Vapor Smoothing Process Research Articles

Investigation on surface roughness of ultrasonic assisted vapour smoothing of acrylonitrile butadiene styrene printed sample

Additive manufacturing offers many benefits, yet it is confronted with the challenge of rough surfaces resulting from the appearance of seam lines on the printed parts due to the layer-by-layer printing process. This study investigates the effect of ultrasonic-assisted vapor smoothing on the surface roughness of 3D-printed ABS samples. The ABS samples were printed with an open-source FDM printer. The vapour smoothing process was conducted by applying acetone and altering the ultrasonic frequencies and times to 0 kHz, 10 kHz, and 20 kHz for the frequencies and 10 min, 20 min, and 30 min for the times. The surface roughness measurements were performed using a Mitutoyo SJ-301 surface roughness tester. The findings demonstrated enhancements in the quality of the surface, reduction in the visibility of layer lines, and improved surface smoothness for all the samples. From the ANOVA analysis, the average value of Ra for 30 kHz frequency is 2.57 μm, which is better than 3.19 μm for 10 kHz frequency. The manipulation of ultrasonic frequencies and exposure durations decreased surface roughness parameters, suggesting enhancement of the time to attain smoother surfaces. This work demonstrates the effectiveness of ultrasonic-assisted vapour smoothing as a feasible post-processing technique for enhancing surface quality in 3D-printed ABS-printed parts.

Predictive modeling of surface and dimensional features of vapour-smoothened FDM parts using self-adaptive cuckoo search algorithm.

Despite numerous advantages of fused deposition modeling (FDM), the inherent layer-by-layer deposition behavior leads to considerable surface roughness and dimensional variability, limiting its usability for critical applications. This study has been conducted to select optimum parameters of FDM and vapour smoothing (chemical finishing) process to maximize surface finish, hardness, and dimensional accuracy. A self-adaptive cuckoo search algorithm for predictive modelling of surface and dimensional features of vapour-smoothened FDM-printed functional prototypes has been demonstrated. The chemical finishing has been performed on hip prosthesis (benchmark) using hot vapours of acetone (using dedicated experimental set-up). Based upon the selected design of experiment technique, 18 sets of experiments (with three repetitions) were performed by varying six parameters. Afterwards, a self-adaptive cuckoo search algorithm was implemented by formulating five objective functions using regression analysis to select optimum parameters. An excellent functional relationship between output and input parameters has been developed using a self-adaptive cuckoo search algorithm which has successfully found the solution to optimization issues related to different responses. The confirmatory experiments indicated a strong correlation between predicted and actual surface finish measurements, along with hardness and dimensional accuracy.

Effect of Acetone Vapor Smoothing Process on Surface Finish and Geometric Accuracy of Fused Deposition Modeling ABS Parts

FDM is a widely used additive manufacturing process, however, it has some limitations, such as surface finish, due to the staircase effect caused by the layer-by-layer deposition. Studies have been conducted on surface finish of ABS parts with the use of acetone, but the process parameters and the resulting effects have not been fully investigated in the literature. Therefore, the aim of this study was to investigate the effects of acetone vapor smoothing process on surface finish and geometric accuracy of fused deposition modeling ABS parts. Specimens with different geometries were created and printed using two directions in different scales. The parts were exposed to acetone vapor for 20, 30 and 40 minutes. 3D deviation maps, roughness and microscopic analyses were conducted. The staircase effect was reduced at the expense of some geometric deviations, which varied according to the exposure time and part orientation. The smoothing process applied to the flat surfaces proved to be quite effective in reducing roughness by 90%, however, this reduction led to an undesirable rounding of the sharp edges. The results obtained in this study are consistent with those found in the literature and may help improve the quality of the ABS printed parts.

State of Art on Vapour Smoothing of Fused Deposition Modelling Components

Fused Deposition Modelling (FDM) is one of the additive manufacturing processes which can produce prototypes or functional components without the use of fixtures, and the lead time required is reduced drastically compared to traditional machining processes. The application of the FDM process in the biomedical and casting industries is limited by its poor surface roughness which is most generally caused by the staircase effect and chordal error of the 3D model. Owing to the drawbacks of mechanical based finishing techniques, researchers have come up with a new technique known as Vapour Smoothing (VS). In this work, past literature of the VS process of FDM components is reported and it has been seen that the VS process is giving a promising improvement in surface roughness of FDM components.

