Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE We investigated the drawing conditions of melt-spun HDPE/UHMW-PE fibers to improve their mechanical properties and fiber diameter. Selecting an appropriate drawing temperature enabled us to produce high-strength PE fibers with a tensile strength of approximately 2.0 GPa. Additionally, a two-step drawing process produced PE fibers with both a smaller diameter and a higher strength.


ABSTRACT
In this study, the drawing conditions of melt-spun high-density polyethylene (HDPE)/ultrahigh-molecular-weight polyethylene (UHMW-PE) fibers were investigated to improve their mechanical properties and fiber diameter. An as-spun HDPE/UHMW-PE blended fiber containing 30 wt% UHMW-PE was prepared by melt spinning. The PE fiber with a high tensile strength of approximately 2.0 GPa was produced by drawing the as-spun fiber at 120°C. This strength was significantly higher than that of previous PE fibers produced by melt spinning. Additionally, a two-step drawing process was also developed to reduce the fiber diameter and increase the strength simultaneously. First, pre-drawing was performed in the molten state at 145°C and a low strain rate. Then, the obtained pre-drawn fiber was drawn at 130°C and a high strain rate. The total draw ratio was higher in the two-step drawing process, resulting in the improved degree of thinning. Lowering the draw ratio during pre-drawing increased the draw ratio during the second drawing, resulting in improved tensile strength. Consequently, the PE fiber with both a smaller diameter (approximately 20 μm) and a higher strength (approximately 1.6 GPa) was produced by the two-step drawing process.