Vapor Smoothing Research Articles

Surface Finish Optimization of Vapor Smoothened PLA Fabricated Parts with Microstructural Analysis

Additive Manufacturing (AM) is a product creation method done layer-by-layer. This process tends to create an unwanted feature known as staircase effect. Vapor smoothing is considered a viable solution for polymer-based AM products to minimized surface roughness. Research literature concerning vapor smoothing of polylactic acid (PLA) parts generally limited unlike its ABS counterpart. This research aims to identify optimum level for both chamber temperature and exposure time of the AM product. Two methods were used to compare their outputs with one another. The two methods are surface roughness tester and optical microscopy. The results provided an impressive 50.88 and 62.72% improvement based on the two test methods. Lastly, a contour-plot was generated to provide future users a guideline if they want to conduct research similar study.

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.

A novel eco-friendly abrasive media based abrasive flow machining of 3D printed PLA parts using IGWO and ANN

PurposeThree-dimensional (3D) printed parts usually have poor surface quality due to layer manufacturing’s “stair casing/stair-stepping”. So post-processing is typically needed to enhance its capabilities to be used in closed tolerance applications. This study aims to examine abrasive flow finishing for 3D printed polylactic acid (PLA) parts.Design/methodology/approachA new eco-friendly abrasive flow machining media (EFAFM) was developed, using paper pulp as a base material, waste vegetable oil as a liquid synthesizer and natural additives such as glycine to finish 3D printed parts. Characterization of the media was conducted through thermogravimetric analysis and Fourier transform infrared spectroscopy. PLA crescent prism parts were produced via fused deposition modelling (FDM) and finished using AFM, with experiments designed using central composite design (CCD). The impact of process parameters, including media viscosity, extrusion pressure, layer thickness and finishing time, on percentage improvement in surface roughness (%ΔRa) and material removal rate were analysed. Artificial neural network (ANN) and improved grey wolf optimizer (IGWO) were used for data modelling and optimization, respectively.FindingsThe abrasive media developed was effective for finishing FDM printed parts using AFM, with SEM images and 3D surface profile showing a significant improvement in surface topography. Optimal solutions were obtained using the ANN-IGWO approach. EFAFM was found to be a promising method for improving finishing quality on FDM 3D printed parts.Research limitations/implicationsThe present study is focused on finishing FDM printed crescent prism parts using AFM. Future research may be done on more complex shapes and could explore the impact of different materials, such as thermoplastics and composites for different applications. Also, implication of other techniques, such as chemical vapour smoothing, mechanical polishing may be explored.Practical implicationsIn the biomedical field, the use of 3D printing has revolutionized the way in which medical devices, implants and prosthetics are designed and manufactured. The biodegradable and biocompatible properties of PLA make it an ideal material for use in biomedical applications, such as the fabrication of surgical guides, dental models and tissue engineering scaffolds. The ability to finish PLA 3D printed parts using AFM can improve their biocompatibility, making them more suitable for use in the human body. The improved surface quality of 3D printed parts can also facilitate their sterilization, which is critical in the biomedical field.Social implicationsThe use of eco-friendly abrasive flow finishing for 3D printed parts can have a positive impact on the environment by reducing waste and promoting sustainable manufacturing practices. Additionally, it can improve the quality and functionality of 3D printed products, leading to better performance and longer lifespans. This can have broader economic and societal benefits.Originality/valueThis AFM media constituents are paper pulp, waste vegetable oil, silicon carbide as abrasive and the mixture of “Aloe Barbadensis Mill” – “Cyamopsis Tetragonoloba” powder and glycine. This media was then used to finish 3D printed PLA crescent prism parts. The study also used an IGWO to optimize experimental data that had been modelled using an ANN.

An experimental examination on surface finish of FDM 3D printed parts

Three-Dimensional (3D) printing, also known as Additive Manufacturing (AM) and Rapid Prototyping (RP), is a technology that takes information from a computer-aided design and prints it on a 3D printer, which creates a solid object by building up successive layers of material. This technique allows customizations and helps to develop tools that perfectly adapt to the required workspace. The material being added can be in the form of solid, liquid, or powder. Fused Deposition Modeling (FDM) is a method of AM where layers of materials are fused in a pattern to create an object. The material is usually melted and then extruded in a pattern next to or on top of previous extrusions, creating an object layer by layer. This process is used for modeling and prototyping functional and non-functional parts which are further used for various industrial applications. The major drawback associated with this technique is poor surface finish and dimensional inaccuracy of prototypes. In the present research work, the effect of various process parameters on the surface roughness of Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) samples produced from the FDM process is studied. Also, the samples are subjected to vapor smoothing to improve the surface roughness. The results of the present studies highlight that layer height and wall thickness are dominant factors affecting surface roughness. When ABS samples were subjected to acetone vapor smoothing, there was a noticeable improvement in the surface finish of the samples.

