scholarly journals Effect of Various Infrared Heaters on Sintering Behavior of UHMWPE in Selective Inhibition Sintering Process

2019 ◽  
Vol 8 (6) ◽  
pp. 725-731 ◽  
Keyword(s):  
Surface Roughness ◽  
Computer Aided Design ◽  
Low Cost ◽  
Laser System ◽  
Selective Laser Sintering ◽  
Heating Surface ◽  
Selective Inhibition ◽  
Sintering Behavior ◽  
Layer By Layer ◽  
Selective Inhibition Sintering

Selective inhibition sintering (SIS) is an emerging powder-based additive manufacturing technology that creates polymer or metal based parts through adhesion of layer-by-layer from three-dimensional computer-aided design model. Replacement of costly laser system in selective laser sintering tremendously reduces the cost of manufacturing. SIS attempts to incorporate low cost heaters to achieve efficient sintering for production of high quality parts. However, SIS demands uniform heating of each layer for effective sintering. The present study focused on examining the heating characteristics of three different types of infrared heaters with respect to various layer thickness and determining the optimal distance between the heating surface and the powder bed. Experiments are conducted using the low-cost heaters to obtain uniform distribution of heat energy across the ultra-high molecular weight polyethylene (UHMWPE) powder surface. The thermal and optical images are captured to observe the temperature distribution on the powder and the surface roughness. Tensile and compressive specimens were fabricated and their corresponding strength was determined and surface roughness was measured to study the surface characteristics of the parts.

An Update on the Use of Alginate in Additive Biofabrication Techniques

2019 ◽  
Vol 25 (11) ◽  
pp. 1249-1264 ◽  
Author(s):  
Amoljit Singh Gill ◽  
Parneet Kaur Deol ◽  
Indu Pal Kaur
Keyword(s):  
Fused Deposition Modeling ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Layer By Layer ◽  
Three Dimension ◽  
Anionic Polymer ◽  
Fused Deposition ◽  
The Status ◽  
Deposition Modeling ◽  
Extrusion Printing

Background: Solid free forming (SFF) technique also called additive manufacturing process is immensely popular for biofabrication owing to its high accuracy, precision and reproducibility. Method: SFF techniques like stereolithography, selective laser sintering, fused deposition modeling, extrusion printing, and inkjet printing create three dimension (3D) structures by layer by layer processing of the material. To achieve desirable results, selection of the appropriate technique is an important aspect and it is based on the nature of biomaterial or bioink to be processed. Result & Conclusion: Alginate is a commonly employed bioink in biofabrication process, attributable to its nontoxic, biodegradable and biocompatible nature; low cost; and tendency to form hydrogel under mild conditions. Furthermore, control on its rheological properties like viscosity and shear thinning, makes this natural anionic polymer an appropriate candidate for many of the SFF techniques. It is endeavoured in the present review to highlight the status of alginate as bioink in various SFF techniques.

scholarly journals Optimization of fatigue strength of selective inhibition sintered polyamide 12 parts using RSM

2020 ◽  
Vol 7 ◽  
pp. 23
Author(s):  
Mesfin Sisay ◽  
Esakki Balasubramanian
Keyword(s):  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Selective Inhibition ◽  
Layer By Layer ◽  
Process Variables ◽  
Polyamide 12 ◽  
Selective Inhibition Sintering ◽  
Nylon 12 ◽  
Rate Optimization ◽  
Feed Rate Optimization

Selective inhibition sintering (SIS) is a powder based that fabricate functional parts through fusion of powder bed on a layer by layer basis. Being a new fabrication method, the correlation between process variables and part properties are not fully comprehended. Polyamide 12 (nylon 12) is one of the widely used materials in powder based AM processes including SIS. Therefore, in this work, the effect of critical SIS process parameters on the fatigue behavior of polyamide 12 parts was experimentally investigated, and the parameter settings were optimized to maximize fatigue strength. The number of experimental runs was determined based on Box-Behnken design, and specimens were fabricated as per ASTM D7791. Specimens were tested by subjected them to fluctuating loading at a frequency of 3 Hz. The test results were analyzed using Minitab statistical analysis software. From the ANOVA result, it was identified that the fatigue life of SIS parts is significantly influenced by layer thickness, heater temperature, and heater feed rate. Optimization of process variables settings was performed using the Minitab response optimizer and maximum fatigue strength of 17.43 MPa was obtained. The verification experiment resulted in 17.93 MPa fatigue strength which is comparable to the predicted value and with the result from the literatures.

