What Limits Interlayer Strength in FDM — Analysed Solutions

ABSTRACTThe present study aims to optimise Fused Deposition Modelling (FDM) printing parameters to enhance the tensile properties of 3D printed specimens adhering to the ASTM D638 standard. The mechanical integrity of printed components is crucial for their successful application in load-bearing scenarios. Through a systematic exploration of key FDM printing parameters, such as layer height, infill density, print speed, and extrusion temperature, their impact on the tensile strength, yield strength, and elongation at break of the ASTM D638 specimens have been explored. The Taguchi design of experiments methodology has been utilised to efficiently traverse the parameter space and identify the optimal combination of printing settings. Tensile tests were conducted on the 3D printed specimens, produced with different parameter configurations, to evaluate their mechanical performance. The results have been analysed to reveal the significant effects of each parameter on the tensile properties and the interactions between multiple parameters. The optimised parameters identified in this rese... Read More

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Photocurable composite materials for 3D printing of construction components that meet industry requirements for material properties such as elastic modulus, strength, and adhesion. The materials are formulated with a balance of acrylate monomers, oligomers, photoinitiators, chopped fibers, flame retardants, processing aids, additives, and fillers, and can be extruded at high speeds while maintaining stability and curing properties. The materials exhibit improved print resolution, reduced warping, and enhanced durability compared to conventional 3D printing materials, enabling the creation of complex structural elements and building components with high precision and quality.

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The economic and technical advantages of 3D printing make it a possible replacement for conventional production processes, especially for complex products and small batches. It is important to point out that technological parameters of 3D printing, such as layer thickness, print density, print speed, melting temperature, and table temperature, have a significant impact on the mechanical properties and productivity of parts obtained by 3D printing. Because of all the above, there is a great interest in research in this area. The paper presents the results of testing the tensile strength of the ABS polymer, in which two parameters were varied: the thickness of the print layer (0.39 mm) and the print density of 60100% in steps of 10% each. The samples were obtained on a ZORTRAX M200+ 3D printer using fused filament deposition (FDM) technology. The selected thickness of the printing layer is relatively large, and with it, parts with lower accuracy and high surface roughness are obtained, although at the same time high productivity is achieved, which can satisfy some requirements. The ob... Read More

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A composite filament for additive manufacturing comprising a glass fiber core, a carbon fiber core, a polypropylene matrix, and a thermoplastic sizing coating. The glass fiber core comprises 10-50% by weight of the filament, the carbon fiber core comprises 5-30% by weight, and the polypropylene matrix comprises 50-80% by weight. The filament exhibits improved mechanical properties compared to conventional polypropylene filaments.

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Additive technologies, also known as 3D printing technologies, are becoming more and more widely used in industrial conditions for the production of finished elements, especially for the production of parts that would be very difficult or even impossible to produce using existing technologies. Technologically difficult elements include parts with a thin-walled spatial structure. This work presents the research results and describes the problems of producing specimens of thin-walled profiles filled with an appropriate spatial structure, also thin-walled, using 3D printing technology. The results of a three-point bending test of specimens of various lengths and specimens filled with chemically cured resin are presented. Print simulations were discussed, paying attention to problems related to applying lines and layers in FDM/FFF technology and the impact of print technological parameters on the properties of the manufactured specimens.

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Apparatus and method for optimizing reinforcement in 3D printing to improve mechanical properties of printed parts. The system determines the most effective locations for reinforcement within a 3D model by iteratively partitioning the model, simulating reinforcement in each partition, and selecting the partitions with the greatest improvement. The system generates production data based on the optimized reinforcement strategy.

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An extrusion head for additive manufacturing, particularly for fused filament fabrication, comprising a material feed unit, a separating device with a blade element, and an offset unit with liquefier units. The blade element is designed to cut the extrusion material cleanly and reliably, with a cutting surface upper side and a cutting surface lower side arranged at an acute angle. The extrusion head also includes a cooling device integrated into the material feed unit and offset unit, which cools the extrusion material after cutting. The extrusion head is designed for high-temperature applications, such as processing high-performance plastics like PEEK, and can be used to manufacture complex products with multiple materials.

