Commercial Fused Deposition Modeling Research Articles

Investigation of layer thickness effect on the performance of low-cost and commercial fused deposition modelling printers

Rapid prototyping is one of the common technologies in additive manufacturing. The layer-by-layer mechanism of rapid prototyping allows this technology to rapidly create and print complex geometries from three-dimensional models of any objects. Fused deposition modelling is one of the common processes in rapid prototyping, and its maturity has given birth to full-scale, commercial fused deposition modelling machines, as well as low-cost, fused deposition modelling machines, which are also referred to as three-dimensional printers. This work compares the effect of layer thickness during printing on the tensile and compressive strengths of samples, for commercial and low-cost fused deposition modelling machines. Standard samples based on ASTM D638 and ASTM D695 were prepared for the tensile and compressive tests, with layer thicknesses of 0·3302 and 0·2540 mm, using acrylonitrile butadiene styrene as the printing material. From the tensile tests, specimens prepared using low-cost fused deposition modelling managed to obtain only 41·87 and 54·69% of the ultimate tensile strength of specimens prepared using commercial fused deposition modelling, for layer thicknesses of 0·3302 and 0·2540 mm. Meanwhile, from the compressive tests, specimens prepared using low-cost fused deposition modelling managed to obtain only 75·55 and 73·79% of the ultimate compressive strength of specimens prepared using commercial fused deposition modelling, for the same layer thicknesses. Ultimately, low-cost fused deposition modelling still needs more improvement in order to give better results, compared to the currently available commercial-grade fused deposition modelling printers.

Rapid tooling using 3D printing system for manufacturing of customized tracheal stent

Purpose – This work aims to present the design of a new continuous tool-path strategy for open-source low-cost fused deposition modeling (FDM) machines, such as Fab@Home or RepRap; and the development of an innovative integrated tool to design and fabricate customized tracheal stents with any FDM machine and six patient parameters. Both contributions were validated and implemented by obtaining a customized medical-grade silicone tracheal stent. Design/methodology/approach – For the design of the new deposition strategy, a Python programming language was used. The new tool-path strategy was proposed as a continuous path to avoid drops and gaps and to improve the accuracy of the final model. Meanwhile, patient parameters were obtained by medical doctors and introduced into the innovative integrated system. On the one hand, one mold generated automatically, and viewed with Matlab® software, was fabricated with a Fab@Home machine, optimized with the continuous tool-path strategy. On the other hand, the same generated mold was viewed in SolidWorks/Excel software and was fabricated using a commercial FDM machine. Finally, the mold was filled with medical grade silicone, and a silicone tracheal stent was obtained. Findings – Path planning for extrusion technologies is still a major concern, especially for open-source FDM machines. The results obtained in this work show the benefits of applying the newly developed continuous tool-path strategy to optimize the performance and efficiency of these machines. In addition, the proposed innovative integrated system allows the fabrication of customized tracheal stents rapidly and affordably. Practical implications – The possibility of obtaining customized tracheal stents is a worthy challenge. Medical doctors could play a more active role and interact during the design process, helping to obtain more suitable stents. The method proposed herein would provide the opportunity to obtain real values from the trachea of a patient in the operating room and quickly fabricate a customized stent that would fit the patient's trachea perfectly. Originality/value – The results obtained in this work are relevant and have future applications in both the medical and the additive manufacturing fields. The optimized tool-path strategy can help to improve and enhance the use of low-cost FDM machines. Moreover, the innovative automatic design approach to fabricate tracheal stents may open new market opportunities in the medical device field.

Curved Layer Fused Deposition Modeling with Varying Raster Orientations

Fused Deposition Modeling (FDM) is one of the relatively more successful Additive Manufacturing (AM) techniques and is more widely applied in the recent past. Apart from finding alternative materials targeting specific industrial application, FDM is also researched for medical applications with biopolymers and composites. While commercial FDM uses flat layer slicing of CAD models as the basic approach for the process, alternative slicing and deposition schemes such as curved layer FDM evolved specifically for thin shell-like parts. Curved layer FDM was shown to be effective in imparting better surface quality as well as mechanical strength of parts produced. Past research also established that raster angle plays a significant role on the mechanical characteristics of FDM parts. The current research attempts to bring the two approaches together and establish the effects of varying raster angles on the performance of parts produced by curved layer FDM. Mathematical algorithms used for curved layer slicing are reviewed and experimental results based on curved layer samples printed with varying raster angels are discussed.

