scholarly journals A comparative study on investment casting of dental crowns for veterinary dentistry by using ABS patterns with and without wax coating

2021 ◽  
Vol 309 ◽  
pp. 01020
Author(s):  
Smruti Ranjan Pradhan ◽  
Rupinder Singh ◽  
Sukhwant Singh Banwait ◽  
Mukesh Singh Puhal ◽  
Satinder Singh ◽  
...  

The fused deposition modelling (FDM) assisted investment casting (IC) is one of the commercially established routes for fabrication of biomedical parts requiring high precision. In past two decades number of studies has been reported on use of thermoplastic and wax based FDM patterns for IC of dental crown (DC) in human dentistry. But hitherto little has been reported on comparison of Ni-Co-Cr based DC prepared by using FDM printed virgin acrylonitrile butadiene styrene (ABS) pattern and wax coated ABS pattern for veterinary patients (VP). In this work, first molar and canine teeth in left side of lower mandible of a 3-year German Shepherd male dog has been prepared by using virgin ABS and wax coated ABS patterns followed by IC of Ni-Co-Cr alloy. The result of study suggests that wax coated ABS samples-based DC has better surface hardness, grain structure, surface roughness (Ra) and controlled surface porosity thus may be used as commercial manufacturing strategy. The results have been supported with scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis.

2019 ◽  
pp. 089270571986462 ◽  
Author(s):  
Rupinder Singh ◽  
Ranvijay Kumar ◽  
Inderpreet Singh

The 3D printing of thermoplastic polymers (both virgin and reinforced with metal/ceramic particles) has been widely explored in recent past with fused deposition modelling (FDM) process. But hitherto very little has been reported on 3D printing of thermoplastics polymers with reinforcement of thermosetting polymers and ceramic particles. This article is an extension of work reported on thermo-mechanical investigations on waste thermosetting polymer bakelite and ceramic (silicon carbide and aluminium oxide) as reinforcement in recycled acrylonitrile butadiene styrene (ABS) thermoplastic matrix for sustainability. The study reports the experimental investigations on mechanical (tensile), morphological, surface hardness and thermal stability analysis of 3D printed functional prototype as tensile specimen (as per ASTM D 638). In the present case study, it has been ascertained that composition/proportion of thermoplastic matrix has a significant role in controlling the mechanical properties, whereas other input process parameters of FDM are insignificant. The results of the study suggest that thermosetting and ceramic-reinforced ABS thermoplastic-based 3D printed parts have mechanical properties at par with unreinforced ABS.


2015 ◽  
Vol 1125 ◽  
pp. 499-503
Author(s):  
Soudeh Iranmanesh ◽  
Mohd Hasbullah Idris ◽  
Alireza Esmaeilzadeh

Investment casting has emerged as the foremost casting process for manufacturing of complex parts where better dimensional accuracy is required. Rapid Prototyping (RP) technologies is able to manufacture prototypes from various modelling materials. Stratasys Fused Deposition Modelling (FDM) is a typical RP process that can fabricate prototypes from acrylonitrile butadiene styrene (ABS) used in investment casting process. Elimination of steps in mould making required in the traditional pattern wax preparation makes it quicker and a cost effective process. This paper characterises the behaviour of two proximal humerus ABS pattern constructions, namely solid and hollow fabricated by the FDM 2000 during flash dewaxing process. The dewaxing process parameters such as, temperature and time were regulated and the remaining weight of ABS material in the ceramic mould was examined.


2018 ◽  
Vol 24 (6) ◽  
pp. 921-934 ◽  
Author(s):  
Mohammad Abu Hasan Khondoker ◽  
Asad Asad ◽  
Dan Sameoto

Purpose This paper aims to target to print functionally gradient materials (FGM) devices made of immiscible polymers in multi-material fused deposition modelling (FDM) systems. The design is intended to improve adhesion of dissimilar thermoplastics without the need for chemical compatibilization so that filaments from many different sources can be used effectively. Therefore, there is a need to invent an alternative solution for printing multiple immiscible polymers in an FDM system with the desired adhesion. Design/methodology/approach In this study, the authors have developed a bi-extruder for FDM systems which can print two thermoplastics through a single nozzle with a static intermixer to enhance bonding between input materials. The system can also change the composition of extrudates continuously. Findings The uniqueness of this extruder is in its easy access to the internal channel so that a static intermixer can be inserted, enabling deposition of mechanically interlocked extrudates composed of two immiscible polymers. Without this intermixer, the bi-extruder extrudes with simple side-by-side co-extrusion having no mechanical interlocking. The bi-extruder was characterized by printing objects using pairs of materials including polylactic acid, acrylonitrile butadiene styrene and high impact polystyrene. Microscope images of the cross-sections of the extrudates confirm the ability of this bi-extruder to control the composition as desired. It was also found that the mechanically interlocked extrudates composed of two immiscible polymers substantially reduces adhesion failures within and between filaments. Originality/value In this study, the first-ever FDM extruder with a mechanical blending feature next to the nozzle has been designed and used to successfully print FGM objects with improved mechanical properties.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1333 ◽  
Author(s):  
Adrián Rodríguez-Panes ◽  
Juan Claver ◽  
Ana Camacho

This paper presents a comparative study of the tensile mechanical behaviour of pieces produced using the Fused Deposition Modelling (FDM) additive manufacturing technique with respect to the two types of thermoplastic material most widely used in this technique: polylactide (PLA) and acrylonitrile butadiene styrene (ABS). The aim of this study is to compare the effect of layer height, infill density, and layer orientation on the mechanical performance of PLA and ABS test specimens. The variables under study here are tensile yield stress, tensile strength, nominal strain at break, and modulus of elasticity. The results obtained with ABS show a lower variability than those obtained with PLA. In general, the infill percentage is the manufacturing parameter of greatest influence on the results, although the effect is more noticeable in PLA than in ABS. The test specimens manufactured using PLA perform more rigidly and they are found to have greater tensile strength than ABS. The bond between layers in PLA turns out to be extremely strong and is, therefore, highly suitable for use in additive technologies. The methodology proposed is a reference of interest in studies involving the determination of mechanical properties of polymer materials manufactured using these technologies.