scholarly journals Development of flotation machine impeller on the base of additive technologies

2021 ◽  
Vol 64 (5) ◽  
pp. 366-373
Author(s):  
L. V. Sedykh ◽  
P. V. Borisov ◽  
A. N. Pashkov ◽  
N. V. Gorbatyuk ◽  
R. Yu. Surkova ◽  
...  
Keyword(s):  
Technological Process ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Low Cost ◽  
Additive Technologies ◽  
Design System ◽  
Layer By Layer ◽  
Fused Deposition ◽  
Foam Flotation ◽  
Flotation Machines

The constant increase in the consumption of ferrous, non-ferrous, precious and rare metals in the national economy requires an increase in the efficiency of minerals mining and processing. One of the main methods of enrichment used in the technological process of processing various ores is foam flotation. The authors provide a brief description of this process and analysis of various designs of flotation machines. The article is devoted to the modernization of the aeration unit of flotation machines with “RIF” design. It is noted that the design of such machines effectively uses the modular principle of assembly aggregates, which allows you to upgrade individual unit, increasing the efficiency of the machine as a whole. The main part of this unit is an impeller – the most complex and fast – wearing part. The paper analyzes various designs of impellers and their manufacturing technologies. It is noted that in the existing designs of flotation machines, the impellers are made of steel. It is proposed to replace this material with polyurethane, which has become widely used as a structural material due to the emergence of additive technologies in the production of various parts. This material has a relatively low cost and has an increased resistance to wear. The article formulates the main requirements for the most important operations of the technological process of impeller manufacturing. For this purpose, a 3D model of the upgraded impeller design was developed in the SolidWorks 3D computer-aided design system. The authors propose an additive technology for layer-by-layer production of an impeller on a 3D printer using the Ultimaker Cura slicer program. For the manufacture of the proposed design of the impeller made of polyurethane, the production technology was developed by the method of layer-by-layer deposition method of Fused Deposition Modeling (FDM).

Comparative Study of High Performance Polymers in Selective Inhibition Sintering Process through Finite Element Analysis

2017 ◽  
Vol 25 (3) ◽  
pp. 199-202 ◽  
Author(s):  
A. Aravind ◽  
T.N. Siddiqui ◽  
P. Arunkumar ◽  
E. Balasubramanian
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Performance ◽  
Laser System ◽  
Selective Inhibition ◽  
Polymer Materials ◽  
Effect Of Temperature ◽  
Element Analysis ◽  
Element Mesh ◽  
Selective Inhibition Sintering

Selective Inhibition Sintering (SIS) is a novel additive manufacturing process which uses indigenously available polymers and the high cost laser system is avoided that makes the system cost-effective. Finite Element Analysis (FEA) is carried out to evaluate the performance of SIS process. The effect of temperature on the polymer structure is examined through coupled field transient thermo-structural analysis of various high performance polymer particles such as Polysulfone (PSU), Polybenzimidazole (PBI), Polyimide (PI), Polyethersulfone (PES), Perfluoroalkoxy alkanes (PFA), Ethylene tetrafluoroethylene (ETFE) and KCl is used as the inhibitor material. The structured finite element mesh model is created and heat flux is applied in equivalent time intervals to study the transient characteristics. Simulation results are presented with displacement, temperature and thermal stress for each polymer materials and their characteristics performance is evaluated.

scholarly journals DEVELOPMENT OF LOW-COST ADDITIVE MANUFACTURING SYSTEM THROUGH SELECTIVE INHIBITION SINTERING (SIS) PROCESS AND EVALUATION OF MECHANICAL CHARACTERISTICS OF FABRICATED PARTS

2020 ◽  
Vol 21 (2) ◽  
pp. 212-229
Author(s):  
Mesfin Sisay Mengesha ◽  
E. Balasubramanian ◽  
P. Arunkumar ◽  
M. Silambarasan ◽  
D. Rajamani
Keyword(s):  
Experimental Investigation ◽  
Additive Manufacturing ◽  
Open Source ◽  
Material Selection ◽  
Low Cost ◽  
Control Unit ◽  
Cost Effective ◽  
Selective Inhibition ◽  
Element Analysis ◽  
Selective Inhibition Sintering