Post processing of low cost Aligners fabricated by additive manufacturing process to enhance the surface quality and functionality

Additive Manufacturing (AM) processes have ample advantages compared to traditional manufacturing processes, including mass customization, material efficiency, bioprinting, and fabrication of complex geometries with reduced lead time. Despite such benefits, it suffers most from staircase effects that deteriorate the fabricated part's surface quality. Nowadays, additively manufactured aligners are suitable for treating malocclusion and temporomandibular defects of teeth. Fused Deposition Modelling (FDM) is one of the best substitutes for clear aligners production to reduce per-unit cost. Glycol-modified Polyethylene Terephthalate (PETG) is opted as the material to fabricate the clear aligners due to its biocompatibility and non-toxicity. However, the poor surface quality of the additively manufactured is a major challenge in developing clear aligners with the FDM. A novel experimental setup is designed and developed to enable Chemical Vapor Smoothing (CVS) to enhance the surface quality of the clear aligners. Furthermore, based on the Surface roughness, the comparison is made between the surface quality polished with various chemicals (namely methylethylketone (also known as 2-butanone), toluene and, cyclohexanone). Moreover, Response Surface Methodology (RSM) is used to analyze the impact of different process parameters (i.e., the chemical volume, exposure time, and workpiece orientation) on the surface quality of the clear aligners. Moreover, RSM shows that the impact of the clear aligners orientation on %ΔRa during the CVS is higher than other process parameters. Results demonstrate that cyclohexanone produces more uniform surface quality with a 92.73% reduction in surface roughness compared to methylethylketone and toluene on PETG, i.e., 89.66% and 88.63%, respectively. The developed surface finishing method is capable of producing uniform, smooth surfaces over the FDM-fabricated PETG clear aligners.

Effects of annealing and acetone vapor smoothing on the tensile properties and surface roughness of FDM printed ABS components

Purpose This study aims to present the optimization of parameters and effects of annealing and vapor smoothing post-processing treatments on the surface roughness and tensile mechanical properties of fused deposition modeling (FDM) printed acrylonitrile butadiene styrene (ABS). Design/methodology/approach Full-factorial test matrices were designed to determine the most effective treatment parameters for post-processing. The parameters for annealing were temperature and time, whereas the parameters for the vapor smoothing were volume of acetone and time. Analysis of surface roughness and tensile test results determined influences of the levels of parameters to find an ideal balance between mechanical properties and roughness. Findings Optimal parameters for vapor smoothing and annealing were determined. Vapor smoothing resulted in significantly higher improvements to surface roughness than annealing. Both treatments generally resulted in decreased mechanical properties. Of all treatments tested, annealing at 100 °C for 60 min provided the greatest benefit to tensile properties and vapor smoothing with 20 mL of acetone for 15 min provided the greatest benefit to surface roughness while balancing effects on properties. Originality/value Vapor smoothing and annealing of FDM ABS have typically been studied independently for their effects on surface roughness and material properties, respectively, with varying materials and manufacturing methods. This study objectively compares the effects of each treatment on both characteristics simultaneously to recommend ideal treatments for maximizing the balance between the final quality and performance of FDM components. The significance of the input variables for each treatment have also been analyzed. These findings should provide value to end-users of 3D printed components seeking to balance these critical aspects of manufacturing.

