• Composites Research
• /
• v.17 no.5
• /
• pp.1-6
• /
• 2004

Composite pressure vessels with HDPE (high density polyethlyne) liner with metal boss at each end were developed by Filament Winding Process. The vessel is composed of a dome-shaped part at each end and a cylinder-shaped part at the middle of the vessel. The environmental tests carried out for possible vessel materials such as High Density Polyethlyn (HDPE), resins and reinforcing fibers up to a year showed no significant damages. The boss was designed to minimize the gas leak which was verified by FEM analysis. Most ideal fiber tension was obtained by experimental method and the fiber volume fraction, $\textrm{V}_{f}$, obtained by image analyzer were 55.4 % in cylinder and 55.6 % in dome parts, respectively. Winding pattern is programmed to control the composite thickness in the dome areas such that the failure of the vessel may occur in the cylinder. During the cure, the vessel was rotated and a constant internal pressure of 0.62 bar was applied. From this, the vessel's burst pressure is improved by 28 %. The burst and fatigue tests for under-wound and fully wound vessel showed satisfactory results.

• Journal of the Korean Society of Radiology
• /
• v.16 no.3
• /
• pp.233-240
• /
• 2022

Research on the presence or absence of radiation shielding for FDM-type filaments has recently begun to be studied, but filaments with shielding capabilities are not sold in Korea, and not studies yet. Therefore, in this research, we will use HDPE (High Density Polyethylene) as a base material, select bismuth as a reinforcing material to manufacture a composite filament, evaluate the shielding ability, and provide basic data for the development of a radiation shielding composite material using 3D printing.A filament is produced by mixing Bismuth with an effective atomic number 83 with HDPE of PE series and adjusting the content of Bismuth to 20% wt, 30% wt, 40% wt. Compounded filaments were evaluated for their physical properties and shielding capabilities by ASTM evaluation methods. As the bismuth content increases, the density, weight, and tensile strength increase, and the shielding capacity is confirmed to be excellent. As a result of the radiation shielding capacity evaluation, it was confirmed that HDPE (80%) + Bi (20%) showed a shielding rate of 82% at 60 kV and a shielding rate of up to 94% or more at 40% bismuth content. In this study, we confirmed that it was possible to produce a radiation shield that is lighter than the metal particle-containing filaments. Furthermore, that have been shield radiation by using HDPE + Bi filaments, and radiation in the medical and radiation industries. The possibility of using it as a shielding complex was confirmed.

• Journal of Aerospace System Engineering
• /
• v.17 no.6
• /
• pp.127-132
• /
• 2023

In this study, designing of a Type 4 pressure vessel using the filament winding method was conducted. In order to prevent leakage in consideration of the design of the hydrogen storage tank, a liner was designed by applying high-density polyethylene (HDPE), and the composite structure was designed by stacking carbon/epoxy in the hoop and helical directions. As a theoretical approach, the angle of the helical fiber and fiber thickness of each hoop and helix were designed. The safety of the design was verified using the commercial software ANSYS.

• Textile Coloration and Finishing
• /
• v.33 no.4
• /
• pp.302-308
• /
• 2021

Air filters are being used in countless places from industrial sites to everyday life. The spread of the COVID-19 virus, which started in 2019, is disrupting people's daily lives, and the importance of air filters as a basic means to prevent the spread of these diseases is further highlighted. In this study, the purpose was to develop another type of air filter media with excellent barrier properties that can replace PP meltblown nonwoven fabrics widely used commercially due to its excellent electrostatic properties, differential pressure and filtration efficiency. Therefore, wet-laid nonwoven for air filters were manufactured using plexi-filaments formed through flash spinning and having various fiber diameter from hundreds of nanometers to tens of micrometers, and its applicability as an air-filter media was investigated compared to the meltblown nonwoven. As a result of the performance evaluation, it was found that the filtration efficiency and barrier performance at 0.3㎛ was superior to that of the meltblown nonwoven of the same weight, although the differential pressure was high due to morphological properties of the plexi-filament.

• Textile Coloration and Finishing
• /
• v.34 no.1
• /
• pp.58-67
• /
• 2022

In this study, self-reinforced composite(SRC) was prepared using HDPE(High density polyethylene) fabric(2×2 plain) and LDPE(Low density polyethylene) film. The optimal conditions were derived by manufacturing specimens according to the temperature of 100 ~ 140℃ using a hot stamping at a pressure of 100bar for 10 minutes in order to find the optimal conditions for the SRC. The manufactured SRC was analyzed for tensile properties, compressive strength and shear strength through a universal testing machine(UTM). As a result of the measurement, the P3 specimen prepared by hot stamping at a temperature of 130℃ and a pressure of 100bar for 10 minutes was found to be higher than other specimens with tensile strength and tensile modulus of 210MPa and 19GPa, compressive strength 69MPa and shear strength 13MPa and it was considered to be optimal condition. Finally, the composite material according to the fabric structure was modeled using experimental values and the physical properties of the composite material according to the fabric structure were predicted using GeoDict and Digimat.