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• Hybridization Process of Carbon Fibre Sheet Moulding Compound with Carbon Fibre Prepregs: a Case Study

  J. Silva, L. Pina, S. Sousa

  Materiales Compuestos (2022). Vol. 05 - Comunicaciones Matcomp19 (2021), (Núm. 3 - Procesos de Fabricación – Materiales Funcionales.), 82

  
  

  Abstract

  The main objective of this work was to show the technical viability of a traditional Sheet Moulding Compound process hybridized with Carbon fibre prepreg reinforcements, in a demonstrative car seat structure. The new reinforced seat is lighter, has better mechanical resistance to impact and the typical carbon fibre visual aspect in the reinforced areas. Currently, the seat structure is composed by the hybrid solution with the matrixes of both materials being epoxy, therefore compatible which promotes a good adhesion under the correct processing conditions. To ensure the viability of this hybridization, an extensive laboratorial test campaign was conducted in a laboratorial hot plate press to study the Sheet Moulding Compound flow dynamics during the moulding process and how it interacts with the prepreg preforms. The cure process of both materials was also analysed to establish the optimal temperature profiles. Finally, mechanical tests were performed according to ASTM D 5868-01 to evaluate the mechanical properties of the bonding between the two materials. The reinforced car seat prototype was validated according to the ECE-R17 and FMVSS202a impact tests on the head rest and a 25% reduction in overall weight was achieved. The life-cycle cost and the visual aspect benefits are expected to compensate the slightly higher manufacturing cost in relation to the original part due to the cost of the prepreg material. Further research will be needed to in terms of process automation to ensure the required process quality.

  Abstract
  The main objective of this work was to show the technical viability of a traditional Sheet Moulding Compound process hybridized with Carbon fibre prepreg reinforcements, in [...]

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• New Materials in Automotive. Adhesive Solutions and their Processes

  J. Arroyo, C. Yebra, A. Martinez, J. Benito, L. Patiño

  Materiales Compuestos (2022). Vol. 05 - Comunicaciones Matcomp19 (2021), (Núm. 3 - Procesos de Fabricación – Materiales Funcionales.), 81

  
  

  Abstract

  Composite introduction to automotive industry create new joining requirements and associated technologies, where adhesives are a key technology to acheive this challenges. This circumstances introduces new parameters onto adhesive solution sorting and characterization. Work completed it is focused onto two diferent areas, first one analyze compatibility of different chemistries available at 3M portfolio (epoxy, polyurethane, acrylic), and how they answer to different question marks created in structural bonding at automotive, several substrates has been considered like: TEPEX®, CFRP or Alumimun with minimal to none surface preparation.Test completed include shear strength before and after different agging cycles with different adhesives and substrates. Second piece of work complete is focus on different induccion/lockup cycles, either for liquid and fillm structrual adhesives, which the goal to create cycle times lower than 90s, and keep line manufacturing process. Research complete is partially covered under ECOVOSS project, which goal is to develop lightweigth structures for automotive, and it also include different 3M researches and experiences bonding composites structures in Automotive.  

  Abstract
  Composite introduction to automotive industry create new joining requirements and associated technologies, where adhesives are a key technology to acheive this challenges. [...]

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• Manufacturing of long recycled carbon fibre composites by injection

  A. Fernández, M. Santangelo-Muro, J. Molina-Aldareguia, C. Lopes

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 55

  
  

  Abstract

  Due to the rapid growth in the use of composite materials, environmental concerns have become an increasingly influential topic, making recyclability of composite materials a key issue. Furthermore, several related European laws have been passed to minimize the environmental impact of composites (EU 2000/53/CE [1], 2000/76/EC [2], 2004/35/EC [3]). Caused by the high energetic requirements and the huge amount of composite materials used in the manufacturing process, recycling supposes a reduction of a 70% in the costs and 98% in the energy demanded [4]. Once the fibers are obtained through pyrolysis, with a high retention of mechanical properties, the next step is the manufacturing process by injection using a thermoplastic polymeric matrix of polypropylene, a polymer widely used in the composite industry. For that purpose, a study of the compatibility of the fiber with the maleic anhydride polypropylene at different relations -10, 20 and 30%- has been carried out. In order to enhance the mechanical properties, a combination of homopolymer polypropylene, maleic anhydride polypropylene and recycled carbon fibers is studied through the production of a masterbach composed of maleic anhydride polypropylene and carbon fibers, followed by the addition of the homopolymer polypropylene. Once the pellets are obtained, they are injected. The samples injected are analyzed in terms of fiber distribution by scanning electron microscopy and tomography, thus the mechanical properties are evaluated through tensile, impact and bending tests, to determine the optimum fiber/resin ratio.

  Abstract
  Due to the rapid growth in the use of composite materials, environmental concerns have become an increasingly influential topic, making recyclability of composite materials [...]

