Homogeneous Low Energy Electron Beam Research Articles

Increasing Bending Strength of Polycarbonate Reinforced by Carbon Fiber Irradiated by Electron Beam.

In an interlayered carbon fiber-reinforced polycarbonate polymer (CFRPC) composite composed of three sized of CF plies, alternating between four PC sheets, designated [PC]4[CF]3, and a new process of activating CF cross-weave cloth plies directly on both sides with homogeneous low-energy electron beam irradiation (HLEBI) before lamination assembly and hot pressing at 6.0 MPa and 537 K for 8 min was produced. Experimental results show that a dose of 215 kGy of HLEBI raised the bending strength, σb, at each experimental accumulative probability, Pa, with the σb at a median Pa of 0.50, increasing by 25% over that of the untreated sample. Three-parameter Weibull analysis showed that when quality can be controlled, a dose of 215 kGy of HLEBI can raise the statistically lowest bending strength, σs, at Pa = 0 (94.3 Mpa), with a high correlation coefficient. This is because, although it had a higher bending strength than that in the other experimental conditions, the weakest sample of the 215 kGy data set had a much lower σb value than that of the others. Electron spin resonance (ESR) of the CF showed that naturally occurring dangling bonds in CF were increased at 215 kGy. Charge transfer to the PC occurs, apparently generating stronger bonds, which are possibly covalent, resulting in enhanced adhesion at the CF-PC interface.

Strengthening Process by Electron Beam to Carbon Fiber for Impact Strength Enhancement of Interlayered Thermoplastic-Polypropylene Carbon Fiber Composite.

Strong adhesion between recyclable thermoplastic (TP) polymer and carbon fiber (CF) has always been highly sought after. Therefore, for an interlayered CF reinforced TP polypropylene (CFRTPP) composite composed of 3 sized CF plies, alternating between 4 PP sheets, designated [PP]4[CF]3, a process of activating CF plies directly on both sides with homogeneous low energy electron beam irradiation (EBI) under N2 gas, prior to lamination assembly and hot press of 4.0 MPa at 493 K for 3 min was carried out. Experimental results showed EBI dose of 43.2, 129, or 216 kGy significantly raised Charpy impact values, auc at all fracture probabilities, Pf. The 129 kGy dose appeared to be at or near optimum increasing auc 103%, 83%, and 65% at low-, median-, and high-Pf = 0.07, 0.50, and 0.93; while raising statistically lowest impact value, as at Pf = 0 calculated by 3-dimensional Weibull equation about 110%, indicating increased safety and reliability. It is assumed dangling bonds generated by the EBI rapidly form covalent bonds CF:C:O:C:PP and CF:C:C:PP at the interface, along with cross-linking in the PP near the CF. This is by charge transfer from CF to PP.

Effects of Homogeneous Low Energy Electron Beam Irradiation (HLEBI) on Adhesive Energy of Peeling Resistance of Laminated Sheet with Polyurethane (PU) and Polyethylene Terephthalate (PET)

2-layer laminated sheets (PU/PET) with Polyurethane (PU) and Polyethylene Terephthalate (PET) were prepared by a new adhesion method, a double-step treatment consisting of applying low dose (≦ 1.72 MGy) homogeneous low energy electron beam irradiation (HLEBI) prior to hot-press under 3 MPa and 348 K. Although the weak hot-press adhesion of the PU/PET was observed without HLEBI, the new adhesion mostly raised the bonding energy as evidenced by the mean adhesive energy of peeling resistance (oEp). Based on the 3-parameter Weibull equation, the lowest oEp value at peeling probability (Pp) of zero (Es) could be estimated. An increasing trend in Es occurred by the double-step treatment applying HLEBI up to 1.29 MGy reaching a maximum at 1.83 kJ·m−1, improving the safety level without radiation damage. When HLEBI cut the chemical bonds in PU and generated terminated atoms with dangling bonds, they probably induced the chemical bonding. Therefore, increasing adhesion energy between the laminated sheets could be explained.

