So what are we really comparing? Carbon fiber vs aramid fibers. And that’s where the classic question shows up.

Hybrid fabric with carbon and aramid fibers

Which one is better? Carbon fiber or aramid?

The honest answer: neither, unless you know what you want it for. But there’s a general rule of thumb:

• Aramid fibers (like Kevlar®) excel in impact resistance, toughness, and abrasion resistance.
• Carbon fiber dominates in stiffness, strength-to-weight ratio, and compressive performance.

The real difference isn’t raw strength, it’s how each material behaves when things go wrong. Let’s see how they compare.

Carbon fiber typically stretches only about 1.5% before failure, while Aramids can elongate up to 4%, allowing them to absorb energy instead of cracking.

Carbon Fiber: The King of Stiffness

Carbon fiber is made from highly aligned crystalline carbon filaments as we explained in an article about What is exactly Carbon Fiber. This structure gives it extraordinary rigidity and one defining characteristic. There are multiple types of carbon fiber and this varies depending on the exact specification, but as a general rule we can say that carbon fiber really doesn’t like to bend.

Its stiffness (Young’s modulus up to hundreds of GPa) allows engineers to create ultra-light structures that remain dimensionally stable under heavy loads.

Why engineers love carbon fiber

• Exceptional strength-to-weight ratio
• Extremely high stiffness
• High compressive strength
• Excellent thermal performance
• Strong UV resistance compared to other fibers

Carbon fiber pattern

That’s exactly why carbon fiber shows up everywhere in high-performance engineering. These applications are some of the most carbon fiber intensive:

• Aircraft structures
• Formula 1 chassis
• High-performance cars
• Drone frames
• High-end bicycles
• Structural panels and robotic arms

When rigidity and precision are needed, carbon fiber wins.

Kevlar®: The King of Toughness

Kevlar was engineered with a completely different philosophy: survive impacts instead of resisting deformation. Its molecular structure allows to absorb more energy, wich makes it shine when experiencing impacts.

What makes Kevlar® and aramids so special?

• Exceptional impact resistance
• Outstanding abrasion resistance
• High toughness and energy absorption
• Slightly lower density than carbon fiber
• Strong resistance to many chemicals and fuels

That’s why aramids are so popular for ballistic protection and impact-heavy environments.

Aramid fabric

The trade-offs of Kevlar®

Kevlar struggles where carbon fiber excels:

• Poor compressive strength (fibers can buckle)
• Lower stiffness
• Sensitive to UV exposure without protection
• Difficult machining and cutting due to high abrasion resistance

Why Carbon Fiber and Kevlar Behave So Differently

The difference comes down to energy management.

Carbon fiber:

• High modulus
• Minimal elongation
• Stores elastic energy
• Tends to fail more suddenly than Kevlar

Kevlar:

• Lower modulus
• Higher elongation
• Dissipates impact energy
• Tends to fail more progressively than carbon fiber

One resists movement. The other absorbs it. Kevlar ® also shows better abrasion resistance, while carbon fiber maintains superior dimensional stability under load.

Carbon fiber plays a key role in hypercar performance and is widely used in many other high-performance sectors.

Carbon Fiber vs Kevlar: Quick Comparison

When to choose carbon fiber over Kevlar®?

Carbon fiber is the correct choice when a rigid lightweight structure is needed. For example, Drone arms, aerospace panels, structural components, etc.

When is aramid better than carbon fiber?

As a general rule, in case impact or abrasion resistance are desirable, aramids tend to provide a better solution than carbon fiber, like for kayak skid plates, protective gear, armor layers, etc.

Hybrid Carbon/Kevlar composites: The best of both materials.

Although some precautions must be taken when using them, hybrid laminates combining both fibers are very common because they take advantage of the strengths of each material.

• Kevlar® inner layers to absorb impacts and prevent catastrophic failure
• Carbon fiber outer layers to provide stiffness and UV protection
• Hybrid fabrics with aramid and carbon fibers

This hybrid approach balances rigidity and survivability, improving it’s overall performance.

TL;DR

Carbon fiber and Kevlar® aren’t better or worse than each other — they’re designed for different jobs.

• Carbon fiber shines when stiffness, dimensional stability, and high strength-to-weight ratio are required.
• Kevlar® (aramid fibers) excels in impact resistance, toughness, and abrasion resistance. It absorbs energy instead of cracking, but lacks stiffness and compressive strength.

Engineering is always more nuanced, but as a quick rule of thumb for rigidity and precision, carbon fiber wins. For impact protection and durability, Kevlar is normally better. Sometimes it is worth combining both using hybrid carbon/Kevlar® composites.

In composites engineering, the real question isn’t which material is stronger — it’s how you want the structure to behave.

