Polymer-processing techniques are of the utmost importance for producing polymeric parts. They must produce parts with the desired qualities, which are usually related to mechanical performance, ...dimensional conformity, and appearance. Aiming to maximize the overall efficiency of the polymer-processing techniques, advanced modeling codes along with experimental measurements are needed to simulate and optimize the processes. Thus, this reprint exploits the digital transformation of the plastics industry, both through the creation of more robust and accurate modeling tools and the development of cutting-edge experimental techniques. Furthermore, it addresses advanced topics, such as crystallization during the solidification processes, prediction of fiber orientation in the cases of short and long fiber composites, prediction of the foaming process (such as microcellular foaming), and flow instabilities by including viscoelastic constitutive equations.
Polymer-processing techniques are of the utmost importance for producing polymeric parts. They must produce parts with the desired qualities, which are usually related to mechanical performance, ...dimensional conformity, and appearance. Aiming to maximize the overall efficiency of the polymer-processing techniques, advanced modeling codes along with experimental measurements are needed to simulate and optimize the processes. Thus, this reprint exploits the digital transformation of the plastics industry, both through the creation of more robust and accurate modeling tools and the development of cutting-edge experimental techniques. Furthermore, it addresses advanced topics, such as crystallization during the solidification processes, prediction of fiber orientation in the cases of short and long fiber composites, prediction of the foaming process (such as microcellular foaming), and flow instabilities by including viscoelastic constitutive equations.
Polymer-processing techniques are of the utmost importance for producing polymeric parts. They must produce parts with the desired qualities, which are usually related to mechanical performance, ...dimensional conformity, and appearance. Aiming to maximize the overall efficiency of the polymer-processing techniques, advanced modeling codes along with experimental measurements are needed to simulate and optimize the processes. Thus, this reprint exploits the digital transformation of the plastics industry, both through the creation of more robust and accurate modeling tools and the development of cutting-edge experimental techniques. Furthermore, it addresses advanced topics, such as crystallization during the solidification processes, prediction of fiber orientation in the cases of short and long fiber composites, prediction of the foaming process (such as microcellular foaming), and flow instabilities by including viscoelastic constitutive equations.
This article aims to provide an overview of applications of rapid prototyping–assisted conformal cooling channel and shows the potential of this technology in different manufacturing processes. This ...review article also reports one case study from open literature where rapid prototyping–assisted conformal cooling channel has been successfully used in the manufacturing process. This study concludes that rapid prototyping technique can replace conventional manufacturing for complicated structure conformal cooling channel which improves quality and productivity. The outcome based on literature review and case study strongly suggested that rapid prototyping–assisted conformal cooling channel might become standard procedure in manufacturing process in near future. Advanced technologies such as computer-aided manufacturing, computer-aided engineering, computer fluid dynamics, and rapid tooling made it possible to fabricate the conformal cooling channel. Rapid prototyping–assisted conformal cooling channel can easily transfer the simulation into actual fabrication. This article is beneficial to study the development and application of rapid prototyping–assisted conformal cooling channel in different manufacturing processes.
Conformal cooling is a promising approach for reducing the cycle time and providing efficient cooling in injection moulding. Evaluating the effectiveness of the cooling performance would ideally be ...achieved via real-time data collection, facilitated by in-mould sensors. However, due to the limited space caused by the presence of conformal channels, embedding the sensors in optimal locations is difficult. The design flexibility of additive manufacturing (AM) for manufacturing complex internal geometries offers opportunities for unique solutions to overcome both cooling and sensorisation challenges presented by traditional manufacturing techniques. In this study, straight-drilled cooling channels are replaced with conformal cooling channels, in a mould for a complex industrial component with variable thin and thick-walled sections. The Selective Laser Sintering (SLS) technique was implemented to additively manufacture sensorised mould inserts incorporating conformal channels as well as curved channels for the targeted placement of flexible thermocouples. These sensorised mould inserts, with conformal channels, were tested in an industrial injection moulding machine, and their performance was compared to the conventional mould inserts using in-mould thermocouple data. The experiment findings revealed that the application of conformal cooling reduced the production cycle time by around 50 % and resulted in better component quality compared to conventional methods. Also, thermocouple readings confirmed temporal trends observed in earlier simulation results, indicating the elimination of hotspot regions, and achieving a more uniform temperature distribution through the use of conformal cooling. The in-mould temperature data provides real-time information on the cooling process at critical points of the component, which can be exploited for more accurate optimisation of the cycle time and ejection temperature. Moreover, the flexible thermocouples in curved channels successfully measured the mould temperature and the effect of coolant on the mould insert at two separate locations of the additively manufactured mould inserts.
