Aramid Fibre – Lightweight, Strong and Remarkably Tough

When it comes to high-performance reinforcement materials, few fibres can match the combination of strength, low weight and impact resistance that aramid has to offer. Used in everything from ballistic protection to aerospace structures and motorsport components, aramid fibre has established itself as one of the most versatile advanced materials available today.

At R&G, we supply high-quality aramid fabrics for professional composite applications—whether you are building lightweight structures, reinforcing critical areas, or working on protective components.

What is Aramid Fibre?

Aramid fibre is a class of heat-resistant and strong synthetic fibre. The name is derived from "aromatic polyamide" - a polymer whose molecular chains are built around aromatic rings, giving the material its exceptional rigidity and thermal stability. Aramid fibres are produced by spinning the polymer into filaments, which are then woven or laid into fabrics for use in composite laminates.

The material was first developed in the early 1960s and has since become a cornerstone of modern lightweight engineering. Its unique combination of properties - particularly its very high tensile strength relative to its weight - makes it an ideal reinforcement for fibre-reinforced plastics (FRP), where it is typically processed with epoxy resin systems.

The Properties of Aramid

Aramid fibre stands out from other reinforcement fibres such as glass or carbon in several key respects:

• Extremely high tensile strength: Aramid offers outstanding resistance to tensile loads, making it suitable for structural applications where forces act predominantly in tension.
• Low density: At roughly 1.44 g/cm³, aramid is significantly lighter than glass fibre (approx. 2.54 g/cm³) and far lighter than steel. This makes it particularly attractive wherever weight savings are critical.
• Excellent impact and cut resistance: Aramid absorbs and dissipates energy exceptionally well. It resists tearing, cutting, and puncture far more effectively than most other structural materials, which is why it is widely used in protective applications.
• Good vibration damping: Aramid laminates dampen vibrations more effectively than carbon fibre, which can be an advantage in applications subject to cyclic or dynamic loads.
• Thermal stability: Aramid does not melt; instead, it begins to degrade at temperatures above approximately 400 °C, making it suitable for thermally demanding environments.
• Limitations to bear in mind: Aramid fibres are not without their weaknesses. They are relatively sensitive to compressive and flexural loads, absorb moisture more readily than carbon or glass fibre, and can be more challenging to cut and machine. UV exposure over time can also reduce the material's performance if left unprotected.

Is Aramid Fibre the Same as Kevlar?

This is one of the most common questions when dealing with aramid materials — and the short answer is: not exactly. Kevlar is a brand name registered by DuPont (now part of DuPont's spinoff Nomex/Kevlar portfolio) for their specific para-aramid fibre. Aramid, by contrast, is the broader material class.

Para-aramid fibres — of which Kevlar is the most well-known example — are characterised by their very high tensile strength and are the type most commonly used in composite reinforcement and ballistic protection. Meta-aramid fibres (such as Nomex, another DuPont brand) are optimised for thermal protection rather than structural strength and are used extensively in flame-resistant clothing and insulating materials.

So whilst Kevlar is an aramid fibre, not all aramid fibres are Kevlar. Other manufacturers produce para-aramid fibres under different trade names — Twaron (Teijin) and Technora being notable examples — which offer comparable performance characteristics.

Which is Better — Aramid or Kevlar?

This question is essentially one of brand versus generic material class, but it is worth addressing directly. In terms of structural composite applications, para-aramid fibres from different manufacturers perform comparably. The choice between products from DuPont (Kevlar), Teijin (Twaron) or other suppliers is often driven by availability, price, specific product grades, and the technical data provided for the intended application.

For most composite work - including laminates, protective panels, and hybrid constructions combining aramid with carbon or glass fibre - the fibre type (para-aramid) and the weave architecture are more decisive factors than the brand name. R&G supplies high-quality aramid fabrics that deliver the performance you need, without unnecessary brand premiums.

Is Aramid Stronger Than Steel?

