Abstract
Polypropylene fibers, prepared by melt-spinning of the resins which have various melt flow rates (MFRs),
were drawn with the laser irradiation heating. As a result of WAXD measurements, it was revealed that the as-spun
fibers made from the resin whose MFR less than 30 contains α crystal. Comparing with the same draw ratio, the higher
tensile strength and Young's modulus were obtained for the lower MFR. However, the maximum draw ratio was
increase with the increase of MFR. Therefore, the maximum Young's modulus of 156 cN/dtex was obtained from the
highest MFR resin. In contrast, the maximum tensile strength of 9.59 cN/dtex was obtained for the fiber made of
MFR11/MFR30 melt-blend. Moreover, the utility as the concrete pieces fall protection sheets was evaluated for the
fabrics made by the drawn fiber. The punching load of 1.5 kN was obtained for the fabric of mock leno weave with the
use of acryl resin adhesive.
