medical field, not only manufacturing medical appliances, study models or building prosthetics. The demand for bone substitution surgeries is growing every year, due to the increase in pathologies affecting bone structure (both traumatic and not traumatic). Nowadays with the possibility of three-dimensional printers becoming bioprinters, engineered bone tissue is starting to become a reality. The aim of this paper is to give the reader an overview of the work done in the last few years towards the advance of three-dimensional printing methods for engineered bone tissue. This paper is divided into six parts, an introduction, then presentation and discussion of the various printing methods with special focus on additive manufacturing (AM), then of bioprinting technologies, further directions of these technologies are considered and a conclusion is done.

scholarly journals Remanufacturing of end-of-life glass-fiber reinforced composites via UV-assisted 3D printing

2019 ◽  
Vol 26 (6) ◽  
pp. 981-992
Author(s):  
Andrea Mantelli ◽  
Marinella Levi ◽  
Stefano Turri ◽  
Raffaella Suriano
Keyword(s):  
Mechanical Properties ◽  
Circular Economy ◽  
Three Dimensional ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Content Type ◽  
Three Dimensional Printing ◽  
Glass Fiber Reinforced ◽  
Complex Shapes ◽  
Dimensional Printing

Purpose The purpose of this study is to demonstrate the potential of three-dimensional printing technology for the remanufacturing of end-of-life (EoL) composites. This technology will enable the rapid fabrication of environmentally sustainable structures with complex shapes and good mechanical properties. These three-dimensional printed objects will have several application fields, such as street furniture and urban renewal, thus promoting a circular economy model. Design/methodology/approach For this purpose, a low-cost liquid deposition modeling technology was used to extrude photo-curable and thermally curable composite inks, composed of an acrylate-based resin loaded with different amounts of mechanically recycled glass fiber reinforced composites (GFRCs). Rheological properties of the extruded inks and their printability window and the conversion of cured composites after an ultraviolet light (UV) assisted extrusion were investigated. In addition, tensile properties of composites remanufactured by this UV-assisted technology were studied. Findings A printability window was found for the three-dimensional printable GFRCs inks. The formulation of the composite printable inks was optimized to obtain high quality printed objects with a high content of recycled GFRCs. Tensile tests also showed promising mechanical properties for printed GFRCs obtained with this approach. Originality/value The novelty of this paper consists in the remanufacturing of GFRCs by the three-dimensional printing technology to promote the implementation of a circular economy. This study shows the feasibility of this approach, using mechanically recycled EoL GFRCs, composed of a thermoset polymer matrix, which cannot be melted as in case of thermoplastic-based composites. Objects with complex shapes were three-dimensional printed and presented here as a proof-of-concept.

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