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Abstract In view of the quality defects of 3D printed workpieces and insufficient mechanical properties of parts, the optimization of mechanical performance parameters of workpieces based on 3D printing was studied. Taking the FDM molding technology and 3D printing technology of PLA material as the research object, better mechanical properties of the device can be obtained by optimizing the printing temperature, filling rate, and other parameters of the workpiece spline. Experimental results show that for printing temperature, an increase in temperature will increase the ultimate strength of the material, but will also decrease the elastic modulus, so 195C was finally selected as the processing temperature. For the filling rate and the number of contour turns, the larger the value is, the better the mechanical properties of the processed workpiece will be. The ultimate strength and elastic modulus will increase, but the elongation at break will decrease. Other parameters such as layer thickness, filling angle, etc. have less impact on mechanical properties.

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Abstract Along with emerging engineering requirements in multiple fields, how to fully realize the three-dimensional (3D) design has become a critical manufacturing challenge. To tackle this challenge, there is continuous research in recent years for development of additive manufacturing processes, that is 3D printing techniques. Fused deposition modeling (FDM) is one among the most extensively studied 3D printing techniques that generate 3D models, prototypes and especially end products from polymers. FDM printer uses a continuous filament of thermoplastic polymer or its nanocomposite, which is fed to the heated printer extruder head and then deposited onto the growing work. This technology offers multiple advantages over existing techniques, including fabricating complex designs, multi-material printing, rapid prototyping, high spatial resolution, on-site and on-demand production, as well as efficient material utilization with little or no waste. For example, according to existing literatures related to the FDM technique, various polymers, and their composites, such as ABS, PLA, PE... Read More

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A method for manufacturing a three-dimensional fabricated object using additive manufacturing technology that improves manufacturing efficiency and produces high-quality objects. The method involves detecting in-situ data on physical or chemical characteristics of the object during fabrication, enabling real-time monitoring and control of the manufacturing process. The detection can be performed from various angles, including the upper surface, side surface, or between layers, and can involve techniques such as X-ray interference imaging, chromaticity measurement, dielectric constant analysis, or electromagnetic wave reflection intensity measurement. The detected data is used to optimize the manufacturing conditions and prevent defects, allowing for the production of high-quality objects with reduced waste and improved manufacturing efficiency.

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3D printing of fused deposition modeling (FDM) technique is one of the most widely used nowadays. One disadvantage of this method is that the printed product has low strength to the fact that the product is developed layer by layer. This research aims to combine PLA, PP, and ABS and determine which results in the highest flexural strength. A Cartesian 3D printer printed specimens according to the ASTM D790 standard. Then, specimens were tested using a universal testing machine. An optic microscope was used to observe the fracture area. The results showed that the combination of PLA-ABS increased flexural strength up to 33.12 MPa. While PLA-PP, PLA-PP-ABS and PP-ABS resulted in a flexural strength of less than half PLA-ABS one, they were 14.90, 14.59 and 12.10 MPa, respectively. All alloy combinations except PLA-ABS were delaminated during the bending test. Delamination causes a decrease in the flexural strength of a specimen.

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Additive manufacturing is becoming a global phenomenon due to its versatile properties and numerous benefits, which is not possible by conventional machining processes. Fused deposition modeling (FDM) shows a huge potential of shift from rapid prototyping toward the rapid manufacturing. Nowadays, the strength of the FDM-printed parts is very important to consider along with all the printing parameters, which affect the strength of these parts. This study includes the investigation of printing parameters (infill density, layer thickness, and shell count) on the strength of FDM-printed parts of acrylonitrile butadiene styrene (ABS) and carbon fiber-reinforced ABS (ABS-CF). These printing parameters directly affect the quality as well as the strength of the 3D-printed parts through FDM. Tensile tests were performed on the universal testing machine on both types of printed parts. The optimized parameters for the 3D-printed samples of the pristine ABS are found to be 0.1045 mm of layer thickness, 57.72% of infill density, and 7.63 numbers of shell count, while the optimum parameters obtai... Read More

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In the current era of additive manufacturing, Fused Deposition Modelling (FDM) method of printing is being studied extensively to print a concept model. Therefore, the dimensional accuracy and the mechanical properties of the FDM 3D printed part are very important. In this study, the tensile specimens are prepared according to ASTM D638 Type I. Dimensions of the specimen is measured in the x -direction (length), y -direction (width), and z -direction (height) and is compared against the standard measurement for accuracy. Tensile stress, strain at break and Youngs modulus were also investigated. Overall, the dimension accuracy achieved is more than 98%. The highest accuracy is obtained by using 0.2mm layer thickness and 0.2mm initial layer thickness. The tensile stress, Youngs modulus and strain at break are found to decrease when the layer thickness is increased. This is due having more layer with lesser and smaller voids which increases the strength and stiffness. Increasing initial layer thickness, however, has a low influence on the tensile stress but can greatly affect the Youn... Read More

