Direct Simulation of Polymer Fused Deposition Modeling (FDM) — An Implementation of the Multi-Phase Viscoelastic Solver in OpenFOAM

2019 ◽  
Vol 17 (01) ◽  
pp. 1844002 ◽  
Author(s):  
Jun Liu ◽  
Kelly L. Anderson ◽  
N. Sridhar

Among the many mature and commercial AM technologies, fused deposition modeling (FDM) is a popular technology commonly used for modeling, prototyping, and production applications. In this process, a filament thermoplastic material is fed into a liquefier chamber, melted to a liquid state, and deposited layer by layer through a nozzle to form the 3D part. As a result, part can be designed in a more freedom way, and fabricated quickly and rapidly to a desired shape. However, different combination of processing parameters may influence the final part quality greatly, which hinders wider application of this technique. In order to investigate the influence of processing parameters on the final part quality, a viscoelastic multi-phase solver is developed, with capability for dynamic meshing and based on OpenFOAM. The solver directly simulates the deposition process of FDM. By implementing this solver for different boundary conditions and geometry, we can evaluate the printed part quality for varied processing conditions. More importantly, the tool enables efficient optimization of the processing conditions for specified material parameters and desired print quality.

2019 ◽  
Vol 25 (11) ◽  
pp. 1249-1264 ◽  
Author(s):  
Amoljit Singh Gill ◽  
Parneet Kaur Deol ◽  
Indu Pal Kaur

Background: Solid free forming (SFF) technique also called additive manufacturing process is immensely popular for biofabrication owing to its high accuracy, precision and reproducibility. Method: SFF techniques like stereolithography, selective laser sintering, fused deposition modeling, extrusion printing, and inkjet printing create three dimension (3D) structures by layer by layer processing of the material. To achieve desirable results, selection of the appropriate technique is an important aspect and it is based on the nature of biomaterial or bioink to be processed. Result & Conclusion: Alginate is a commonly employed bioink in biofabrication process, attributable to its nontoxic, biodegradable and biocompatible nature; low cost; and tendency to form hydrogel under mild conditions. Furthermore, control on its rheological properties like viscosity and shear thinning, makes this natural anionic polymer an appropriate candidate for many of the SFF techniques. It is endeavoured in the present review to highlight the status of alginate as bioink in various SFF techniques.


2021 ◽  
pp. 089270572110530
Author(s):  
Nagarjuna Maguluri ◽  
Gamini Suresh ◽  
K Venkata Rao

Fused deposition modeling (FDM) is a fast-expanding additive manufacturing technique for fabricating various polymer components in engineering and medical applications. The mechanical properties of components printed with the FDM method are influenced by several process parameters. In the current work, the influence of nozzle temperature, infill density, and printing speed on the tensile properties of specimens printed using polylactic acid (PLA) filament was investigated. With an objective to achieve better tensile properties including elastic modulus, tensile strength, and fracture strain; Taguchi L8 array has been used for framing experimental runs, and eight experiments were conducted. The results demonstrate that the nozzle temperature significantly influences the tensile properties of the FDM printed PLA products followed by infill density. The optimum processing parameters were determined for the FDM printed PLA material at a nozzle temperature of 220°C, infill density of 100%, and printing speed of 20 mm/s.


Author(s):  
Meng Zhang ◽  
Xiaoxu Song ◽  
Weston Grove ◽  
Emmett Hull ◽  
Z. J. Pei ◽  
...  

Additive manufacturing (AM) is a class of manufacturing processes where material is deposited in a layer-by-layer fashion to fabricate a three-dimensional part directly from a computer-aided design model. With a current market share of 44%, thermoplastic-based additive manufacturing such as fused deposition modeling (FDM) is a prevailing technology. A key challenge for AM parts (especially for parts made by FDM) in engineering applications is the weak inter-layer adhesion. The lack of bonding between filaments usually results in delamination and mechanical failure. To address this challenge, this study embedded carbon nanotubes into acrylonitrile butadiene styrene (ABS) thermoplastics via a filament extrusion process. The vigorous response of carbon nanotubes to microwave irradiation, leading to the release of a large amount of heat, is used to melt the ABS thermoplastic matrix adjacent to carbon nanotubes within a very short time period. This treatment is found to enhance the inter-layer adhesion without bulk heating to deform the 3D printed parts. Tensile and flexural tests were performed to evaluation the effects of microwave irradiation on mechanical properties of the specimens made by FDM. Scanning electron microscopic (SEM) images were taken to characterize the fracture surfaces of tensile test specimens. The actual carbon nanotube contents in the filaments were measured by conducting thermogravimetric analysis (TGA). The effects of microwave irradiation on the electrical resistivity of the filament were also reported.


