scholarly journals A Novel Additive Manufacturing Method of Cellulose Gel

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6988
Author(s):  
Hossein Najaf Zadeh ◽  
Daniel Bowles ◽  
Tim Huber ◽  
Don Clucas
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Material Design ◽  
Potential Method ◽  
Support Material ◽  
Gel Structure ◽  
Manufacturing Method ◽  
Wide Range ◽  
Need For Support ◽  
Cellulose Gel

Screen-additive manufacturing (SAM) is a potential method for producing small intricate parts without waste generation, offering minimal production cost. A wide range of materials, including gels, can be shaped using this method. A gel material is composed of a three-dimensional cross-linked polymer or colloidal network immersed in a fluid, known as hydrogel when its main constituent fluid is water. Hydrogels are capable of absorbing and retaining large amounts of water. Cellulose gel is among the materials that can form hydrogels and, as shown in this work, has the required properties to be directly SAM, including shear thinning and formation of post-shearing gel structure. In this study, we present the developed method of SAM for the fabrication of complex-shaped cellulose gel and examine whether successive printing layers can be completed without delamination. In addition, we evaluated cellulose SAM without the need for support material. Design of Experiments (DoE) was applied to optimize the SAM settings for printing the novel cellulose-based gel structure. The optimum print settings were then used to print a periodic structure with micro features and without the need for support material.

scholarly journals Additive Manufacturing of Biopolymers for Tissue Engineering and Regenerative Medicine: An Overview, Potential Applications, Advancements, and Trends

2021 ◽  
Vol 2021 ◽  
pp. 1-20 ◽  
Author(s):  
Dhinakaran Veeman ◽  
M. Swapna Sai ◽  
P. Sureshkumar ◽  
T. Jagadeesha ◽  
L. Natrayan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Regenerative Medicine ◽  
Tissue Regeneration ◽  
Three Dimensional ◽  
Porous Scaffolds ◽  
Wide Range ◽  
Potential Applications ◽  
Pharmaceutical Industries

As a technique of producing fabric engineering scaffolds, three-dimensional (3D) printing has tremendous possibilities. 3D printing applications are restricted to a wide range of biomaterials in the field of regenerative medicine and tissue engineering. Due to their biocompatibility, bioactiveness, and biodegradability, biopolymers such as collagen, alginate, silk fibroin, chitosan, alginate, cellulose, and starch are used in a variety of fields, including the food, biomedical, regeneration, agriculture, packaging, and pharmaceutical industries. The benefits of producing 3D-printed scaffolds are many, including the capacity to produce complicated geometries, porosity, and multicell coculture and to take growth factors into account. In particular, the additional production of biopolymers offers new options to produce 3D structures and materials with specialised patterns and properties. In the realm of tissue engineering and regenerative medicine (TERM), important progress has been accomplished; now, several state-of-the-art techniques are used to produce porous scaffolds for organ or tissue regeneration to be suited for tissue technology. Natural biopolymeric materials are often better suited for designing and manufacturing healing equipment than temporary implants and tissue regeneration materials owing to its appropriate properties and biocompatibility. The review focuses on the additive manufacturing of biopolymers with significant changes, advancements, trends, and developments in regenerative medicine and tissue engineering with potential applications.

scholarly journals Manufacturing methods for medical artificial prostheses– a review

2017 ◽  
Vol 13 (4-2) ◽  
pp. 464-469 ◽  
Author(s):  
Rosdayanti Fua-Nizan ◽  
Ahmad Majdi Abdul Rani ◽  
Mohamad Yazid Din
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Material Design ◽  
Incremental Sheet Forming ◽  
Numerical Control ◽  
Process Efficiency ◽  
Manufacturing Method ◽  
Direct Fabrication ◽  
Manufacturing Methods ◽  
Selection Of

The main objective of this paper is to review the manufacturing methods that can be used for fabricating medical prostheses. The medical prostheses have different functions and applications. Selection of manufacturing method is made based on the material, design, and mechanical properties of the prostheses.  The conventional manufacturing methods that had been applied for manufacturing prostheses are machining, incremental sheet forming and investment casting. The combination of computer numerical control and additive manufacturing has been able to improve the process efficiency of these methods. However, direct fabrication by additive manufacturing has been able to replace the conventional method with better process efficiency and product accuracy. 

