Anisotropy control on recycling molding material and appearance of effective fiber orientation on Fatigue Crack Propagation property by mesoscopic factor (Anisotropy control by tetrapod-shaped whisker and aramide fiber)

The fatigue reliability of recycled advanced fiber-reinforced thermoplastic (FRTP) resin was examined, with a focus on the effects of the mesoscopic factor on the Fatigue Crack Propagation property. The main results were as follows: (1) In spite of the low weight percentage of carbon fiber, the rate of decrease the FCP property of PPS/ZW+CF materials was similar to that for PPS/GF materials with high weight percentages of glass fibers. The rate of decrease of the mechanical property of PA46/AF materials were low, but the rate of decrease of the FCP property of PA46/AF materials was very high remarkably. (2) The carbon fibers in PPS/ZW+CF materials were not oriented in one direction because of the three dimensionality of the zinc oxide whiskers in the molding process, and effective orientation of the carbon fibers appeared on FCP resistance. (3) The value of da/dN was constant on the FCP property of PPS/ZW+CF materials at low stress intensity factor range (ΔK) because of microcrack initiation. (4) Aramide fibers (AF) were not broken and not unidirectionally oriented because of their flexibility during molding at high temperatures. The FCP property of recycled PA46/AF materials was influenced by the winding shape of the AF.