What are aramid granules (Kevlar granules)?

Aramid granules, also known as Kevlar granules, are PPTA-based polymer granules used to manufacture aramid fiber, aramid paper, friction materials, and polymer composites. They feature high strength, high modulus, and excellent thermal and chemical resistance.

What is the typical service temperature of aramid granules?

Aramid materials made from these granules can typically be used continuously at 200–220 °C, withstand short-term exposure to 400 °C, and show decomposition above 500 °C in inert atmospheres.

How are aramid (Kevlar) granules manufactured?

They are produced by polymerizing p-phenylenediamine (PDA) with terephthaloyl chloride (TPC) in sulfuric acid or NMP/CaCl2 at low temperature, then precipitated, washed, dried, and granulated by spray drying or pelletizing.

What are the key applications of aramid granules?

Key applications include protective equipment (ballistic vests, gloves, helmets), friction and sealing components (brake pads, clutch linings), electrical insulation (aramid paper, cable wraps), polymer reinforcement for thermoplastics, and emerging uses such as 3D printing powders and hydrogen storage composites.

Aramid Granules - Kevlar Granules -Excellent Thermal Stability

Name: Aramid Granules - Kevlar Granules -Excellent Thermal Stability
Brand: shenghetech.com
SKU: SHPF-019
Availability: InStock
Rating: 5 (1 reviews)

Basic Information & Characteristics

Aramid granules—also called Kevlar granules—are advanced polymer intermediates based on poly(p-phenylene terephthalamide) (PPTA). They are the feedstock for making aramid fiber, aramid paper, friction materials, and high-performance composites.

Appearance: Light yellow to beige granules with uniform crystallinity
Molecular structure: Rigid aromatic chains with strong hydrogen bonding and π–π stacking
Thermal stability: Continuous service at 200–220 °C; short-term up to ~400 °C; decomposition >500 °C (inert)
Key features: High tensile strength and modulus, low creep, excellent flame resistance, superior fatigue/radiation resistance, and chemical durability

Manufacturing Process

Monomer preparation — p-Phenylenediamine (PDA) (impurities <50 ppm) and terephthaloyl chloride (TPC) (controlled moisture/byproducts).
Polymerization — Conducted in concentrated H₂SO₄ or NMP/CaCl₂ at −10 to 0 °C to obtain high-molecular-weight PPTA (intrinsic viscosity ≥ 5 dl/g).
Precipitation & washing — Neutralization and removal of residual acids/salts.
Drying — Vacuum drying to <0.5% moisture.
Granulation — Spray drying or pelletizing to form uniform aramid granules (typ. 50–500 µm).
Post-treatment — Surface modification (coupling agents, antistatic coats) and particle size classification per end-use.

Technical Parameters

Property	Typical Value
Appearance	Light yellow, uniform granules
Density	1.39–1.44 g/cm³
Glass Transition (T_g)	~370 °C
Melting Point	Does not melt; decomposes directly
Decomposition (T_d)	>500 °C (N₂), ~450 °C (air)
Moisture Absorption	3–7% (equilibrium)
Continuous Service Temp.	200–220 °C
Mechanical (fiber form)	Tensile 2.8–3.6 GPa; Modulus 70–110 GPa; Elongation 2–4%
Electrical	Resistivity ~10¹⁵ Ω·cm; Dielectric constant ~3.4
Chemical Resistance	Excellent vs. most solvents, weak acids/bases; poor in conc. H₂SO₄ or NaOH
Granule Size Range	50–500 µm (customizable)

Applications

Protective Equipment

Ballistic vests, cut-resistant gloves, helmets; firefighter and racing suits; high-strength ropes and reinforcement yarns.

Kevlar granules aramid fiber

Friction & Sealing

Automotive brake pads and clutch linings; aerospace/high-speed rail braking; durable gaskets and seals.

friction materials

Electrical Insulation

Aramid paper for honeycomb cores, insulating boards, flexible circuits; motor slot insulation; heat-resistant tapes.

aramid paper

Polymer Reinforcement

Enhancing thermoplastics (PA, PBT, PPS, PEEK, PEI) for lightweight aerospace structures and premium sports gear.

aramid composites

Emerging Uses

3D printing powders, electromagnetic shielding textiles, hydrogen storage tanks and composite cylinders.

PPTA granules

Future Outlook

Aerospace & Defense: Increased substitution of metals with lightweight aramid composites in missiles, satellites, and aircraft.
New Energy Vehicles: Reinforcement of battery separators and Type IV/V hydrogen storage tanks.
Eco-friendly Processes: Transition from sulfuric acid routes to ionic liquids and greener solvents.
Recycling: Growing chemical recycling of used Kevlar protective gear and aramid composites.

FAQ

What is the difference between aramid granules and Kevlar granules?

"Kevlar" is a well-known brand name for para-aramid fiber. In this context, aramid granules and Kevlar granules are commonly used interchangeably to describe PPTA-based granules used as raw materials.

Can aramid granules be customized?

Yes. Particle size distribution (e.g., 50–200 µm, 200–500 µm), moisture content, and surface treatments (coupling agents, antistatic) can be tailored to the end application.