scholarly journals Effect of Fibre Orientation on Novel Continuous 3D-Printed Fibre-Reinforced Composites

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2524
Author(s):  
Ilaria Papa ◽  
Alessia Teresa Silvestri ◽  
Maria Rosaria Ricciardi ◽  
Valentina Lopresto ◽  
Antonino Squillace
Keyword(s):  
Low Cost ◽  
High Strength ◽  
Raw Material ◽  
Layer By Layer ◽  
Compression Tests ◽  
Fused Filament Fabrication ◽  
Calorimetric Analysis ◽  
Surface Finishes ◽  
3D Printed ◽  
Manufacturing Techniques

Among the several additive manufacturing techniques, fused filament fabrication (FFF) is a 3D printing technique that is fast, handy, and low cost, used to produce complex-shaped parts easily and quickly. FFF adds material layer by layer, saving energy, costs, raw material costs, and waste. Nevertheless, the mechanical properties of the thermoplastic materials involved are low compared to traditional engineering materials. This paper deals with the manufacturing of composite material laminates obtained by the Markforged continuous filament fabrication (CFF) technique, using an innovative matrix infilled by carbon nanofibre (Onyx), a high-strength thermoplastic material with an excellent surface finish and high resistance to chemical agents. Three macro-categories of samples were manufactured using Onyx and continuous carbon fibre to evaluate the effect of the fibre on mechanical features of the novel composites and their influence on surface finishes. SEM (Scanning Electron Microscopy) analysis and acquisition of roughness profile by a confocal lens were conducted. Tensile and compression tests, thermogravimetric analysis and calorimetric analysis using a DSC (differential scanning calorimeter) were carried out on all specimen types to evaluate the influence of the process parameters and layup configurations on the quality and mechanical behaviour of the 3D-printed samples.

Tensile properties of the FFF-processed thermoplastic polyurethane (TPU) elastomer

2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Low Cost ◽  
Thermoplastic Polyurethane ◽  
High Strength ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Fused Filament Fabrication ◽  
Raster Angle ◽  
Manufacturing Techniques

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.

The elasto-plastic analysis of 3D-printed thermoplastics using the NNRPIM and a modified hill yield criterion

2021 ◽  
pp. 146442072098589
Author(s):  
Daniel Rodrigues ◽  
J Belinha ◽  
RMN Jorge
Keyword(s):  
Mechanical Performance ◽  
Interpolation Method ◽  
Yield Criterion ◽  
Low Cost ◽  
Great Influence ◽  
Numerical Approach ◽  
Compression Tests ◽  
Fused Filament Fabrication ◽  
Point Interpolation Method ◽  
3D Printed

The Fused Filament Fabrication is a 3D printing technology that allows the production of components and structures with complex geometries at low-cost, using thermoplastic materials as feedstock. This additive manufacturing technique is not yet extensively used in industries mainly due to parts’ anisotropy – which is the consequence of the deposition strategy – and residual stresses, caused by successive heating cycles. Thus, these topics have great influence on the non-linear mechanical performance of 3D printed parts. Additionally, the materials used in the Fused Filament Fabrication have distinct mechanical behaviours under tensile and compression loads. This work proposes a computational framework – using a meshless method as the numeric discretization technique, the Natural Neighbour Radial Point Interpolation method – capable to analyse the elastoplastic response of ductile materials showing distinct compressive and tensile responses, through the implementation of a modified version of the Hill yield surface. In those conditions, 3D-printed specimens of polylactic acid are tested experimentally and numerically using standard tensile and compression tests. The numerical approach is validated by comparing the numerical and the experimental curves. Then, the accuracy of the methodology is proved and the purpose of using the modified Hill yield criterion is clearly shown using a benchmark example.

scholarly journals Metallization of Thermoplastic Polymers and Composites 3D Printed by Fused Filament Fabrication

Technologies ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 49
Author(s):  
Alessia Romani ◽  
Andrea Mantelli ◽  
Paolo Tralli ◽  
Stefano Turri ◽  
Marinella Levi ◽  
...  
Keyword(s):  
Physical Vapor Deposition ◽  
Test Sample ◽  
Tensile Tests ◽  
Layer By Layer ◽  
Post Processing ◽  
Thermoplastic Polymers ◽  
Fused Filament Fabrication ◽  
Scanning Calorimetry ◽  
3D Printed ◽  
Manufacturing Technologies

