Professor Kim Sang-yup’s Research Team Publishes Paper in Composites Part A
A research team led by Professor Kim Sang-yup of the Department of Mechanical Engineering at Sogang University developed a benchtop wet filament winding-based prepreg manufacturing platform to address tensile instability issues arising during the carbon fiber prepreg manufacturing process. The team published the results of this research in Composites Part A: Applied Science and Manufacturing (IF 8.9), a prestigious international journal in the field of composite materials. Kim Min-soo, an M.S.–Ph.D. student in the Department of Mechanical Engineering, served as the first author of this study, with Professor Kim Sang-yup acting as the corresponding author.
Carbon fiber reinforced polymer (CFRP) composites are widely used as high-performance structural materials in aerospace, automotive, and defense industries. However, the manufacture of prepregs—an intermediate material—requires precise control of fiber tension, resin impregnation, and fiber orientation. In particular, small-scale laboratory equipment has a shorter fiber transport path and lower system inertia compared to industrial equipment, resulting in significant tension fluctuations caused by bobbin friction and resin resistance. Such tension instability can lead to fiber bending, uneven resin distribution, and defect formation, which may reduce the reproducibility of the final composite’s mechanical properties.
To address this issue, the research team designed a hybrid tension control system that combines a magnetic particle brake, a pneumatic dancer roller, and load cell-based PI feedback control. The developed system stably maintained the tension of the carbon fiber tow within ±5% of the target tension even along a short fiber transport path and effectively suppressed transient tension disturbances. Furthermore, a comparison of the surface quality, resin impregnation behavior, microstructure, and tensile properties of prepregs manufactured under different tension control levels confirmed that stably controlling tension fluctuations is more critical for ensuring uniform fiber alignment and resin distribution than simply applying high tension. As a result of applying the control system, tensile strength improved by approximately 55% and elastic modulus by approximately 35% compared to composites manufactured without tension control, and the variation in physical properties among specimens was significantly reduced.
This study is significant in that it demonstrated the ability to systematically analyze the relationship between process conditions and composite performance using a small-scale, modular prepreg manufacturing platform. It is expected to be utilized in the future development of manufacturing processes for next-generation composites, such as high-heat-resistant resins, functional particles, and multifunctional composite materials.
First author Kim Min-soo (an M.S.–Ph.D. student) stated, “Through this study, we were able to confirm that tension control has a significant impact on fiber orientation, resin impregnation, and the final composite properties even in laboratory-scale prepreg manufacturing.” He added, “I would like to thank Professor Kim Sang-yup for his extensive advice and guidance throughout the research process, and I intend to continue researching various manufacturing processes for high-performance composites based on this platform.”
▶ Paper Title: Development of a benchtop prepreg manufacturing platform with integrated tension control of short-travel-path carbon fiber tow
▶ Journal: Composites Part A: Applied Science and Manufacturing (IF 8.9)
▶ Paper Link: https://doi.org/10.1016/j.compositesa.2026.109972
[SEO Keyword]
Carbon fiber prepreg manufacturing, composite material tension control, mechanical property enhancement
Carbon fiber reinforced polymer (CFRP) composites are widely used as high-performance structural materials in aerospace, automotive, and defense industries. However, the manufacture of prepregs—an intermediate material—requires precise control of fiber tension, resin impregnation, and fiber orientation. In particular, small-scale laboratory equipment has a shorter fiber transport path and lower system inertia compared to industrial equipment, resulting in significant tension fluctuations caused by bobbin friction and resin resistance. Such tension instability can lead to fiber bending, uneven resin distribution, and defect formation, which may reduce the reproducibility of the final composite’s mechanical properties.
To address this issue, the research team designed a hybrid tension control system that combines a magnetic particle brake, a pneumatic dancer roller, and load cell-based PI feedback control. The developed system stably maintained the tension of the carbon fiber tow within ±5% of the target tension even along a short fiber transport path and effectively suppressed transient tension disturbances. Furthermore, a comparison of the surface quality, resin impregnation behavior, microstructure, and tensile properties of prepregs manufactured under different tension control levels confirmed that stably controlling tension fluctuations is more critical for ensuring uniform fiber alignment and resin distribution than simply applying high tension. As a result of applying the control system, tensile strength improved by approximately 55% and elastic modulus by approximately 35% compared to composites manufactured without tension control, and the variation in physical properties among specimens was significantly reduced.
This study is significant in that it demonstrated the ability to systematically analyze the relationship between process conditions and composite performance using a small-scale, modular prepreg manufacturing platform. It is expected to be utilized in the future development of manufacturing processes for next-generation composites, such as high-heat-resistant resins, functional particles, and multifunctional composite materials.
First author Kim Min-soo (an M.S.–Ph.D. student) stated, “Through this study, we were able to confirm that tension control has a significant impact on fiber orientation, resin impregnation, and the final composite properties even in laboratory-scale prepreg manufacturing.” He added, “I would like to thank Professor Kim Sang-yup for his extensive advice and guidance throughout the research process, and I intend to continue researching various manufacturing processes for high-performance composites based on this platform.”
▶ Paper Title: Development of a benchtop prepreg manufacturing platform with integrated tension control of short-travel-path carbon fiber tow
▶ Journal: Composites Part A: Applied Science and Manufacturing (IF 8.9)
▶ Paper Link: https://doi.org/10.1016/j.compositesa.2026.109972
[SEO Keyword]
Carbon fiber prepreg manufacturing, composite material tension control, mechanical property enhancement