scholarly journals Design and Fabrication of Strong Parts from Poly (Lactic Acid) with a Desktop 3D Printer: A Case with Interrupted Shell

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 760 ◽  
Author(s):  
Kuznetsov ◽  
Tavitov ◽  
Urzhumtsev ◽  
Mikhalin ◽  
Solonin
Keyword(s):  
Poly Lactic Acid ◽  
Bottom Surface ◽  
Fabrication Technology ◽  
Shape Modification ◽  
Fused Filament Fabrication ◽  
Flat Surfaces ◽  
Sample Shape ◽  
Low Weight ◽  
Dense Shell ◽  
Typical Part

The ability to form closed cavities inside the part printed is an important feature of Fused Filament Fabrication technology. A typical part consists of a dense shell bearing the primary load, filled with low-density plastic scaffold (infill). Such a constitution of the part provides in most cases appropriate strength and low weight. However, if the printed part shape includes horizontal (orthogonal to printer’s Z axis) flat surfaces other than its top and bottom surface, then the shell of the part becomes interrupted, which may lead to drastic drop in the ability of the part to withstand loads. In the current study, a representative sample of a part with interrupted shell and testing apparatus is developed. Influence of shell and base thicknesses, as well as influence of the infill density on the part strength, are studied. Different approaches to the sample shape modification were applied and tested. The part shape optimization made with respect to peculiarities of Fused Filament Fabrication technology resulted in increment of the force, required to fracture the part from 483 to 1096 N and in decreased part mass from 36.9 to 30.2 g.

scholarly journals Strength Increasing Additive Manufacturing Fused Filament Fabrication Technology, Based on Spiral Toolpath Material Deposition

Machines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 57 ◽  
Author(s):  
Artem Avdeev ◽  
Andrey Shvets ◽  
Ilya Gushchin ◽  
Ivan Torubarov ◽  
Aleksey Drobotov ◽  
...  
Keyword(s):  
Deposition Method ◽  
Compression Tests ◽  
Fabrication Technology ◽  
Standard Samples ◽  
Fused Filament Fabrication ◽  
Material Deposition ◽  
Layer Deposition ◽  
Point Bend ◽  
Five Axis ◽  
Printing Method

The paper provides an overview of ways to increase the strength of polymer products obtained by fused filament fabrication (FFF) technology. An algorithm for calculating the spiral toolpaths for the material deposition using multi-axis printing is proposed. The design of the five-axis device for spiral-shaped deposition of the material is shown. The description of the proposed printing method is given. The results of comparative three-point bend and compression tests are presented. The standard samples obtained in the usual way by FFF technology, as well as samples with 2, 4, 6, 8 and 10 reinforcing layers obtained by spiral deposition of the material were investigated. The description of the tests is given, the dependences of the strength of the products on the number of reinforcing layers are obtained. Conclusions about the influence of the layer deposition method on the strength of the products are formulated.

scholarly journals Bio-composites for Fused Filament Fabrication. Effects of Maleic Anhydride Grafting on Poly(Lactic Acid) and Microcellulose

2021 ◽  
Author(s):  
Daniele Rigotti ◽  
Luca Fambri ◽  
Alessandro Pegoretti
Keyword(s):  
Lactic Acid ◽  
Maleic Anhydride ◽  
Nucleating Agent ◽  
Mechanical Analysis ◽  
Poly Lactic Acid ◽  
Crystalline Cellulose ◽  
Fused Filament Fabrication ◽  
Scanning Calorimetry ◽  
Electron Microscopy Analysis ◽  
Reactive Mixing

Abstract Composite filaments consisting of poly(lactic acid) (PLA) and micro crystalline cellulose (MCC) were successfully used for additive manufacturing (AM) by fused filament fabrication (FFF). PLA and MCC bio-composites were obtained by direct mixing in a melt compounder; maleic anhydride (MAH) was also grafted onto PLA in reactive mixing stage to evaluate its effect on the final properties of the printed material. Filaments with various concentrations of MCC (up to a maximum content of 10 wt%) were produced with a single screw extruder and used to feed a commercial desktop FFF printer. Upon grafting of PLA with MAH, a more coherent interfacial morphology between PLA and MCC was detected by electron microscopy analysis. The thermal degradation of the PLA was unaffected by the presence of MCC and MAH. According to differential scanning calorimetry and dynamic mechanical analysis results, micro-cellulose acted as nucleating agent for PLA. In fact, the crystallization peak shifted towards lowers temperature and a synergistic effect when MCC was added to PLA grafted with MAH was observed possibly due to the increase of the chain mobility. Micro cellulose led to an increase in the stiffness of the material in both filaments and 3D printed specimen, however, a different fracture behavior was observed due to the peculiar structure of printed samples.

