Composites Based on Polyphtalamides Matrices and Continuous Glass Fibers: Rheology- Processing and Properties Relationships (original) (raw)
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Journal of Composite Materials, 2019
The present research aims at studying the kinetics of non-isothermal crystallization of the polyamide 66 matrix and its composites with the presence of a glass fiber load. To achieve that goal, the non-isothermal crystallization of polyamide 66 has been studied by means of DSC. The ratio of tested reinforcement varies from 7% to 50% of glass fiber in mass. The modeling, by the theories of Jeziorny and those of Mo, has allowed us to study the influence of adding this reinforcement, as well as the variation of the rate of cooling, on the kinetics of crystallization of the composites in question, which has been manifested by a remarkable change in the nucleation mechanism of the polyamide 66 matrix. Regarding the reinforcement effect, the incorporation of the glass fibers load into the polyamide 66 matrix has caused the appearance of exothermic peaks in a higher temperature range and that for all the working materials. Finally, the results showed that the Mo model is the most suitable ...
Journal of Composite Materials, 2019
Characterizing the thermomechanical properties of thermoplastic resins and associated composites is of outmost importance to understand the development of process-induced stresses. To that extent, the characterization of a low viscosity PA66 matrix is proposed thanks to a homemade volumetric dilatometer named PvT-XT and a dynamic mechanical analyser on a wide temperature range. The PvT-XT results, reported for the first time, permit to identify the evolution of the coefficients of thermal expansion, of crystallization shrinkage and of the bulk modulus with temperature. Dynamic mechanical analyser experiments lead to the estimation of the Young’s modulus. The shear modulus as well as the Poisson’s ratio are then estimated thanks to analytical relations for isotropic and homogeneous materials. These properties are used to feed a new analytical model estimating the coefficients of thermal expansion of quasi-unidirectional composites. All the results are compared with the values from th...
Nowadays, additive manufacturing is being used in various industries such as automotive, aviation and space, medical applications, etc. Although additive manufacturing methods offer more freedom in design and manufacturing, they usually have low production speed and mechanical properties. Continuous carbon fiber reinforced thermoplastic (CFRTP) composites are one of the investigated methods in the literature to increase the mechanical properties of the additively manufactured parts. This study utilized a production line based upon the melt impregnation method to obtain continuous carbon fiber reinforced thermoplastic filaments using polyamide and continuous carbon fibers. In the printing process, an infrared heat source was utilized to further increase the mechanical properties by improving the interlaminar bonding. The mechanical properties of the printed parts were measured using three-point bending tests. A significant increase was observed in flexural modulus of elasticity and flexural strength with infrared heaters at low printing speeds. A maximum value of 418.99 MPa flexural strength and 52.15 GPa flexural modulus was achieved.
THERMOMECHANICAL BEHAVIOUR OF SHORT GLASS FIBRE REINFORCED POLYAMIDE
Short Glass Fibre Reinforced Polyamide 6.6 composites are increasingly used in structural automotive applications. The resulting fibre distribution within injection-moulded components has a major impact on their mechanical properties due to the complex flow path taking place while filling the mould. Even for simple structural geometries, resulting mechanical fields are heterogeneous. Moreover, the mechanical behaviour of polyamide composites is sensitive to mechanical loads and especially to environmental hygrothermal conditions. In this work, we propose to use Infrared Thermography to monitor heterogeneous energy dissipation during tensile tests for different PA66GF35 specimens with non uniform fibre distributions. In addition, Launay's thermoelasto-viscoplastic constitutive model was used to simulate temperature evolution during the tests. It is shown that particular attention must be paid to improve filling particles distribution considerations for a right prediction of thermoelastic coupling.
Nucleus, 2009
Short glass fiber (SGF) reinforced composite materials were principally fabricated using polypropylene (PP) as thermoplastic matrix. Short glass fiber and polypropylene frequently suffer from lack of adequate fiber-matrix adhesion. This problem was addressed by grafting polypropylene (PP) with maleic anhydride (MA) in the presence of benzyl peroxide (BPO) as an initiator. The results revealed that by increasing fiber contents from 5 to 40 %, tensile strength increases while elongation at break decreases. Rheological behavior was found to be pseudoplastic, whereas viscosity increases by increasing SGF contents. A decrease in die swell was observed with increase in SGF contents.