Additive manufacturing (AM) is widely being used in today’s contemporary industry; however, products fabricated by the existing AM techniques are costly due to the high machine cost and low production rate. Therefore, the focus of this work is to design and fabricate a cost-effective and novel powder based selective inhibition sintering (SIS) system. Various subsystems of the machine such as the infrared heater assembly, inhibition deposition mechanism, build and feed tank assemblies, powder deposition, and the compaction system have been indigenously designed and fabricated. An electronic control system is also established through integrating sensors, linear and rotary actuators, belt and pulley mechanism, and temperature feedback control unit. The customized SIS system is developed by integrating the assembly of all the subsystems, and the electronic modules with an open-source platform to generate the necessary motion characteristics. Besides, an open source RepRap user interface firmware has been used to control the machine. Thermo-structural finite element analysis has been used to study the sintering behaviour of powder material. Inhibitor material selection and preparation have been carried out by performing an experimental investigation on the inhibition effects of various materials. The machine has been tested through fabricating parts from HDPE polymer powder. Finally, the performance of the produced parts has been evaluated by conducting an experimental investigation. The results of the investigation indicated that the fabricated parts have attained sufficient mechanical strength and, hence, the developed SIS system can be utilized to manufacture functional parts. ABSTRAK: Industri pembuatan bahan tambahan (AM) banyak digunakan dalam industri kontemporari semasa; walau bagaimanapun, produk yang terhasil daripada teknik sedia ada AM adalah mahal disebabkan harga mesin yang mahal dan kadar penghasilan yang rendah. Oleh itu, tujuan kajian ini adalah bagi mereka cipta serbuk baharu dengan harga berpatutan berdasarkan sistem pensinteran rencatan pilihan (SIS). Pelbagai mesin subsistem seperti pemasangan pemanas inframerah, mekanisme pemendapan rencatan, binaan dan pemasangan tangki suapan, deposisi serbuk, dan sistem pemadatan telah direka cipta secara alami dan dipasang siap. Sistem kawalan elektronik juga diadakan melalui integrasi sensor, lelurus dan penggerak putaran, jaluran dan mekanisme takal dan suhu unit kawalan suap balik. Sistem SIS yang dibuat mengikut pesanan ini dihasilkan dengan mengintegrasi pemasangan kesemua subsistem, dan modul elektronik melalui platfom sumber terbuka bagi menghasilkan ciri-ciri pergerakan bersesuaian. Selain itu, sumber terbuka RepRap perisian tegar antara muka telah digunakan bagi mengawal mesin. Analisis unsur terhingga struktur-terma digunakan bagi mempelajari perihal pensinteran bahan serbuk. Pilihan bahan perencat dan persediaan telah dijalankan dengan menjalankan siasatan eksperimen pada kesan perencat pelbagai bahan. Mesin diuji melalui pemasangan bahagian daripada HDPE serbuk polimer. Akhirnya, bahagian yang terhasil diuji melalui ujian eksperimen. Hasil kajian menunjukkan pemasangan bahagian telah mencapai kekuatan mekanikal mencukupi, dengan itu sistem SIS yang dibina boleh digunakan bagi mengilang bahagian berkaitan.

Optimization of Process Parameters Applied to a Prototype Selective Laser Sintering System

2017 ◽  
Author(s):  
Abass Enzi ◽  
James A. Mynderse
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Crack Width ◽  
Selective Laser Sintering ◽  
Optimal Solution ◽  
Laser Sintering ◽  
Powder Layer ◽  
Layer By Layer

Selective laser sintering is an additive manufacturing technique that uses a high power laser to sinter or melt powder layer by layer to build 3D shapes. This paper focuses on creating a mathematical model of the crack width and surface roughness that occur during the selective laser sintering process. Response surface methodology is used to build and determine a mathematical model. Five variables at five levels are selected: forward step, side step, speed, platform temperature and layer depth. Based on response surface methodology, 32 experiments are used to determine the mathematical model of two selective laser sintering defects: crack width and surface roughness. Next, a genetic algorithm is used to determine the optimal solution to minimize crack width and surface roughness of the part. Results show that the five selected parameters have an effect on the target defects as confirmed by the resulting main effects plots, interaction plots, and contour plots. An optimal set of parameters is determined for future use.

scholarly journals Additive Manufacturing in the Geopolymer Construction Technology: A Review

2020 ◽  
Vol 14 (1) ◽  
pp. 150-161
Author(s):  
Salmabanu Luhar ◽  
Ismail Luhar
Keyword(s):  
3D Printing ◽  
Computer Aided Design ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Layer By Layer ◽  
Construction Technology ◽  
Fused Deposition ◽  
Labor Requirements ◽  
Net Shaping