Yes, when measured by specific tensile strength (strength relative to weight), aramid is substantially stronger than steel. A typical para-aramid fibre has a tensile strength in the range of 2,800–3,600 MPa, whilst structural steel sits at roughly 400–600 MPa. More importantly, aramid achieves this at a fraction of the density: approximately 1.44 g/cm³ versus 7.85 g/cm³ for steel.

This means that for the same weight, an aramid component can withstand tensile forces many times greater than an equivalent steel one. This is precisely why aramid is used in high-performance ropes, ballistic vests, helmets, cut-resistant gloves, and aerospace structures - wherever maximum strength at minimum weight is paramount.

It is worth noting, however, that steel outperforms aramid in compressive strength and stiffness, and is far more resistant to UV degradation and moisture absorption. The two materials serve very different engineering purposes, and neither is universally superior to the other.

What to Consider When Buying Aramid Fibres

Choosing the right aramid fabric for your application requires attention to several technical parameters:

• Weave architecture: Plain weave fabrics offer good drapability and are suitable for complex geometries, whilst twill or satin weaves provide a smoother surface and improved conformability. The weave structure affects both the mechanical properties and the ease of processing.
• Areal weight (g/m²): Lighter fabrics (e.g. 60–100 g/m²) are used for surface reinforcement and weight-critical layups; heavier fabrics (e.g. 170–350 g/m²) deliver greater structural thickness and impact resistance per layer.
• Hybrid or single-fibre fabrics: Aramid can be woven together with carbon fibre to create hybrid fabrics that combine aramid's impact resistance with carbon's stiffness - a popular choice for sporting goods, automotive parts, and aerospace components.
• Processing compatibility: Aramid fabrics are typically processed with epoxy resin systems. Cutting aramid requires sharp, dedicated scissors or tools, as the fibres are highly resistant to conventional cutting. Dedicated aramid scissors are strongly recommended.
• Moisture management: Aramid fibres are hygroscopic. Fabrics should be stored in a dry environment and dried before lamination if they have been exposed to humidity, to avoid compromising the fibre-matrix bond.

Aramid fibre fabric selection guide

Aramid Fabrics from R&G

At R&G, we stock a range of high-performance aramid fabrics suited to professional composite applications:

• Aramid Fabric 61 g/m², Plain Weave: A lightweight plain-weave aramid fabric ideal for surface reinforcement, impact protection layers, and weight-sensitive structures. Its low areal weight makes it an excellent choice for hybrid laminates and areas requiring cut and abrasion resistance without adding significant mass.
• Aramid Fabric, Twill Weave (AT): A twill-weave aramid fabric offering superior drapeability and a more uniform surface finish. Well suited for curved geometries, protective shells, and structural laminates where conformability and a smooth surface are important.

Both fabrics are compatible with standard epoxy laminating systems and can be combined with carbon or glass fibre layers to create tailored hybrid laminates.

FAQ – Frequently Asked Questions about Aramid Fibre

What is aramid fibre?

Aramid fibre is a heat-resistant, high-strength synthetic fibre made from aromatic polyamide. It is used as a reinforcement material in fibre-reinforced plastics, ballistic protection, and thermally demanding applications.

Is aramid the same as Kevlar?

Kevlar is a brand name for a specific para-aramid fibre produced by DuPont. Aramid is the broader material class. All Kevlar is aramid, but not all aramid is Kevlar - other manufacturers produce equivalent para-aramid fibres under different trade names.

Which is better: Aramid or Kevlar?

For composite applications, the performance of para-aramid fibres from different manufacturers is broadly comparable. The fibre type, weave architecture, and areal weight are more important selection criteria than the brand name.

Is aramid stronger than steel?

By specific tensile strength (strength-to-weight ratio), yes. Para-aramid fibres achieve tensile strengths of 2,800–3,600 MPa at a density of approximately 1.44 g/cm³ - far superior to structural steel on a per-kilogram basis. However, steel outperforms aramid in compression and stiffness.