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This paper aims to investigate the water absorption behaviors and mechanical properties, according to water absorption and temperature, of components fabricated by fused deposition modeling (FDM) and injection molding. The mechanical properties of FDM and injection molded parts were studied under several environmental conditions.

FDM components can be used as load-carrying elements under a range of moisture and temperature conditions. FDM parts show anisotropic mechanical properties according to build orientation. Components were fabricated from acrylonitrile-butadiene-styrene in three different orientations. The mechanical properties of parts fabricated by FDM were compared to injection molded components made from the same material. Water absorption tests were conducted in distilled water between 20 and 60°C to identify the maximum water absorption rate. Both moisture and temperature were considered as environmental variables in the tensile tests, which were conducted under various conditions to measure the effects on mechanical properties.

The water absorption behavior of FDM components obeyed Fickian diffusion theory, irrespective of the temperature. High temperatures accelerated the diffusion rate, although the maximum water absorption rate was not affected. The tensile strength of FDM parts under dry, room temperature conditions, was approximately 26-56 per cent that of injection molded parts, depending on build orientation. Increased temperature and water absorption had a more significant effect on FDM parts than injection molded components. The tensile strength was decreased by 67-71 per cent in hot, wet environments compared with dry, room temperature conditions.

The water absorption behavior of FDM components was investigated. The quantitative effects of temperature and moisture on tensile strength, modulus and strain were also measured. These results will contribute to the design of FDM parts for use under various environmental conditions.

Rapid prototyping (RP) technologies provide the ability to fabricate initial prototypes from various model materials. Stratasys' fused deposition modeling (FDM) is a typical RP process that can fabricate prototypes out of ABS plastic. Translucent plastics are commonly used in packaging for mechanical and electrical components. Although various materials are used in RP, translucent RP parts are not readily available from most RP processes. In this paper, two post‐processing techniques were applied in order to increase the optical transmissivity of the parts made of ABSi. First, elevated temperature was applied resulting in increased transmissivity while dimensional shrinkage was observed. Second, resin infiltration and surface sanding provided up to 16 percent transmissivity without shrinkage. These post‐processes can be selectively applied to increase the transmissivity of ABSi parts. Thus, translucent FDM parts can be fabricated from the regular FDM process followed by the post‐processes developed in this study.

The purpose of this research, is to develop a nano composite deposition system (NCDS) to fabricate three dimensional functional nano composite parts.

The NCDS is a hybrid system in which material removal process by mechanical micro machining and/or the deposition process is combined.

Hybrid RP technology showed higher precision than those made by casting or deposition process. Tensile strength of the hydroxyapatite‐acrylic composite was about four times higher than that of resin‐only specimen while MWCNT composite did not show much improvement.

The paper illustrates new approaches for rapid prototyping techniques with various materials and high precision.

Rapid prototyping (RP) technology has been widely applied in biomedical research. The purpose of this paper is to describe how a scaffold composite drug delivery system (DDS) was fabricated using a nano composite deposition system (NCDS).

A biocompatible and biodegradable thermoplastic polymer (poly(DL‐lactide‐co‐glycolide acid)) was used as the matrix, and a mixture of anti‐cancer drug (5‐fluorouracil) and bio‐ceramic (hydroxyapatite – HA) was added to the polymer to form a bio‐composite material for the DDS. An in vitro drug release test showed that the release rate of the drug composite could be controlled by the amount of HA for 50 days.

Faster release was observed for the DDS with higher weight percent of HA. The relationship between release rate and the amount of HA showed a bi‐linear manner, and bi‐linear drug release models were developed based on the experimental results.

Cylindrical scaffolds were fabricated with polymer/drug/additive using an NCDS. A series of in vitro drug release tests was performed to evaluate the effectiveness of the additive, HA. Drug release models were developed based on the experimental results.

