Browse Topic: Fibers
Due to their high specific modulus and specific strength, carbon fiber reinforced polymer (CFRP) composites have been widely adopted in the aviation field. However, CFRP components produced by conventional vacuum assisted resin transfer molding (VARTM) often exhibit defects such as Pores and dry spots. To address these limitations, this study develops a large-area, highly uniform vibration-assisted VARTM (UAVR) system and conducts ultrasound-assisted experiments. The results demonstrate that ultrasonic treatment at various frequencies consistently improves moulding uniformity. In particular, when the ultrasound frequency is 22 kHz, the tensile strength increases by up to 13.23%, and the compressive strength increases by up to 8.48%. This study has practical significance for improving the performance of CFRP.
Cu-Fe alloys exhibit excellent performance, and increasing Fe content reduces costs. However, high-Fe Cu-Fe alloys exhibit limited formability at room temperature, while warm rolling improves their processability. This research investigates the effect of rolling temperature on the microstructural transformations and texture development in the Cu-10Fe alloys. The experimental result is that during cold rolling, the morphology of Fe phases is mainly fibrous. With the rolling temperature rising, the microstructural morphology of Fe phases becomes globular / elliptical. The difference is that with the increase in rolling temperature, the average grain size of the Cu-10Fe alloy first decreases and then increases. The matrix microstructure remains dominated by deformed grains, with significant recovery observed at 500 °C. The Fe-phase microstructure primarily consists of substructured grains, and dynamic recovery intensifies with rising temperature. During cold rolling, high dislocation density and localized strain heterogeneity lead to dispersed texture orientations and low strength. In contrast, warm rolling promotes dislocation climb and dynamic recovery, triggering partial recrystallization. This reduces randomly oriented grains, enhances the strength and continuity of specific textures, and establishes a more concentrated texture distribution. This forms a structure with fine recrystallized grains embedded within deformed grains, exhibiting slightly lower strength than cold-rolled samples but better elongation. These findings reveal the crucial role of deformation temperature in controlling microstructure transformation and texture evolution, especially by regulating the recovery and recrystallization behaviors of Cu-10Fe alloys. The above results hope to provide some theoretical and experimental basis for a new approach to improve processing technologies for new Cu-Fe-based composites.
This Purchasing Specification (PS), AMS3970/3, specifies the batch release and delivery requirements for carbon fiber fabric epoxy prepreg used for repair. This specification is applicable only when the carbon fiber fabric epoxy prepreg is used as part of the repair system defined in AMS3970 and AMS3970/1. This specification also defines the procedure and requirements for storage life extension of materials purchased against this specification. It is only applicable for materials that are qualified against AMS3970 (refer to PRI QPL AMS3970) and shall be carried out within the responsibility of the purchaser and under control of its Quality organization.
This Purchase Specification (PS), AMS3970/5, specifies the batch release and delivery requirements for the companion non-structural glass fiber fabric prepreg. This specification also defines the procedure and requirements for storage life extension of materials purchased against this specification. It is only applicable for materials which are qualified and shall be carried out within the responsibility of the purchaser and under control of its Quality organization.
For sustainability reasons, the automotive market is requesting 100% monomaterial noise treatments, particularly for the end-of-life recycling without any part separation operation. But also, OEMs require super light, highly performance insulating noise treatments for electric vehicles in order to extend vehicle autonomy. PP melt-blown fiber felts present good mono-material characteristics with very good absorption, but generally not so good insulation properties behind an airtight barrier due to lack of stiffness. Moreover, these PP melt-blown fiber felts are relatively expensive and not thermoformable, thus forcing them to be used as 2D die-cut parts behind existing hard or soft trims classically. The shown optimization approach proposes to return to 100% thermoformable recycled and recyclable PET formulations blending unusual coarse mechanical specific fibers, in order to optimize the viscothermal exchanges, while maintaining good mechanical properties, with microfibers for best dissipation properties bonded by bi-component fibers. The insulation properties obtained as poroelastic spring behind a barrier allow a weight reduction of -50% compared to cotton felt while being 1 dB better for the Insertion Loss values (2 dB compared to a flexible foam) and perform as well as best PP melt-blown fiber felts while being more competitive as well as thermoformable. It is possible to adjust the sound insulation properties, sound absorption and hardness (static compressibility) using optimal PET fibers formulations but also thanks to felt verticalization processes. These optimization levers will be illustrated in this paper.