2020 ◽  
Vol 1 (2) ◽  
pp. 81-91
Author(s):  
Frince Marbun ◽  
Richard A.M. Napitupulu

3D printing technology has great potential in today's manufacturing world, one of its uses is in making miniatures or prototypes of a product such as a piston. One of the most famous and inexpensive 3D printing (additive manufacturing) technologies is Fused Deposition Modeling (FDM), the principle FDM works by thermoplastic extrusion through a hot nozzle at melting temperature then the product is made layer by layer. The two most commonly used materials are ABS and PLA so it is very important to know the accuracy of product dimensions. FDM 3D Printing Technology is able to make duplicate products accurately using PLA material. FDM machines work by printing parts that have been designed by computer-aided design (CAD) and then exported in the form of STL or .stl files and uploaded to the slicer program to govern the printing press according to the design. Using Anet A8 brand 3D printing tools that are available to the public, Slicing of general CAD geometry files such as autocad and solidwork is the basis for making this object. This software is very important to facilitate the design process to be printed. Some examples of software that can be downloaded and used free of charge such as Repetier-Host and Cura. by changing the parameters in the slicer software is very influential in the 3D printing manufacturing process.


2014 ◽  
Vol 592-594 ◽  
pp. 400-404 ◽  
Author(s):  
Sandeep V. Raut ◽  
Vijaykumar S. Jatti ◽  
T.P. Singh

Fused deposition modeling (FDM) is one of the thirty techniques of rapid prototyping methods that produce prototypes from polymer materials (natural or with different grades). Acrylonitrile butadiene styrene (ABS) is one of the good material among all polymer materials. It is used in the layer by layer manufacturing of the prototype which is in the semi-molten plastic filament form and built up on the platform from bottom to top. In FDM, one of the critical factor is to select the built up orientation of the model since it affects the different areas of the model like main material, support material, built up time, total cost per part and most important the mechanical properties of the part. In view of this, objective of the present study was to investigate the effect of the built-up orientation on the mechanical properties and total cost of the FDM parts. Experiments were carried out on STRATASYS FDM type rapid prototyping machine coupled with CATALYST software and ABS as main material. Tensile and Impact specimens were prepared as per the ASTM standard with different built-up orientation and in three geometrical axes. It can be concluded from the experimental analysis that built orientation has significant affect on the tensile, impact and total cost of the FDM parts. These conclusions will help the design engineers to decide on proper build orientation, so that FDM parts can be fabricated with good mechanical properties at minimum manufacturing cost.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2980
Author(s):  
Andrea Costanzo ◽  
Umberto Croce ◽  
Roberto Spotorno ◽  
Seif Eddine Fenni ◽  
Dario Cavallo

International newspapers and experts have called 3D printing the industrial revolution of this century. Among all its available variants, the fused deposition modeling (FDM) technique is of greater interest since its application is possible using simple desktop printers. FDM is a complex process, characterized by a large number of parameters that influence the quality and final properties of the product. In particular, in the case of semicrystalline polymers, which afford better mechanical properties than amorphous ones, it is necessary to understand the crystallization kinetics as the processing conditions vary, in order to be able to develop models that allow having a better control over the process and consequently on the final properties of the material. In this work it was proposed to study the crystallization kinetics of two different polyamides used for FDM 3D printing and to link it to the microstructure and properties obtained during FDM. The kinetics are studied both in isothermal and fast cooling conditions, thanks to a home-built device which allows mimicking the quenching experienced during filament deposition. The temperature history of a single filament is then determined by mean of a micro-thermocouple and the final crystallinity of the sample printed in a variety of conditions is assessed by differential scanning calorimetry. It is found that the applied processing conditions always allowed for the achievement of the maximum crystallinity, although in one condition the polyamide mesomorphic phase possibly develops. Despite the degree of crystallinity is not a strong function of printing variables, the weld strength of adjacent layers shows remarkable variations. In particular, a decrease of its value with printing speed is observed, linked to the probable development of molecular anisotropy under the more extreme printing conditions.


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