Development of Scaffold Building Units and Assembly for Tissue Engineering Using Fused Deposition Modelling

In tissue engineering (TE), a porous scaffold structure of biodegradable material is required as a template to guide the proliferation, growth and development of cells appropriately in three dimensions. The scaffold must meet design requirements of appropriate porosity, pore size and interconnected structure to allow cell proliferation and adhesion. This paper presents a methodology for design and manufacture of TE scaffolds with varying porosity by employing open structure building units and Fused Deposition Modeling (FDM) rapid prototyping technique. A computer modeling approach for constructing and assembly of three-dimensional unit cell structure is presented to provide a solution of scaffolds design that can potentially meet the diverse requirements of TE applications. A parametric set of open polyhedral unit cells is used to assist the user in designing the required micro-architecture of the scaffold with required porosity and pore size and then the Boolean operation is used to create the scaffold of a given CAD model from the designed microstructure. The procedure is verified by fabrication of physical scaffolds using the commercial FDM system.

Fused deposition modelling using direct extrusion

In the present work, a process based on the principle of polymer extrusion is developed: the extruder deposition process (EDP). This system uses a screw extruder to deposit the material on a computer-controlled positioning system to build components. Experiments (Box–Behnken technique is used for experimental design) are carried out to study the influence of three process variables: nozzle temperature, chamber temperature and road gap on bond strength (inter-road and interlayer) and surface finish. Surface roughness and ultimate tensile strength values are measured for test specimens. Analysis of variance (ANOVA) is used to determine the significance of process variables. It is concluded that the developed EDP eliminates many of the shortcomings of the systems developed based on the principles of extrusion and produces components having higher bond strength than that achieved in commercial fused deposition modelling (FDM) systems.

New developments in fused deposition modeling of ceramics

PurposeTo shift from rapid prototyping (RP) to agile fabrication by broadening the material selection, e.g. using ceramics, hence improving the properties (e.g. mechanical properties) of fused deposition modeling (FDM) products.Design/methodology/approachThis paper presents the development of a novel extrusion system, based on the FDM technology. The new set‐up, consisting of a mini‐extruder mounted on a high‐precision positioning system, is fed with bulk material in granulated form, instead that with the more common filament.FindingsPrevious research showed that the applications of new materials with specific characteristics in a commercial FDM system are limited by the use of intermediate precursors, i.e. a filament. The new design described in this paper overcomes the problem thanks to the new feeding system.Research limitations/implicationsThe work presented in this paper is only the starting point for further development. The new system design was tested and encouraging improvements of the final product were achieved. However, several parameters, e.g. size of the feeding granules, still need to be optimized.Practical implicationsThis configuration opens up opportunities for the use of wider range of materials, making the FDM to become a viable alternative manufacturing process for specialty products.Originality/valueThe mini‐extruder deposition system developed in this study exploits the advantages of the RP technologies: ability to shorten the product design and development time; suitability for automation; and ability to build many geometrically complex shapes. Hence, applying the described technology, it will be possible to manufacture customer‐driven product with important cost and time (from design to final product) savings.

Structural quality of parts processed by fused deposition

Commercial solid freeform fabrication (SFF) systems, which have been developed for fabrication of wax and polymer parts for form and fit and secondary applications, such as moulds for casting, etc., require further improvements for use in direct processing of structural ceramic and metal parts. Defects, both surface as well as internal, are undesirable in SFF processed ceramic and metal parts for structural and functional applications. Process improvements are needed before any SFF technique can successfully be commercialized for structural ceramic and metal processing. Describes process improvements made in new SFF techniques, called fused deposition of ceramics (FDC) and metals (FDMet), for fabrication of structural and functional ceramic and metal parts. They are based on an existing SFF technique, fused deposition modelling (FDM) and use commercial FDM systems. The current state of SFF technology and commercial FDM systems results in parts with several surface and internal defects which, if not eliminated, severely limit the structural properties of ceramic and metal parts thus produced. Describes systematically, in detail, the nature of these defects and their origins. Discusses several novel strategies for elimination of most of these defects. Shows how some of these strategies have successfully been implemented to result in ceramic parts with structural properties comparable to those obtained in conventionally processed ceramics.