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• Sustainable composites based on carbon fiber recycled for the automotive sector

  K. Gondra, A. Allue, J. Alonso

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 56

  
  

  Abstract

  In the automotive sector, lightening weight is a key issue in the designing of vehicle components, to reach the CO2 emission limits that have been defined in Europe for the year 2020. That is why the strategy in the sector is to use fiber-reinforced composites, that allow to lighten the metal structures between 15 and 40% depending on the type of fiber. On the other hand, the recyclability is another important point, since the directives on the end of the useful life of the vehicles, stipulates that will be obligatory the recycling of 85% of the vehicle, not contemplating the "recovery of energy" of polymers as a means for its recycling. Composites, although they are lightweight and have a high resistance, have the disadvantage of their recyclability, and the reality is that environmental legislation is becoming increasingly restrictive, and it is urgent to find solutions to landfill. This is one of the reasons why the pyrolysis of carbon composites for the recovery of carbon fiber, and its reuse in the form of non-woven MAT, and the thermostable resins that can be recycled and reprocessed, can lead to a new generation of sustainable and recyclable composites in the automotive sector.

  Abstract
  In the automotive sector, lightening weight is a key issue in the designing of vehicle components, to reach the CO2 emission limits that have been defined in Europe for the [...]

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• Study of the influence of using recycled brass fibres from electrical discharge machining process on the physical, thermal and mechanical properties of the resulting mortar

  R. Borinaga, A. Orbe, J. Canales, S. Plaza

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 53

  
  

  Abstract

  Nowadays, metallic fibre reinforced cementitious composites are widely used on many different construction elements: concrete beds, slabs, precast concrete industry, etc. Fibres reduce the crack generation due to the cementitious composite shrinkage and improves its flexural strength, toughness and durability. If metallic waste materials from the industrial manufacturing sector were used instead of using the commercially available metallic fibres, the energy of both the waste recycling process and the manufacturing of the actual commercial metallic fibres would be saved. This paper studies the use of the waste residual brass fibres generated during the electrical discharge machining process as a reinforcement on mortars. With that in mind, two different fibre types (brass covered steel and recycled brass) on two different mix proportions (0.65% and 1.3% by unit volume of mortar) were added to a self-leveling non-reinforced mortar taken as a reference to evaluate their influence on the physical, thermal and mechanical properties of the resulting mortar. According to the results, for both types of fibres studied, the higher the fibre proportion used, the higher were the density, the thermal conductivity, the flexural strength and the compressive strength.of the resulting mortars. Recycled brass fibres increased the thermal conductivity and decreased the volumetric heat capacity of the resulting mortars more than the steel fibres, which is interesting, for example, on self-levelling mortars used on radiant floor heat exchangers. However, less increase was observed on the mechanical properties of the recycled brass fibre reinforced mortars than that of the steel fibre reinforced mortars, due to the shorter length of the former fibres (5-10 mm for the recycled brass fibres, 13 mm for the steel fibres). Therefore, the parameter that controls the cutting frequency of the waste wire of the electrical discharge machine should be modified to adapt the final fibre length to that of the commercially available fibres.

  Abstract
  Nowadays, metallic fibre reinforced cementitious composites are widely used on many different construction elements: concrete beds, slabs, precast concrete industry, etc. [...]

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• Compressive behavior of a natural core

  E. Gómez-Meisel, S. Sánchez-Saez, E. Barbero

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 52

  
  

  Abstract

  Composite sandwich structures with core cellular materials are widely used in diverse industries such as the aerospace, marine, car, and wind industries due to their good mechanical properties on bending. The growing environmental awareness has increased the interest in the use of materials from biodegradable and renewable sources. During recent years, there has been an increasingly growing interest in the use of agglomerated cork as a core material in sandwich structures, replacing synthetic polymeric foams in specific applications. Among its remarkable combination of properties, we can find a hyperelastic behaviour, low thermal conductivity, low permeability, and good energy absorption and vibration damping properties. Additionally agglomerated cork is produced from the waste of the cork industry, being a renewable and biodegradable material that is environmentally sustainable. The aim of this work is to address the quasi-static and dynamic compression testing of two types of agglomerated cork of different densities, using a servo-hydraulic testing machine and drop weight tower. The mechanical behaviour and energy absorption properties at different strain rates are evaluated from the contact force measurements and estimations of impact kinetic energy. Additionally, Digital Image Correlation (DIC) is used to estimate the variability in the local strain through the test specimen.

  Abstract
  Composite sandwich structures with core cellular materials are widely used in diverse industries such as the aerospace, marine, car, and wind industries due to their good [...]

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• Characterization of light mortars with alkali activated SiMn slag and recycled expanded polystyrene

  H. Hafez, V. Ferrándiz, E. Alcocel, . R.Navarro, I. Sánchez, E. Zornoza

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 51

  
  

  Abstract

  One of the main challenges of binder manufacturing industry is the reduction of its environmental impact. In this context, the key is the obtention of materials whose fabrication uses lower amount of natural resources and energy consumption. One of the the main strategies to achieve that goal is the incorporation of alkali activation processes to waste material or by-products. In this work, a SiMn slag has been alkali activated to prepare light mortars in which partial substitution of the aggregates by expanded polystyrene has been applied. An aggregate replacement up to 45% by volume has been used. In addition, also the SiMn has been used as aggregate in order to explore its valorization through that application. The following properties have been evaluated: fresh mortar workability, compressive strength, drying and autogenous shrinkage, water absorption by capillarity, apparent density and thermal conductivity. The intended application for this type of material would be as light cladding with improved isolation properties. Results have shown that the replacement up to 45% of natural aggregate by expanded polystyrene produces a decrease of the compressive strength up to 70%, a reduction of the density of 32%, an increase of the water absorption of 75% and a decrease of the thermal conductivity up to 87%.

