scholarly journals Comparison of the Processing of Epoxy Resins in Pultrusion with Open Bath Impregnation and Closed-Injection Pultrusion

2019 ◽  
Vol 3 (3) ◽  
pp. 87 ◽  
Author(s):  
Sebastian Strauß ◽  
Andreas Senz ◽  
Jessica Ellinger
Keyword(s):  
Shear Strength ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Interlaminar Shear Strength ◽  
Time Interval ◽  
Bending Stress ◽  
Epoxy Resin System ◽  
Pot Life ◽  
Interlaminar Shear ◽  
Composite Properties

In this study, the influence of the open bath and closed-injection pultrusion (CIP) processing methods of epoxy resins on the quality of glass fiber composites was investigated. In addition to the state-of-the-art epoxy resin system with long pot life, new resin systems with short pot life have recently been developed. These systems require processing by closed-injection pultrusion. The epoxies with long pot life allow both processing variants. The experimental work was carried out with two types of injection and impregnation chambers (ii_chamber), namely with a conical and a teardrop design. Fully impregnated composites, which were used for further analyses, could be produced by using the conical ii_chamber. The composite properties of the open bath and the conical ii_chamber impregnation methods were compared. No significant influence on the bending stress could be determined; the interlaminar shear strength was up to 10% better with open bath impregnation than with ii_chamber. For the composites investigated, it was shown that the open bath and ii_chamber impregnation methods can be used to produce parts with partially comparable properties, as demonstrated for the epoxy formulation with long pot life. These results indicate that processing of epoxy systems with a short pot life is also possible by closed-injection pultrusion. Furthermore, the influence on the composite properties of the time interval between the mixing of an epoxy resin and processing in an open bath was investigated. No significant effect on the bending stress and interlaminar shear strength could be determined.

Mechanical properties of multiwall carbon nanotubes/unidirectional carbon fiber-reinforced epoxy hybrid nanocomposites in transverse and longitudinal fiber directions

2021 ◽  
pp. 096739112098651
Author(s):  
Saeedeh Saadatyar ◽  
Mohammad Hosain Beheshty ◽  
Razi Sahraeian
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Epoxy Resin ◽  
Interlaminar Shear Strength ◽  
Lap Shear Strength ◽  
Transverse Tensile ◽  
Lap Shear ◽  
Longitudinal Fiber ◽  
Interlaminar Shear ◽  
Multiwall Carbon

Unidirectional carbon fiber-reinforced epoxy (UCFRE) is suffering from weak transverse mechanical properties and through-thickness properties. The effect of different amount (0.1, 0.3 and 0.5 phr which is proportional to 0.09, 0.27 and 0.46 wt%, respectively) of multiwall carbon nanotube (MWCNT), on transverse tensile properties, flexural strength, fracture toughness in transverse and longitudinal fiber directions, interlaminar shear strength and lap shear strength of UCFRE has been investigated. Dicyandiamide was used as a thermal curing agent of epoxy resin. MWCNT was dispersed in the epoxy resin by ultrasonic instrument and their dispersion state was investigated by scanning electron microscopy (SEM). The curing behavior of epoxy resin and its nanocomposites was assessed by differential scanning calorimetry. Results show that transverse tensile strength, modulus and strain-at-break were increased by 28.5%, 25% and 14%, respectively by adding 0.1 phr of MWCNT. Longitudinal flexural properties of UCFRE was not changed by adding different amount of MWCNT. Although longitudinal flexural strength was increased by 5% by adding 0.1 phr of MWCNT. Fracture toughness in transverse and longitudinal fiber directions was increased by 39% and 9%, respectively at 0.3 phr of MWCNT. Results also show that interlaminar shear strength and lap shear strength were increased at 0.3 phr of MWCNT by 8% and 5%, respectively. These increases in mechanical properties were due to the good adhesion of fibers to the matrix, interlocking and toughening action of MWCNT as revealed by SEM.

Addition of a small amount of multiwalled carbon nanotubes and flaked graphene to epoxy resin

2017 ◽  
Vol 36 (9) ◽  
pp. 640-654 ◽  
Author(s):  
Mateusz Koziol ◽  
Marcin Jesionek ◽  
Piotr Szperlich
Keyword(s):  
Carbon Nanotubes ◽  
Shear Strength ◽  
Flexural Strength ◽  
Epoxy Resin ◽  
Impact Resistance ◽  
Gelation Time ◽  
Interlaminar Shear Strength ◽  
Multiwalled Carbon ◽  
Professional Literature ◽  
Interlaminar Shear