High Adhesive Force between Laminated Sheets of Titanium and Polyurethane Improved by Homogeneous Low Energy Electron Beam Irradiation Prior to Hot-Press

2-layer copper/polyurethane (Cu/PU) laminated sheets were prepared by a new adhesion method, a double-step treatment consisting of applying low dose (1⁄40.43MGy) homogeneous low energy electron beam irradiation (HLEBI) prior to hot-press under 5MPa and 413K. Although the weak hot-press adhesion of the Cu/PU was observed without HLEBI, the new adhesion raised the bonding forces as evidenced by the mean adhesive forces of peeling resistance (Fp). Based on the 3-parameter Weibull equation, the lowest Fp value at peeling probability (Pp) of zero (Fs) could be estimated. An increasing trend in Fs occurred by the double-step treatment applying HLEBI up to 0.13MGy reaching a maximum at 27.1Nm11, improving the safety level without radiation damage. When HLEBI cut the chemical bonds in PU polymer and generated terminated atoms with dangling bonds, they probably induced the chemical bonding and intermolecular coulomb attractive forces. Therefore, increasing adhesion force between the laminated sheets could be explained. [doi:10.2320/matertrans.MBW201312]

Internal Activation of Thermoplastic Polypropylene GFRTP Composite by Homogeneous Low Energy Electron Beam Irradiation (HLEBI) of the Interlayered Glass Fiber Chopped Strand Mats (GF-CSM) Prior to Assembly

Internal Activation of Thermoplastic Polypropylene GFRTP Composite by Homogeneous Low Energy Electron Beam Irradiation (HLEBI) of the Interlayered Glass Fiber Chopped Strand Mats (GF-CSM) Prior to Assembly

低エネルギー電子線均質照射によるポリプロピレン(PP)とナイロン 6(PA6)積層シートの高速接着

2-layer laminated sheets (PP/PA6) with polypropylene (PP) and nylon 6(PA6) were prepared by applying low dose homogeneous low energy electron beam irradiation (HLEBI) prior to hot-press under 10 MPa, 403 K and 3 min. Although the adhesion of the PP/PA6 was often observed with a weak hot-press without HLEBI, the HLEBI (≦1.29 MGy) induced adhesion raised the bonding forces as evidenced by using the adhesive forces of peeling resistance (oFp). Based on the 3-parameter Weibull equation, the lowest oFp value at peeling probability (Pp) of zero (Fs) could be estimated. An increasing trend in Fs occurred by applying HLEBI up to 0.64 MGy reaching a maximum at 21.98 Nm−1, improving the safety level without radiation damage. When HLEBI cut the chemical bonds in PP polymer and generated not-terminated atoms having dangling bonds, they probably induced the chemical bonding. Thus, increasing adhesion force between the laminated sheets could be explained.

Effects of Homogeneous Low Energy Electron Beam Irradiation (HLEBI) on Adhesive Force of Peeling Resistance of Laminated Sheet with Polyethylene (PE) and Austenitic 18-8 Stainless Steels

Effects of Homogeneous Low Energy Electron Beam Irradiation (HLEBI) on Adhesive Force of Peeling Resistance of Laminated Sheet with Polyethylene (PE) and Austenitic 18-8 Stainless Steels

電子線微量照射によるポリウレタン(PU)とポリエチレンテレフタレート(PET)の高速均質接着

電子線微量照射によるポリウレタン(PU)とポリエチレンテレフタレート(PET)の高速均質接着

電子線照射したガラス繊維強化熱可塑性ポリプロピレン樹脂の弾性率と引張強度の向上

Homogeneous low energy electron beam irradiation (HLEBI) to surface mostly improved the bending elastic modulus (b(dσ/dε)i) and tensile stiffnesst (t(dσ/dε)i) of composites sheets of glass fiber reinforced thermoplastic polypropylene (GFRTP). Although increasing dose of HLEBI decayed the ductility, optimal dosage of HLEBI from 0.22 to 0.86 MGy often improved the tensile strength (tσb) of the GFRTP with smaller variation in the data than untreated one. Based on the three parameter Weibull equation, the tσb at the lowest cummulative probability of fracture (Pf=zero) was estimated and defined as the lowest tensile strength (tσs). The highest tσs value estimated was 54 MPa for GFRTP irradiated at 0.65 MGy. Strengthening of both glass fiber and polypropylene, as well as their interfacial friction force mainly contributed to the results.