An Experimental Study of Surface Improvement in FDM Parts by Vapor Treatment Process

Fused deposition modeling (FDM) is one of the most adaptable additive manufacturing method owing to the cost-effectiveness and environment-friendly nature. However, FDM technique still possesses major difficulties in terms of poor surface quality because of adding layer by layer manufacturing process for the prototypes. It is desirable to explore an efficient technique for FDM parts to enhance the poor surface quality and dimensions precision. In the present paper, an effort has been made to enhance the surface quality and optimize the critical processing parameter of FDM based benchmark using vapor smoothing process (VSP). A comparative experimental study has been performed by design of experiments (DOE), Taguchi technique to find the influence of input design parameters on the surface finish of benchmark FDM parts. The results of the present investigation show that VSP treatment improves the surface quality of FDM parts to micro level with negligible dimensional variation. It is observed that improved surface quality is found in the 1,2, -Dichloroethane chemical at 90° part build orientation, 0.25 mm layer thickness, 10% fill density and 90 second exposure times.

Influence of Vapour Smoothing Process Parameters on Fused Deposition Modelling Parts Surface Roughness at Different Build Orientation

Additive Manufacturing is becoming increasingly important to the manufacturing industry with the gradual rise in the complexity of products and technology. In this paper, influence of finishing method i.e vapour smoothing process parameters on fused deposition modelling surface finish is studied. Process parameters considered for investigation in this study are build orientation, volume of chemical solution used for finishing and vapour smoothing process time. The test specimen is fabricated in polylactic acid thermoplastic using CubePro FDM machine and THF (Tetra Hydro Flouride) solution is used for vapour smoothing. From experimentation, it is observed that finishing method has significant influence and among the process parameters notable impact is observed in build orientation. Minimum surface roughness is observed at 90°orientation, 10ml volume of THF and VS process time of 5 minutes. Work presented in this study will further enhance the application of FDM parts in patterns for casting, and consumer goods which required high surface finish

Performance analysis of vapour finishing apparatus for surface enhancement of FDM parts

Additive manufacturing is one of the most useful technologies that have been studied by many researchers in terms of the ability to create complex geometries, eliminating wastages, reducing human interventions etc. Fused Deposition Modeling (FDM) is one of the most commonly used manufacturing technology due to easy fabrication process, flexibility of materials, accuracy and portability. It has the potential to generate complex geometrical shapes within few hours and such printers are adaptable and fulfil the desired needs of the present demands. But the poor surface characteristic is one of the barriers that need to be focused on for commercialization of products. As an extension to approaches adopted to overcome the surface issues, a dedicated finishing apparatus was developed and tested for efficacy. It was found that hot chemical vapours mixed with heated air fastens the vapour smoothing process and yields excellent surface finish. The experiments were conducted and it was experienced that higher temperature and time of mild chemical vapours resulted in better surface finish (maximum 89% improvement). Permanent weight gain in Acrylonitrile butadiene styrene (ABS) parts was noted with increase in finishing time which could hinder its usability.

Vapor smoothing process for surface finishing of FDM replicas

This paper explores the possibilities of utilizing acetone as an alternative solvent for finishing of acrylonitrile butadiene styrene (ABS) parts in controlled environment. The experiments were conducted on replicas of hip implant master pattern prepared through fused deposition modelling (FDM) to highlight its applicability in manufacturing of biomedical implant via rapid casting (RC) route. The series of experiments were conducted to evaluate impact of smoothing duration and repetition of smoothing cycles on surface finish and stability of ABS replicas. It was experienced that increase in exposure of acetone vapors manifested better surface finish but, beyond critical limit, the adverse effects was appeared leading to distortion of the upper surface. The excessive reflow of upper layers of ABS parts reduced weight and disturbed the geometry of hip replicas. The upper and lower limits of smoothing duration to safeguard the surface integrity and profile of hip replicas have been successfully chalked out. The acetone has been recommended to be used as solvent for finishing of ABS replicas which can revolutionize the production of biomedical implants through RC.

