The Experts below are selected from a list of 501 Experts worldwide ranked by ideXlab platform
Shia-chung Chen - One of the best experts on this subject based on the ideXlab platform.
-
Effect of asymmetric cooling system on in-Mold roller injection Molded part warpage☆
International Communications in Heat and Mass Transfer, 2015Co-Authors: Hui Li Chen, Shia-chung ChenAbstract:Abstract In-Mold decoration (IMD) injection Molding has been the most promising surface decoration technique in recent years, with the in-Mold roller (IMR) injection Molding being the most automated production process. During the IMR process, heat transfer in the cavity surface is significantly retarded because of the low thermal conductivity of film. As a result of the asymmetric melt and Mold temperature, thermal-induced part warpage easily occurs. To understand the variation in the temperature field of the Core and cavity caused by the plastic film, this research uses simulation and experiments to investigate the influence of the Mold's (Core-and-cavity) asymmetric cooling system temperature on product warpage, and examines the impact of the film's heat retardation effect on the crystallinity, tensile strength, and surface roughness of the treated products. Our results show that the film causes a higher contact temperature between the hot melt and Mold during the Molding process, resulting in asymmetric temperature in the Mold (Core and cavity), increasing the crystallinity of the cavity and consequently increasing product warpage. In plastic, the warpage increase is from 0.03 mm to 0.62 mm when the film thickness is 0.175 mm and the temperatures of the Mold and hot melt are 50 °C and 230 °C, respectively, a great increase than with steel (P20). With the asymmetric cooling system design, in which the cavity temperature is 50 °C and the Core temperature is 65 °C, the warpage can be reduced by 53%. For crystallinity and crystalline size, the film heat retardation effect of the IMR process increases the crystallinity of the cavity by 16%, and the crystallite size by 12%, along with some increase in tensile strength. In addition, the IMR process can also increase the smoothness of the product surface, reducing the surface roughness by 50%.
-
Using thermally insulated polymer film for Mold temperature control to improve surface quality of microcellular injection Molded parts
International Communications in Heat and Mass Transfer, 2008Co-Authors: Hui Li Chen, Rean-der Chien, Shia-chung ChenAbstract:Abstract Microcellular injection Molding provides many advantages over conventional foams and their unfoamed counterparts, but its applications are limited by visible surface quality problems such as silver streaks and swirl marks. In this study, a Mold temperature control method was proposed which a thermally insulated composite polymer film (82%PET + 18%PC) stick on the surface of Mold Core is used to achieve heat transfer delay at the plastic's melt–Mold surface interface during the microcellular injection Molding process to improve surface quality of Molded parts. Effect of film thickness on the part surface quality, was also investigated using surface roughness measurements and visual inspection of the Molded parts. It was found that the surface quality of parts can be greatly improved without a significant increase in cycle time when comparing with parts Molded without polymer film. The surface roughness can decreases from 5.6 to 1.8 μm when polymer film thickness increases from 0.125 to 0.188 mm. Meanwhile, the flow marks of gas bubbles on the part surface can be removed completely at film thickness of 0.188 mm. The usefulness by stick a polymer film on the surface of Mold Core for Mold temperature control in improving part surface quality during microcellular injection Molding has been successfully demonstrated.
Hui Li Chen - One of the best experts on this subject based on the ideXlab platform.