AMS6885/1 gives information about the technical requirements and qualification procedure for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The repair system includes an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
AMS6885/2 gives specific information about the qualification program for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The prepreg system shall include an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
The increasing pressure to decarbonize manufacturing systems is pushing industry beyond conventional lightweighting strategies toward material and process paradigms, capable of delivering functional performance with radically lower environmental impact. In this context, polymer-based composite Additive Manufacturing (AM) offers an underexplored yet highly promising pathway for sustainable production of load-bearing components. This study presents a preliminary comparative cradle-to-gate Life Cycle Assessment (LCA) of a Formula SAE brake pedal, assessing the environmental transition from conventional sheet metal fabrication and finishing operations of Aluminum 7075-T6 to additive manufacturing solutions, with specific focus on Carbon-Fiber-Reinforced Polymer (CFRP) composites. Two topology-optimized designs, respectively for Powder Bed Fusion (PBF) in AlSi10Mg and Material Extrusion (MEX) in Polyethylene Terephthalate Glycol with Carbon Fiber (PETG-CF) are compared to conventional fabrication aluminum benchmark. The analysis is integrated in the product and process design following ISO 14040/14044 standards and is implemented using the Environmental Footprint 3.0 methodology within the 3DEXPERIENCE platform. Results outline that Material Extrusion (MEX) composite manufacturing achieves the lowest environmental impact across all evaluated categories. Compared to conventional manufacturing, the PETG-CF solution enables an approximate 50% reduction in Global Warming Potential and an almost complete elimination of mineral depletion. Unlike metal additive manufacturing, which remains constrained by high process energy demand, MEX benefits from low processing temperatures, minimal auxiliary systems, and highly efficient material deposition. Crucially, these sustainability gains are achieved while maintaining functional performance through design-driven topology optimization. AM composite solutions, by merging advanced material science with additive flexibility, may lead to design approaches which cease to be ‘potential’ enablers of sustainable manufacturing for the Industry 5.0 transition.
This research investigates the fabrication and evaluation of Delrin (polyoxymethylene, POM) composites reinforcing 5-20 wt.% chopped ramie fiber (RF). The polymer composites were fabricated via the injection moulding technique. Glass transition temperature (Tg), thermal conductivity, Vicat softening temperature (VST), heat deflection temperature (HDT), melt flow index (MFI), and coefficient of linear thermal expansion (CLTE) were the various thermal characteristics of the sustainable composites that were systematically evaluated as per the ASTM standards. The addition of RF drastically altered the Delrin matrix's performance. Among the formulations, the composite with 15 wt.% RF had the best combination of properties: higher VST and HDT values, which provide greater dimensional stability at high temperatures; lower CLTE, resulting in less thermal expansion; comparatively better thermal conductivity; and improved heat dissipation. Eventually, there was a moderate drop in the MFI, indicating more rigid polymer chains that restrict the flowability of the composite, thereby increasing its heat-withstanding capabilities. DSC analysis revealed a slight upward shift in Tg and increased crystallinity, suggesting restricted polymer chain mobility and enhanced load transfer at 20 wt.% RF loadings, agglomeration effects, and weaker interfacial bonding with the matrix led to deterioration in properties. Aircraft cabin components like interior panels, ducting supports, and lightweight non-structural fittings requires dimensional stability, thermal resistance, and mechanical reliability under fluctuating flight conditions.
Carbon fiber has become indispensable in high-performance industries such as automotive engineering and aerospace. It’s lightweight, extremely durable, and can be shaped in almost any way. The start-up Blackwave, founded at the Technical University of Munich (TUM), specializes in this versatile composite material. What began with custom components for sports cars and aircraft has evolved into the development of high-pressure tanks for space applications.
Researchers from CompPair and the European Space Agency have developed a new composite material for spacecraft with an embedded healing agent. European Space Agency, Paris, France Healable spacecraft structures could soon be possible thanks to cutting-edge composite technology. Swiss companies CompPair and CSEM, and Belgian company Com&Sens have partnered with the European Space Agency (ESA) to modify their self-healing carbon fiber product for use in space transportation. Project Cassandra - an abbreviation for Composite Autonomous Sensing and Repair - includes sensors and a heating element within a composite carbon-fiber material, allowing spacecraft to autonomously repair initial stages of damage.