Set-Up of an Experimental Procedure for the Surface Smoothing of FDM Parts through Acetone Vapor

Fused deposition modeling (FDM) is an additive manufacturing technology where three-dimensional physical models are manufactured by layer-by-layer deposition. However, the layered surface built with FDM suffers from poor surface quality and dimensional accuracy even for basic part geometries. This proves to be unacceptable and not satisfactory for most general purposes with the consequence of a decreased value of the final product. Several methods for post-processing were proposed to achieve fine surface of manufactured components. In particular, for components manufactured with polylactic acid (PLA) the chemical post-processing with dimethyl ketone (acetone), named vapor smoothing process, seems to be very promising to significantly improve the surface roughness. Moreover, acetone has the main advantage to have a low cost, low toxicity and high diffusion rate. However, this polishing procedure may dissolve the outer surface of the parts affecting the structural reliability of the part. In this work, a novel device, consisting of a cylindrical chamber in Pyrex, is set-up for the vapor smoothing process with acetone. The system is designed to permit the injection of a gas containing acetone at different concentrations and at different operating conditions (temperature, contact time). The samples used for the test are truncheon design manufactured using different printer settings; each truncheon is built at inclination angles varying from 0° to 45° in step of 5°. The variation of the surface roughness was investigated using a confocal microscope Leica DCM3D, equipped with the software LeicaScan and LeicaMap.

Integration of FDM and vapor smoothing process: Analyzing properties of fabricated ABS replicas

Fused deposition modelling (FDM) technique occupied a key position in additive manufacturing (AM) processes for the fabrication of functional and non-functional industrial parts. However, surface texture generated due to the fundamental working principle (layered manufacturing) and dimensional inaccuracy of fabricated parts, limits its domain particularly in precision industrial applications. In this research work, initially FDM based acrylonitrile butadiene styrene (ABS) replicas have been fabricated by varying the selected FDM parameters and their effect on the surface finish, shore hardness and dimensional accuracy has been determined as a pre-processing stage. In the post-processing stage, the exposure of hot vapors of acetone has been applied to the same fabricated replicas and the changes occurred in the surface finish, shore hardness and dimensional accuracy have been investigated. The study highlighted that post-processing of ABS replicas with hot vapors of acetone resulted in dramatic improvement of surface finish and shore hardness with negligible variations in part dimensions. Finally, parameter setting that gives acceptable results while considering all the responses simultaneously have been obtained using Minitab software..

Numerical evaluation of ABS parts fabricated by fused deposition modeling and vapor smoothing

Fused deposition modeling (FDM) is one of the popular 3D printing technologies due to an inexpensive extrusion machine and multi-material printing. However, FDM could only use thermoplastics such as ABS and PLA and has a problem related to the post-processing. In this study, themechanical properties of ABS parts fabricated by FDM were measured. The ABS parts were divided into one with vapor smoothing process and the other without the vapor smoothing process which is one of the the post-processing methods. Using dynamic mechanical analysis (DMA) anddilatometer, temperature-dependent storage modulus and CTE for ABS specimens were observed. Based on the measured thermo-mechanical properties of ABS parts, finite element analysis was performed for an automotive bumper made of ABS. Moreover, response surface methodologywas applied to study the relationship among design parameters of thickness of the bumper, ambient temperature, and application of the vapor smoothing process. In result, a design guideline for a ABS product could be provided without time-consuming experiments.

Temperature-dependent mechanical properties of ABS parts fabricated by fused deposition modeling and vapor smoothing

3D printing technologies have gotten an attention as a viable option for future manufacturing. Among them, FDM is the most popular one because it is inexpensive and can process with multiples materials. Layered surface, that has high roughness, is obtained with the technology due to layer-by-layer based process. This result highly decreases value of the final product. Various methods for postprocessing were proposed to achieve fine surface. Among them, vapor smoothing process is one of powerful methods because of its cost-effectiveness and usefulness. However, this process could affect mechanical property of the printed structure. In this study, we investigated the effect of the vapor smoothing technique with 3D printed structures in terms of thermal-dependent mechanical property. ABS structure was fabricated with FDM and applied into the post-processing. Then, temperature-dependent storage modulus and tan δ of the structure were measured with dynamic mechanical analysis (DMA) in the variation of amount of acetone. The results showed that the process highly affects to the thermal stability. Below 50°C, any differences were not observed. However, lower modulus and higher tan δ were shown in the higher temperature. This experiment provides very useful data for FEM simulation to predict mechanical property of a 3D printed structure.