Rapid Prototyping (RP) technologies provide the ability to fabricate initial prototypes from various model materials. Stratasys Fused Deposition Modeling (FDM) is a typical RP process that can fabricate prototypes out of ABS plastic. To predict the mechanical behavior of FDM parts, it is critical to understand the material properties of the raw FDM process material, and the effect that FDM build parameters have on anisotropic material properties. This paper characterizes the properties of ABS parts fabricated by the FDM 1650. Using a Design of Experiment (DOE) approach, the process parameters of FDM, such as raster orientation, air gap, bead width, color, and model temperature were examined. Tensile strengths and compressive strengths of directionally fabricated specimens were measured and compared with injection molded FDM ABS P400 material. For the FDM parts made with a 0.003 inch overlap between roads, the typical tensile strength ranged between 65 and 72 percent of the strength of injection molded ABS P400. The compressive strength ranged from 80 to 90 percent of the injection molded FDM ABS. Several build rules for designing FDM parts were formulated based on experimental results.

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.

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.

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.

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.

Material extrusion (MEX) is a class of additive manufacturing (AM) process based on MEX principle. In the viewpoint of Industry 4.0 and sustainable manufacturing, AM technologies are gaining importance than conventional manufacturing route (subtractive manufacturing). Because of the ease of use and lesser operation skills, MEX had wide popularity in industry for product and prototype development. This study aims to analyze energy consumption of MEX-based AM process and its influencing factors.

A group of factors were identified pertaining to MEX-based AM process. In this viewpoint, this study presents the configuration of a structural model using interpretive structural modeling (ISM) to depict dominant factors in MEX-based AM process. A total of 18 influencing factors are identified and ranked using ISM methodology for MEX process. The Impact Matrix Cross-reference Multiplication Applied to a Classification analysis was done to categorize influencing factors into four groups for MEX-based AM process.

The derivation of structural model would enable AM practitioners to systematically analyze the factors and to derive key factors which enable comprehensive energy modeling and energy assessment studies. Also, it facilitates the development of energy efficient AM system.

The development of structural model for analysis of factors influencing energy consumption of MEX-based AM is the original contribution of the authors.

The objective is to carry out a thorough literature review and analysis of sustainable production system (SPS) and identify avenues for the future research.

A sample of 903 articles published from 1996 to 2019 in 40 journals were considered in the analysis. The classification and analysis of articles was done based on: time, focus area, methodology, research stream, authorship, industry sector, critical elements, implementation status, type of support and performance. Based on the analysis the future scope development needs are identified.

The findings are: increasing trend in empirical and conceptual research articles, need of sustainable principles implementation in the product development with combination of all the areas, need of more intercontinental research collaborations as the sustainable production is interconnected rather than isolated, need of sustainable constructs implementation as a coherent set instead of individual constructs, need of integration of sustainable philosophy with other manufacturing philosophies to achieve sustainable results and need of testing and validation of the support by researchers.

The results from the study will be useful to the researchers, academicians and professionals to trace the gaps, growth, pertinence and research developments in the field of SPS.

The purpose of this paper is to investigate the effect of a sealing protective treatment on the water absorption and mechanical properties of acrylonitrile butadiene styrene (ABS)-printed parts by fused deposition modelling. Protective products include aqueous acetone solutions with different concentrations, polyurethane wood sealer and aqueous acrylic-based varnish.

Open porosity was estimated by the absorption coefficient and the total amount of water retained, obtained from water absorption tests. Mechanical characterization was performed by compressive and tensile tests. Different specimens with different build directions and raster angles were used.

The treatments with acetone solutions were not effective in reducing the porosity of ABS parts, as the amount of acetone that reduces effectively the porosity will also affect the sample dimensional stability. The polyurethane treatment was found to reduce the absorption coefficient, but the maximum water content and the open porosity remain almost unchanged in comparison with the ones obtained for untreated specimens. The treatment with an acrylic-based varnish was found to preserve the dimensional stability of the specimens, to reduce the open porosity and to maintain the compression and tension properties of the specimens in different build directions and raster angles.

Surface modification for water tight applications of ABS 3D printing parts enables new designs where both sealing and the preservation of mechanical properties are important. As per the knowledge of the authors, the water absorption and the mechanical behaviour of ABS 3D printed parts, before and after treatment, were not previously investigated.