German startup Blackwave is building carbon parts for rocket tanks. Technical University of Munich, Munich, Germany Carbon fiber has become indispensable in high-performance industries such as automotive engineering and aerospace. It's lightweight, extremely durable, and can be shaped in almost any way. The start-up Blackwave, founded at the Technical University of Munich (TUM), specializes in this versatile composite material. What began with custom components for sports cars and aircraft has evolved into the development of high-pressure tanks for space applications. As is so often the case in engineering, a small detail determines technological progress. In the case of rockets, it is the high-pressure tanks that are specially designed for the fuel systems. As rockets are designed to be as light as possible, they lose structural stability when the fuel tanks, known as primary tanks, are emptied. A trick is used to counteract this: alongside fuel combustion, noble gases are released from internal high-pressure tanks, known as secondary tanks. These gases fill the resulting empty space, maintaining structural integrity.
Healable spacecraft structures could soon be possible thanks to cutting-edge composite technology. Swiss companies CompPair and CSEM, and Belgian company Com&Sens have partnered with the European Space Agency (ESA) to modify their self-healing carbon fiber product for use in space transportation.
Live-line operation is a critical technique for maintaining the reliability and continuity of power supply in modern distribution networks. Insulating mats serve as essential protective equipment during such operations by providing both electrical insulation and mechanical shielding. In practical service conditions, insulating mats are subjected to repeated mechanical contact and friction against conductors, metallic fittings, and ground surfaces, which progressively deteriorates their surface integrity and compromises operational safety. Current performance standards for insulating mats emphasize dielectric and tensile properties, while tribological durability remains unaddressed. In this study, an EVA – PA6 composite film fabricated via the tape casting method was selected as the representative outer insulating layer of insulating mats. Reciprocating friction tests were conducted using an SDR339 abrasion tester to evaluate the effects of normal load and sliding speed on wear behavior. The results indicate that wear mass increased monotonically with friction cycles at a given speed, whereas the incremental wear rate gradually decreased due to contact area evolution. A pronounced transition from mild surface abrasion to severe material removal was observed when the applied load reached 5 N, accompanied by surface scratching and exposure of the internal fibrous layer. These findings demonstrate that the wear resistance of the EVA – PA6 composite film is insufficient for long-term service under realistic frictional conditions. The results provide experimental evidence supporting the necessity of incorporating standardized wear resistance evaluation into performance criteria for insulating mats used in live-line operations.
AMS6885/5 is the Material Specification (MS) which defines the requirements of a unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. It also defines the requirements of an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
This paper investigates the feasibility of using flax fiber-reinforced composites in combination with additively manufactured polymer cores for helicopter rotor blades. A new rotor blade with flax composite spar and skin laminates and a 3D-printed ASA Aero core was designed to be geometrically equivalent to an existing carbon fiber/foam reference blade of the MERIT rotor test rig and manufactured using identical tooling. Material characterization included compression testing of the printed core at ambient and elevated temperatures, single-lap shear adhesion testing with epoxy laminates, and hygroscopic conditioning of core and laminate specimens. Structural testing comprised static beam bending, experimental modal analysis with axial pre-loading to approximate centrifugal stiffening, and sustained-load creep and recovery testing of the flax blade. The results show that the 3D-printed core provides sufficient compressive stiffness at curing temperature and adhesion to epoxy laminates, enabling its use as an internal consolidation tool during blade manufacturing. Compared to the carbon reference blade, the flax/3D blade exhibits reduced flapwise and lead–lag bending stiffness, altered modal behavior, and pronounced viscoelastic effects, including creep, incomplete recovery, and strong hygroscopic swelling. Component-level hygroscopic tests reveal that moisture-induced mass and thickness changes can generate sufficient internal stresses to locally initiate structural damage. Overall, the study identifies key limitations and design considerations for applying flax fiber composites in primary rotor blade structures.