scholarly journals Algorithm for the Conformal 3D Printing on Non-Planar Tessellated Surfaces: Applicability in Patterns and Lattices

2021 ◽  
Vol 11 (16) ◽  
pp. 7509
Author(s):  
Consuelo Rodriguez-Padilla ◽  
Enrique Cuan-Urquizo ◽  
Armando Roman-Flores ◽  
José L. Gordillo ◽  
Carlos Vázquez-Hurtado
Keyword(s):  
3D Printing ◽  
Target Surface ◽  
Layer By Layer ◽  
Hilbert Curve ◽  
Planar Surface ◽  
Fused Filament Fabrication ◽  
Flat Surfaces ◽  
Mathematical Algorithm ◽  
Projection Direction ◽  
Planar Surfaces

In contrast to the traditional 3D printing process, where material is deposited layer-by-layer on horizontal flat surfaces, conformal 3D printing enables users to create structures on non-planar surfaces for different and innovative applications. Translating a 2D pattern to any arbitrary non-planar surface, such as a tessellated one, is challenging because the available software for printing is limited to planar slicing. The present research outlines an easy-to-use mathematical algorithm to project a printing trajectory as a sequence of points through a vector-defined direction on any triangle-tessellated non-planar surface. The algorithm processes the ordered points of the 2D version of the printing trajectory, the tessellated STL files of the target surface, and the projection direction. It then generates the new trajectory lying on the target surface with the G-code instructions for the printer. As a proof of concept, several examples are presented, including a Hilbert curve and lattices printed on curved surfaces, using a conventional fused filament fabrication machine. The algorithm’s effectiveness is further demonstrated by translating a printing trajectory to an analytical surface. The surface is tessellated and fed to the algorithm as an input to compare the results, demonstrating that the error depends on the resolution of the tessellated surface rather than on the algorithm itself.

scholarly journals Surface treatment of incrementally produced components in FFF (Fused Filament Fabrication) technology

Polimery ◽  
2020 ◽  
Vol 65 (01) ◽  
pp. 51-59
Author(s):  
Maciej Mrowka ◽  
Machoczek Machoczek ◽  
Malgorzata Szymiczek ◽  
Przemyslaw Gagol ◽  
Slawomir Duda ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Fabrication Technology ◽  
Fused Filament Fabrication

scholarly journals Study on the 3D printability of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(lactic acid) blends with chain extender using fused filament fabrication

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Miguel A. Vigil Fuentes ◽  
Suman Thakur ◽  
Feng Wu ◽  
Manjusri Misra ◽  
Stefano Gregori ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
Fused Filament Fabrication

scholarly journals Evaluation of the Deterioration of the Mechanical Properties of Poly(lactic acid) Structures Fabricated by a Fused Filament Fabrication 3D Printer

Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Miho Suzuki ◽  
Asahi Yonezawa ◽  
Kohei Takeda ◽  
Akira Yamada
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Tensile Tests ◽  
Poly Lactic Acid ◽  
3D Printer ◽  
Fused Filament Fabrication ◽  
Tensile Direction ◽  
Test Pieces ◽  
3D Printers ◽  
Scan Pattern

A fused filament fabrication (FFF) 3D printer is a simple device capable of manufacturing three-dimensional structures in a series of easy steps. Commercial-level FFF 3D printers have spread rapidly in many fields in recent years. Poly(lactic acid) (PLA) is a biodegradable thermoplastic polymer used as a typical printing medium for FFF 3D printers. The FFF printer constructs an object with melted polymer extruded from a tiny scanning nozzle. The mechanical properties of FFF 3D structures printed with different scan patterns can therefore vary in accordance with the directions from which forces act upon them. The nozzle scan pattern also influences the deterioration of the mechanical properties of the structures in accordance with the degradation caused by the hydrolysis of PLA. In this study we conducted tensile tests to evaluate the strength characteristics of 3D printed test pieces formed from PLA using four different scan patterns: parallel, vertical, parallel-and-vertical, and cross-hatched at opposing diagonal angles to the tensile direction. We also formed test pieces by an injection molding method using the same material, for further comparison. We evaluated the deterioration of the test pieces after immersing them in saline for certain periods. After the test pieces formed by different nozzle scan patterns were immersed, they exhibited differences in the rates by which their maximum tensile stresses deteriorated and their masses increased through water uptake. The influences of the scan patterns could be classified into two types: the unidirectional scan pattern influence and bidirectional scan pattern influence. The data obtained in this research will be applied to structural design when the FFF 3D printer is employed for the fabrication of structures with PLA filament.

