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Conference Presentations by Bahri Barış Vatandaş
Fused deposition modeling (FDM), which is one of the additive manufacturing methods, is currently... more Fused deposition modeling (FDM), which is one of the additive manufacturing methods, is currently widely
used. Although it is possible to produce various parts with the geometric freedom provided by the FDM method,
its strength remains limited due to inherited problems such as high porosity, low interlayer strength, etc. Various methods are used in the literature, such as applying vibration in the print head and printing under force to reduce
porosity. In order to remove the porous areas caused by the moisture remaining in the filament and the printing
method, printing methods under a vacuum are also tried. However, only partial improvements have been
achieved due to the fact that the method of printing under a vacuum has been tried at relatively low vacuum
values. Within the scope of this study, a vacuum cabinet has been designed that will enable reaching very low
pressure (high vacuum) values , and an FDM printer can be placed in it. In the design of the vacuum cabinet, first
of all, attention was paid to the ability of the cabinet to withstand high vacuum values mechanically and to have a
volume in which the three-dimensional printer and its attachments could fit. In addition to these, considering that
the heat transfer will decrease considerably with convection under vacuum, it has been realized that the circuit
elements that will be affected by the heat are taken out of the cabinet. Stepper motors, which cannot be taken out
but can still be badly affected by heat, are cooled by open circuit water cooling. Similarly, liquid cooling is used
in the print head in order not to cause problems such as the expansion of the filament in the print head and thus to
cause clogging.
Nowadays, additive manufacturing is being used in various industries such as automotive, aviation... more Nowadays, additive manufacturing is being used in various industries such as automotive, aviation and space, medical applications, etc. Although additive manufacturing methods offer more freedom in design and manufacturing, they usually have low production speed and mechanical properties. Continuous carbon fiber reinforced thermoplastic (CFRTP) composites are one of the investigated methods in the literature to increase the mechanical properties of the additively manufactured parts. This study utilized a production line based upon the melt impregnation method to obtain continuous carbon fiber reinforced thermoplastic filaments using polyamide and continuous carbon fibers. In the printing process, an infrared heat source was utilized to further increase the mechanical properties by improving the interlaminar bonding. The mechanical properties of the printed parts were measured using three-point bending tests. A significant increase was observed in flexural modulus of elasticity and flexural strength with infrared heaters at low printing speeds. A maximum value of 418.99 MPa flexural strength and 52.15 GPa flexural modulus was achieved.
The continuous carbon fiber-reinforced thermoplastic (CFRTP) printing process has been used more ... more The continuous carbon fiber-reinforced thermoplastic (CFRTP) printing process has been used more widely in recent years and is an alternative production method, especially in sectors such as aviation, automotive, prototyping, medical applications, and aerospace. Although additive manufacturing reduces the design limitations and makes it easier to manufacture, it is one of the disadvantages of this method: it has relatively low thermal and mechanical properties compared to standard production techniques. Therefore, in this study, printing parameters such as nozzle temperature, printing speed, layer thickness, and heated bed temperatures were investigated for fused deposition modeling. In this regard, a polymer impregnation line based on the melt impregnation technique was utilized to obtain CFRTP filaments using polylactic acid (PLA) and 3K carbon fiber. Obtained filaments were then used to print three-point bending test samples in order to investigate mechanical performance. The test result showed flexural strength between 108 and 224 MPa and flexural modulus between 9.67 and 17.69 GPa with a 23% fiber ratio. Results from this study proclaim that CFRTPs manufactured with this method and optimized printing parameters have great potential for implementing future production methods.
