The design of three-dimensional printing based conformal cooling channels(CCCs)in injection molding holds great significance.Compared to CCCs,conformal cooling(CC)cavity solutions show promise in delivering enhanced c...The design of three-dimensional printing based conformal cooling channels(CCCs)in injection molding holds great significance.Compared to CCCs,conformal cooling(CC)cavity solutions show promise in delivering enhanced cooling performance for plastic products,although they have been underexplored.In this research,CC cavity is designed within the mold geometry,reinforced by body-centered cubic(BCC)lattice structures to enhance mechanical strength.Three distinct BCC lattice variations have been integrated into the CC cavity:the BCC structure,BCC with cubes,and BCC with pillars.The thermal performances of the BCC lattice-added CC cavity are assessed numerically after experimental validation.To provide feasible solutions from viewpoints of thermal performances,various BCC lattice structure thicknesses are analyzed in the range of 0.8–1.2mm.Thermal simulation outcomes reveal that thicker lattice structures enhance mechanical strength but simultaneously lead to an increase in cooling time.Upon examining all the proposed CC cavity solutions supported by BCC,the cooling times range from 2.2 to 4 s,resulting in a reduction of 38.6%to 66.1%when compared to conventional straightdrilled channels.In contrast to CCCs,CC cavities have the potential to decrease the maximum temperature nonuniformity from 8.5 to 6 K.Nevertheless,the presence of lattice structures in CC cavity solutions results in an elevated pressure drop,reaching 2.8MPa,whereas the results for CCCs remain below2.1MPa.展开更多
This paper presents simulation study on Milled Grooved conformal cooling channels(MGCCC)in injection molding.MGCCC has a more effective cooling surface area which helps to provide efficient cooling as compared to conv...This paper presents simulation study on Milled Grooved conformal cooling channels(MGCCC)in injection molding.MGCCC has a more effective cooling surface area which helps to provide efficient cooling as compared to conventional cooling.A case study of Encloser part is investigated for cycle time reduction and quality improvement.The performance designs of straight drilled are compared with MGCCC by using Autodesk Moldflow Insight(AMI)2016.The results show total 32.1% reduction of cooling time and 9.86% reduction of warpage in case of MGCCC as compared to conventional cooling.展开更多
Cooling system improvement is important in injection molding to get betterquality and productivity. The aim of this paper was to compare the different shapes of theconformal cooling channels (CCC) with constant surfac...Cooling system improvement is important in injection molding to get betterquality and productivity. The aim of this paper was to compare the different shapes of theconformal cooling channels (CCC) with constant surface area and CCC with constantvolume in injection molding using Mold-flow Insight 2016 software. Also the CCC resultswere compared with conventional cooling channels. Four different shapes of the CCC suchas circular, elliptical, rectangular and semi-circular were proposed. The locations of thecooling channels were also kept constant. The results in terms of cooling time, cycle timereduction and improvement in quality of the product shows that no significant effect ofCCC’s shapes when surface area of CCC kept constant. On the other hand, the rectangularCCC shows better result as compared to other shapes of CCC when volume of CCC werekept constant.展开更多
The use of plastic-based products is continuously increasing. The increasing demands for thinner products, lower production costs, yet higher product quality has triggered an increase in the number of research project...The use of plastic-based products is continuously increasing. The increasing demands for thinner products, lower production costs, yet higher product quality has triggered an increase in the number of research projects on plastic molding processes. An important branch of such research is focused on mold cooling system. Conventional cooling systems are most widely used because they are easy to make by using conventional machining processes. However, the non-uniform cooling processes are considered as one of their weaknesses. Apart from the conven- tional systems, there are also conformal cooling systems that are designed for faster and more uniform plastic mold cooling. In this study, the conformal cooling system is applied for the production of bowl-shaped product made of PP AZ564. Optimization is conducted to initiate machine setup parameters, namely, the melting temperature, injection pressure, holding pressure and holding time. The genetic algorithm method and Moldflow were used to optimize the injection process parameters at a minimum cycle time. It is found that, an optimum injection molding processes could be obtained by setting the parameters to the following values： TM=180℃; Pinj = 20MPa; Phold= 16MPa and thold=8s, with a cycle time of 14.11 s. Experiments using the conformal cooling system yielded an average cycle time of 14.19 s. The studied conformal cooling system yielded a volumetric shrinkage of 5.61% and the wall shear stress was found at 0.17 MPa. The difference between the cycle time obtained through simulations and experiments using the conformal cooling system was insignificant （below 1%）. Thus, combining process parameters optimization and simulations by using genetic algorithm method with Moldflow can be considered as valid.展开更多