Improvement of Low-Temperature Impact Value of Sandwich-Structural (CFRP/ABS/CFRP) Laminate Plies by Homogeneous Low-Energy Electron Beam Irradiation (HLEBI)

Improvement of Low-Temperature Impact Value of Sandwich-Structural (CFRP/ABS/CFRP) Laminate Plies by Homogeneous Low-Energy Electron Beam Irradiation (HLEBI)

WeB-3-4 Adhesion of Lamination Joint of Austenite Stainless Steel and CFRP treated by Homogeneous Low Energy Electron Beam Irradiation (HLEBI) Prior to Hot-Press

WeB-3-4 Adhesion of Lamination Joint of Austenite Stainless Steel and CFRP treated by Homogeneous Low Energy Electron Beam Irradiation (HLEBI) Prior to Hot-Press

Effects of Homogeneous Low Energy Electron Beam Irradiation (HLEBI) on Adhesive Force of Peeling of Carbon Fiber Reinforced Epoxy Polymer (CFRP) and Polytetrafluoroethylene (PTFE)

Effects of Homogeneous Low Energy Electron Beam Irradiation (HLEBI) on Adhesive Force of Peeling of Carbon Fiber Reinforced Epoxy Polymer (CFRP) and Polytetrafluoroethylene (PTFE)

Adhesive Force Improvement of Polyethylene Terephthalate (PET)/Epoxy Resin Joint by Electron Beam to PET Prior to Assembly

Adhesive 2-layer lamination joints of polyethylene terephthalate (PET)/epoxy resin were prepared without the use of hot press using a new adhesion method of applying homogeneous low energy electron beam irradiation (HLEBI) to the PET prior to assembly by hand pressure. HLEBI treatment within the range of 0.13 to 0.43 MGy increased the adhesive force of peeling (oFp) substantially over the untreated. The largest oFp values at optimal dose 0.30 MGy were 12.4, 37.2 and 190 Nm−1, which were more than 2.2, 2.8 and 9.5 times larger than 5.76, 13.5 and 20.0 Nm−1 of the untreated at low-, median- and high peeling force accumulative probability, Pp of 0.06, 0.50 and 0.94, respectively. The statistically lowest oFp for safety design (Fs at Pp = 0) iterated by the 3-parameter Weibull equation was raised from zero for the untreated to 10.7 Nm−1 for the 0.30 MGy samples indicating increased reliability by the HLEBI. XPS (X-Ray Photoelectron Spectroscopy) observations of the peeled 0.30 MGy HLEBI PET revealed generation of a C-O peak at 286 eV possibly explaining the increased adhesion. Therefore residual epoxy deposition is apparently found to be retained on the PET sheet by inter-matrix fracture of epoxy resin further into the thickness. This can be explained by the adhesion force from crosslinking between PET/epoxy being stronger than the cohesive force of epoxy polymer itself. Since the experimental data shows the optimum HLEBI dose is about 0.30 MGy, above which at 0.43 MGy the oFp begins to drop, carefulness in optimization is highly recommended when applying in industry to insure safety.