Continuous fiber-reinforced thermoplastic composite (CFRTP) manufacturing with fused deposition m... more Continuous fiber-reinforced thermoplastic composite (CFRTP) manufacturing with fused deposition modeling (FDM) platform is an up-and-coming method to produce parts with high mechanical properties. Mechanical performance of CFRTP is still limited by interlayer bonding performance and fiber-matrix interface. In this study, CFRTP samples were produced using carbon fiber and PEEK thermoplastic, and it was aimed to improve the mechanical properties by developing a more suitable fiber-polymer interface. The sizing process has been applied to the fiber in order to ensure that the applied force is transferred to the fibers more efficiently, with the polymer holding onto the fiber surface more firmly. In the sizing process, a production method was applied in the form of cleaning the fiber surfaces, activation with Meldrum acid, and completing the sizing by using PEKK powder. CFRTP filament was produced using the fibers coated with the sizing agent in the melt impregnation method. Three-point bending test specimens were produced by using the obtained filaments on an FDM-based printer. When the results were examined, it was observed that the maximum stresses obtained from the threepoint bending test were 9.72%, and the elasticity modulus improved by 56.76%. An average of 974.75 MPa flexural strength and 166.97 GPa modulus of elasticity were obtained in sizing applied samples. The stages of the sizing process and its effects on the fiber were examined using SEM images.
Papers by Bahri Barış Vatandaş
3D printing and additive manufacturing, Feb 15, 2023
Composites Part A: Applied Science and Manufacturing
European Journal of Science and Technology
Nowadays, additive manufacturing is being used in various industries such as automotive, aviation... more Nowadays, additive manufacturing is being used in various industries such as automotive, aviation and space, medical applications, etc. Although additive manufacturing methods offer more freedom in design and manufacturing, they usually have low production speed and mechanical properties. Continuous carbon fiber reinforced thermoplastic (CFRTP) composites are one of the investigated methods in the literature to increase the mechanical properties of the additively manufactured parts. This study utilized a production line based upon the melt impregnation method to obtain continuous carbon fiber reinforced thermoplastic filaments using polyamide and continuous carbon fibers. In the printing process, an infrared heat source was utilized to further increase the mechanical properties by improving the interlaminar bonding. The mechanical properties of the printed parts were measured using three-point bending tests. A significant increase was observed in flexural modulus of elasticity and flexural strength with infrared heaters at low printing speeds. A maximum value of 418.99 MPa flexural strength and 52.15 GPa flexural modulus was achieved.
Open Journal of Nano, Jun 30, 2022
This study investigated the effects of different heat treatments on continuous fiberreinforced th... more This study investigated the effects of different heat treatments on continuous fiberreinforced thermoplastic (CFRTP) 's. CFRTP composite is produced using fused deposition modeling (FDM), which is one of the additive manufacturing methods. Polylactic acid (PLA) was used as a matrix, and carbon fibers (3K) were utilized as reinforcement material. First, CFRTP filament was produced on a specially designed melt impregnation line. Afterward, test samples were manufactured via a conventional 3D printer. Then, heat treatments (re-melting in salt, microwave oven, oven) were applied to the produced samples, and the effects of these processes on mechanical properties were investigated. Three-point bending tests were used to investigate the mechanical properties of the test samples. As a result of the heat treatments applied to the CFRTP specimens, flexural stresses between 200 and 220 MPa was achieved. The highest bending stress was obtained by re-melting in salt. As a result of the heat treatments, the stress values are similar, but the re-melting in salt application exhibited a more rigid behavior.
This study investigated the effects of different heat treatments on continuous fiberreinforced th... more This study investigated the effects of different heat treatments on continuous fiberreinforced thermoplastic (CFRTP) 's. CFRTP composite is produced using fused deposition modeling (FDM), which is one of the additive manufacturing methods. Polylactic acid (PLA) was used as a matrix, and carbon fibers (3K) were utilized as reinforcement material. First, CFRTP filament was produced on a specially designed melt impregnation line. Afterward, test samples were manufactured via a conventional 3D printer. Then, heat treatments (re-melting in salt, microwave oven, oven) were applied to the produced samples, and the effects of these processes on mechanical properties were investigated. Three-point bending tests were used to investigate the mechanical properties of the test samples. As a result of the heat treatments applied to the CFRTP specimens, flexural stresses between 200 and 220 MPa was achieved. The highest bending stress was obtained by re-melting in salt. As a result of the heat treatments, the stress values are similar, but the re-melting in salt application exhibited a more rigid behavior.