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•Developing sensorised additively manufactured (AM) moulds with conformal cooling•Significantly better quality and shorter cycle time compared to conventional cooling•Elimination of hotspots confirmed by simulation and thermocouple (TC) data•Flexible TCs functioned well in AM curved channels between the cooling channels•In-mould TCs identify optimal point of ejection more accurately than simulation
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A topology optimization approach is developed to design the conformal cooling system for injection molding in this paper. During the design process, the cycle-averaged approach is used to simplify ...the analysis of the cooling process, and the boundary element method (BEM) is adopted to solve the governing equations and calculate the sensitivities. The optimization starts from the complicated network of channels, and the radius of each channel section and the location of each node are selected as the design variables. The topology of the cooling system can be modified by deleting excessively thin channel sections. We pick out two representative example models with areas that are hard to cool to test the effectiveness of the proposed optimization approach. The results show that our method can improve both efficiency and uniformity of the cooling process.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The recent developments in the additive manufacturing make easier and affordable the fabrication of conformal cooling channels (CCCs) compared with the traditional machining techniques. Conformal ...cooling channels (CCCs) achieve better cooling performances than the conventional (straight-drilled) channels during the injection molding process since they can follow the pathways of the molded geometry while the conventional channels fail. Cooling time, total injection time, uniform temperature distribution, thermal stress, warpage thickness, etc. are some of the objectives that are improved via CCC applications. However, the CCC design process is more complex than the conventional channels; therefore, computer-aided engineering (CAE) simulations have significant importance for the effective and affordable design. This review study presents the main design steps of CCCs as follows: (1) a background of the CCC fabrication process is projected, (2) the thermal and mechanical models are presented with respect to the 1D analytical model, (3) the CAE-supported design criteria are discussed for the 3D models of CCCs and relevant mold materials, (4) some of the illustrative CAE simulations are explained in detail according to the computational thermal and mechanical objectives, and (5) the single- and multi-objective optimization procedures are defined. By following the aforementioned steps, clearer and effective CAE steps can be obtained for the designers before the on-site fabrication of CCCs.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Designing cooling channels for the thermoplastic injection process is a very important step in mold design. A conformal cooling channel can significantly improve the efficiency and the quality of ...production in plastic injection molding. This paper introduces an approach to generate spiral channels for conformal cooling. The cooling channels designed by our algorithms has very simple connectivity and can achieve effective conformal cooling for the models with complex shapes. The axial curves of cooling channels are constructed on a free-form surface conformal to the mold surface. With the help of boundary-distance maps, algorithms are investigated to generate evenly distributed spiral curves on the surface. The cooling channels derived from these spiral curves are conformal to the plastic part and introduce nearly no reduction at the rate of coolant flow. Therefore, the channels are able to achieve uniform mold cooling. Moreover, by having simple connectivity, these spiral channels can be fabricated by copper duct bending instead of expensive selective laser sintering.
•Spiral conformal cooling channels with high speed coolants.•An efficient algorithm to generate smooth spiral curves on free-form surfaces.•Spiral curves are governed by an approximated boundary-distance-map (BDM).•Region decomposition for covering by contours of BDM.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•Conformal cooling was applied successfully in gravity die casting mold.•Cooling efficiency was increased with cooling channels around the pusher pin regions.•Cycle time was reduced by 28% with ...conformal cooling channel in gravity die casting.•The average grain size of casted parts was reduced by 13.5%.
In the gravity die casting process, cooling directly affects the unit cost and microstructure quality of casting products. In the conventional manufacturing methods, cooling channels in gravity casting molds are usually produced linearly in circular profiles. When cooling is not conformal, molding defects such as hot spots and distortions form in the products. This study investigated the effects of cooling channels on the casting steps and final properties of the products in standard and conformal cooling gravity die casting molds. Numerical analysis results were compared with the experimental data and then were verified. The pressure losses in cooling channels, the times for molds to reach the required temperature and the cycle times were all measured. The pressure losses in standard and conformal cooling channels were measured at 5250 Pa and 12100 Pa, respectively. In addition, a more homogeneous mold surface temperature distribution was achieved in the conformal cooling mold, as well as a 28% shorter cycle time. The average particle size of the parts cast with conformal molds was 13.5% smaller than those cast with standard molds. Finally, the mechanical properties of the parts cast with conformal cooling channel molds were found to be better than those cast with standard channel molds.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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