Momen Qasaimeh | Jordan University of Science and Technology (original) (raw)
Papers by Momen Qasaimeh
Multiscale science and engineering, Jan 19, 2022
Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in ... more Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in which, continuously extruded semi-molten filaments are deposited in a layer-by-layer manner. The quality of the manufactured part heavily depends on filament-filament contact, filament-filament interfacial adhesion and overall void fraction. In our earlier work, we used a novel fabrication method that applied additional compression to newly deposited filaments using an in situ roller ball. We then studied the effect of in situ compression on the quality of adhesion, and subsequently, on the thermal and mechanical properties of the printed parts. Under an optimized set of experimental conditions, a significant improvement in material toughness and tensile strength was measured. Here, we have developed an integrated theoretical model that predicts the impact of in situ compression rolling on filament-filament contact during deposition. The impact of key parameters associated with the rolling process, such as ball weight, ball temperature and filament temperature on printed part height, void fraction and filament adhesion are studied. Based on the Johnson–Kendall–Roberts (JKR) contact theory and the theory of elasticity, our mathematical model predicts the evolution of filament-to-filament contact width, the corresponding void fraction and part height in a representative volume element of the printed part. Our theoretical predictions are in good agreement with experimental measurements. Later, the theoretical model is used to optimize the filament temperature during the rolling process. Specifically, we find that isothermal contact between filaments results in optimal adhesion. We have concluded that parts fabricated from a system integrated with an in situ preheating and in situ post-rolling would yield 3D printed plastic parts with enhanced mechanical properties suitable for various structural applications.
Additive manufacturing, Apr 1, 2021
Bonding between polymer filaments deposited during Fused Filament Fabrication (FFF) is a critical... more Bonding between polymer filaments deposited during Fused Filament Fabrication (FFF) is a critical process that determines the quality of the printed part. This process is governed by the temperature history of the deposited filament. In general, the longer the filament stays above glass transition temperature, the greater is the quality of bonding. This paper presents a technique to enhance FFF quality by localized dispensing of hot air from nozzles integrated with the main polymer-dispensing nozzle, thereby providing a hot micro-environment around the filament. The temperature field during this process is measured using infrared thermography. It is shown that under the correct process conditions, this approach results in significantly reduced heat transfer from the filament, thereby increasing the cool down time and improving the quality of bonding with the adjacent filaments. The improved thermal history of the filament due to hot air dispensing is shown to translate into increased neck size, leading to 35% increase in thermal conductivity, 19% increase in tensile strength and 145% increase in tensile toughness. Compared to other thermal techniques for improving the FFF process proposed in the past, the present approach provides a highly localized, in situ thermal enhancement of the local environment around the deposited filament, and integrates seamlessly with the filament-dispensing nozzle. It is expected that the technique described here may help improve the quality of FFF process and enable the printing of parts with improved thermal and mechanical properties.
Virtual and Physical Prototyping, Mar 4, 2021
ABSTRACT The rastering of discrete polymer filaments during Fused Filament Fabrication (FFF) resu... more ABSTRACT The rastering of discrete polymer filaments during Fused Filament Fabrication (FFF) results in the formation of voids between filaments, leading to poor properties and performance of the printed part. Minimising voids and improving filament-to-filament adhesion remains a key technological challenge for FFF. While mechanical rolling is commonly used in traditional manufacturing, its use in polymer 3D printing has not been explored much. This paper discusses the in situ compression of just-deposited filament using a roller that is integrated with the filament-dispensing nozzle. The roller travels with the filament nozzle, and compresses the filament immediately after deposition when it is still soft. The rolling process is characterised using high speed imaging and infrared (IR) thermography. The effects of compression force and roller temperature on print quality is investigated. In situ compression of the filaments is shown to result in 10X reduction in void formation. Tensile test results show 154% improvement in Ultimate Tensile Stress (UTS) and 417% improvement in material toughness due to compressive rolling. It is expected that implementation of the rolling technique discussed in this work may help print parts with improved properties and functionality.
Multiscale Science and Engineering, 2022
Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in ... more Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in which, continuously extruded semi-molten filaments are deposited in a layer-by-layer manner. The quality of the manufactured part heavily depends on filament-filament contact, filament-filament interfacial adhesion and overall void fraction. In our earlier work, we used a novel fabrication method that applied additional compression to newly deposited filaments using an in situ roller ball. We then studied the effect of in situ compression on the quality of adhesion, and subsequently, on the thermal and mechanical properties of the printed parts. Under an optimized set of experimental conditions, a significant improvement in material toughness and tensile strength was measured. Here, we have developed an integrated theoretical model that predicts the impact of in situ compression rolling on filament-filament contact during deposition. The impact of key parameters associated with the rolli...