This research paper presents a scientific attempt of a comprehensive systematic review of three-dimensional printing in geopolymer construction technology. The concept of 3D printing is an automated manufacturing process, layer- by- layer command, with computer-aided design model to create physical objects, acquiring swift development for the last few decades. An expansion of novel Geopolymer technology has been adopted in the construction and infrastructure industries for decades. The critical challenges of construction and infrastructure industries, such as the need for architectural, holistic, and rational designs, can be dealt with 3D printing techniques. Plentiful advantages of this emerging novel technology include a reduced amount of cost, ease of construction, a lesser amount of time, freedom of design, less wastage, aptitude to create complex structures, decrease in labor requirements, etc. Accordingly, The paper discusses common 3D techniques, such as Fused Deposition Modelling, Selective Laser Sintering, Stereolithography, 3D plotting, Laminated Object Manufacturing technique, Direct Energy deposition technique or laser engineered net shaping, Powder Bed Fusion and Inject Head 3D printing and direct deposition method. Overall, this study provides an introduction of 3D printing automation and robotics processes in a geopolymer construction industry. Ultimately, the paper emphasizes to motivate researchers towards future studies about 3D printing.

Fabrication of 3D Temperature Sensor Using Magnetostrictive Inkjet Printhead

2020 ◽  
Vol 64 (5) ◽  
pp. 50405-1-50405-5
Author(s):  
Young-Woo Park ◽  
Myounggyu Noh
Keyword(s):  
Flexible Electronics ◽  
Inkjet Printing ◽  
Temperature Sensor ◽  
Computer Aided Design ◽  
Low Cost ◽  
Three Dimensional ◽  
Drop On Demand ◽  
Aided Design ◽  
Nanoparticle Ink ◽  
Inkjet Printhead

Abstract Recently, the three-dimensional (3D) printing technique has attracted much attention for creating objects of arbitrary shape and manufacturing. For the first time, in this work, we present the fabrication of an inkjet printed low-cost 3D temperature sensor on a 3D-shaped thermoplastic substrate suitable for packaging, flexible electronics, and other printed applications. The design, fabrication, and testing of a 3D printed temperature sensor are presented. The sensor pattern is designed using a computer-aided design program and fabricated by drop-on-demand inkjet printing using a magnetostrictive inkjet printhead at room temperature. The sensor pattern is printed using commercially available conductive silver nanoparticle ink. A moving speed of 90 mm/min is chosen to print the sensor pattern. The inkjet printed temperature sensor is demonstrated, and it is characterized by good electrical properties, exhibiting good sensitivity and linearity. The results indicate that 3D inkjet printing technology may have great potential for applications in sensor fabrication.

scholarly journals Modeling the Layer-by-Layer Growth of HKUST-1 Metal-Organic Framework Thin Films

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1631
Author(s):  
Qiang Zhang ◽  
Yohanes Pramudya ◽  
Wolfgang Wenzel ◽  
Christof Wöll
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Deposition Rate ◽  
Layer Growth ◽  
Coarse Grained ◽  
Structural Defects ◽  
Effect Of Temperature ◽  
Layer By Layer ◽  
Reactant Concentration ◽  
Metal Organic

Metal organic frameworks have emerged as an important new class of materials with many applications, such as sensing, gas separation, drug delivery. In many cases, their performance is limited by structural defects, including vacancies and domain boundaries. In the case of MOF thin films, surface roughness can also have a pronounced influence on MOF-based device properties. Presently, there is little systematic knowledge about optimal growth conditions with regard to optimal morphologies for specific applications. In this work, we simulate the layer-by-layer (LbL) growth of the HKUST-1 MOF as a function of temperature and reactant concentration using a coarse-grained model that permits detailed insights into the growth mechanism. This model helps to understand the morphological features of HKUST-1 grown under different conditions and can be used to predict and optimize the temperature for the purpose of controlling the crystal quality and yield. It was found that reactant concentration affects the mass deposition rate, while its effect on the crystallinity of the generated HKUST-1 film is less pronounced. In addition, the effect of temperature on the surface roughness of the film can be divided into three regimes. Temperatures in the range from 10 to 129 °C allow better control of surface roughness and film thickness, while film growth in the range of 129 to 182 °C is characterized by a lower mass deposition rate per cycle and rougher surfaces. Finally, for T larger than 182 °C, the film grows slower, but in a smooth fashion. Furthermore, the potential effect of temperature on the crystallinity of LbL-grown HKUST-1 was quantified. To obtain high crystallinity, the operating temperature should preferably not exceed 57 °C, with an optimum around 28 °C, which agrees with experimental observations.

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