Life Cycle Engineering of Carbon Fibres for Lightweight Structures

Carbon Fiber Reinforced Plastics in Space: Life Cycle Assessment towards Improved Sustainability of Space Vehicles

Composite materials, specifically carbon fiber reinforced plastics (CFRPs), are used in various applications such as the automotive, aerospace, and renewable energy industries, thus increasing their global production and volume consumption and creating a subsequent increase in CFRP waste. Especially in space applications and Vega launcher construction, the use of CFRP components to replace metal envisages significant benefits in the use phase by reducing weight and fuel consumption requirements. The current and future waste management and environmental legislation, considering the actual and impending EU framework on waste management, requires all engineering materials to be properly recovered and recycled from EoL products. In this study, the potential of recycling and the subsequent environmental benefits have been assessed by investigating the EoL of CFRPs through a life cycle assessment (LCA). LCA is a valuable tool for evaluating a composite material’s environmental ecological burdens over its lifetime. Therefore, it is important to the composites industry as a material selection tool when determining the applicability of recycled composites in the design phase. Particularly, the benefits from recycling methods were systematically studied in order to assess the environmental impacts of EoL scenarios, to underline the importance and necessity for the maturity increase in recycling technologies for CFRPs.

The Effect of Stacking Sequence and Ply Orientation on the Mechanical Properties of Pineapple Leaf Fibre (PALF)/Carbon Hybrid Laminate Composites

In this paper, the effects of stacking sequence and ply orientation on the mechanical properties of pineapple leaf fibre (PALF)/carbon hybrid laminate composites were investigated. The hybrid laminates were fabricated using a vacuum infusion technique in which the stacking sequences and ply orientations were varied, which were divided into the categories of cross-ply symmetric, angle-ply symmetric, and symmetric quasi-isotropic. The results of tensile and flexural tests showed that the laminate with interior carbon plies and ply orientation [0°, 90°] exhibited the highest tensile strength (187.67 MPa) and modulus (5.23 GPa). However, the highest flexural strength (289.46 MPa) and modulus (4.82 GPa) were recorded for the laminate with exterior carbon plies and the same ply orientation. The fracture behaviour of the laminates was determined by using scanning electron microscopy, and the results showed that failure usually initiated at the weakest PALF layer. The failure modes included fibre pull-out, fibre breaking, matrix crack, debonding, and delamination.

Hybrid Polymer Composites of Bio-Based Bast Fibers with Glass, Carbon and Basalt Fibers for Automotive Applications-A Review

Composites with reinforcements based on bast fibers such as flax, hemp and kenaf offer many advantages such as weight reduction, improved specific impact, flexural, acoustic properties, and balanced performance to cost that can be achieved by properly designing the material composition. Their position is well established, especially in the nonstructural automotive applications. However, in structural applications of composites, their mechanical property profile is not comparable to the dominant reinforcements such as glass and carbon fibers. The low mechanical properties of these composites could be improved by hybridization that involves adding high-performance fibers to the bast fiber composites that could improve the low mechanical performance of the bast fiber composites. The review presented in this article provides an overview of the developments in the field of hybrid polymer composites composed of bio-based bast fibers with glass, carbon, and basalt fibers. The focus areas are the composite manufacturing methods, the influence of hybridization on the mechanical properties, and the applications of hybrid composites.

Improving the Vertical Thermal Conductivity of Carbon Fiber-Reinforced Epoxy Composites by Forming Layer-by-Layer Contact of Inorganic Crystals

A carbon fiber-reinforced polymer (CFRP) is a light and rigid composite applicable in various fields, such as in aviation and automobile industry. However, due to its low thermal conductivity, it does not dissipate heat sufficiently and thus accumulates heat stress. Here, we reported a facile and effective strategy to improve the through-thickness thermal conductivity of CFRP composites by using a layer-by-layer coating of inorganic crystals. They could provide efficient heat transfer pathways through layer-by-layer contact within the resulting composite material. The high thermally conductive CFRP composites were prepared by employing three types of inorganic crystal fillers composed of aluminum, magnesium, and copper on prepreg through the layer-by-layer coating process. The vertical thermal conductivity of pure CFRP was increased by up to 87% on using magnesium filler at a very low content of 0.01 wt %. It was also confirmed that the higher the thermal conductivity enhancement was, the better were the mechanical properties. Thus, we could demonstrate that the layer-by-layer inclusion of inorganic crystals can lead to improved through-thickness thermal conductivity and mechanical properties of composites, which might find applications in varied industrial fields.