Virtual and Physical Prototyping
Multiscale science and engineering, Jan 19, 2022
Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in ... more Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in which, continuously extruded semi-molten filaments are deposited in a layer-by-layer manner. The quality of the manufactured part heavily depends on filament-filament contact, filament-filament interfacial adhesion and overall void fraction. In our earlier work, we used a novel fabrication method that applied additional compression to newly deposited filaments using an in situ roller ball. We then studied the effect of in situ compression on the quality of adhesion, and subsequently, on the thermal and mechanical properties of the printed parts. Under an optimized set of experimental conditions, a significant improvement in material toughness and tensile strength was measured. Here, we have developed an integrated theoretical model that predicts the impact of in situ compression rolling on filament-filament contact during deposition. The impact of key parameters associated with the rolling process, such as ball weight, ball temperature and filament temperature on printed part height, void fraction and filament adhesion are studied. Based on the Johnson–Kendall–Roberts (JKR) contact theory and the theory of elasticity, our mathematical model predicts the evolution of filament-to-filament contact width, the corresponding void fraction and part height in a representative volume element of the printed part. Our theoretical predictions are in good agreement with experimental measurements. Later, the theoretical model is used to optimize the filament temperature during the rolling process. Specifically, we find that isothermal contact between filaments results in optimal adhesion. We have concluded that parts fabricated from a system integrated with an in situ preheating and in situ post-rolling would yield 3D printed plastic parts with enhanced mechanical properties suitable for various structural applications.
Additive manufacturing, Apr 1, 2021
Bonding between polymer filaments deposited during Fused Filament Fabrication (FFF) is a critical... more Bonding between polymer filaments deposited during Fused Filament Fabrication (FFF) is a critical process that determines the quality of the printed part. This process is governed by the temperature history of the deposited filament. In general, the longer the filament stays above glass transition temperature, the greater is the quality of bonding. This paper presents a technique to enhance FFF quality by localized dispensing of hot air from nozzles integrated with the main polymer-dispensing nozzle, thereby providing a hot micro-environment around the filament. The temperature field during this process is measured using infrared thermography. It is shown that under the correct process conditions, this approach results in significantly reduced heat transfer from the filament, thereby increasing the cool down time and improving the quality of bonding with the adjacent filaments. The improved thermal history of the filament due to hot air dispensing is shown to translate into increased neck size, leading to 35% increase in thermal conductivity, 19% increase in tensile strength and 145% increase in tensile toughness. Compared to other thermal techniques for improving the FFF process proposed in the past, the present approach provides a highly localized, in situ thermal enhancement of the local environment around the deposited filament, and integrates seamlessly with the filament-dispensing nozzle. It is expected that the technique described here may help improve the quality of FFF process and enable the printing of parts with improved thermal and mechanical properties.
Virtual and Physical Prototyping, Mar 4, 2021
ABSTRACT The rastering of discrete polymer filaments during Fused Filament Fabrication (FFF) resu... more ABSTRACT The rastering of discrete polymer filaments during Fused Filament Fabrication (FFF) results in the formation of voids between filaments, leading to poor properties and performance of the printed part. Minimising voids and improving filament-to-filament adhesion remains a key technological challenge for FFF. While mechanical rolling is commonly used in traditional manufacturing, its use in polymer 3D printing has not been explored much. This paper discusses the in situ compression of just-deposited filament using a roller that is integrated with the filament-dispensing nozzle. The roller travels with the filament nozzle, and compresses the filament immediately after deposition when it is still soft. The rolling process is characterised using high speed imaging and infrared (IR) thermography. The effects of compression force and roller temperature on print quality is investigated. In situ compression of the filaments is shown to result in 10X reduction in void formation. Tensile test results show 154% improvement in Ultimate Tensile Stress (UTS) and 417% improvement in material toughness due to compressive rolling. It is expected that implementation of the rolling technique discussed in this work may help print parts with improved properties and functionality.
Multiscale Science and Engineering, 2022
Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in ... more Fused filament fabrication (FFF) is one of the most common additive manufacturing techniques, in which, continuously extruded semi-molten filaments are deposited in a layer-by-layer manner. The quality of the manufactured part heavily depends on filament-filament contact, filament-filament interfacial adhesion and overall void fraction. In our earlier work, we used a novel fabrication method that applied additional compression to newly deposited filaments using an in situ roller ball. We then studied the effect of in situ compression on the quality of adhesion, and subsequently, on the thermal and mechanical properties of the printed parts. Under an optimized set of experimental conditions, a significant improvement in material toughness and tensile strength was measured. Here, we have developed an integrated theoretical model that predicts the impact of in situ compression rolling on filament-filament contact during deposition. The impact of key parameters associated with the rolli...
Virtual and Physical Prototyping