2016 ◽  
Vol 22 (1) ◽  
pp. 123-143 ◽  
Author(s):  
Sunpreet Singh ◽  
Rupinder Singh

Purpose – This paper aims to review the industrial and biomedical applications of state-of-the-art fused deposition modelling (FDM)-assisted investment casting (FDMAIC). Brief literature survey of methodologies, ideas, techniques and approaches used by various researchers is highlighted and use of hybrid feedstock filament-based pattern to produce metal matrix composite is duly discussed. Design/methodology/approach – Pattern replica required for investment casting (IC) of biomedical implant, machine parts, dentistry and other industrial components can be directly produced by using FDM process is presented. Relevant studies and examples explaining the suitability of FDMAIC for various applications are also presented. Findings – Researches to optimize the conventional IC with FDM solutions and develop new hybrid feedstock filament of FDM done by researchers worldwide are also discussed. The review highlights the benefit of FDMAIC to surgeons, engineers and manufacturing organizations. Research limitations/implications – The research related to this survey is limited to the suitability and applicability of FDMAIC. Originality/value – This review presents the information regarding potential IC application, which facilitates the society, engineers and manufacturing organizations by providing variety of components for assisting FDM. The information reported in this paper will serve doctors, researchers, organizations and academicians to explore the new options in the field of FDMAIC.


Author(s):  
Andrew Aitchison ◽  
Qing Wang

Abstract Additive manufacture, specifically Fused Deposition Modeling (FDM), is an advancing manufacture method opening up new possibilities in design previously impossible to machine, in a relatively affordable way. However, its use in functional products is limited due to anisotropic strength and reduced strength from injection molded components. This paper aims to increase the tensile strength of Acrylonitrile Butadiene Styrene (ABS) in the weakest direction (Z axis), where poor interlayer fusion and air gaps between extruded trails reduce strength. Extra thermal energy was applied to the top surface layer during the printing process (through hot air) to encourage more polymer chain diffusion across the boundary, and spreading out to fill air gaps. Multiple tensile test samples were printed at a variety of heat levels. The ultimate tensile strength σuts was plotted against these temperatures and a weak positive correlation was found. However, only air temperatures above 81°C increased strength past the control to a maximum of 1.4MPa. Heat application has proven to increase tensile strength, but needs to be applied with a more precise method, to the boundary interface, to allow greater thermal energy transfer without sacrificing print quality.


Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 651 ◽  
Author(s):  
David Moises Baca Lopez ◽  
Rafiq Ahmad

The application of single homogeneous materials produced through the fused deposition modelling (FDM) technology restricts the production of high-level multi-material components. The fabrication of a sandwich-structured specimen with different material combinations using conventional thermoplastics such as poly (lactic acid) (PLA), acrylonitrile butadiene styrene (ABS) and high impact polystyrene (HIPS) through the filament-based extrusion process can demonstrate an improvement on its properties. This paper aims to assess among these materials, the best material sandwich-structured arrangement design, to enhance the mechanical properties of a part and to compare the results with the homogeneous materials selected. The samples were subjected to tensile testing to identify the tensile strength, elongation at break and Young’s modulus of each material combination. The experimental results demonstrate that applying the PLA-ABS-PLA sandwich arrangement leads to the best mechanical properties between these materials. This study enables users to consider sandwich structure designs as an alternative to manufacturing multi-material components using conventional and low-cost materials. Future work will consider the flexural tests to identify the maximum stresses and bending forces under pressure.


2020 ◽  
Vol 40 (5) ◽  
pp. 745-754
Author(s):  
Gurpartap Singh ◽  
Rupinder Singh ◽  
S.S. Bal

Purpose The purpose of this study is to investigate dimensional accuracy (Δd), surface roughness (Ra) and micro hardness (HV) of partial dentures (PD) prepared with synergic combination of fused deposition modelling (FDM) assisted chemical vapour smoothing (CVS) patterns and conventional dental casting (DC) from multi-factor optimization view point. Design/methodology/approach The master pattern for PD was prepared with acrylonitrile butadiene styrene (ABS) thermoplastic on FDM set-up (one of the low cost additive manufacturing process) followed by CVS process. The final PD as functional prototypes was casted with nickel–chromium-based (Ni-Cr) alloy by varying Ni% (Z). The other input parameters were powder to water ratio P/W (X) and pH value (Y) of water used. Findings The results of this study suggest that for controlling the Δd and Ra of the PD, most important factor is X, followed by Z. For hardness of PD, the most important factor is Z. But from overall optimization viewpoint, the best settings are X-100/12, Y-10 and Z-61% (in Ni-Cr alloy). Further, based upon X-bar chart (for HV), the FDM-assisted DC process used for preparation of PD is statistically controlled. Originality/value This study highlights that PD prepared with X-100/12, Y-10 and Z-61% gives overall better results from multi-factor optimization view point. Finally, X-bar chart has been plotted to understand the statistical nature of the synergic combination of FDM, CVS and DC.


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