Pre and post processing techniques to improve surface characteristics of FDM parts: a state of art review and future applications

2017 ◽  
Vol 23 (3) ◽  
pp. 495-513 ◽  
Author(s):  
Jasgurpreet Singh Chohan ◽  
Rupinder Singh

Purpose The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition modelling (FDM)-based acrylonitrile butadiene styrene (ABS) prototypes. FDM being simple and versatile additive manufacturing technique has a calibre to comply with present need of tailor-made and cost-effective products with low cycle time. But the poor surface finish and dimensional accuracy are the primary hurdles ahead the implementation of FDM for rapid casting and tooling applications. Design/methodology/approach The consequences and scope of FDM pre-processing and post-processing parameters have been studied independently. The comprehensive study includes dominance, limitations, validity and reach of various techniques embraced to improve surface characteristics of ABS parts. The replicas of hip implant are fabricated by maintaining the optimum pre-processing parameters as reviewed, and a case study has been executed to evaluate the capability of vapour smoothing process to enhance surface finish. Findings The pre-processing techniques are quite deficient when different geometries are required to be manufactured within limited time and required range of surface finish and accuracy. The post-processing techniques of surface finishing, being effective disturbs the dimensional stability and mechanical strength of parts thus incapacitates them for specific applications. The major challenge for FDM is the development of precise, automatic and controlled mass finishing techniques with low cost and time. Research limitations/implications The research assessed the feasibility of vapour smoothing technique for surface finishing which can make consistent castings of customized implants at low cost and shorter lead times. Originality/value The extensive research regarding surface finish and dimensional accuracy of FDM parts has been collected, and inferences made by study have been used to fabricate replicas to further examine advanced finishing technique of vapour smoothing.

2016 ◽  
Vol 22 (2) ◽  
pp. 281-299 ◽  
Author(s):  
Kamaljit Singh Boparai ◽  
Rupinder Singh ◽  
Harwinder Singh

Purpose The purpose of this study is to highlight the direct fabrication of rapid tooling (RT) with desired mechanical, tribological and thermal properties using fused deposition modelling (FDM) process. Further, the review paper demonstrated development procedure of alternative feedstock filament of low-cost composite material for FDM to extend the range of RT applications. Design/methodology/approach The alternative materials for FDM and their processing requirements for fabrication in filament form as reported by various researchers have been summarized. The literature demonstrates the role of various post-processing techniques on surface finish of FDM prints. Further, low-cost materials for feedstock filament have been investigated experimentally to check their adaptability/suitability for commercial FDM setup. The approach was to realize the requirements of FDM (melt flow rate, flexibility, stiffness, glass transition temperature and mechanical strength), necessary for the successful run of an alternative filament. The effect of constituents (additives, plasticizers, surfactants and fillers) in polymeric matrix on mechanical, tribological and thermal properties has been investigated. Findings It is possible to develop composite material feedstock as filament for commercial FDM setup without changing its hardware and software. Surface finish of the parts can further be improved by applying various post-processing techniques. Most of the composite parts have high mechanical strength, hardness, thermal stability, wear resistant and better bond formation than standard material parts. Research limitations/implications Future research may be focused on improving the surface quality of parts fabricated with composite feedstock, solving issues related to the uniform distribution of filled materials during the fabrication of feedstock filament which in turns further increases mechanical strength, high dimensional stability of composite filament and transferring the technology from laboratory scale to various industrial applications. Practical implications Potential applications of direct fabrication with RT includes rapid manufacturing (RM) of metal-filled parts and ceramic-filled parts (which have complex shape and cannot be rapidly made by any other manufacturing techniques) in the field of biomedical and dentistry. Originality/value This new manufacturing methodology is based on the proper selection and processing of various materials and additives to form high-performance, low-cost composite material feedstock filament (which fulfil the necessary requirements of FDM process). Finally, newly developed feedstock filament material has both quantitative and qualitative advantage in RT and RM applications as compared to standard material filament.