Creation of Adhesive Force between Laminated Sheets of Polytetrafluoroethylene (PTFE) and Polyethylene (PE) by Homogeneous Low Energy Electron Beam Irradiation Prior to Hot-Press for Bio-Adaptable Application

Bio-adaptable 2-layer polytetrafluoroethylene/polyethylene (PTFE/PE) laminated sheets were prepared by a new adhesion method, a double-step treatment consisting of applying low dose (¼0.43MGy) homogeneous low energy electron beam irradiation (HLEBI) to the 2-layer assembly where the HLEBI penetrates through the PTFE and PE layers, respectively, prior to hot-press under 5MPa and 433K. Although the adhesion of the PTFE/PE sheets cannot be observed without the new double-step treatment, bonding forces were created as evidenced by the mean adhesive forces of peeling resistance ( o Fp). The adhesion cannot be observed without HLEBI. On the other hand, application of a small dose of HLEBI (less than 0.43MGy) prior to hot-press lamination enhances the o Fp at each Pp. The maximum o Fp values at each Pp (0.06, 0.50 and 0.94) of the laminated sheet irradiated at 0.13, 0.13, and 0.22MGy are 5.44, 10.7, and 19.7Nm ¹1 , respectively. Based on the 3-parameter Weibull equation, the lowest o Fp value at Pp of zero (Fs) could be estimated. An increasing trend in Fs occurs by the double-step treatment applying HLEBI up to 0.43MGy reaching a maximum at 2.66Nm¹1, improving the safety level without radiation damage of PTFE/PE. It was more than 6 times higher than that of PTFE/Polyurethane (PU) (0.4Nm ¹1 ). When HLEBI cuts the chemical bonds and generates dangling bonds with nonbonding electrons in PTFE and PE, the created adhesion between the laminated sheets can be explained. Based on X-ray photoelectron spectrometer (XPS) surface analysis of the PTFE/PE laminated sheets after the peeling tests, fluorine (F) was detected on the PE peeled surface, indicating both strong chemical and intermolecular bonds generated by the double-step treatment. For these reasons, double-step treatment is a useful method for quick lamination of PTFE and PE with sterilization without the use of glue. [doi:10.2320/matertrans.M2013247]

Shear Strength of Adhesive Lamination Joint of Aluminum and CFRP Sheets Treated by Homogeneous Low Energy Electron Beam Irradiation Prior to Lamination Assembly and Hot-Press

Adhesive 2-layer lamination joint of aluminum/carbon fiber reinforced epoxy polymer (Al/CFRP) were prepared by a new adhesion method, a double-step treatment consisting of applying low dose (= 0.22MGy) of homogeneous low energy electron beam irradiation (HLEBI) to the CFRP and Al prior to lamination assembly and hot-press in vacuum below 1Pa for 2h at 403K. No fasteners or external adhesives were applied: the cured epoxy enhanced by the HLEBI acts as the adhesive to the Al. The new treatment apparently boosted shear strength (¸) of the Al/CFRP 45% at low shear strength probability (Ps=0.06) at 0.22MGy. XPS (X-ray photoelectron spectrometry) measurements detected carbon on the shear fractured Al interface indicating the residual epoxy adhered well to the Al by the HLEBI. This is probably a result of adhesion force of Al/CFRP being made stronger than the cohesive force of epoxy polymer in the CFRP itself. When HLEBI cuts the chemical bonds and generates active terminated atoms with dangling bonds in epoxy polymer, the nonbonding electrons probably induced the chemical bonding and intermolecular coulomb attractive forces at the interface. Hence, the increased adhesion force in the Al/CFRP joint can be explained. [doi:10.2320/matertrans.MAW201419]

Effects of Homogeneous Low Energy Electron Beam Irradiation (HLEBI) on Water Absorption and Hydrolysis Suppression of High Strength Polycarbonate