Effects of surface treatments on ABS mechanical properties from fused filament fabrication

This paper examines the influence of surface treatments on the mechanical properties of acrylonitrile butadiene styrene (ABS) samples printed by fused filament fabrication (FFF). Prior efforts have applied brushing, painting, solvent dipping, infiltration, and vapor smoothing as post-processing surface treatments to improve the mechanical properties of FFF components. Additionally, because FFF can produce components with undesirable surface roughness, mechanical abrasion, epoxy coating, and acetone treatment may increase tensile strength by decreasing stress concentrations. Ridged surface texture may provide desirable tribological or handling properties. Based on these opportunities, this paper investigates abrasive media blasting, epoxy coating, acetone immersion, and ridged texturing surface treatments on the tensile strength and other mechanical properties of FFF ABS samples. ASTM D638-14 Type-I samples were printed, treated on all sample sides, and tested. From tensile tests, the elastic modulus, tensile strength, and fracture strain for both the untreated and treated ABS samples were calculated. For each sample, the surface finish and fracture macromorphology were observed with optical microscopy and the roughness values for the surface finish were calculated from profilometer data. Furthermore, samples were submerged in water and weighed periodically to measure mass changes due to water absorption. From surface profilometry and optical miscopy data, mechanical media blasting, epoxy coating, and immersion in all concentrations of acetone decreased surface roughness. Overall, on average, grit blasting with large beads and epoxy coating led to 2.6% and 1.2% increases in tensile strength, respectively; immersion in 40% acetone led to a 1.9% increase in tensile strength while treatment in 60% and 80% acetone decreased tensile strength by 4.9% and 1.9%, respectively. The study concludes that only grit blasting with large beads, immersion in 60% acetone, and the ridged texture significantly affected the tensile strength.

Property enhancement approaches of fused filament fabrication technology: A review

AbstractThe shift from rapid prototyping to rapid manufacturing using 3D printing is prominent after the development of volumetric 3D printing, multi‐material printing, and functional materials development. Fused filament fabrication (FFF) is a fast‐growing additive manufacturing technology with widespread end‐user applications. The key constraints to its growth are the lower surface and mechanical properties compared to conventional manufacturing paradigms. The goal of this review is to look at the numerous pre‐processing and post‐processing parameters for the property enhancement of FFF. Pre‐processing methods included optimization of process parameters (infill percentage, pattern, layer height, nozzle and platform temperature, raster angle and width, build orientation, and air gap) and adaptive slicing techniques. Mechanical (hot air jetting, barrel finishing, sand blasting, laser polishing, etc.), chemical (vapor smoothing, dipping, plating, and painting), and thermal (thermal annealing and normalizing) post‐processing techniques were successful in improving the mechanical strength and surface finish of fused filament fabricated parts. This paper outlines the various methodologies a FFF user could incorporate for enhancing the final finished product's properties. The potential future prospects for the development of the 3D printing sector are also examined.

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.

Additively manufactured nasopharyngeal swabs for the use in Covid-19 testing

A new methodology to manufacture mucosal membrane contact Covid-19 diagnostic items using powder-bed Additive Manufacturing (AM) and vapor smoothing methods was developed and introduced to fulfill the population testing demand. The technique can rapidly manufacture oral/respiratory diagnostic items at the point of use and at scale. Surface medical device tests were performed to evaluate biocompatibility of such Additively Manufactured Covid-19 diagnostic items. The presented results are the most in-depth medical study of vapor smoothed Additively Manufactured medical articles to date.

On improving the surface finish of 3D printing polylactic acid parts by corundum blasting

PurposeFused filament fabrication or fused deposition modeling (FFF/FDM) has as one of its main restrictions the surface quality intrinsic to the process, especially linked to the layer thickness used during manufacture. The purpose of this paper is to study the possibility of improving the surface quality of polylactic acid (PLA) parts manufactured by FFF using the shot blasting technique.Design/methodology/approachThe influence of corundum blasting on 0.2 mm layer thickness FDM PLA parts treated with two sizes of abrasive, different exposure times and different incidence pressures.FindingsAs a result, improvements of almost 80% were obtained in the surface roughness of the pieces with high exposure times, and more than 50% in just 20 s.Originality/valueThis technique is cheap, versatile and adaptable to different part sizes and geometries. Furthermore, it is a fast and environmentally friendly technique compared to conventional machining or vapor smoothing. Despite this, no previous studies have been carried out to improve the quality of this technology.

Surface roughness of PLA parts by FDM with chemical treatment

Chemical treatment can effectively reduce the surface roughness of fused deposition modeling (FDM) parts. An effort is made in this study to appraise the surface finish of poly lactic acid (PLA) parts by FDM with hot vapor smoothing treatment. The tests were designed as per the Taguchi L16 orthogonal array based factorial design of experimentation while varying process parameters such as time, temperature and solution concentration of hot vapor smoothing. The surface roughness of PLA parts after chemical treatment reduces in different degrees compared with FDM prototypes. The results of the statistical study indicate that the surface roughness is affected by treatment temperature. The optimum parameters that have been verified by performing the experiments may provide a theoretical basis for FDM parts in practical application.

