Documents published in Scipedia

• Thermoforming of thermoset composites manufactured by pultrusion

  I. Aranberri, A. Salaberria, G. Hoyos, A. Rekondo, H. Grandea, M. Landab, X. Pavónc, D. Ramosc

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 1

  
  

  Abstract

  In this work the development of a profile manufactured by pultrusion and thereafter curved by thermoforming is presented. The pultrusion profile is based on a new thermostable epoxy resin with dynamic bonds capable of being reprocessed, repaired and recycled thanks to the incorporation of reversible links within its reticulated structure (3R Technology). Being a resin that contains dynamic bonds, the cured composite shows unexpected properties for thermosetting materials. In a first phase, a new resin/hardener formulation processable by pultrusion with a viscosity, adhesion to the fibre and speed of curing similar to a conventional formulation have been developed and in a second phase, taking into account the properties of the new composite material, the parameters of the thermoforming process (pressure, temperature or speed of thermoforming) have been analysed and optimized. Thanks to the combination of pultrusion and thermoforming processes, longitudinal 3R composite profiles acquire a new curved geometry defined by the design of a mould. In this way, the thermoforming of the straight profiles will allow manufacturing curved parts from profiles of thermostable composites with high mechanical performance manufactured by pultrusion in medium-high rates, typical of the automotive sector. Additionally, it will be shown that the profiles manufactured using these composites can be recycled, reducing the amount of waste generated and offering these materials a second useful life.

  Abstract
  In this work the development of a profile manufactured by pultrusion and thereafter curved by thermoforming is presented. The pultrusion profile is based on a new thermostable [...]

  • 22
  •  read

• Optimization and characterization of the T_RTM process for polyamide 6

  I. Harismendy, A. Calle, S. García-Arrieta, . C.Elizetxea

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 2

  
  

  Abstract

  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.

  Abstract
  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 [...]

  • 0
  •  read

• Analysis of the manufacturing process of a car bonnet using Compression Resin Transfer Moulding (CRTM)

  L. Aretxabaleta, C. Rytka, L. Walker, J. Maldonado, M. Baskaran, J. Aurrekoetxea

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 13

  
  

  Abstract

  Compression resin transfer moulding (CRTM) can help to reduce costs and increase the productivity of composite parts in the automotive industry. This process is suited for fast production of high quality parts, but a number of parameters must be precisely characterised and well controlled during the process. This work describes the CRTM manufacturing process of a real sports car bonnet. Resin and carbon fibre reinforcement have been characterised (viscosity, permeability), and this information has been used to perform numerical simulations to optimise the process parameters in order to reduce the cycle time. The heating cycle has also been optimised and the possible implementation of an induction heating system has been analysed. Once the process parameters have been defined, the mould has been manufactured and bonnet prototypes have been manufactured. This work has been carried out within the framework of the project ADVANCRTM.

  Abstract
  Compression resin transfer moulding (CRTM) can help to reduce costs and increase the productivity of composite parts in the automotive industry. This process is suited for [...]

  • 1
  •  read

• A microlevel capillary study in composite materials by X-ray tomography

  J. Castro, F. Sket, C. González

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 12

  
  

  Abstract

  One of the main problems associated with the manufacture of composite materials by liquid moulding (injection, infusion, etc.) is the generation of porosity. The optimization of the properties of the composites passes through a better understanding of the mechanisms of pore formation and transport. This pore formation is associated with a non-homogeneity of resin flow during the manufacturing process as a consequence of the double-scale porosity present in textile preforms. In the channels between bundles of fibers, the resin flows controlled by the pressure gradient and its viscosity. However, within the fiber bundles, the resin flows as a result of the capillary pressure. As a consequence, if the viscous and capillary forces are not balanced, non-homogeneous local flow occurs and the formation of pores, either between the fiber bundles, or internally to the bundles is produced.In this work a systematic study of the spontaneous wetting process of an E glass fiber bundle through wicking tests, using several fluids with different properties, viscosity, surface tension and contact angle is presented. The visualization of the front position of the resin flow at microscopic scale, as well as the formation of the menisci between fibers has been performed using X-ray tomography techniques using synchrotron radiation. The reconstructed volumes have made it possible to obtain detailed quantitative information on the geometry of the menisci which occur as a consequence of the surface tension operating at such scale. These characterization techniques constitute a fundamental tool for the optimization of the processing of composite materials buy liquid moulding.

