Effects of Irradiation Dose of Sheet-Like Electron Beam and its Cathode Voltage on Impact Strength of Carbon Fiber Reinforced Thermoplastic Polyamide just before Shipping

Abstract

Achieving a strong bond between carbon fiber (CF) and recyclable thermoplastic polymer (TP) has always been highly sought after. So far, applying electron beam (EB) irradiation with optimal dose and cathode potential (Vc) has shown success in increasing mechanical properties of interlayered CFRTPs. However, with concern for durability and safety, higher strength is desired. Therefore, EB setting applying electron beam (EB) irradiation with cathode potential (Vc) to 170, 210, 225 or 250 kV was applied to CFRTPA (carbon fiber reinforced thermoplastic polyamide) articles just before shipping. Specimens were 9 CF plies alternating between 10 PA (polyamide) sheets, designated [TPA]10[CF]9. When optimal EB dose of 43.2 kGy is applied to both finished specimen surfaces after fabrication, experimental results show higher Vc setting of 250 kV can increase impact strength of the [TPA]10[CF]9 over that at 170 kV. In summary, the 250 kV-EB (250 kV) strengthens [TPA]10[CF]9 significantly, about 25 to 27% larger than that of 170 kV and zero (untreated). Based on Christenhusz and Reimer equation to calculate penetration depth, Dth of EBI into polymers, increasing Vc to 250 kV increased Dth to more than 2 times that at 170 kV.