Fused deposition modeling (FDM), which is one of the additive manufacturing methods, is currently... more Fused deposition modeling (FDM), which is one of the additive manufacturing methods, is currently widely
used. Although it is possible to produce various parts with the geometric freedom provided by the FDM method,
its strength remains limited due to inherited problems such as high porosity, low interlayer strength, etc. Various methods are used in the literature, such as applying vibration in the print head and printing under force to reduce
porosity. In order to remove the porous areas caused by the moisture remaining in the filament and the printing
method, printing methods under a vacuum are also tried. However, only partial improvements have been
achieved due to the fact that the method of printing under a vacuum has been tried at relatively low vacuum
values. Within the scope of this study, a vacuum cabinet has been designed that will enable reaching very low
pressure (high vacuum) values , and an FDM printer can be placed in it. In the design of the vacuum cabinet, first
of all, attention was paid to the ability of the cabinet to withstand high vacuum values mechanically and to have a
volume in which the three-dimensional printer and its attachments could fit. In addition to these, considering that
the heat transfer will decrease considerably with convection under vacuum, it has been realized that the circuit
elements that will be affected by the heat are taken out of the cabinet. Stepper motors, which cannot be taken out
but can still be badly affected by heat, are cooled by open circuit water cooling. Similarly, liquid cooling is used
in the print head in order not to cause problems such as the expansion of the filament in the print head and thus to
cause clogging.
Nowadays, additive manufacturing is being used in various industries such as automotive, aviation... more Nowadays, additive manufacturing is being used in various industries such as automotive, aviation and space, medical applications, etc. Although additive manufacturing methods offer more freedom in design and manufacturing, they usually have low production speed and mechanical properties. Continuous carbon fiber reinforced thermoplastic (CFRTP) composites are one of the investigated methods in the literature to increase the mechanical properties of the additively manufactured parts. This study utilized a production line based upon the melt impregnation method to obtain continuous carbon fiber reinforced thermoplastic filaments using polyamide and continuous carbon fibers. In the printing process, an infrared heat source was utilized to further increase the mechanical properties by improving the interlaminar bonding. The mechanical properties of the printed parts were measured using three-point bending tests. A significant increase was observed in flexural modulus of elasticity and flexural strength with infrared heaters at low printing speeds. A maximum value of 418.99 MPa flexural strength and 52.15 GPa flexural modulus was achieved.
The continuous carbon fiber-reinforced thermoplastic (CFRTP) printing process has been used more ... more The continuous carbon fiber-reinforced thermoplastic (CFRTP) printing process has been used more widely in recent years and is an alternative production method, especially in sectors such as aviation, automotive, prototyping, medical applications, and aerospace. Although additive manufacturing reduces the design limitations and makes it easier to manufacture, it is one of the disadvantages of this method: it has relatively low thermal and mechanical properties compared to standard production techniques. Therefore, in this study, printing parameters such as nozzle temperature, printing speed, layer thickness, and heated bed temperatures were investigated for fused deposition modeling. In this regard, a polymer impregnation line based on the melt impregnation technique was utilized to obtain CFRTP filaments using polylactic acid (PLA) and 3K carbon fiber. Obtained filaments were then used to print three-point bending test samples in order to investigate mechanical performance. The test result showed flexural strength between 108 and 224 MPa and flexural modulus between 9.67 and 17.69 GPa with a 23% fiber ratio. Results from this study proclaim that CFRTPs manufactured with this method and optimized printing parameters have great potential for implementing future production methods.