  Abstract
  One of the main challenges of binder manufacturing industry is the reduction of its environmental impact. In this context, the key is the obtention of materials whose fabrication [...]

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• Improvement in the resistance against moisture presence in plasters and self-levelling screeds based of natural anhydrite waste

  C. Polo, E. Zornoza, P. Garcés, E. Alcocel

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 50

  
  

  Abstract

  The anhydrite is a natural compound that co-exists alongside with the gypsum rock in some geological formations. Formulating new products for plasters and self-levelling screeds is the most common way to treat and recover the anhydrite waste in Europe. In this case, we´ll re-use natural anhydrite waste originated in a gypsum quarry located in the province of Alicante (Spain), having in mind this could be extrapolated to any other gypsum quarries. The compound is chemically composed of anhydrous calcium sulfate that could be activated through catalysts, hydrating and turning itself into dehydrate calcium sulphate (gypsum). The aforementioned material presents great aptitudes for self-levelling screeds due to its good reology and little shrinkage. Generally, they are used in building industry once the building envelope is finished and water tight as its water solubility restricts its use in damp environments. The current paper presents improvements in the resistance against water presence by dosing damp-proof product as siloxan derivatives and zinc stearate. There have been obtained important improvements in the reduction of superficial absorption and capilarity absortion. Also the effect of these aditives on the mechanical properties of the self-levelling compound have been studied in this paper.

  Abstract
  The anhydrite is a natural compound that co-exists alongside with the gypsum rock in some geological formations. Formulating new products for plasters and self-levelling screeds [...]

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• Additive Manufacturing, an opportunity for Composite recycling

  G. López, J. Vázquez, F. Móstoles, E. Fernández, T. Varela, J. Gómez

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 49

  
  

  Abstract

  Composite materials are one of the fundamental pillars of the aerospace industry due to their high strength and specific stiffness. However, their use involves large amounts of waste that require difficult and expensive treatments for its disposal. The objective of this analysis is to present the additive manufacturing by means of deposition of molten filament as a process capable of giving a second life to the waste of both the composite materials and the auxiliary materials used during its manufacturing process. The printing filaments are developed from a PA 6,6 matrix obtained from vacuum bags used for the manufacture of pre-impregnated composites and by means of a reinforcement of short carbon fiber obtained from the residues of pieces of composite material or uncured fibre. The printing trials as well as the specimens for tests and demonstrators have been produced in an open printing system allowing to obtain the optimal process parameters for this type of materials. The application of these materials and technologies within the aerospace field in flying parts as well as in production jigs and tools as well as in other industries such as automotive, sporting goods or accessories constitutes a key element to align the use of composite materials with the objectives of eco-efficiency that society demands for the immediate future.

  Abstract
  Composite materials are one of the fundamental pillars of the aerospace industry due to their high strength and specific stiffness. However, their use involves large amounts [...]

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• Development of new filaments for 3D printing based on bio-inspired ceramics

  J. Rojas-Lozano, P. Diaz-Rodriguez, P. Barreiro, E. López-Senra, C. Rodríguez-Valencia, M. López-Álvarez, M. Landin, P. González, J. Serra

  Materiales Compuestos (2022). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 4 - País invitado: Colombia. Materiales Multifuncionales. Reciclaje y Sostenibilidad), 48

  
  

  Abstract

  3D printing allows the development of devices in a wide range of sectors, including the automotive industry, construction, aeronautics, food, textiles and also biomedical, among others. There are several technologies being the impression by molten deposition (FDM) one of the most widespread. In the particular case of biomedical engineering, three are the main application and research axes: (1) biomodels for the preparation of surgical interventions, (2) design and manufacture of customized biomedical devices and (3) porous scaffolds for regenerative medicine. The objective of the present study focuses on the development of a new filament for 3D-FDM printing composed of polylactic acid (PLA) and a biphasic crystalline bioceramic of marine origin (Biofast). Several filament formulations were obtained after extrusion of mixtures with variable proportions PLA / Biofast. The physical-chemical properties of both the filament and the printed pieces were studied by scanning electron microscopy, Raman and IR spectroscopy. The analyzes show that the bioceramic particles are evenly distributed in the polymer matrix and their incorporation can be controlled depending on the selected mixture. As for the crystal structure and links, manufacturing processes do not originate modifications that may affect the biocompatibility of the final device. Thus, these new filaments are shown as potential candidates for application in biomedical engineering.

  Abstract
  3D printing allows the development of devices in a wide range of sectors, including the automotive industry, construction, aeronautics, food, textiles and also biomedical, [...]

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