Unmanned aerial vehicle (UAV) primary structures require high specific strength and stiffness, traditionally necessitating expensive carbon fiber composites. This study evaluates simulation-driven, additively manufactured polymer alternatives fabricated from PLA and computationally optimized via macroscopic Topology Optimization (TO), mesoscopic Variable-Thickness Lattices (VTL), and uniform Triply Periodic Minimal Surfaces (TPMS). Evaluations were conducted under a superimposed, multi-axial flight envelope. Physical testing demonstrated that VTL architectures maximized the Structural Efficiency Index (SEI) by pushing mass to the extreme geometric fibers and increasing global flexural rigidity. In contrast, mass-constrained TO yielded misleading specific strength due to volumetric starvation and elevated compliance, while the uniform TPMS baseline exhibited favorable specific stiffness but lacked targeted root robustness, resulting in reduced specific strength. Off-axis testing further showed that Diamond lattices dominated vertical bending and inverted impulse loading, whereas Octet and Kelvin geometries more efficiently resolved transverse shear. Experimental data identified a performance-optimized efficiency asymptote in the 73-79 g VTL specimens, which achieved a 19-24% mass reduction relative to a 97 g carbon fiber baseline. To assess assembled-vehicle relevance, the selected fully 3D-printed replacement arms were installed on the baseline quadcopter and subjected to nine dynamic ground tests comprising staircase and cyclic propulsive loading under freestream conditions of 0, 10, and 20 knots. The optimized arms completed the full test matrix without fracture, mount failure, screw loosening, visible yielding, or permanent deformation, demonstrating structural viability in a realistic multi-part UAV assembly without carbon fiber reinforcement.
The world is hurtling rapidly toward a developed future, and carbon fiber-reinforced polymers (CFRPs) play a key role in enabling technological and industrial progress. These composite materials are lightweight and highly strong, making them desirable for applications in various fields, including aviation, aerospace, automotive, wind power generation, and sports equipment.
Engineers at the University of California San Diego have developed a new cooling technology that could significantly improve the energy efficiency of data centers and high-powered electronics. The technology features a specially engineered fiber membrane that passively removes heat through evaporation. It offers a promising alternative to traditional cooling systems like fans, heat sinks and liquid pumps. It could also reduce the water use associated with many current cooling systems.
With the exponential growth of global data traffic driven by AI, big-data analytics, and cloud computing, today’s single-mode fiber (SMF) networks are edging toward their Shannon-capacity limits. Space-division multiplexing (SDM) in multimode fiber (MMF) has emerged as a leading candidate for the next-generation bandwidth breakthrough because a single MMF can carry many orthogonal transverse modes in parallel. However, random mode coupling during propagation mixes these modes into complex speckle patterns, severely complicating signal recovery. Although conventional digital signal processing (DSP) algorithms are theoretically capable of mode demultiplexing, their computational complexity scales rapidly with the number of modes, rendering them impractical for high-capacity MMF networks.
Carbon fiber-reinforced polymers (CFRPs) have become essential in modern aerospace structures, from fuselage skins and wing components to nacelles, interior structures, and a growing range of primary load-bearing parts. Their high strength-to-weight ratio delivers major benefits in fuel efficiency, payload capacity, and fatigue performance. Yet achieving reliable adhesive bonds on CFRP surfaces remains a persistent engineering challenge. The low intrinsic surface energy of composites - particularly under thermal cycling, vibration, and moisture exposure - limits bond durability unless surfaces are properly prepared. Plasma surface treatment has emerged as a pivotal solution, offering a fast, controllable, and non-destructive way to increase surface energy, improve wettability, and enhance adhesion across complex geometries. This is especially important as the aerospace industry transitions from thermoset to thermoplastic composites (TPCs), which enable faster processing, lower production costs, and better recyclability.
Auburn University's Applied Research Institute in Huntsville is adding some serious fiber to its diet. Auburn University, Auburn, AL In collaboration with Auburn University's Center for Polymers and Advanced Composites (CPAC) and the Department of Aerospace Engineering, the institute recently acquired a CF3D Enterprise Cell - a next-generation 3D carbon fiber composites printer set to define the future of the nation's hypersonic programs. Developed by Idaho-based Continuous Composites, the CF3D system represents a highly specialized advanced manufacturing capability and is the only system of its kind currently operating in Alabama.
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