Abstract

Resin Transfer Moulding Technology (RTM) is gaining attention on developing composite structural components for aeronautical industry, due to its high-cadence production, and as a consequence, a significant manufacturing cost reduction. This document describes the manufacturing of a composite fuselage frame oriented in dry reinforcement preform construction that, it’s one of the main factors that intervene in RTM process and has a direct influence on the component structural quality.

It’s exposed the definition of an overlap strategy for dry Non-Crimp Fabric adaption on structural aeronautical components of large dimensions and implementation of such strategy for manufacture a real-scale demonstrator, exposing process time reduction base on a tooling design that facilitate the cycle time reduction. Simultaneously, it’s described a procedure to study the overlap influence at a dimensional and structural level and defects generation. Also, it’s exposed different overlap strategies for preform consolidation by commercial adhesives incorporation for fabrics and thermoplastic binders.

Abstract

The growing utilization of carbon fiber reinforced polymers (CFRP) in industry involves the generation of high quantities of this kind of waste. This tendency has fomented the investigation of different alternatives to recycle CFRP waste with the aim of reclaiming the carbon fibers, a material with high specific economic value. Among the alternatives, pyrolysis is the only one runnig at commercial scale nowadays. This process consists on heating the waste in an inert or oxygen-poor atmosphere, which causes the decomposition of the polymeric resin of the material and consequently the reclamation of the carbon fibers. The resin decomposes into organic vapors, which are normally incinerated and released to the atmosphere. The objective of this paper is to present the economic and energy benefit of a method for treating the vapors coming from the resin decomposition, through which high value chemicals can be obtained, avoiding the vapors incineration and emission. By means of this recently patented method a gas fraction with a higher energetic content than that of the vapors without treatment can be obtained. Besides, this gaseous fraction contains high quantities of hydrogen, which could be separated and sold. The commercialization of this hydrogen could increase 6 times the economic value of the gaseous fraction compared to the gas fraction without treatment.

Abstract

The following article proposes a methodology for the creation of a fork of a single-seater of formula 1 with composite material of bidirectional carbon fiber and epoxy resin in a laminate of 6 layers with angles [90, -45, + 45] having as aim a fork with a faster and less expensive process compared to those used in the world of formula 1.

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

While fiber reinforced polymer (FRP) composites are widely utilized in structural components due to their favorable mechanical properties, delamination between reinforcing plies remains a major problem, weakening the composite structure and limiting more widespread applications of FRPs. Carbon nanotubes (CNTs) carry the promise of enhancing this poor out-of-plane mechanical performance, although their integration has been challenging. In this work, macroscopic CNT veils with controlled nano-meso structure were drawn from the gas-phase using a semi-industrial process and then integrated into woven carbon fiber/epoxy matrix composites utilizing a facile and scalable approach. Interlaminar fracture toughness (ILFT) of the resulting composites was determined in Mode-I (opening mode) test. Additionally, crack propagation and interlaminar toughening mechanisms were systematically analyzed by means of optical microscope, SEM, and Raman analysis. The results showed that mode I ILFT was improved as much as 60% when interleaving as-received fluffy CNT veils and also revealed that interlaminar crossing between CNT veil/CF interfaces is of paramount importance in toughening mechanism.

Abstract

The aluminum and its alloys stand out thermal conductivity and good mechanical properties, which, combined with a low density, high environmental resistance and a reasonable cost, makes them very suitable for multiple applications. In spite of this, different applications, such as In the case of LED-based lighting systems, it is necessary to increase the thermal conductivity; while the transport sector demands to improve its mechanical properties, like rigidity and strength. To meet these requirements aluminum composite materials reinforced with unidirectional carbon fiber and woven have been developed, initially manufacturing pieces of simple geometry, but coming to manufacture complex elements, such as luminaires or clutch housings, with improved mechanical and thermal properties compared to those manufactured without reinforcement meeting the demands of this class of applications. The process used has been based on the injection of high pressure aluminum on the dry tissue giving rise to a very fast and efficient process in which the formation of fragile interfaces is avoided and there are no viscosity problems, such as those that occur in the manufacturing processes most commonly employed. In conclusion, through a process of high pressure injection of aluminum on carbon fibers, unidirectional or fabrics, pieces of metal matrix composite material that have superior thermal and mechanical properties with respect to uncoated aluminum alloys have been manufactured.