The selective laser melting(SLM) method has a great potential for fabricating injection mold with complex structure. However, the microstructure and performance of the SLM molds show significantly di erent from those ...The selective laser melting(SLM) method has a great potential for fabricating injection mold with complex structure. However, the microstructure and performance of the SLM molds show significantly di erent from those manufac?tured by traditional technologies. In this study, the microstructure, hardness and especially corrosion behavior of the samples fabricated by SLM and casting were investigated. The XRD results exhibit that the γ?Fe phase is only obtained in the SLM parts, and the α?Fe peak slightly moves to low di raction angle compared with casting counterparts. Due to the rapid cooling rate, the SLM samples have fine cellular microstructures while the casting ones have coarse grains with obvious elements segregation. Besides, the SLM samples show anisotropy, hardness of side view and top view are 48.73 and 50.31 HRC respectively, which are 20% higher than that of casting ones. Corrosion results show that the SLM samples have the better anti?corrosion resistance(in a 6% FeCl3 solution for 48 h) but the deeper corrosion pits than casting ones. Finally, the performance of the SLM molds could meet the requirement of injecting production. Moreover, the molds especially present a significant decrease(20%) of cooling time and increases of cooling uniform?ity due to the customized conformal cooling channels.展开更多
The study proves that the conformal cooling channel can overcome the disadvantages of the conventional cooling channel resulting from the limitation in complicated shape.The simulation analyses of the fragrance lamp w...The study proves that the conformal cooling channel can overcome the disadvantages of the conventional cooling channel resulting from the limitation in complicated shape.The simulation analyses of the fragrance lamp with different cooling layouts show that the conformal cooling channel can offer a more uniform heat dissipation,lower volume shrinkage and shorter time to freeze than the conventional channel,which indicates significantly improvements in productivity and quality.展开更多
Conformal cooling coils have been developed during the last decades through the use of additive manufacturing(AM)technologies.The main goal of this study was to analyze how the presence of an internal channel that cou...Conformal cooling coils have been developed during the last decades through the use of additive manufacturing(AM)technologies.The main goal of this study was to analyze how the presence of an internal channel that could act as a conformal cooling coil could affect compressive strength and quasi-elastic gradient of AlSi10Mg lattice structures produced by laser powder bed fusion(LPBF).Three different configurations of samples were tested in compression at 25℃ and 200℃.The reference structures were body centered cubic(BBC)in the core of the samples with vertical struts along Z(BCCZ)lattices in the outer perimeter,labelled as NC samples.The main novelty consisted in inserting a straight elliptical channel and a 45°elliptical channel inside the BCCZ lattice structures,labelled as SC and 45C samples respectively.All the samples were then tested in as-built(AB)condition,and after two post process heat treatments,commonly used for AlSi10Mg LPBF industrial components,a stress relieving(SR)and a T6 treatment.NC lattice structures AB exhibited an overall fragile fracture and therefore the SC and 45C configuration samples were tested only after thermal treatments.The test at 25℃ showed that all types of samples were characterized by negligible variations in their quasi-elastic gradients and yield strength.On the contrary,the general trend of stress-strain curves was influenced by the presence of the channel and its position.The test at 200℃ showed that NC,SC and 45C samples after SR and T6 treatments exhibited a metal-foam like deformation.展开更多
文摘The design of three-dimensional printing based conformal cooling channels(CCCs)in injection molding holds great significance.Compared to CCCs,conformal cooling(CC)cavity solutions show promise in delivering enhanced cooling performance for plastic products,although they have been underexplored.In this research,CC cavity is designed within the mold geometry,reinforced by body-centered cubic(BCC)lattice structures to enhance mechanical strength.Three distinct BCC lattice variations have been integrated into the CC cavity:the BCC structure,BCC with cubes,and BCC with pillars.The thermal performances of the BCC lattice-added CC cavity are assessed numerically after experimental validation.To provide feasible solutions from viewpoints of thermal performances,various BCC lattice structure thicknesses are analyzed in the range of 0.8–1.2mm.Thermal simulation outcomes reveal that thicker lattice structures enhance mechanical strength but simultaneously lead to an increase in cooling time.Upon examining all the proposed CC cavity solutions supported by BCC,the cooling times range from 2.2 to 4 s,resulting in a reduction of 38.6%to 66.1%when compared to conventional straightdrilled channels.In contrast to CCCs,CC cavities have the potential to decrease the maximum temperature nonuniformity from 8.5 to 6 K.Nevertheless,the presence of lattice structures in CC cavity solutions results in an elevated pressure drop,reaching 2.8MPa,whereas the results for CCCs remain below2.1MPa.
文摘This paper presents simulation study on Milled Grooved conformal cooling channels(MGCCC)in injection molding.MGCCC has a more effective cooling surface area which helps to provide efficient cooling as compared to conventional cooling.A case study of Encloser part is investigated for cycle time reduction and quality improvement.The performance designs of straight drilled are compared with MGCCC by using Autodesk Moldflow Insight(AMI)2016.The results show total 32.1% reduction of cooling time and 9.86% reduction of warpage in case of MGCCC as compared to conventional cooling.
文摘Cooling system improvement is important in injection molding to get betterquality and productivity. The aim of this paper was to compare the different shapes of theconformal cooling channels (CCC) with constant surface area and CCC with constantvolume in injection molding using Mold-flow Insight 2016 software. Also the CCC resultswere compared with conventional cooling channels. Four different shapes of the CCC suchas circular, elliptical, rectangular and semi-circular were proposed. The locations of thecooling channels were also kept constant. The results in terms of cooling time, cycle timereduction and improvement in quality of the product shows that no significant effect ofCCC’s shapes when surface area of CCC kept constant. On the other hand, the rectangularCCC shows better result as compared to other shapes of CCC when volume of CCC werekept constant.