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.

Investigations for surface roughness and dimensional accuracy of biomedical implants prepared by combining fused deposition modelling, vapour smoothing and investment casting

ABSTRACT Fused deposition modelling (FDM) is one of the most commonly used additive manufacturing (AM) processes to obtain 3D prototypes/patterns with compromised surface roughness and dimensional accuracy (mainly due to stair case effect). Some studies have been reported on use of vapour smoothing (VS) as post process (which has been applied post-production of FDM patterns) with the aim of enhancing its surface quality for biomedical application The patterns of thermoplastic, wax etc. obtained through FDM and VS can be further used as sacrificial patterns in investment casting (IC) applications (which is a renowned process for its capabilities of producing dimensionally accurate and highly finished casts). But hitherto little has been reported on combining FDM, VS and IC for controlling surface roughness and dimensional accuracy of biomedical implants. In this paper, two controlling parameters of each process (FDM, VS and IC) were utilised with Taguchi’s parametric approach and their effects on dimensional accuracy and surface roughness of final casts of implants were evaluated and studied using analysis of variance (ANOVA). The results specified that the combined process is highly capable and thus, prepared biomedical implants are statistically approved according to ISO UNI EN 20286-I standard for assembly purpose.

Investigations for partial denture casting by fused deposition modelling-assisted chemical vapour smoothing

PurposeThe 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/approachThe 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.FindingsThe 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/valueThis 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.

Chemical vapour treatment for enhancing the surface finish of PLA object produced by fused deposition method using the Taguchi optimization method

In this study, the effect of process parameter and various post-processing techniques on surface roughness of PLA object produced by fused deposition method is investigated. The economical and versatile method with the proper design of the experiments to reduce the surface roughness is our objective. The PLA is selected as the workpiece material, a biodegradable material which is vastly used in medical implants, where surface roughness is a major issue. The various post-processing technique is analyzed, and the parameter optimization is taken into consideration. Post-processing technique like chemical treatment, vapour smoothing, sanding and polishing is carried out. Taguchi design of the experiment is also used to optimize the parameter that affects the targeted surface roughness. Taguchi L9 orthogonal array is used to organize the different parameters, and Minitab software is used to determine the optimum parameter setting. The dichloromethane chemical is found to be the best chemical for dissolving the PLA material and reducing the layer lines so that the surface roughness can be reduced. The final results confirmed that the chemical vapour treatment using dichloromethane and the Taguchi method sufficient to improve the surface roughness.

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.

Investigations on hardness of investment-casted implants fabricated after vapour smoothing of FDM replicas

Fused deposition modelling (FDM) is one of the additive manufacturing processes, which is used to produce three-dimensional functional and non-functional prototypes. This process is commercially acceptable for producing parts with different materials (thermoplastic, wax, etc.), which can be formed into desired shape and can be used as consumable pattern in investment casting (IC) process. The IC process has been established for production of difficult to made parts with high accuracy and finish. By combining both these novel processes, the researchers are serving the field of medicine to satisfy the needs of society. The vapour smoothing is one of the recently developed surface finishing techniques, which has potential to draw remarkable results to improve the quality of FDM replicas and support the IC process to enhance the properties of casted parts. So, in this paper an attempt has been made to develop a biomedical implant by combining these three processes. Also the effects of controlling parameters of combined processes on the hardness and microstructure of the casted implants have been investigated.

Post-processing of ABS Replicas with Vapour Smoothing for Investment Casting Applications

The need of customized products with tight dimensional tolerances, lower production cost and shorter lead times led to the development of additive manufacturing techniques like fused deposition modelling (FDM). The digitally fabricated ABS patterns prepared on FDM needs to be processed by vapour smoothing (VS) in order to reduce the surface roughness. The post-processing of FDM-based patterns/replicas with VS increases their density, which increases heat input and complexities in ash removal during burnout stage from ceramic shell in investment casting (IC). This study highlights the step-by-step procedure for controlling the density of master patterns/replicas after processing with VS for IC applications.