Experimental investigations for dimensional accuracy and surface finish of polyurethane prototypes fabricated by indirect rapid tooling: a case study

In this research work, an effort has been made to study the influence of selected input parameters on the dimensional accuracy (linear as well as radial) and surface finish of polyurethane prototypes fabricated by vacuum casting (VC) process as a case study. The master pattern required for making a silicone mould has been fabricated by fused deposition modelling and its surface finish has been enhanced by chemical vapour smoothing process. Maximum shrinkage of 2.29 and 4.77% has been observed in the selected linear and radial dimension, respectively, after the VC process. Optimal parameter settings that were different for both the dimensions as well as surface finish have been obtained using Taguchi’s L18 orthogonal array. Finally, parameter setting that simultaneously minimizes the dimensional deviation and surface roughness has been found out using response optimization module of Minitab 17 software and the results obtained have been verified by performing the confirmation experiments. The tolerance grades for the selected dimension of the prototypes were found to be acceptable as per the ISO standard UNI EN 20286-I (1995) and DIN16901 for plastic materials. In addition, the C pk value greater than 1.3 indicated that the proposed process is highly capable. The surface finish and dimensional accuracy of prototypes are at par with the traditional moulding patterns, and hence, they can be used as end-products or plastic-based master patterns for investment casting applications.

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

PurposeThe 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/approachThe 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.FindingsThe 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/implicationsThe 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/valueThe 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.

Dimensional accuracy analysis of coupled fused deposition modeling and vapour smoothing operations for biomedical applications

Abstract Fused Deposition Modeling (FDM) is one of the most extensively used Additive Manufacturing technique which has substantially shortened the product development time and cost. The application has been extended to fabricate biomedical implants through investment casting process. But the FDM replicas exhibit poor surface quality which requires further post finishing. Thus, it is very difficult to achieve adequate dimensional accuracy as surface finishing techniques resulted in material removal and erosion of upper surface. The vapour smoothing is an advanced finishing technique which eliminates tool-workpiece contact and yield ultra smooth finish but dimensional accuracy of FDM replicas is yet to be ascertained. In present research, the efforts are made to explore the influence of FDM and VS process parameters in dimensional features of complex designs. The influence of six parameters on radial (head diameter) and linear dimensions (neck and stem thickness) is studied using Taguchi orthogonal array. The CMM measurements showed shrinkage in head diameter while positive deviation has been observed in linear dimensions before vapour smoothing with maximum impact of orientation angle. The vapour smoothing process caused shrinkage in both linear and radial dimensions with maximum effect of smoothing time. The process parameters and their levels are optimized and confirmatory experiments indicated reduced deviations in dimensional features with consistency in IT grades.

Investigations for improving the surface finish of FDM based ABS replicas by chemical vapor smoothing process: a case study

PurposeThis research work aims to make an effort to investigate the effect of fused deposition modelling (FDM) process parameters on the surface finish of acrylonitrile butadiene styrene (ABS) replicas (as pre-processing stage), followed by chemical vapor smoothing (CVS) process (as a post-processing stage) as a case study.Design/methodology/approachThe Taguchi L18 orthogonal array has been used for optimizing process parameters of FDM and CVS processes.FindingsThis study highlights that orientation and part density, and the interaction between these two have a significant effect on the surface finish at the pre-processing stage of FDM. However, after post-processing with CVS, there is hardly any influence of pre-processing FDM parameters.Originality/valueThe study highlights that for improving the productivity of the FDM process, the parametric optimization of process may be made on the basis of production cost and time in place of surface finish of ABS replicas. The results obtained have been verified by performing the confirmation experiments.