The post Carbon Fiber vs Kevlar®: Which One Is Better? appeared first on Managing Composites.

Let’s kick off our newsfeed with very exciting news: The NCC successfully demonstrates AFP manufacture of CMC parts!

Engineers at the National Composites Centre (NCC, Bristol, U.K.) have completed what they say is a European first by manufacturing ceramic matrix composites (CMC) using automated fiber placement (AFP) technology, paving the way for the materials’ high-temperature capabilities to be unlocked within engines.

The project — completed as part of the NCC’s Core Research program, and supported by Rolls-Royce, Reaction Engines, MBDA and 3M — has demonstrated that a novel oxide-based ceramic towpreg material from 3M can be used in automated deposition.

While conventional nickel-based superalloys have a maximum continuous temperature of approximately 800°C, oxide-based CMC can operate at 1,000°C, with the higher operating temperature potentially improving the efficiency of aerospace engines and reducing fuel consumption and subsequent CO2 emissions.

Interested to know more about this project? Check out this link:

https://www.compositesworld.com/news/ncc-successfully-demonstrates-afp-manufacture-of-cmc-parts

Mubea to collaborate on production of carbon fiber exoskeletons!

Automotive supplier Mubea (Attendorn, Germany) has entered into a cooperation agreement to commence production of robotic exoskeletons for smart power suits developer German Bionic (Augsburg, Germany).

German Bionic’s Cray X power suits, which feature carbon fiber composite frames, aid workers when lifting heavy loads by actively amplifying their movements and thus protecting the lower back from excessive strain. 

“Mubea is a specialist in high-quality lightweight components and is a ‘hidden champion’ world market leader with many of its products,” says Dr. Thomas Muhr, managing partner of Mubea. “Over the past decades, we have developed into a leading supplier for the automotive industry with our products for body, chassis and powertrain. Together with German Bionic, we are now expanding our new micromobility business area to include the future field of robotic exoskeletons.”

https://www.compositesworld.com/news/mubea-to-collaborate-on-production-of-carbon-fiber-exoskeletons

Now, let’s talk about the 3D printing of carbon fiber composites in the drone industry:

3D-printed composite tail rotor gear box housing enhances Discovery super drone

Discovery is a 75-kilogram maximum takeoff weight (MTOW) unmanned single-rotor helicopter. It is Flying-Cam’s newest, largest and most versatile system so far with increased endurance features. Fully integrated state-of-art sensors were carefully chosen to match the platform quality for a variety of applications ranging from entertainment, homeland security, earth monitoring and high-precision remote sensing generally.

The aim of the “super drone” project was to create a lightweight yet rigid physical and aerodynamic protection for the tail rotor actuators and the GPS antenna. Flying-Cam opted for CRP Technology’s proprietary high-performance Windform Top-Line range of composite materials, particularly Windform XT 2.0, a carbon fiber-filled polyamide-based 3D printing composite especially suitable in demanding applications for such a sector as motorsports, aerospace and UAV.

The material replaced the previous formula of Windform XT in the Windform Top-Line family of materials for PBF created by CRP Technology, featuring improvements in mechanical properties including +8% increase in tensile strength, +22% in tensile modulus and a +46% increase in elongation at break.

https://www.compositesworld.com/news/3d-printed-composite-tail-rotor-gear-box-housing-enhances-discovery-super-drone

Our last story covers thermoplastic composites!

One-shot manufacture of 3D knitted hybrid thermoplastic composite structures!

To help realize industrialized lightweight vehicle components, the European Commission backed a project called MAPICC 3D (2011-2016). It sought to develop a process capable of producing net-shape, high-performance structural 3D thermoplastic textile composite preforms with topology-optimized fiber reinforcement orientation made in one shot using a knitting technique.

The project included the development of virtual tools capable of modeling 3D composite structures and predicting their mechanical behavior according to textile architecture and resin choice, allowing for customized end products and better accessibility to SMEs/OEMs. It also saw the development of thermoplastic hybrid yarns comprising both matrix and reinforcing fibers. The resulting manufacturing procedure can precisely steer the fibers in three dimensions, tailoring them to the component’s load paths with minimal raw material waste.

Volvo Group Europe used the MAPICC 3D project to develop and validate a thermoplastic textile composite seat reinforcement plate for its N2 class truck (axle weight between 3.5 and 12.5 metric tons) to replace a steel plate. The resulting composite part was to match the steel version’s technical requirements, including the strength needed to pass the mandatory ECE R14 seat belt anchorage test for the N2 class vehicle, and realize significant weight savings.

https://www.compositesworld.com/articles/one-shot-manufacture-of-3d-knitted-hybrid-thermoplastic-composite-structures

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