Continuous fiber-reinforced thermoplastic composite (CFRTP) manufacturing with fused deposition m... more Continuous fiber-reinforced thermoplastic composite (CFRTP) manufacturing with fused deposition modeling (FDM) platform is an up-and-coming method to produce parts with high mechanical properties. Mechanical performance of CFRTP is still limited by interlayer bonding performance and fiber-matrix interface. In this study, CFRTP samples were produced using carbon fiber and PEEK thermoplastic, and it was aimed to improve the mechanical properties by developing a more suitable fiber-polymer interface. The sizing process has been applied to the fiber in order to ensure that the applied force is transferred to the fibers more efficiently, with the polymer holding onto the fiber surface more firmly. In the sizing process, a production method was applied in the form of cleaning the fiber surfaces, activation with Meldrum acid, and completing the sizing by using PEKK powder. CFRTP filament was produced using the fibers coated with the sizing agent in the melt impregnation method. Three-point bending test specimens were produced by using the obtained filaments on an FDM-based printer. When the results were examined, it was observed that the maximum stresses obtained from the threepoint bending test were 9.72%, and the elasticity modulus improved by 56.76%. An average of 974.75 MPa flexural strength and 166.97 GPa modulus of elasticity were obtained in sizing applied samples. The stages of the sizing process and its effects on the fiber were examined using SEM images.
3D printing and additive manufacturing, Feb 15, 2023
Composites Part A: Applied Science and Manufacturing
European Journal of Science and Technology
Nowadays, additive manufacturing is being used in various industries such as automotive, aviation... more Nowadays, additive manufacturing is being used in various industries such as automotive, aviation and space, medical applications, etc. Although additive manufacturing methods offer more freedom in design and manufacturing, they usually have low production speed and mechanical properties. Continuous carbon fiber reinforced thermoplastic (CFRTP) composites are one of the investigated methods in the literature to increase the mechanical properties of the additively manufactured parts. This study utilized a production line based upon the melt impregnation method to obtain continuous carbon fiber reinforced thermoplastic filaments using polyamide and continuous carbon fibers. In the printing process, an infrared heat source was utilized to further increase the mechanical properties by improving the interlaminar bonding. The mechanical properties of the printed parts were measured using three-point bending tests. A significant increase was observed in flexural modulus of elasticity and flexural strength with infrared heaters at low printing speeds. A maximum value of 418.99 MPa flexural strength and 52.15 GPa flexural modulus was achieved.
Open Journal of Nano, Jun 30, 2022
This study investigated the effects of different heat treatments on continuous fiberreinforced th... more This study investigated the effects of different heat treatments on continuous fiberreinforced thermoplastic (CFRTP) 's. CFRTP composite is produced using fused deposition modeling (FDM), which is one of the additive manufacturing methods. Polylactic acid (PLA) was used as a matrix, and carbon fibers (3K) were utilized as reinforcement material. First, CFRTP filament was produced on a specially designed melt impregnation line. Afterward, test samples were manufactured via a conventional 3D printer. Then, heat treatments (re-melting in salt, microwave oven, oven) were applied to the produced samples, and the effects of these processes on mechanical properties were investigated. Three-point bending tests were used to investigate the mechanical properties of the test samples. As a result of the heat treatments applied to the CFRTP specimens, flexural stresses between 200 and 220 MPa was achieved. The highest bending stress was obtained by re-melting in salt. As a result of the heat treatments, the stress values are similar, but the re-melting in salt application exhibited a more rigid behavior.
This study investigated the effects of different heat treatments on continuous fiberreinforced th... more This study investigated the effects of different heat treatments on continuous fiberreinforced thermoplastic (CFRTP) 's. CFRTP composite is produced using fused deposition modeling (FDM), which is one of the additive manufacturing methods. Polylactic acid (PLA) was used as a matrix, and carbon fibers (3K) were utilized as reinforcement material. First, CFRTP filament was produced on a specially designed melt impregnation line. Afterward, test samples were manufactured via a conventional 3D printer. Then, heat treatments (re-melting in salt, microwave oven, oven) were applied to the produced samples, and the effects of these processes on mechanical properties were investigated. Three-point bending tests were used to investigate the mechanical properties of the test samples. As a result of the heat treatments applied to the CFRTP specimens, flexural stresses between 200 and 220 MPa was achieved. The highest bending stress was obtained by re-melting in salt. As a result of the heat treatments, the stress values are similar, but the re-melting in salt application exhibited a more rigid behavior.