In order to evaluate effects of homogeneous low energy electron beam irradiation (HLEBI) on water absorption and hydrolysis suppression, the mass gain and loss of high strength polycarbonate (PC) dipped in boiling water after drying was obtained. Dipping for less than 5 © 103 s increased the mass gain ratio (Cw) for all PC samples, although remarkable mass gain could not be detected from 5 © 103 to 2 © 105 s. HLEBI with small dose from 0.04 to 0.13MGy mostly suppressed the Cw value for initial dipping time for less than 5 © 103 s. 0.04MGy-HLEBI slightly enhanced the experimental saturated Cw values at 104 s-dipping (Cw). Based on the Johnson-Mehl equation, the initial absorption index (n) for PC with and without HLEBE was approximately equal to 0.5, which was approximately equal to that of nylon6. Since esteratic sites attracted the water molecules in PC polymers, the water absorption can be explained. On the other hand, the small mass loss could be detected of PC dipped in boiling water for 105 s prior to drying, although that for 104 s could not be detected. HLEBI suppressed the mass loss, 40 +/1 20% smaller than that untreated, for PC dipped in boiling water for 2 © 105 s prior to drying. Since HLEBI probably cut off the >C=O bonds in aldehyde base in PC polymers. Based on the FT-IR (>C=O bonds) signals, the intensity of untreated PC polymer is more than 15.7% higher than that after 0.13MGy irradiation. Thus, HLEBI suppressed the hydrolysis of PC. [doi:10.2320/matertrans.MBW201314]

High Adhesive Force between Laminated Sheets of Copper and Polyurethane Improved by Homogeneous Low Energy Electron Beam Irradiation (HLEBI) Prior to Hot-Press

High Adhesive Force between Laminated Sheets of Copper and Polyurethane Improved by Homogeneous Low Energy Electron Beam Irradiation (HLEBI) Prior to Hot-Press

Creation of Adhesive Force between Laminated Sheets of Polyurethane (PU) and Polytetrafluoruethylene (PTFE) by Homogeneous Low Energy Electron Beam Irradiation Prior to Hot-Press for Bio-Adaptable Application

Bio-adaptable 2-layer polyurethane/polytetrafluoroethylene (PU/PTFE) laminated sheets were prepared by a new adhesion method, a double-step treatment consisting of: (1) applying low dose <0.65MGy homogeneous low energy electron beam irradiation (HLEBI) to the 2-layer assembly where the HLEBI penetrates through the PU and PTFE layers, respectively, prior to: (2) hot-press under 5MPa and 403K. Although the adhesion of the PU/PTFE sheets cannot be observed without the new double-step treatment, bonding forces were created as evidenced by the mean adhesive forces of peeling resistance ( o Fp). Based on the 3-parameter Weibull equation, the lowest o Fp value at Pp of zero (Fs) could be estimated. An increasing trend in Fs occurs by the double-step treatment applying HLEBI up to 0.43MGy reaching a maximum at 0.38Nm ¹1 , improving the safety level without radiation damage. When HLEBI cuts the chemical bonds and generates dangling bonds with nonbonding electrons in PU and PTFE, the created adhesion between the laminated sheets can be explained. Based on X-ray photoelectron spectrometer (XPS) surface analysis of the PU/PTFE laminated sheets after the peeling tests, fluorine (F) was detected on the PU peeled surface, indicating the strong chemical bonding generated by the double-step treatment. For these reasons, double-step treatment is a useful method for quick lamination of PU and PTFE with sterilization without the use of glue. [doi:10.2320/matertrans.MBW201216]

Creation of Adhesive Force between Laminated Sheets of Aluminum and Polyurethane by Homogeneous Low Energy Electron Beam Irradiation Prior to Hot-Press

2-layer aluminum/polyurethane (Al/PU) laminated sheets were prepared by a new adhesion method, a double-step treatment consisting of: (1) applying low dose 50:43MGy homogeneous low energy electron beam irradiation (HLEBI) to the 2-layer assembly where the HLEBI penetrates through the Al and PU layers, respectively, prior to: (2) hot-press under 5MPa and 403K. Although the adhesion of the Al/PU sheets cannot be observed without the new double-step treatment, bonding forces were created as evidenced by the mean adhesive forces of peeling resistance (Fp). Based on the 3-parameter Weibull equation, the lowest Fp value at peeling probability (Pp) of zero (Fs) could be estimated. An increasing trend in Fs occurs by the double-step treatment applying HLEBI up to 0.22MGy reaching a maximum at 34.0Nm11, improving the safety level without radiation damage. When HLEBI cuts the chemical bonds and generates dangling bonds with nonbonding electrons in Al and PU, the created adhesion between the laminated sheets can be explained. [doi:10.2320/matertrans.MAW201314]