One of the advantages of the T_RTM process of polyamide 6 is that the low viscosity of the molten monomer, ɛ-caprolactam (CL), allows to infiltrate it through the fiber, in a process very similar to the RTM of the thermoset materials. In this process the APA6 polymerizes and crystallizes during the molding process, being these two factors the ones that will provide the final properties to the material.
Therefore, the knowledge, modeling and simulation of the effect of the process variables on these two phenomena would allow to optimize time/properties ratio in order to develop a strong and competitive manufacturing process.
In the RTM 4.0 project, the effect of the different process variables on the crystallization and polymerization of APA6 has been studied through of different characterization and monitoring techniques. This work presents the results of the study of the influence of the type of reinforcement of the polymerization of the material. The results obtained indicate that repetitive and homogeneous polymerization degrees are achieved regardless of the type of reinforcement used.
Under the NANOTEK+ project, POLIFLUOR and TECNALIA propose to develop and scale industrially a polyamide obtained by direct synthesis. These properties, mainly thermal ones, have to be improved by the addition of nanoparticles. To this end, it has been worked in the dispersión of the nanoparticles and the process of polymerization, and in the industrial production process and its evaluation from the point of view of the health security. In-situ polymerization process of anionic polyamide 6 offers important advantages for the incorporation of nanoparticles because the low viscosity of the monomer make easier the dispersion of the nanoscale reinforcemenet. Several parameters of the process have to be taken into account during the up scaling: Selection of the suitable nanoparticles and their percentage, taking into account the dispersion ability in the matrix and their chemical compatibility. Percentage of catalytic system, which can be affected by the nature of the nanoparticles. Melting, feeding and polymerization temperatures, which should not degrade the nanoparticle. Mixing rates, since the dispersion of the nanoparticles by mechanical stirring can produce air inside the obtaindes polymer. The distribution of the nanomaterial in the polymer matrix and the adhesion degree between both, have studied under formulated material, using techniques such as SEM/EDS. The correct distribution of the nanoparticles in the polyamide 6 has been observed thoughout the industrialization.
Abstract
Under the NANOTEK+ project, POLIFLUOR and TECNALIA propose to develop and scale industrially a polyamide obtained by direct synthesis. These properties, mainly thermal ones, have to be improved by the addition of nanoparticles. To this end, it has been worked in the dispersión [...]
The main objective of this work has been the manufacture , and subsequent flexural and fatigue tests, of automotive real parts, made of thermoplastic composites. This has been achieved by incorporation continuous carbon fiber (textile) to polyamide matrix, through an specific process very similar to a thermoplastic RTM. The fatigue behaviour of any composite is governed by the toughness of the material. Because of this and the low cost, the polyamide has been considered as a polymer matrix. The process involves an in-situ polymerization, that the low viscosity of the monomer,e-caprolactama (e-CL), allows the infiltration of preforms and textiles. The demonstration part has been completely redesigned by BATZ and TECNALIA to fullfill mechanical requirements and manufacture ability. In particular, it has been fabricated a suspension subframe with an 52%vol. of a commercial carbon fiber and thickness variations from 3 to 8mm within the same part, obtaining a significant reduction in weight relative to the metal part (6,8 kg vs 3,48 kg) and the established mechanical requirements. As far as the fatigue/durability test are concerned, they have been performed to evaluate the strength of the composite and to increase the correlation between CAE analysis and the real behavior of the hybrid component. All the tested parts support 2.000.000 cycles (the stipulated for this part in metal) without break, only with small deformations in the bushings holes. As far as the flexural test are concerned, they evaluate the maximum quasi-static strength of the component. All the parts tested deform considerably, recovering much of this deformation once the load is removed.
Abstract
The main objective of this work has been the manufacture , and subsequent flexural and fatigue tests, of automotive real parts, made of thermoplastic composites. This has been achieved by incorporation continuous carbon fiber (textile) to polyamide matrix, through an specific [...]
Optimization and characterization of the T_RTM process for polyamide 6