Investigation of additive manufacturing surface smoothing process

PurposeThe additive manufacturing technologies have been facing an extraordinary growth along the past years. This phenomenon might be correlated with rise of low-cost FDM technologies into the non-professional market segment. In contrast with that, among the main disadvantages found in this sort of equipment are the final object finishing and low mechanical strength. For that reason, the purpose of this paper is to present and characterise a surface treatment which is based on solvent vapour attack and that is also known as smoothing process. In addition, a concise overview about the theory beneath this process is presented besides an experimental study that evaluates the main effects on the mechanical properties of object.Design/methodology/approachTo analyse the benefits of this process, the authors preliminarily investigated the working mechanism that supports such surface treatment. It allowed them to identify and select a proper solvent for each material. The authors have also established that the exposure time repetition numbers (passes) were the main variables, whereas temperature, solvent type, drying time, object direction and object shape were constants. The main object dimensions, surface roughness, absorbed solvent mass and mechanical strength were the main study responses.FindingsAs a result of this work, the peak-peak roughness was reduced in 71 per cent, indicating the potential benefit of this process. On the other hand, excessive solvent exposure implied on relevant dimensional distortions and internal disruptures. It was also possible to see that the vapourised solvent penetrate into the object surface and fused layers and filaments. As consequence, the mechanical strength was also improved.Originality/valueDespite the growth that additive manufacturing market segment has seen along the past years, the finishing and mechanical strength of low-cost equipment still lack for improvements. For that reason, applications like solvent vapour attack or smoothing process new perspectives for this non-professional segment, whereas roughness and mechanical strength are improved after its treatment. As a consequence, it is possible to consider a final object to be obtained directly from low-cost FDM in combination with smoothing process.

Investigation for surface finish improvement of FDM parts by vapor smoothing process

Abstract Fused deposition modelling (FDM) is one of the most widely used cost-effective additive manufacturing (AM) technique for modelling and prototyping of functional/non-functional parts subjected to different industrial applications. However, this technique still possesses substantial problems in-terms of poor surface finish and dimensional accuracy of the prototypes. In the present research work, an effort has been made to improve the surface finish of FDM based benchmarks through chemical (acetone) exposure by using vapor smoothing station (VSS). Experimental analysis has been carried out by using design of experiments (DOE) technique in-order to find out the effect of input factors on surface finish of the benchmarks. The results of the present study highlights the capability of the VSS for improving the surface finish of the FDM based parts to nano-level with negligible dimensional deviations.

Parametric optimization of fused deposition modeling and vapour smoothing processes for surface finishing of biomedical implant replicas

Abstract This study focuses on formulation of robust design for vapour smoothing, an advanced surface finishing technique for finishing ABS replicas where hot vapours tend to level the uneven surface asperities. The process parameters of combined Fused Deposition Modeling (FDM) and Vapour smoothing (VS) process are optimized for sustainability of ABS replicas for biomedical applications. Six input parameters have been investigated, two of FDM and four of VS processes while surface roughness and hardness of ABS part is taken as response. The vapour smoothing process ensue ultra smooth finish with negligible deterioration of upper surface deducing maximum contribution of smoothing time (51.07%) and number of cycles (40.08%) on surface roughness. Hardness of replica has been slightly increased by maximum impact of orientation angle (34.69%) and postcooling time (44.46%) of ABS replicas which endorsed the use of FDM replicas for investment casting of biomedical implants.

Repeatability of linear and radial dimension of ABS replicas fabricated by fused deposition modelling and chemical vapor smoothing process: A case study

In this research work, an effort has been made to study the influence of fused deposition modelling (FDM) and chemical vapor smoothing (CVS) process parameters on the selected linear and radial dimension as well as on repeatability of acrylonitrile butadiene styrene (ABS) replicas as a case study. The study highlights that orientation of parts on FDM build platform, part density (part interior style) and interaction between these two parameters significantly affect the accuracy of selected dimensions. Shrinkage has been observed in the selected radial dimension of the prototypes, but there is a positive deviation in the linear dimension from the desired value. The CVS process reduces both the dimensions slightly due to reflow of the material. Optimum parameter settings that were different for both linear and radial dimensions have been investigated using Taguchi’s L18 orthogonal array. The IT grades of ABS replicas prepared by this combined process were found to be consistent with the permissible range of tolerance grades as per ISO standard UNI EN 20286-I (1995) and DIN 16901 for plastic materials. Finally, optimum level of process parameters that simultaneously minimizes the deviation in both the dimensions have been found out using response optimization module of Minitab 17 software and the results obtained have been verified by performing the confirmation experiments.