scholarly journals Toolpath Strategies for 5DOF and 6DOF Extrusion-Based Additive Manufacturing

2019 ◽  
Vol 9 (19) ◽  
pp. 4168 ◽  
Author(s):  
Mathias Laustsen Jensen ◽  
Rasoul Mahshid ◽  
Greta D’Angelo ◽  
Jeppe U. Walther ◽  
Malte K. Kiewning ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Projection Method ◽  
Degrees Of Freedom ◽  
Tool Path ◽  
Final Part ◽  
Support Material ◽  
Need For Support ◽  
Am Processes ◽  
Case Effect ◽  
Parent Child

This paper introduces two new deposition-strategies for five degrees of freedom (5DOF) and 6DOF extrusion-based additive manufacturing (AM), called the tool path projection- and parent-child-approach, respectively. The tool path projection method can be automated, and allows for the generation of concentric shells layers, which remedy geometrical deviations (known as the stair-case effect) that are typically seen in 3DOF AM processes that potentially require secondary post treatment by machining or grinding of the final part. In the parent-child approach, the designer specifies the manufacturing direction for each distinct feature, thereby helping to remove the need for support material, as well as enabling new features to be dynamically added to the part.

Design for Additive Manufacturing: Valves Without Moving Parts

2017 ◽  
Author(s):  
A. Gaymann ◽  
F. Montomoli ◽  
M. Pietropaoli
Keyword(s):  
Additive Manufacturing ◽  
Gas Turbines ◽  
Design Method ◽  
Three Dimensional ◽  
Automatic Generation ◽  
Two Dimensions ◽  
Steepest Descent Method ◽  
Wide Range ◽  
Tesla Valve ◽  
Moving Parts

This work presents an innovative design method to obtain valves without moving parts that can be built using additive manufacturing and applied to gas turbines. Additive manufacturing offers more flexibility than traditional manufacturing methods, which implies less constraints on the manufacture of engineering parts and it is possible to build complex geometries like the Tesla valve. The Tesla valve is a duct that shows a diodicity behavior: it allows a fluid to flow in one direction with lower losses than in the other one. Unfortunately the design of the Tesla valve is two dimensional and it relies on the designer experience to obtain good performance. The method presented here allows the automatic generation of valves similar to the Tesla one, obtained automatically by a topology optimization algorithm. It is the first time that a three dimensional method is presented, the available algorithms in the open literature works in two dimensions. A fluid sedimentation process enables the creation of a new geometry optimized to meet a prescribed set of performance, such as pressure losses. The steepest descent method is used to approximate the integrals met during the calculation process. The optimizer is used to obtain three dimensional geometries for different multi-objective functions. The geometry is compared to an existing similar solution proposed in the open literature and validated. The results are compared to a Tesla valve to show the performance of the optimized geometries. The advantage of the proposed solution is the possibility to apply the design method with any spatial constraints and for a wide range of mass flow.

scholarly journals 3D Puzzle in Cube Pattern for Anisotropic/Isotropic Mechanical Control of Structure Fabricated by Metal Additive Manufacturing

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 959
Author(s):  
Naoko Ikeo ◽  
Hidetsugu Fukuda ◽  
Aira Matsugaki ◽  
Toru Inoue ◽  
Ai Serizawa ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Functional Performance ◽  
Three Dimensional ◽  
Material Design ◽  
Metal Additive Manufacturing ◽  
Anisotropic Mechanical Properties ◽  
Innovative Material ◽  
Living Tissues ◽  
Metal Additive

Metal additive manufacturing is a powerful tool for providing the desired functional performance through a three-dimensional (3D) structural design. Among the material functions, anisotropic mechanical properties are indispensable for enabling the capabilities of structural materials for living tissues. For biomedical materials to replace bone function, it is necessary to provide an anisotropic mechanical property that mimics that of bones. For desired control of the mechanical performance of the materials, we propose a novel 3D puzzle structure with cube-shaped parts comprising 27 (3 × 3 × 3) unit compartments. We designed and fabricated a Co–Cr–Mo composite structure through spatial control of the positional arrangement of powder/solid parts using the laser powder bed fusion (L-PBF) method. The mechanical function of the fabricated structure can be predicted using the rule of mixtures based on the arrangement pattern of each part. The solid parts in the cubic structure were obtained by melting and solidifying the metal powder with a laser, while the powder parts were obtained through the remaining nonmelted powders inside the structure. This is the first report to achieve an innovative material design that can provide an anisotropic Young’s modulus by arranging the powder and solid parts using additive manufacturing technology.