  Abstract
  One of the main problems associated with the manufacture of composite materials by liquid moulding (injection, infusion, etc.) is the generation of porosity. The optimization [...]

  • 3
  •  read

• Optimization of liquid resin infusion process (LRI) using finite element simulation software

  C. Churiaque, J. Sánchez-Amaya, J. Botana, R. Páez, L. Utrera

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 11

  
  

  Abstract

  Infusion processes as LRI (Liquid Resin Infusion) can lead to a significant cost reduction but are not yet so widespread in aeronautical applications. Some of its advantages are: no need of autoclave, lower costs of materials, and the possibility of fabricating integrated structures that reduce the number of joints. However this process still presents some drawbacks such as the need to apply the "Test-Error" method or availability of extensive experience in the design of structures. The risk and cost associated with the infusion process is high, so the industry tends to use more conservative designs or adopt other less competitive alternative technologies and materials. For this reason, a simulation tool is essential to optimize the LRI process. In this work, the optimization and validation of a demonstrator of a wing box of an aircraft has been carried out using the PAM-COMPOSITES simulation software. Firstly, a geometric study and discretization of model has been carried out, secondly, the parameters that govern the process have been defined, and finally an analysis and validation of results have been carried out by means of a experimental infusion of the demonstrator. The obtained results have allowed us to control manufacturing times, improve injection and vacuum ports, and predict dry zones and front flow velocity. Simulations have allowed us to optimise the LRI process of the demonstrator, thus giving continuity to other studies on the viability of the infusion processes in primary structures in the aeronautical sector.

  Abstract
  Infusion processes as LRI (Liquid Resin Infusion) can lead to a significant cost reduction but are not yet so widespread in aeronautical applications. Some of its advantages [...]

  • 0
  •  read

• Additive manufacturing of 3D reinforced structures: effects of process parameters on mechanical properties

  . M.A.Caminero, ,. J.M.Chacón, E. García-Plaza, . P.J.Núñez, I. García-Moreno, G. Rodríguez

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 10

  
  

  Abstract

  Three dimensional (3D) printing or Rapid Prototyping (RP) provides an innovative additive manufacturing method for prototypes and functional components. Fused deposition modeling (FDM) is a fast growing rapid prototyping technology for fabricating thermoplastic parts due to its ability to build functional parts having complex geometrical shapes in reasonable time periods with the advantages of low cost, minimal wastage, and no tooling or touch labour. The quality of a built part (surface finish, dimensional accuracy or mechanical properties) depends on several process variables. Assessing the influence of these process parameters on mechanical properties is vital for understanding the performance of 3D printed materials, and to determine the needs for further research. The aim of this study is to characterize and assess of different process parameters on the mechanical performance of PLA and ABS samples manufactured with low cost 3D printing. Tensile and three-point bending tests series were carried out to determine the mechanical response of the printed specimens with different process parameters. Finally, the practicality of the results was assessed by testing an evaluation structure as a case example.

  Abstract
  Three dimensional (3D) printing or Rapid Prototyping (RP) provides an innovative additive manufacturing method for prototypes and functional components. Fused deposition modeling [...]

  • 1
  •  read

• Manufacturing tests of the lower skin of a wing in dry fiber by laying in FP and subsequent forming and infusion

  P. Tabarés, B. Fantina

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 9

  
  

  Abstract

  In recent years many of the developments in the field of composite materials have focused on processes of dry carbon fiber, and efforts have been directed to achieve with these materials the same levels of industrialization as with pre-impregnated materials, since it is a technology of low cost and with a high productivity. The objective of this project has been to develop dry carbon fiber manufacturing methods to obtain an automated, robust and efficient process for reaching manufacture the lower skin of a wing with stringers and integrated spars by automatic laying in Fiber Placement, posterior Hot forming and finally a process of resin infusion by "Vacuum Assisted Process". To achieve this objective, the Fiber Placement machine has been set up to optimize the laying parameters for the processing of the material to be used (½” Hexcel Hi-Tape fiber). On the other hand, several tests of hot forming of this laminates have been carried out by means of the previous process, modifying process variables, tooling details and forming bag configuration, in order to obtain the preforms of stringers and spars. Finally, the integration of spars, stringers and skin was performed by a resin infusion process using the VAP technique "Vacuum Assisted Process".