The paper presents an attempt to evaluate the technically important properties of epoxy resin modified alternatively with multi-walled carbon nanotubes and flaked graphene. It is a presentation of experimental results supported by extensive referring to the professional literature. The nano-components were added in the amount which was economically justified and provides hope for a significant improvement of some of the properties of pure resin. Flowability, glass wettability, curing process and gelation time and curing shrinkage of the resin were evaluated. After the resin was cured, inner and outer hardness, thermal conductivity, flexural strength and impact resistance were measured. Glass fibre-reinforced laminates were also prepared with use of the nano-modified resin. The mechanical properties, interlaminar shear strength and flexural strength of the laminates, were evaluated for them. The obtained results showed either no effect or only technically slight effect of the nano-modification on the evaluated properties. Noticeable improvement in interlaminar shear strength and impact resistance for laminates containing resin filled with graphene can predestine this kind of modification as a method of increasing the delamination resistance of laminates.

scholarly journals Ultrasound assisted process for enhanced interlaminar shear strength of carbon fiber/epoxy resin composites

2010 ◽  
Vol 29 (2) ◽  
pp. 149 ◽  
Author(s):  
Gordana Bogoeva-Gaceva ◽  
Niko Heraković ◽  
Dimko Dimeski ◽  
Viktor Stefov
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Interlaminar Shear Strength ◽  
Carbon Fiber Composites ◽  
Resin Composites ◽  
Scanning Calorimetry ◽  
Epoxy Resin Composites ◽  
Interlaminar Shear ◽  
Carbon Fiber Epoxy

The influence of ultrasonic treatment, applied during the impregnation of carbon fiber bundle by resin system, on interface sensitive properties of carbon fiber/epoxy resin composites has been analyzed. The formation of the network has been followed on model composites containing untreated, oxidized and epoxy sized fibers by Fourier transform infrared microscopy (FTIR-microscopy) and differential scanning calorimetry (DSC). The enhanced interlaminar shear strength (ILSS), found for the composites treated by ultrasound, is attributed to the formation of more homogeneous and dense network, which is especially pronounced for epoxy sized carbon fiber composites.

Effect of consolidation force on interlaminar shear strength of CF/PEEK laminates manufactured by laser-assisted forming

2021 ◽  
Vol 266 ◽  
pp. 113779
Author(s):  
Qiuyu Miao ◽  
Zhihong Dai ◽  
Guangyi Ma ◽  
Fangyong Niu ◽  
Dongjiang Wu
Keyword(s):  
Shear Strength ◽  
Interlaminar Shear Strength ◽  
Interlaminar Shear

Surface and Composite Interface of Carbon Fiber Modified by Grafting of Diethanolamine

2009 ◽  
Vol 79-82 ◽  
pp. 497-500 ◽  
Author(s):  
Lei Chen ◽  
Zhi Wei Xu ◽  
Jia Lu Li ◽  
Xiao Qing Wu ◽  
Li Chen
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Functional Groups ◽  
Carbon Fibers ◽  
Irradiation Dose ◽  
Interlaminar Shear Strength ◽  
Epoxy Composites ◽  
Composite Interface ◽  
Γ Ray ◽  
Interlaminar Shear

The γ-ray co-irradiation method was employed to study the effect of diethanolamine modification on the surface of carbon fiber (CF) and the interfacial properties of CF/epoxy composites. Compared with the original carbon fiber, the surface of modified fibers became rougher. The amount of oxygen-containing functional groups was increased and the nitrogen element was detected after irradiation grafting. The interlaminar shear strength (ILSS) of composites reinforced by carbon fibers irradiated in diethanolamine solution was increased and then decreased as the irradiation dose increased. The ILSS of CF/epoxy composites was enhanced by 16.1% at 200kGy dose, compared with that of untreated one. The γ-ray irradiation grafting is expected to be a promising method for the industrialized modification of carbon fibers.

Ramie fiber reinforced composites with flame retardant structure design: flammability, smoke suppression, and mechanical properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chenkai Zhu ◽  
Lei Nie ◽  
Xiaofei Yan ◽  
Jiawei Li ◽  
Dongming Qi
Keyword(s):  
Shear Strength ◽  
Iron Oxide ◽  
Heat Release ◽  
Flame Retardant ◽  
Interlaminar Shear Strength ◽  
Smoke Suppression ◽  
Strength Analysis ◽  
Ramie Fiber ◽  
Composite Surface ◽  
Interlaminar Shear

Abstract In this work, the structure of composite was designed as Core Stack and Surface Stack, which was treated with the expandable graphite (EG) and metal oxides such as iron oxide (IO), hydroxyapatite (HA), and aluminum tri-hydroxide (ATH). The mechanical performance of composites was characterized via flexural performance and interlaminar shear strength analysis. The flame retardance and smoke suppression of composite was explored in detail by LOI, UL-94, and cone calorimeter test. The findings presented that flexural properties of composites were observed to decrease due to delamination of surface stack, whilst no significant effect on interlaminar shear strength. In comparison with control composite, the loading of metal oxide into composite Surface Stack led to the reduction of peak heat release rate, total heat release, and fire growth index effectively. Moreover, the remarkable decrease in total smoke production could be observed due to the addition of iron oxide and the flame retardant mechanism was discussed. This study was the preliminary exploration of composite with flame retardant design which could be potential solution to improve flame retardancy and smoke suppression of composite with better mechanical structure preservation.

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