2019 ◽  
Vol 25 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Joseph Nsengimana ◽  
Jacobus Van der Walt ◽  
Eujin Pei ◽  
Maruf Miah

Purpose This paper aims to investigate the effect of post-processing techniques on dimensional accuracy of laser sintering (LS) of Nylon and Alumide® and fused deposition modelling (FDM) of acrylonitrile butadiene styrene (ABS) materials. Design/methodology/approach Additive manufacturing (AM) of test pieces using LS of Nylon and Alumide® powders, as well as the FDM of ABS materials, were first conducted. Next, post-processing of the test pieces involved tumbling, shot peening, hand finishing, spray painting, CNC machining and chemical treatment. Touch probe scanning of the test pieces was undertaken to assess the dimensional deviation, followed by statistical analysis using Chi-square and Z-tests. Findings The deviation ranges of the original built parts with those being subjected to tumbling, shot peening, hand finishing, spray painting, CNC machining or chemical treatment were found to be different. Despite the rounding of sharp corners and the removal of small protrusions, the dimensional accuracy of relatively wide surfaces of Nylon or Alumide® test pieces were not significantly affected by the tumbling or shot peening processes. The immersion of ABS test pieces into an acetone bath produced excellent dimensional accuracy. Research limitations/implications Only Nylon PA2200 and Alumide® processed through LS and ABS P400 processed through FDM were investigated. Future work could also examine other materials and using parts produced with other AM processes. Practical implications The service bureaus that produce prototypes and end-use functional parts through AM will be able to apply the findings of this investigation. Originality/value This research has outlined the differences of post-processing techniques such as tumbling, shot peening, hand finishing, spray painting, CNC machining and chemical treatment. The paper discusses the advantages and disadvantages of each of those methods and suggests that the immersion of ABS test pieces into an acetone bath produced excellent dimensional accuracy.


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.


2019 ◽  
Vol 821 ◽  
pp. 174-180
Author(s):  
Ramil Kesvarakul ◽  
Khompee Limpadapun

Fused Deposition Modelling (FDM) has been extensively used in low-cost printers. However, the fundamental working principle (layered manufacturing) is resulted in the poor quality of the surface texture, the dimensional inaccuracy of fabricated parts, the limits its domain all issues often take place in precision industrial applications. In this paper, initially FDM based acrylonitrile butadiene styrene (ABS) model have been fabricated. In the post-processing stage, the vapor of acetone has been applied to the specimen. Then the changes in the surface finish and surface roughness have been investigated. The study highlighted that the post-processing of ABS specimen with acetone vapor treatment resulted in dramatic improvement of surface finish. Finally, parameter setting that gave the acceptable results while considering all the responses simultaneously.


2014 ◽  
Vol 20 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Wayne M. Johnson ◽  
Matthew Rowell ◽  
Bill Deason ◽  
Malik Eubanks

Purpose – The purpose of this paper is to present a qualitative and quantitative comparison and evaluation of an open-source fused deposition modeling (FDM) additive manufacturing (AM) system with a proprietary FDM AM system based on the fabrication of a custom benchmarking model. Design/methodology/approach – A custom benchmarking model was fabricated using the two AM systems and evaluated qualitatively and quantitatively. The fabricated models were visually inspected and scanned using a 3D laser scanning system to examine their dimensional accuracy and geometric dimensioning and tolerancing (GD&T) performance with respect to the computer-aided design (CAD) model geometry. Findings – The open-source FDM AM system (CupCake CNC) successfully fabricated most of the features on the benchmark, but the model did suffer from greater thermal warping and surface roughness, and limitations in the fabrication of overhang structures compared to the model fabricated by the proprietary AM system. Overall, the CupCake CNC provides a relatively accurate, low-cost alternative to more expensive proprietary FDM AM systems. Research limitations/implications – This work is limited in the sample size used for the evaluation. Practical implications – This work will provide the public and research AM communities with an improved understanding of the performance and capabilities of an open-source AM system. It may also lead to increased use of open-source systems as research testbeds for the continued improvement of current AM processes, and the development of new AM system designs and processes. Originality/value – This study is one of the first comparative evaluations of an open-source AM with a proprietary AM system.