Fused filament fabrication allows the direct manufacturing of customized and complex products although the layer-by-layer appearance of this process strongly affects the surface quality of the final parts. In recent years, an increasing number of post-processing treatments has been developed for the most used materials. Contrarily to other additive manufacturing technologies, metallization is not a common surface treatment for this process despite the increasing range of high-performing 3D printable materials. The objective of this work is to explore the use of physical vapor deposition sputtering for the chromium metallization of thermoplastic polymers and composites obtained by fused filament fabrication. The thermal and mechanical properties of five materials were firstly evaluated by means of differential scanning calorimetry and tensile tests. Meanwhile, a specific finishing torture test sample was designed and 3D printed to perform the metallization process and evaluate the finishing on different geometrical features. Furthermore, the roughness of the samples was measured before and after the metallization, and a cost analysis was performed to assess the cost-efficiency. To sum up, the metallization of five samples made with different materials was successfully achieved. Although some 3D printing defects worsened after the post-processing treatment, good homogeneity on the finest details was reached. These promising results may encourage further experimentations as well as the development of new applications, i.e., for the automotive and furniture fields.

Design and Analysis of Hybrid Fused Filament Fabrication Apparatus for Fabrication of Composites

2021 ◽  
Vol 14 ◽  
Author(s):  
Aniket Yadav ◽  
Piyush Chohan ◽  
Ranvijay Kumar ◽  
Jasgurpreet Singh Chohan ◽  
Raman Kumar
Keyword(s):  
Additive Manufacturing ◽  
Composite Materials ◽  
Design Process ◽  
Low Cost ◽  
Matrix Material ◽  
Fabrication Process ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Composite Manufacturing ◽  
Tool Paths

Background: Additive manufacturing is the most famous technology which requires materials or composites to be fabricated with layer by layer deposition strategy. Due to its lower cost, higher accuracy and less material wastage; this technology is used in almost every sector. But in many applications there is a need to alter the properties of a product in a certain direction with the help of some reinforcements. With the use of reinforcements, composite layers can be fabricated using additive manufacturing technique which will enhance the directional properties. A novel apparatus is designed to spray the reinforcement material into the printed structures in a very neat and precise manner. This spray nozzle is fully automated, which works according to tool-paths generated by slicing software. The alternate deposition of layers of reinforcement and build materials helped to fabricate customized composite products. Objective: The objective of present study is to design and analyze the working principle of novel technique which has been developed to fabricate composite materials using additive manufacturing. The apparatus is numerically controlled by computer according to CAD data which facilitates the deposition of alternate layers of reinforcement and matrix material. The major challenges during the design process and function of each component has been explored. Methods: The design process is initiated after comprehensive literature review performed to study previous composite manufacturing processes. The recent patents published by different patent offices of the world are studied in detail and analysis has been used to design a low cost composite fabrication apparatus. A liquid dispensing device comprises a storage tank attached with a pump and microprocessor. The microprocessor receives the signal from the computer as per tool paths generated by slicing software which decides the spray of reinforcements on polymer layers. The spraying apparatus moves in coordination with the primary nozzle of the Fused Filament Fabrication process. Results: The hybridization of Fused Filament Fabrication [process with metal spray process has been successfully performed. The apparatus facilitates the fabrication of low cost composite materials along with flexibility of complete customization of composite manufacturing process. The anisotropic behaviour of products can be easily controlled and managed during fabrication which can be used for different applications.

SYNTHESIS AND CHARACTERISATION OF WOVENROVING GLASS MAT FOR EPOXYCOMPOSITES

2020 ◽  
Vol 15 (4) ◽  
Author(s):  
Mahesh Mallampati ◽  
Sreekanth Mandalapu ◽  
Govidarajulu C
Keyword(s):  
Tensile Strength ◽  
Glass Fiber ◽  
Low Cost ◽  
Weight Ratio ◽  
High Strength ◽  
Hardness Test ◽  
Industrial Applications ◽  
Sem Analysis ◽  
Low Thermal Expansion ◽  
Manufacturing Techniques