-
Effect of asymmetric cooling system on in-Mold roller injection Molded part warpage☆
International Communications in Heat and Mass Transfer, 2015Co-Authors: Hui Li Chen, Shia-chung ChenAbstract:Abstract In-Mold decoration (IMD) injection Molding has been the most promising surface decoration technique in recent years, with the in-Mold roller (IMR) injection Molding being the most automated production process. During the IMR process, heat transfer in the cavity surface is significantly retarded because of the low thermal conductivity of film. As a result of the asymmetric melt and Mold temperature, thermal-induced part warpage easily occurs. To understand the variation in the temperature field of the Core and cavity caused by the plastic film, this research uses simulation and experiments to investigate the influence of the Mold's (Core-and-cavity) asymmetric cooling system temperature on product warpage, and examines the impact of the film's heat retardation effect on the crystallinity, tensile strength, and surface roughness of the treated products. Our results show that the film causes a higher contact temperature between the hot melt and Mold during the Molding process, resulting in asymmetric temperature in the Mold (Core and cavity), increasing the crystallinity of the cavity and consequently increasing product warpage. In plastic, the warpage increase is from 0.03 mm to 0.62 mm when the film thickness is 0.175 mm and the temperatures of the Mold and hot melt are 50 °C and 230 °C, respectively, a great increase than with steel (P20). With the asymmetric cooling system design, in which the cavity temperature is 50 °C and the Core temperature is 65 °C, the warpage can be reduced by 53%. For crystallinity and crystalline size, the film heat retardation effect of the IMR process increases the crystallinity of the cavity by 16%, and the crystallite size by 12%, along with some increase in tensile strength. In addition, the IMR process can also increase the smoothness of the product surface, reducing the surface roughness by 50%.
-
Using thermally insulated polymer film for Mold temperature control to improve surface quality of microcellular injection Molded parts
International Communications in Heat and Mass Transfer, 2008Co-Authors: Hui Li Chen, Rean-der Chien, Shia-chung ChenAbstract:Abstract Microcellular injection Molding provides many advantages over conventional foams and their unfoamed counterparts, but its applications are limited by visible surface quality problems such as silver streaks and swirl marks. In this study, a Mold temperature control method was proposed which a thermally insulated composite polymer film (82%PET + 18%PC) stick on the surface of Mold Core is used to achieve heat transfer delay at the plastic's melt–Mold surface interface during the microcellular injection Molding process to improve surface quality of Molded parts. Effect of film thickness on the part surface quality, was also investigated using surface roughness measurements and visual inspection of the Molded parts. It was found that the surface quality of parts can be greatly improved without a significant increase in cycle time when comparing with parts Molded without polymer film. The surface roughness can decreases from 5.6 to 1.8 μm when polymer film thickness increases from 0.125 to 0.188 mm. Meanwhile, the flow marks of gas bubbles on the part surface can be removed completely at film thickness of 0.188 mm. The usefulness by stick a polymer film on the surface of Mold Core for Mold temperature control in improving part surface quality during microcellular injection Molding has been successfully demonstrated.
Matthew S. Dargusch - One of the best experts on this subject based on the ideXlab platform.
-
Reduced consumption of materials and hazardous chemicals for energy efficient production of metal parts through 3D printing of sand Molds
Journal of Cleaner Production, 2019Co-Authors: Tharmalingam Sivarupan, Mohamed El Mansori, Meet Upadhyay, Yahia Ali, Matthew S. DarguschAbstract:Metals remain essential structural materials for many demanding engineering applications requiring high strength at elevated temperatures and good performance in environments subjected to high thermal fluctuations such as often encountered in the automotive, rail and aircraft industries. The sand-casting process is one of the most preferred methods of producing complex and intricate shaped components out of metals with good strength at elevated temperatures. Unfortunately, the sand casting process also leads to the direct and indirect production of carbon dioxide. Three-dimensional sand Mold printing has been revolutionizing traditional production methods by reducing the unnecessary consumption of metal and chemicals when manufacturing a part through sand casting. This paper explores the opportunities that are emerging in the area of 3D printing of sand Molds and the positive impact that these new technologies and practices are having on the environmental impact of current sand-casting processes. The paper demonstrates that 3D printing of sand Molds enables new manufacturing strategies reducing the direct CO emissions and reducing the amount of metal required by enabling design optimization of both the component and Mold/Core assembly. Further benefits will be realized through the development of environmentally friendly binder systems.