scholarly journals Mechanisms and modeling of electrohydrodynamic phenomena

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Jack Zhou ◽  
Dajing Gao ◽  
Donggang Yao ◽  
Steven K. Leist ◽  
Yifan Fei
Keyword(s):  
Additive Manufacturing ◽  
High Resolution ◽  
Inkjet Printing ◽  
Scaling Laws ◽  
Current Trend ◽  
Three Dimensional ◽  
Theoretical Models ◽  
Manufacturing Method ◽  
Cone Development ◽  
Key Factor

The purpose of this paper is to review the mechanisms of electrohydrodynamic (EHD) phenomenon. From this review, researchers and students can learn principles and development history of EHD. Significant progress has been identified in research and development of EHD high-resolution deposition as a direct additive manufacturing method, and more effort will be driven to this direction soon. An introduction is given about current trend of additive manufacturing and advantages of EHD inkjet printing. Both theoretical models and experiment approaches about the formation of cone, development of cone-jet transition and stability of jet are presented. The formation of a stable cone-jet is the key factor for precision EHD printing which will be discussed. Different scaling laws can be used to predict the diameter of jet and emitted current in different parametrical ranges. The information available in this review builds a bridge between EHD phenomenon and three-dimensional high-resolution inkjet printing.

An Investigation of Key Design for Additive Manufacturing Constraints in Multimaterial Three-Dimensional Printing

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Nicholas Meisel ◽  
Christopher Williams
Keyword(s):  
Additive Manufacturing ◽  
Statistical Significance ◽  
Three Dimensional ◽  
Manufacturing Constraints ◽  
Support Material ◽  
Design For Additive Manufacturing ◽  
Three Dimensional Printing ◽  
Automated Method ◽  
Key Variables ◽  
The One

The PolyJet material jetting process is uniquely qualified to create complex, multimaterial structures. However, key manufacturing constraints need to be explored and understood in order to guide designers in their use of the PolyJet process including (1) minimum manufacturable feature size, (2) removal of support material, (3) survivability of small features, and (4) the self-supporting angle in the absence of support material. The authors use a design of experiments (DOE) approach to identify the statistical significance of geometric and process parameters and to quantify the relationship between these significant parameters and part manufacturability. The results from this study include the identification of key variables, relationships, and quantitative design thresholds necessary to establish a preliminary set of design for additive manufacturing (DfAM) guidelines for material jetting. Experimental design studies such as the one in this paper are crucial to provide designers with the knowledge to ensure that their proposed designs are manufacturable with the PolyJet process, whether designed manually or by an automated method, such as topology optimization (TO).

Light Assisted Hybrid Direct Write Additive Manufacturing of Thermosets

2020 ◽  
Author(s):  
Abdulrahman Alrashdan ◽  
William Jordan Wright ◽  
Emrah Celik
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Uv Light ◽  
Crosslinking Agent ◽  
Complex Geometries ◽  
Direct Write ◽  
Direct Writing ◽  
Manufacturing Method ◽  
Wide Range ◽  
Material Systems