  Abstract
  In recent years many of the developments in the field of composite materials have focused on processes of dry carbon fiber, and efforts have been directed to achieve with [...]

  • 2
  •  read

• Flexible, efficient and automated fast manufacturing of high performance composite parts

  . R.Mezzacasa, . M.Segura, . X.Irastorza, . I.Harismendy, . H.Sehrschon

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 8

  
  

  Abstract

  Fibre-reinforced polymer composite materials are leading candidates as component materials to improve the efficiency and sustainability of many transport modes. Advantages of high performance composites are numerous including lighter weight and reduced assembly costs due to high level of integration potential. This translates into greater weight savings resulting in improved performance, greater payloads, fuel savings and emissions reductions. However, the current manufacturing processes used in aeronautic and automotive still represent high capital investments for SMEs and this represents a major barrier for their deployment in sectors like automotive and others. In this context, during the LOWFLIP project, Tecnalia, Fill and other partners have recently developed a low cost manufacturing process dedicated to structural composite parts for sectors like automotive and others, with the following features: • New fully automated process chain with pick and place multigripper solution providing high production capacity and high quality/ structural performance, with low level of investment, accessible for SMEs. • Fast preforming, heating and curing with snap cure prepregs and very significant reduction of energy consumption during the process due to innovative toolings The automated cell developed is ready for implementation in the main sectors using composites.

  Abstract
  Fibre-reinforced polymer composite materials are leading candidates as component materials to improve the efficiency and sustainability of many transport modes. Advantages [...]

  • 0
  •  read

• Development and automation of a new composites manufacturing process based on UV curing prepregs

  A. Aramburu, F. Vallejo

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 7

  
  

  Abstract

  With the aim of improving composites manufacturing process costs and properties, in order to compete with others materials, a new process of impregnation, compaction and curing of fibre glass reinforcing composites, has been developed. This new process based on UV curing prepregs could be an alternative to the traditional manufacturing process, including infusion process and autoclave curing. These new process consists of two stages. First, the automated manufacturing of the UV curing prepregs. Second, the compaction of the composite by means of application of pressure and UV radiation giving rise to the finished part. In this work, the UV prepregs manufacturing process will be analysed, and the effect of the control parameters of the all process, composed by impregnation, resin content adjustment and precuring, will be analysed. The durability of different manufactured UV prepregs and the mechanical behaviour of the resulted composite will be also studied. Finally, the prototypes necessary to the automation of the two stages of the process will be described.

  Abstract
  With the aim of improving composites manufacturing process costs and properties, in order to compete with others materials, a new process of impregnation, compaction and curing [...]

  • 0
  •  read

• Study of curing of composite by DEA and DSC in the automotive industry

  G. Oteo, S. Knappe

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 3 - Procesos de Fabricación II y Materiales Avanzados), 6

  
  

  Abstract

  Fiber reinforced plastics are the current protagonist in the automotive industry, their mechanical properties and their lightweight make them unique in reducing the impact of the weight on fuel consumption. The curing of thermosetting resins as the polymer matrix for an FRP is one of the main issues facing this sector. Through applications examples, it is demonstrated how the behavior of curing of thermosetting resins can be studied by the techniques of dielectric analysis (DEA) and differential scanning calorimetry (DSC). In-situ cure monitoring is possible by DEA.

  Abstract
  Fiber reinforced plastics are the current protagonist in the automotive industry, their mechanical properties and their lightweight make them unique in reducing the impact [...]

  • 0
  •  read