基金Supported by Ministry of Research,Technology and Higher Education of the Republic of Indonesia
文摘The use of plastic-based products is continuously increasing. The increasing demands for thinner products, lower production costs, yet higher product quality has triggered an increase in the number of research projects on plastic molding processes. An important branch of such research is focused on mold cooling system. Conventional cooling systems are most widely used because they are easy to make by using conventional machining processes. However, the non-uniform cooling processes are considered as one of their weaknesses. Apart from the conven- tional systems, there are also conformal cooling systems that are designed for faster and more uniform plastic mold cooling. In this study, the conformal cooling system is applied for the production of bowl-shaped product made of PP AZ564. Optimization is conducted to initiate machine setup parameters, namely, the melting temperature, injection pressure, holding pressure and holding time. The genetic algorithm method and Moldflow were used to optimize the injection process parameters at a minimum cycle time. It is found that, an optimum injection molding processes could be obtained by setting the parameters to the following values： TM=180℃; Pinj = 20MPa; Phold= 16MPa and thold=8s, with a cycle time of 14.11 s. Experiments using the conformal cooling system yielded an average cycle time of 14.19 s. The studied conformal cooling system yielded a volumetric shrinkage of 5.61% and the wall shear stress was found at 0.17 MPa. The difference between the cycle time obtained through simulations and experiments using the conformal cooling system was insignificant （below 1%）. Thus, combining process parameters optimization and simulations by using genetic algorithm method with Moldflow can be considered as valid.
基金National Natural Science Foundation of China(Grant No.51605176)National Hi-tech R&D Program of China(863 Program,Grant No.2015AA042501)+3 种基金Hubei Provincial Natural Science Foundation of China(Grant No.2018CFB502)Guangdong Provincial Technology Major Project of China(Grant No.2017B090911007)State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(Grant No.P2019-006)Engineering Research Center of Rock-Soil Drilling&Excavation and Protection,Ministry of Education(Grant No.201804)
文摘The selective laser melting(SLM) method has a great potential for fabricating injection mold with complex structure. However, the microstructure and performance of the SLM molds show significantly di erent from those manufac?tured by traditional technologies. In this study, the microstructure, hardness and especially corrosion behavior of the samples fabricated by SLM and casting were investigated. The XRD results exhibit that the γ?Fe phase is only obtained in the SLM parts, and the α?Fe peak slightly moves to low di raction angle compared with casting counterparts. Due to the rapid cooling rate, the SLM samples have fine cellular microstructures while the casting ones have coarse grains with obvious elements segregation. Besides, the SLM samples show anisotropy, hardness of side view and top view are 48.73 and 50.31 HRC respectively, which are 20% higher than that of casting ones. Corrosion results show that the SLM samples have the better anti?corrosion resistance(in a 6% FeCl3 solution for 48 h) but the deeper corrosion pits than casting ones. Finally, the performance of the SLM molds could meet the requirement of injecting production. Moreover, the molds especially present a significant decrease(20%) of cooling time and increases of cooling uniform?ity due to the customized conformal cooling channels.
基金the National Natural Science Foundation of China (No.50875096)
文摘The study proves that the conformal cooling channel can overcome the disadvantages of the conventional cooling channel resulting from the limitation in complicated shape.The simulation analyses of the fragrance lamp with different cooling layouts show that the conformal cooling channel can offer a more uniform heat dissipation,lower volume shrinkage and shorter time to freeze than the conventional channel,which indicates significantly improvements in productivity and quality.
基金Open access funding provided by Politecnico di Torino within the CRUI-CARE Agreement.
文摘Conformal cooling coils have been developed during the last decades through the use of additive manufacturing(AM)technologies.The main goal of this study was to analyze how the presence of an internal channel that could act as a conformal cooling coil could affect compressive strength and quasi-elastic gradient of AlSi10Mg lattice structures produced by laser powder bed fusion(LPBF).Three different configurations of samples were tested in compression at 25℃ and 200℃.The reference structures were body centered cubic(BBC)in the core of the samples with vertical struts along Z(BCCZ)lattices in the outer perimeter,labelled as NC samples.The main novelty consisted in inserting a straight elliptical channel and a 45°elliptical channel inside the BCCZ lattice structures,labelled as SC and 45C samples respectively.All the samples were then tested in as-built(AB)condition,and after two post process heat treatments,commonly used for AlSi10Mg LPBF industrial components,a stress relieving(SR)and a T6 treatment.NC lattice structures AB exhibited an overall fragile fracture and therefore the SC and 45C configuration samples were tested only after thermal treatments.The test at 25℃ showed that all types of samples were characterized by negligible variations in their quasi-elastic gradients and yield strength.On the contrary,the general trend of stress-strain curves was influenced by the presence of the channel and its position.The test at 200℃ showed that NC,SC and 45C samples after SR and T6 treatments exhibited a metal-foam like deformation.