Youshou Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Study of Environmentally Friendly Phosphate-Bonded No-Bake Sand
Advanced Materials Research, 2012Co-Authors: Lu Xia, Jin Huang, Youshou ZhangAbstract:Regarding dry strength as the index, and considering liftability and storage stability, effects of solidification agent amount and organics N on the property of high neutralization degree phosphate no-bake sand Mold/Core were studied by modifying the binder coded 32B8M15 and adding solidification agent fused MgO in sand mixing. A new type of compound phosphate binder coded 32B8M15N4 is developed, and results indicate that, at environment condition of below 15°C and 50% RH, the proper solidification agent amount is 5% when using high neutralization degree binder coded 32B8M15N4 (its addition amount is 3%) to make no-bake sand, its Molding sand sample has high dry strength and good storage stability, its compressive strength, σ0, σ1, σ2, σ3, σ4 is 2.33 MPa, 2.27 MPa, 2.01 MPa, 2.03 MPa, 2 MPa separately.
-
mechanism of strength loss of no bake phosphate bonded sand Mold Core
Journal of Wuhan University of Technology-materials Science Edition, 2009Co-Authors: Youshou Zhang, Yiyu Xue, Jin Huang, Lu Xia, Caihua HuangAbstract:The strength loss mechanism of the phosphate bonded sand Mold/Core was studied. The morphology and composition of phosphate membrane on the surface of sands was analyzed with electron probe X-ray microanalyzer. Results show that magnesium causes cracks in cured phosphate membrane and results in the decrease of sand Molds/Cores strength. However, the addition of magnesium significantly enhanced hygroscopy resistance of phosphate membrane. In addition, the phosphate binder added with the magnesium modifier has more rapid hardening reaction speed compared that without or with low magnesium binder. It can be concluded that the phosphate binder with the addition of magnesium modifier is favorably used in high humid and cold circumstance.
-
Mechanism of strength loss of no-bake phosphate bonded sand Mold/Core
Journal of Wuhan University of Technology-Mater. Sci. Ed., 2009Co-Authors: Youshou Zhang, Yiyu Xue, Jin Huang, Lu Xia, Li Sinian, Caihua HuangAbstract:The strength loss mechanism of the phosphate bonded sand Mold/Core was studied. The morphology and composition of phosphate membrane on the surface of sands was analyzed with electron probe X-ray microanalyzer. Results show that magnesium causes cracks in cured phosphate membrane and results in the decrease of sand Molds/Cores strength. However, the addition of magnesium significantly enhanced hygroscopy resistance of phosphate membrane. In addition, the phosphate binder added with the magnesium modifier has more rapid hardening reaction speed compared that without or with low magnesium binder. It can be concluded that the phosphate binder with the addition of magnesium modifier is favorably used in high humid and cold circumstance.
Tharmalingam Sivarupan - One of the best experts on this subject based on the ideXlab platform.
-
Reduced consumption of materials and hazardous chemicals for energy efficient production of metal parts through 3D printing of sand Molds
Journal of Cleaner Production, 2019Co-Authors: Tharmalingam Sivarupan, Mohamed El Mansori, Meet Upadhyay, Yahia Ali, Matthew S. DarguschAbstract:Metals remain essential structural materials for many demanding engineering applications requiring high strength at elevated temperatures and good performance in environments subjected to high thermal fluctuations such as often encountered in the automotive, rail and aircraft industries. The sand-casting process is one of the most preferred methods of producing complex and intricate shaped components out of metals with good strength at elevated temperatures. Unfortunately, the sand casting process also leads to the direct and indirect production of carbon dioxide. Three-dimensional sand Mold printing has been revolutionizing traditional production methods by reducing the unnecessary consumption of metal and chemicals when manufacturing a part through sand casting. This paper explores the opportunities that are emerging in the area of 3D printing of sand Molds and the positive impact that these new technologies and practices are having on the environmental impact of current sand-casting processes. The paper demonstrates that 3D printing of sand Molds enables new manufacturing strategies reducing the direct CO emissions and reducing the amount of metal required by enabling design optimization of both the component and Mold/Core assembly. Further benefits will be realized through the development of environmentally friendly binder systems.