Composites Part A: Applied Science and Manufacturing, 1996
The tensile dynamic behaviour of glass fibre-reinforced phenolic and polyester resins has been determined in order to find the influence of strain rate on the mechanical properties of composite materials produced by the resin transfer moulding (RTM) and pultrusion processes. Data and experimental test systems from the literature are analysed. A new specimen design is created and validated using drop-weight dynamic tests. The dynamic elastic modulus and strength tend to increase in an important ratio for the majority of the materials studied. The shear modulus measured with off-axis and f 45" coupons produces different effects as a function of strain rate. The influence of the reinforcement structure is emphasized and shown to be effective. Copyright 0 1996 Elsevier Science Limited (Keywords: tensile bebaviour; strain rate eff&, pbenolic and polyester resins, glass fibres)
Hybrid Manufacturing and Experimental Testing of Glass Fiber Enhanced Thermoplastic Composites
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Additive Manufacturing (AM) is gaining enormous attention from academic and industrial sectors for product development using different materials. Fused Deposition Modelling (FDM) is a popular AM method that works with thermoplastics. This process offers benefits of customisation both in terms of hardware and software in the case of desktop-based FDM systems. Enhancement of mechanical properties for the traditional thermoplastic material is a widely researched area and various materials have been added to achieve this goal. This paper focuses on the manufacture of glass fiber reinforced plastic (GFRP) composites using Hybrid Fused Deposition Modelling (HFDM). Commonly available polylactic acid or polylactide (PLA) material was inter-laced with 0.03 mm thick glass fiber sheets to manufacture GFRP products followed by tensile testing. This was done to investigate whether adding more layers increases the tensile strength of the GFRP products or not. Furthermore, the maximum number of gl...
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Composites Part A: Applied Science and Manufacturing, 1996
The fundamental aspects of the processing of thermosetting matrix composites with short fibres in compression moulding technologies are presented. The reaction kinetics and the rheology of compounds based on unsaturated polyester matrices have been characterized as a function of different processing variables (temperature and shear rate). The effects of the filler (calcium carbonate) and the reinforcement (glass fibres) on the curing kinetics of unsaturated polyester resins were studied by differential scanning calorimetry (d.s.c.), and the rheological properties of the compounds were analysed using parallel-plate rheometry. The results of the d.s.c. characterization were used to develop an empirical kinetic model accounting for diffusion control effects, while d.s.c. and rheological measurements were combined to obtain correlations between viscosity, extent of reaction, temperature and shear rate. The complete chemorheological model was verified through rheological tests performed at different heating rates and angular frequencies. The model developed in this work has been integrated into a general processing model for the description of the moulding behaviour of thermosetting matrix compounds for automotive applications. Excellent agreement between model predictions and experimental results has been obtained.
Polymer Composites, 2010
An innovative manufacturing process for continuous fiber composites with the polymeric matrix made up of polypropylene and epoxy resin, as a model reactive low molecular weight component, was developed; variable process parameters give rise to different morphologies of matrix components surrounding the woven fabric reinforcement. Furthermore, the combination of both thermoplastic and thermosetting polymers permitted intimate fibers impregnation, typical of thermosetting matrix composites, with short process cycle time, which usually occurs in manufacturing process of thermoplastic matrix composites. Polypropylene (PP) films, glass fibers fabric, and epoxy resin film were used to produce flat composite through film-stacking technique. The preparation process focused on control of both epoxy resin cure process and polypropylene melting. The process was able to induce the two matrix components to form either a planar (sandwichlike) structure or a three-dimensional (3D) network by means of controlling the process parameters such as pressure and heating rate. The strong enhancement of the mechanical properties (Young's modulus and tensile strength of the composites with the 3D structure were almost twice as high of those of the composites with sandwich-like matrix structure) was due to the different microstructures produced by the interplanar flow of the thermoplastic polymer.
New thermoplastic matrix composites for demanding applications
Plastics, Rubber and Composites, 2009
The PRIMOSPIRE ® PR 120 thermoplastic polymer from Solvay Advanced Polymers, a new polymeric material for highly demanding applications, was studied in this work. The relevant properties of the polymer were determined and a new prototype powder coating equipment was designed and manufactured in order to use the primospire polymer as a powder matrix in the production of carbon fibre based towpregs [1]. The obtained results lead us to conclude that this new polymer has very interesting mechanical properties for highly demanding markets. It was also possible to produce continuously good primospire/carbon fibre towpregs for being subsequently processed by compression moulding into final composite plates. Finally, relevant mechanical properties were determined on the manufactured composite plates.