The composite materials are replacing the traditional materials because oftheir superior properties such as high tensile strength, low thermal expansion, high strength to weight ratio, low cost, lightweight, high specific modulus, renewability and biodegradability which are the most basic & common attractive features of composites that make them useful for industrial applications. The developments of new materials are on the anvil and are growing day by day. The efforts to produce economically attractive composite components have resulted in several innovative manufacturing techniques currently being used in the composites industry. Generally, composites consist of mainly two phases i.e., matrix and fiber. In this study, woven roving mats (E-glass fiber orientation (-45°/45°,0°/90°, - 45°/45°),UD450GSM)were cut in measured dimensions and a mixture of Epoxy Resin (EPOFINE-556, Density-1.15gm/cm3), Hardener (FINE HARDTM 951, Density- 0.94 gm/cm3) and Acetone [(CH3)2CO, M= 38.08 g/mol] was used to manufacture the glass fiber reinforced epoxy composite by hand lay-up method. Mechanical properties such as tensile strength, SEM analysis, hardness test, density tests are evaluated.

scholarly journals 3D Printed Radar Lenses with Anti-Reflective Structures

Designs ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 28 ◽  
Author(s):  
Ross J. Friel ◽  
Maria Gerling-Gerdin ◽  
Emil Nilsson ◽  
Björn P. Andreasson
Keyword(s):  
Computer Aided Design ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Circuit Board ◽  
60 Ghz ◽  
Fused Filament Fabrication ◽  
Actual Measurement ◽  
3D Printed ◽  
Radar Measurements ◽  
Aided Design

Background: The purpose of this study was to determine if 3D printed lenses with wavelength specific anti-reflective (AR) surface structures would improve beam intensity and thus radar efficiency for a Printed Circuit Board (PCB)-based 60 GHz radar. This would have potential for improved low-cost radar lenses for the consumer product market. Methods: A hyperbolic lens was designed in 3D Computer Aided Design (CAD) software and was then modified with a wavelength specified AR structure. Electromagnetic computer simulation was performed on both the ‘smooth’ and ‘AR structure’ lenses and compared to actual 60 GHz radar measurements of 3D printed polylactic acid (PLA) lenses. Results: The simulation results showed an increase of 10% in signal intensity of the AR structure lens over the smooth lens. Actual measurement showed an 8% increase in signal of the AR structure lens over the smooth lens. Conclusions: Low cost and readily available Fused Filament Fabrication (FFF) 3D printing has been shown to be capable of printing an AR structure coated hyperbolic lens for millimeter wavelength radar applications. These 3D Printed AR structure lenses are effective in improving radar measurements over non-AR structure lenses.

scholarly journals Mechanical Performance of 3D-Printed Biocompatible Polycarbonate for Biomechanical Applications

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3669
Author(s):  
Giovanni Gómez-Gras ◽  
Manuel D. Abad ◽  
Marco A. Pérez
Keyword(s):  
Mechanical Performance ◽  
Cost Savings ◽  
Bone Scaffold ◽  
Fused Filament Fabrication ◽  
Synthetic Materials ◽  
3D Printed ◽  
Biomedical Industry ◽  
Manufacturing Techniques ◽  
Manufacturing Time ◽  
Printing Parameters

Additive manufacturing has experienced remarkable growth in recent years due to the customisation, precision, and cost savings compared to conventional manufacturing techniques. In parallel, materials with great potential have been developed, such as PC-ISO polycarbonate, which has biocompatibility certifications for use in the biomedical industry. However, many of these synthetic materials are not capable of meeting the mechanical stresses to which the biological structure of the human body is naturally subjected. In this study, an exhaustive characterisation of the PC-ISO was carried out, including an investigation on the influence of the printing parameters by fused filament fabrication on its mechanical behaviour. It was found that the effect of the combination of the printing parameters does not have a notable impact on the mass, cost, and manufacturing time of the specimens; however, it is relevant when determining the tensile, bending, shear, impact, and fatigue strengths. The best combinations for its application in biomechanics are proposed, and the need to combine PC-ISO with other materials to achieve the necessary strengths for functioning as a bone scaffold is demonstrated.

scholarly journals Simulated and Experimental Investigation of Mechanical Properties for Improving Isotropic Fracture Strength of 3D-Printed Capsules