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The top and bottom shells of fused deposition 3D-printed PLA models are exposed to the highest stresses. To improve the bending performance of PLA models under three-point bending conditions, the models were strengthened by a selective enhancement method. Several sets of PLA models were fabricated using FDM technology, and three-point bending experiments were conducted to compare the bending strength of PLA models when the layer height, top/bottom shell thickness, and extrusion rate were varied. The bending strength of the PLA models increased as the layer height of the top/bottom shell decreased, the thickness increased, and the extrusion rate increased. The average bending strength of the PLA models after selective enhancement was 84.4 MPa, and the average bending modulus of elasticity was 0.816 GPa, which were higher than the average bending strength of 68.6 MPa and the average bending modulus of elasticity of 0.736 GPa of the conventional groups. These results indicated that the selective enhancement method improved the bending performance of 3D-printed PLA models, and it also pr... Read More

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A method and apparatus for enhancing the heating and melting of a polymer being extruded, such as in additive manufacturing, by introducing shear within a nozzle structure. The nozzle structure is rotated to generate heat through viscous friction, augmenting heat provided by a heating element. The rotation speed is controlled based on backpressure sensed within the nozzle, allowing for dynamic adjustment of the frictional heating.

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Controlling toolpaths in additive manufacturing to improve the mechanical properties of 3D printed objects. The technique involves specifying desired manufacturing paths along which to build the object before slicing and generating toolpaths. These paths can follow geometries of the 3D model, approximate curves, or be user-selected sequences. The toolpaths are then sorted and oriented based on the desired paths. This allows controlling the toolpath of the additive manufacturing apparatus to manufacture the object using the desired paths. This can result in the printed object more closely conforming to the intended design and taking into account unique properties of the build materials.

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For small-scale and single production, FDM printing is considered as a technology competing with the well-known method injection molding. However, due to the specifics of the printing process associated with layer-by-layer formation printed parts are significantly inferior to parts obtained by injection molding in terms of strength and surface quality, minimizing the advantages of 3D-printing. The methods that make it possible to improve the physical and mechanical characteristics of a printed parts include bulk treatment methods based on thermal effects on the whole part. The aim of this paper is to compare the technologies of bulk thermal post-processing in terms of the effect on the physical and mechanical properties of FDM-printed samples. Three methods of bulk thermal post-treatment are considered: annealing in a dispersed environment, annealing in a dispersed environment with pressure, annealing in a vacuum bag. The properties and deformations of ABS plastic samples printed by the FDM-method are investigated. The research results showed that all the considered technologies of... Read More

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FDM (Fused Deposition Modelling) is the most popular 3D printing technology worldwide due to its simplicity and low costs. One of the key points of FDM is the need for supporting material to realize the overhanging features. In general, however, both in the case of printing supports with the same material as the part and in the case of printing with soluble supports, there is a high waste of material and a significant increase in the printing time to get the finished part. One of the fundamental parameters for generating supports within the slicer software is the so-called "support overhang angle", which consists of the maximum achievable angle beyond which the slicer generates supports. The other key parameter in FDM printing is the "layer height", which directly determines both the quality of the final part, its strength, and the printing time itself. This paper will therefore attempt to investigate the relationship present between "layer height" and "support overhang angle", bringing some examples of how with proper layer height one can significantly reduce support generation, was... Read More

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This study investigates the comparison of Young's Modulus value from tensile and three-point bendingBending methods for two build orientations (0 and 90 build angles) of ABS material. Twenty specimens were printed using FDM 3D printer with parameters of 200 m layer thickness, solid print strength and cross print pattern for each method. The tensile experiment was following ASTM D638, and the three-point bendingBending experiment was also following ASTM D790 to find the Young's Modulus value. The results obtained from both experiments were compared to each other as well as to theoretical and standard values. The results show that highest Young's modulus value was from the three-point bendingBending method with 0 build angle orientation. This is due to the different ways of loading are used to test mechanical properties and orientation of 3D printing build angle.

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This paper represents a literature review on FDM-3D printing technique in additive manufacturing, Several variables affect the end product's features in fused deposition modelling (FDM), and these variables must be considered while selecting process settings. The study illustrates the effects of various materials and process parameters on final product mechanical properties. It concludes that too many polymer materials can be used as a filament in FDM printing techniques. And although FDM is the most common printing process but characterization of its parameters and their signification need to be covered with more studying, and analysis experimentally and statistically (DOE techniques) in order to control the final product quality.

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