scholarly journals Composite Polyurethane-Polylactide (PUR/PLA) Flexible Filaments for 3D Fused Filament Fabrication (FFF) of Antibacterial Wound Dressings for Skin Regeneration

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6054
Author(s):  
Paweł Szarlej ◽  
Iga Carayon ◽  
Przemysław Gnatowski ◽  
Marta Glinka ◽  
Martyna Mroczyńska ◽  
...  
Keyword(s):  
Thermoplastic Polyurethane ◽  
Wound Dressings ◽  
Poly Lactic Acid ◽  
Processing Temperature ◽  
Antibacterial Effects ◽  
Fused Filament Fabrication ◽  
E Coli ◽  
Modification Method ◽  
Mechanical Tensile ◽  
Thermal Stability Of

This paper addresses the potential application of flexible thermoplastic polyurethane (TPU) and poly(lactic acid) (PLA) compositions as a material for the production of antibacterial wound dressings using the Fused Filament Fabrication (FFF) 3D printing method. On the market, there are medical-grade polyurethane filaments available, but few of them have properties required for the fabrication of wound dressings, such as flexibility and antibacterial effects. Thus, research aimed at the production, characterization and modification of filaments based on different TPU/PLA compositions was conducted. The combination of mechanical (tensile, hardness), structural (FTIR), microscopic (optical and SEM), degradation (2 M HCl, 5 M NaOH, and 0.1 M CoCl2 in 20% H2O2) and printability analysis allowed us to select the most promising composition for further antibacterial modification (COMP-7,5PLA). The thermal stability of the chosen antibiotic—amikacin—was tested using processing temperature and HPLC. Two routes were used for the antibacterial modification of the selected filament—post-processing modification (AMI-1) and modification during processing (AMI-2). The antibacterial activity and amikacin release profiles were studied. The postprocessing modification method turned out to be superior and suitable for wound dressing fabrication due to its proven antimicrobial activity against E. coli, P. fluorescens, S. aureus and S. epidermidis bacteria.

scholarly journals Screening of Additive Manufactured Scaffolds Designs for Triple Negative Breast Cancer 3D Cell Culture and Stem-Like Expansion

2018 ◽  
Vol 19 (10) ◽  
pp. 3148 ◽  
Author(s):  
Emma Polonio-Alcalá ◽  
Marc Rabionet ◽  
Antonio Guerra ◽  
Marc Yeste ◽  
Joaquim Ciurana ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Culture ◽  
Porous Scaffold ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Poly Lactic Acid ◽  
Tumor Initiating Cells ◽  
Fused Filament Fabrication ◽  
Open Issue

Breast cancer stem cells (BCSCs) are tumor-initiating cells responsible for metastasis and tumor reappearance, but their research is limited by the impossibility to cultivate them in a monolayer culture. Scaffolds are three-dimensional (3D) cell culture systems which avoid problems related with culturing BCSC. However, a standardized scaffold for enhancing a BCSC population is still an open issue. The main aim of this study is to establish a suitable poly (lactic acid) (PLA) scaffold which will produce BCSC enrichment, thus allowing them to be studied. Different 3D printing parameters were analyzed using Taguchi experimental design methods. Several PLA scaffold architectures were manufactured using a Fused Filament Fabrication (FFF) 3D printer. They were then evaluated by cell proliferation assay and the configurations with the highest growth rates were subjected to BCSC quantification by ALDH activity. The design SS1 (0.2 mm layer height, 70% infill density, Zigzag infill pattern, 45° infill direction, and 100% flow) obtained the highest proliferation rate and was capable of enhancing a ALDH+ cell population compared to 2D cell culture. In conclusion, the data obtained endorse the PLA porous scaffold as useful for culturing breast cancer cells in a microenvironment similar to in vivo and increasing the numbers of BCSCs.

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