2017 ◽  
Vol 23 (5) ◽  
pp. 845-857 ◽  
Author(s):  
Parlad Kumar Garg ◽  
Rupinder Singh ◽  
IPS Ahuja

Purpose The purpose of this paper is to optimize the process parameters to obtain the best dimensional accuracy, surface finish and hardness of the castings produced by using fused deposition modeling (FDM)-based patterns in investment casting (IC). Design/methodology/approach In this paper, hip implants have been prepared by using plastic patterns in IC process. Taguchi design of experiments has been used to study the effect of six different input process parameters on the dimensional deviation, surface roughness and hardness of the implants. Analysis of variance has been used to find the effect of each input factor on the output. Multi-objective optimization has been done to find the combined best values of output. Findings The results proved that the FDM patterns can be used successfully in IC. A wax coating on the FDM patterns improves the surface finish and dimensional accuracy. The improved dimensional accuracy, surface finish and hardness have been achieved simultaneously through multi-objective optimization. Research limitations/implications A thin layer of wax is used on the plastic patterns. The effect of thickness of the layer has not been considered. Further research is needed to study the effect of the thickness of the wax layer. Practical implications The results obtained by the study would be helpful in making decisions regarding machining and/or coating on the parts produced by this process. Originality/value In this paper, multi-objective optimization of dimensional accuracy, surface roughness and hardness of hybrid investment cast components has been performed.


2015 ◽  
Vol 21 (6) ◽  
pp. 686-696 ◽  
Author(s):  
Alberto Boschetto ◽  
Luana Bottini

Purpose – The purpose of this paper is to study the integration between this technology and barrel finishing (BF) operation to improve part surface quality. Fused deposition modeling (FDM) processes have limitation in term of accuracy and surface finishing. Hence, post-processing operations are needed. A theoretical and experimental investigations have been carried out. Design/methodology/approach – A geometrical model of the profile under the action of machining is proposed. The model takes into account FDM formulation and allows to predict the surface morphology achievable by BF. The MR needed in the model is obtained by a particular profilometer methodology, based on the alignment of Firestone–Abbot (F–A) curves. The experimental performed on a suitable geometry validated geometrical model. Profilometer and dimensional measurements have been used to assess the output of the coupled technologies in terms of surface roughness and accuracy. Findings – The coupling of FDM and BF has been assessed and characterized in terms of obtained part surfaces and dimension evolution. Deposition angle strongly affects the BF removal speed and alters nominal dimensions of part. The geometric profile model gave interesting information about profile morphology and machining mechanism; moreover, the height prevision allows to estimate BF working time to accomplish part requirements. Research limitations/implications – The prediction of the geometric profile as a function of FDM fabrication parameters is a powerful tool which permits to investigate surface properties such as mechanical coupling or tribological aspects. The coupling of BF and FDM has been assessed and now optimization of this process can be performed just evaluating effects of parameters. Practical implications – This research has been focused to an industrial application, and results can be used in a computer-aided manufacturing. The prevision of surface obtainable by this integration is a tool to find the part optimum orientation to accomplish the drawing requirements. Both the experimental findings and the model can guide operator toward a proper process improvement, thus reducing or eliminating expensive trial and error phase in the post-processing operation of FDM prototypes. Originality/value – In this paper, a novel model has been presented. It allows to know in advance profile morphology achievable by a specific surface of a FDM part after a determined BF working time. A particular application of FA curves gives the MR values.


2018 ◽  
Vol 24 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Jasgurpreet Singh Chohan ◽  
Rupinder Singh ◽  
Kamaljit Singh Boparai

