I. Core Characteristics and Protection Principles of Aramid Fiber

1. Ultra-high Strength and High Modulus

1. The tensile strength of aramid fiber is 5-6 times that of steel wire, and the modulus is 2-3 times that of steel wire, with a density only 1/5 of steel wire. Under the same protection effect, the weight is reduced by more than 40% compared with traditional protective materials. Its molecular chain is in a rigid rod-like structure. When impacted, it absorbs the impact kinetic energy of bullets, shrapnel, and sharp weapons through fiber tensile deformation + energy dispersion, avoiding penetration and blunt trauma, which is the core of realizing "lightweight high-strength protection".
2. High Temperature Resistance and Flame Retardancy

1. The long-term service temperature of aramid can reach above 200℃, and the decomposition temperature is as high as 370℃. It does not burn, melt, or drip when exposed to fire, only carbonization occurs, and the Limiting Oxygen Index (LOI) is greater than 28, belonging to non-combustible materials. In scenarios such as explosive ordnance disposal, fire rescue, and riot control, it can resist high-temperature flames, thermal radiation, and Molotov cocktail impacts, avoiding equipment burning and sticking to the skin, making it a key flame-retardant material for bomb suits, tactical face shields, and other equipment.
2. Chemical Corrosion Resistance and Aging Resistance

1. Aramid has excellent corrosion resistance to strong acids, strong alkalis, organic solvents, etc., and is also resistant to ultraviolet rays, high and low temperatures (-50℃~+200℃), and fatigue. It does not age or brittle after long-term use. In extreme environments such as deserts, oceans, and chemicals, the protection performance is stable, and the service life is 3-5 times that of ordinary fibers.
2. Flexible Fit Adaptation

1. Aramid fiber has good flexibility and weaveability, and can be made into flexible protective layers through lamination, weaving, composite and other processes, fitting the human body contour (such as torso, joints, hands) without restricting tactical movements. At the same time, the breathable mesh composite process can improve air permeability and avoid stuffiness and sweating during long-term wearing.

II. Main Categories and Performance Comparison of Aramid Fiber

III. Core Applications of Aramid Fiber in Military and Police Protection

• Bulletproof Vests/Bulletproof Jackets: Para-aramid (Kevlar) is used as the core bulletproof layer, which can resist the penetration of pistol bullets and submachine gun bullets of NIJ Level IIIA and below. Matching with ceramic inserts can be upgraded to NIJ Level IV to resist direct rifle bullet impact;
• Bulletproof Helmets: Para-aramid is laminated and formed, with light weight and high protection strength, which can resist explosive shrapnel and blunt object impacts, and is compatible with extended equipment such as night vision goggles and tactical face shields;
• Bulletproof Inserts: Para-aramid + ceramic composite structure, as the core reinforcement layer of bulletproof vests, upgrading the ballistic protection level to NIJ Level III/IV.

• Riot Shields: Meta-aramid + PC composite structure, which can resist stick blows, brick impacts, and explosive shrapnel impacts, and is also high temperature resistant and flame retardant, suitable for riot control and riot management scenarios;
• Tactical Knee & Elbow Pads: Para-aramid woven layer + EVA buffer layer, which can resist repeated kneeling and climbing impacts, wear-resistant and anti-slip, without restricting joint movement;
• Tactical Gloves: Para-aramid knitted layer, cut-resistant, stab-resistant, and wear-resistant, suitable for counter-terrorism assaults, explosive ordnance disposal and other scenarios, protecting hands from sharp weapons and shrapnel injuries.

• Bomb Suits: Meta-aramid (Aramid 1313) is used as the outer flame-retardant layer, which can resist high-temperature flames above 500℃ and explosive shock waves. The inner layer is matched with a para-aramid buffer layer to achieve dual protection of "flame retardant + bulletproof";
• Tactical Face Shields: Meta-aramid + PC composite lenses, high temperature resistant, anti-glare, and anti-chemical splashes, suitable for riot and chemical emergency disposal scenarios;
• Fire Suits: Meta-aramid multi-layer composite structure, high temperature resistant, flame retardant, waterproof and stain-resistant, which is the core protective equipment for fire rescue and explosive ordnance disposal.

IV. Processing Technology and Technical Points of Aramid Fiber

1. Lamination Process

1. Aramid fiber is laminated into sheets (such as bulletproof helmets, bulletproof insert base materials) through resin impregnation + high temperature and high pressure, with tight fiber arrangement and high protection strength, which is the core process for manufacturing rigid protective equipment.
2. Weaving Process

1. Aramid fiber is spun into yarn, and woven into fabrics (such as bulletproof vests, tactical gloves, bomb suit outer layers) through plain weave, twill weave, satin weave and other weaving methods, with good flexibility and fit, which is the core process for manufacturing flexible protective equipment.
2. Composite Process

1. Aramid fiber is compounded with materials such as ceramic, PC, EVA, glass fiber to achieve the dual performance of "rigid protection + flexible buffer" (such as bulletproof vests, riot shields, tactical face shields), balancing protection strength and wearing comfort.
2. Surface Treatment Process

1. Aramid fabrics are subjected to surface treatments such as water repellent, stain resistant, wear resistant, and UV resistant to improve the service life and protection stability of equipment in extreme environments.

V. Selection and Application Points of Aramid Fiber

1. Select the corresponding category according to the protection scenario
   • Ballistic protection and puncture resistance scenarios: Prioritize para-aramid (Kevlar/Twaron) to ensure high-strength protection;
   • High temperature resistance, flame retardancy, and riot resistance scenarios: Prioritize meta-aramid (Aramid 1313/1414), balancing flame retardancy and cost.
2. Pay attention to fiber specifications and process quality
   • Para-aramid: Prioritize 1000D/1500D high denier fibers with lamination density ≥0.9g/cm³ to ensure bulletproof and stab-resistant performance;
   • Meta-aramid: Prioritize 200D/400D fibers with weaving density ≥200g/㎡ to ensure high temperature resistance, flame retardancy and wear resistance;
   • Inspection process: Laminated sheets have no bubbles or delamination, woven fabrics have no jumping or breakage, and composite structures are firmly bonded.
3. Balance lightweight and protection performance

1. Under the same protection level, aramid materials are more than 40% lighter than traditional protective materials (such as steel wire, nylon). Prioritize aramid products with high modulus and low density to avoid tactical mobility restrictions caused by "heavy protection".
2. Verify environmental adaptability and durability

1. Select aramid products that have passed tests such as high and low temperature, salt spray, ultraviolet rays, and fatigue resistance to ensure that the protection performance does not decay or age in extreme environments such as deserts, oceans, and chemicals; at the same time, check the wear resistance and water repellency of the fabric to extend the service life of the equipment.
2. Recognize authoritative certification

1. Export products need to match standards such as EN 1492 (bearing), EN 166 (eye), EN 14120 (joint), NIJ (ballistic); domestic procurement must comply with industry standards such as GA 889-2010 (police protective gear), GA 890-2010 (police tactical belts) to ensure that the protection performance of aramid materials and products meets the standards.

VI. Summary