Abstract In the past recent years, numerous studies have been conducted on additive manufacturing of thermosets and thermoset composites. Thermosets are an important class of polymers used in engineering applications. Monomer units in these material systems irreversibly cross-link when external stimuli or a chemical crosslinking agent is applied in terms of the curing or photopolymerization process. Thermally curing thermosets mark unique mechanical properties including, high temperature resistance, strong chemical bond, and structural integrity and therefore these materials find wide range of applications currently. However, direct write additive manufacturing of these material systems at high resolution and at complex geometries is challenging. This is due to the slow curing rate of thermally curing thermoset polymers which can adversely affect the printing process, and the final shape of the printed object. On the other hand, VAT Polymerization additive manufacturing, which is based on curing the photopolymer resin by Ultraviolet (UV) light, can allow the fabrication of complex geometries and excellent surface finish of the printed parts due to the fast curing rate of photopolymers used in this technique. Mechanical properties of photopolymers, however, are usually weaker and more unstable compared to the thermally curing polymers used in the direct write additive manufacturing method. Therefore, this study focuses on taking the advantages of these two thermoset additive manufacturing methods by utilizing both the thermally cured epoxy and photopolymer resins together. Using the direct writing, the resin mixture is extruded though a nozzle and the final 3D object is created on the print bed. Simultaneously, the deposited ink is exposed to the UV light enhancing the yield strength of the printed material and partially curing it. Therefore, thermally cured epoxy is used to obtain the desirable mechanical properties, while the addition of the photopolymer resin allows the thermoset mixture to partially solidify the printed ink when exposed to the UV light. The results achieved in this study showed that, the hybrid additive manufacturing technology is capable of fabricating complex and tall structure which cannot be printable via additive manufacturing method. In addition, mechanical properties of the hybrid thermoset ink are comparable to the thermally cured thermoset polymer indicating the great potential of the light-assisted, hybrid manufacturing to fabricate mechanically strong parts at high geometrical resolution.

Additive Manufacturing Sustainability in Industries

2020 ◽  
Vol 12 (7) ◽  
pp. 894-899
Author(s):  
Devendra Kumar Prajapati ◽  
Ravinder Kumar
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Complex Shape ◽  
Three Dimensional ◽  
Core Knowledge ◽  
Research Papers ◽  
Advanced Technique ◽  
The Core ◽  
Wide Range ◽  
Dimensional Object

Additive manufacturing (AM) is an advanced technique to fabricate a three-dimensional object while utilizing materials with minimal wastage to produce complex shape geometries. This technique has escalated practically as well as academically, resulting in a wide range of utility in the current global scenario to ease the manufacturing of complex and intricate objects with the use of various materials, depending upon the properties and availability of the same. Every industries wants to achieve the sustainability, easily can be possible through this manufacturing process. Due to the scope for a large number of design, material and processing combinations, a detailed outlook to how additive manufacturing can be optimized for a highly sustainable and standardized manufacturing practice needs to be assessed and understood. This paper discusses the core knowledge available regarding this manufacturing process and highlights the different processes related to this technique through review of various research papers. And also discuss the sustainability of important additive manufacturing process. Along with the fundamental analysis of this process, the paper also discusses the various attributes of the process and the growth with respect to the latest trends and techniques currently used in industries.

Additive Manufacturing of Honeycombs Seal Strips

2018 ◽  
Author(s):  
Ole Geisen ◽  
Lisa Kersting ◽  
Lukas Masseling ◽  
Jan Pascal Bogner ◽  
Johannes Henrich Schleifenbaum
Keyword(s):  
Additive Manufacturing ◽  
Gas Turbines ◽  
Process Development ◽  
Three Dimensional ◽  
Parameter Study ◽  
Powder Bed ◽  
Require Time ◽  
Need For Support ◽  
Assembly Operations ◽  
High Degree

Laser-Powder Bed Fusion (L-PBF) is an additive manufacturing technique used to melt metal material into solid three-dimensional parts. While offering a high degree of design freedom, L-PBF still has technical restrictions, like the achievable surface roughness, resolution and the need for support structures in overhanging areas. [1] Currently, L-PBF is used mainly to produce small batches of parts and prototypes. [2] In order to fully industrialize the technology, the research campus in Aachen is investigating possible future applications in turbomachinery while developing the corresponding processes with industry partners. Sealing systems, like honeycomb seal strips in gas turbines often require time-consuming joining and assembly operations that can be avoided by building up the structure monolithically using L-PBF. The following process development study proves the feasibility of manufacturing honeycombs with L-PBF using the Nickel-based super-alloy Inconel 718 (IN718) on an EOS M290 machine. Here, we have evaluated the economic aspects of different build orientations of the seal strips. Afterwards, we conducted a systematic parameter study with continuous and pulsed wave laser emission and investigated the resulting wall thicknesses. A reduction in wall thickness of about 30% can be observed when a modulated laser is used.

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