Purpose This paper aims to focus on the changes in thermal and surface characteristics of acrylonitrile butadiene styrene (ABS) material when exposed to chemical vapours for surface finishing. The poor surface finish and the dimensional accuracy of the fused deposition modelling parts (of ABS material) because of the stair-stepping hinder their use for rapid tooling applications, which can be improved by vapour finishing process. The differential scanning calorimetry (DSC) tests are performed to investigate the thermal behaviour of ABS thermoplastic after vapour finishing. Design/methodology/approach The hip prosthesis replica has been used to highlight the efficacy of chemical finishing process for intricate and complex geometries. The replicas are treated with chemical vapours for different durations. The DSC tests are performed along with surface roughness, surface hardness and dimensional measurements of exposed replicas and compared with unexposed replica. Findings The longer finishing time, i.e. 20 s, manifested higher melting peak temperature, higher melting enthalpy and higher heat capacity along with smoother and harder surface as compared with unexposed replica. The finishing process enhanced the bonding strength and the heat-bearing capacity of ABS material. The vapour finishing process enhanced the thermal stability of the material which may extend its sustainability at higher temperatures. Practical implications The improved thermal stability of ABS thermoplastic after chemical vapour finishing has been demonstrated. This advancement allows the use of ABS in functional tooling suitable for small production runs with higher flexibility and lead time savings. Originality/value The heat effects associated with phase transitions as a function of temperature are studied in case of replicas finished with chemical vapours. The relationship between melting enthalpy and surface characteristics has been ascertained.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sugavaneswarn M. ◽  
Prashanthi B. ◽  
John Rajan A.

Purpose This paper aims to enhance the surface finish of the fused deposition modeling (FDM) part using the vapor smoothening (VS) post-processing method and to study the combined effect of FDM and VS process parameters on the quality of the part. Design/methodology/approach Analysis of variance method is used to understand the significance of the FDM and VS process parameters. Following this, the optimized parameter for multiple criteria response is reported using the technique for order preference by similarity to ideal solution. The process parameters alternatives are build orientation angle, build surface normal and exposure time and the criteria are surface roughness and dimensional error percentage. Findings The result observed contradicts the result reported on the independent parameter optimization of FDM and VS processes. There is a radical improvement in the surface finish on account of the coating process and an increase in the exposure time results in the decrease of the surface roughness. Minimum surface roughness of 0.11 µm is observed at 1,620 build angle and the least dimensional error of 0.01% is observed at build orientation angle 540. The impact of VS on the up-facing surface is different from the down-facing surface due to the removal of support material burrs and the exposure of the surface to vapor direction. Originality/value A study on the multi-criteria decision-making to ascertain the effect of post-processing on FDM component surface normal directed both to downward (build angle 0°–90°) and to upward (build angle 99°–180°) are reported for the first time in this article. The data reported for the post-processed FDM part at the build angle 0°–180° can be used as a guideline for selecting the optimal parameter and for assigning appropriate tolerance in the CAD model.


2016 ◽  
Vol 22 (3) ◽  
pp. 445-455 ◽  
Author(s):  
Sunpreet Singh ◽  
Rupinder Singh

Purpose This paper aims to investigate the dimensional accuracy of aluminium (Al) matrix composites (AMCs) prepared by using an alternative reinforced fused deposition modeling (FDM)-based sacrificial patterns in investment casting (IC) process. Further in this work, a barrel finishing (BF) process has been introduced as an intermediate step for the improvement of surface finish of sacrificial patterns and to study the effect of BF process parameters on dimensional features of the casted AMCs. In the present research, an effort has been made to ascertain the capability/producibility of the proposed route for obtaining good geometrical tolerances. Design/methodology/approach Alternative reinforced FDM filaments were developed using single screw extruder whose melt flow index was matched with the commercial acrylonitrile–butadiene–styrene filament. IC sacrificial patterns, fabricated on existing FDM system without making any change in its hardware/software, were barrel finished for improving the surface finish. The effect of FDM, BF and IC process parameters, namely, type of filament, volume of CAD-based cubical pattern, pattern density, BF time, BF media weight and numbers of IC slurry layers, was studied using Taguchi L18 OA approach. Findings Dimensional accuracy of casted AMCs developed was optimized successfully using Taguchi L18 orthogonal array. Optical microscopic analysis made on the castings highlighted the presence of Al2O3 particles which will result into the improvement of mechanical and tribological properties. International tolerance grade of cast AMCs was calculated and found acceptable as per ISO standard UNI-EN-20286-I (1995). Further, there are strong possibilities of process to be under statistical control at proposed settings. Originality/value The paper describes a new route for the development of AMC. The effect of FDM, BF and IC process parameters on dimensional accuracy of AMCs developed is also highlighted in the present research.


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