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4677
Author(s):  
Taeuk Lim ◽  
Hao Cheng ◽  
Wonil Song ◽  
Jasung Lee ◽  
Sunghoon Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Strength ◽  
High Speed ◽  
Applied Load ◽  
Low Cost ◽  
Powder Layer ◽  
Strength Analysis ◽  
Self Healing ◽  
Compression Tests ◽  
3D Printed

Three-dimensional (3D) printer-based self-healing capsules, embedded in cement composites, were proposed to heal cracks, as they allow for various structural designs of capsules, repeatable fabrication, and strength analysis. Out of many 3D printing methods, such as fusion deposition modeling (FDM), powder layer fusion, and PolyJet printing, FDM was used to design, analyze, and produce new self-healing capsules, which are widely used due to their high-speed, low-cost, and precise manufacturing. However, the PLA extruded in the FDM had low adhesion energy between stacked layers, which caused a degradation of the performance of the self-healing capsule, because it had different strengths depending on the angle between the stacked layers and the applied load within the concrete structure. Therefore, in this paper, specimens were produced, in accordance with ASTM specifications, using the FDM PLA method, and mechanical properties were obtained through tensile, shear, and compression tests. Additionally, the isotropic fracture characteristics of the four types of capsules were analyzed through finite element method analysis. Subsequently, the 3D-printed capsules were produced, and the fracture strength was analyzed in the x, y and z directions of the applied load through a compression test. As a result, the newly proposed capsule design was verified to have an isotropic fracture strength value of 1400% in all directions compared to conventional spherical thin film capsules

Evaluation of Dimensional Accuracy of 3D printed mandibular model using two different Additive Manufacturing Techniques based on Cone Beam Computed Tomography scan data (A Diagnostic Accuracy Study)

2019 ◽  
Author(s):  
Noha Hamada Mohamed ◽  
Hossam Kandil ◽  
Iman Ismail Dakhli
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Low Cost ◽  
Dimensional Accuracy ◽  
3D Models ◽  
The Body ◽  
Reference Standard ◽  
Linear Measurements ◽  
3D Printed ◽  
Manufacturing Techniques

Abstract In dentistry, 3D printing already has diverse applicability, and holds a great deal of promise to make possible many new and exciting treatments and approaches to manufacturing dental restorations. Better availability, shorter processing time, and descending costs have resulted in the increased use of RP. Concomitantly the development of medical applications is expanding. (Zaharia et al., 2017)Many different printing technologies exist, each with their own advantages and disadvantages. Unfortunately, a common feature of the more functional and productive equipment is the high cost of the equipment, the materials, maintenance, and repair, often accompanied by a need for messy cleaning, difficult post-processing, and sometimes onerous health and safety concerns (Dawood et al., 2015)Low-cost 3D printers represent a great opportunity in the dental and medical field, as they could allow surgeons to use 3D models at a very low cost and, therefore, democratize the use of these 3D models in various indications. However, efforts should be made to establish a unified validation protocol for low-cost RP 3D printed models, including accuracy, reproducibility, and repeatability tests. Asaumi et al., suggested that dimensional changes may not affect the success of surgical applications if such changes are within a 2% variation .However, the proposed cut-off of 2% should be furthermore discussed, as the same accuracy may be not required for all types of indications. (Silva et al., 2008; Maschio et al., 2016)This aim of the present study is to evaluate the dimensional accuracy of the 3D printed mandibular models fabricated by two different additive manufacturing techniques, using highly precise one as selective laser sintering (SLS) and a low-cost one as fused filament fabrication and whether they are both comparable in terms of precision. In addition to evaluation of dimensional accuracy of linear measurements of the mandible in CBCT scans.7 mandibular models will be recruited. Radio-opaque markers of gutta-percha balls will be applied on the model to act as guide pointsTen linear measurements (5 long distances: Inter-condylar, inter-coronoidal, inter-mandibular notch, length of left ramus, length of right ramus; as well as 5 short distances: Length of the body of the mandible at midline, length of the body of the mandible in the area of last left molar, as well as that of the last right molar, the distance between the tip of right condyle to the tip of the right coronoid, as well as that of their left counterparts) will be obtained using digital calliper, to act as the reference standard later. Scanning of the model by CBCT will be next , 3D printing of the scanned image using SLS and FFF printers will be done. Recording of same linear measurment will be done on printed models. Comparison of the recorded values vs reference standard is the last step

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