TEXTILES IN DEFENCE Protective clothing

TEXTILE IN DEFENCE Defense forces either at land sea or air are reliant on technical textiles Textiles have to meat the following requirements for military applications Physical requirements Environmental requirements Camouflage requirements Flame heat and flash protection Specific battle field hazards

Physical requirements for military textiles Textile in defense Physical requirements for military textiles

Specific battlefield hazards Textile in defence Specific battlefield hazards

PROTECTIVE CLOTHING Protective clothing provide protection against Dangerous material and process of their work Work place or environment from the people People from the people Protects the products

PROTECTIVE CLOTHING Function of protective clothing Cut and abrasion Ballistic and impact resistance Fire and extreme heat Gas and chemicals Nuclear and biological materials (not against nuclear beams) Extreme cold Static electricity Foul weather and high visibility

PROTECTIVE CLOTHING Materials Fibres through yarn, woven, knitted and nonwoven fabrics Specialized coatings and membranes

PROTECTIVE CLOTHING Combined protection and physiological functions Stylish aspects of clothing Ergonomics functions fit and comfort etc Hold the body temperature at 37 C

BALLISTIC BODY PROTECTION Most of the causes of casualties in a military conflict is not due to bullets but the fragments

BALLISTIC BODY PROTECTION Providing protection to a person is not a problem but the problem is related to the weight, bulk, rigidity and thermo physiological discomfort Textiles are a good candidate for providing protection because of their low density and comfort Textile armor could provide protection against low velocity bullets and fragments but not high velocity bullets (5.62, 7.62 and 12.7mm calibre) and sharp objects

BALLISTIC BODY PROTECTION Reduction in casualties by wearing a body armor Troops standing in open threatened by mortar bomb

BALLISTIC BODY PROTECTION Explosive ordnance disposable clothing weighing more than 15kg Body armor weighing about 4kg

BALLISTIC BODY PROTECTION Ballistics Science of projectile movement Projectile speeds up with explosion or reaction Gravity and friction affect projectile path Soft and hard ballistics

BALLISTIC BODY PROTECTION SOFT PROTECTION Bullet proof vests Fragment proof vests Anti blow vests Car armor HARD PROTECTION Bullet and fragment proof helmets Bullet proof sheets Puncture protection

BALLISTIC BODY PROTECTION HISTORY Iron shirts used in middle ages Total weight with the armor 35 kg Steel helmets used in world wars increased the survival chances Natural fibres used in these time but now the market is concurred by man made fibres

BALLISTIC BODY PROTECTION Mechanism of protective clothing Change of kinetic energy to deformation and thermal energy Material of projectile Hard core Soft core Soft core with lead Soft core with lead and steel penetrator Round or flat nose projectiles play

BALLISTIC BODY PROTECTION VELOCITY AND ENERGY DEPENDS ON Power of explosion Length of the gun Projectile stability Distance and spin Angle between the gun and the vest Where the bullet hits the vest (middle of the vest or edges) Climatic conditions (temperature and moisture)

BALLISTIC BODY PROTECTION HIGHER PERFORATING FORCE Higher kinetic energy Smaller cross section Smaller point Firmer (solid) material of the bullet Faster it spins Higher moisture Protective clothing Change the kinetic energy to deformation Counter the shock

BALLISTIC BODY PROTECTION HOW BALLISTIC VESTS WORK Bullet hits and penetrate through up to a or 5 layers Friction between bullet and yarn decreases the speed 6 and 7th layer yarn is pulled out Wave spread out along with the fibres depends on the velocity of bullets Waves reflect from the edges of the vest

BALLISTIC BODY PROTECTION STANDARDS Protection class 1 hand gun (9mm soft core bullets) Protection class 2 sub machine gun (9mm soft core bullets) Protection class 3 Soft core long rifle projectiles Protection class 4 Hard core long rifle projectiles Protection class ST bullets projectiles and knives

BALLISTIC BODY PROTECTION TRAUMA EFFECT Stopping of bullets cause a bump Depth of the bump is called trauma effect Abrasion of skin and bleeding Broken bones and ribs Contusion of lungs Deeper than 40 mm causes injury Heart failure

BALLISTIC BODY PROTECTION

BALLISTIC BODY PROTECTION Textile materials for ballistic protection In order to arrest the flight of projectile in a short distance the fibres must have High modulus Very high tensile strength Low elasticity

BALLISTIC BODY PROTECTION Different materials for ballistic protection

COLD PROTECTIVE CLOTHING

COLD PROTECTIVE CLOTHING For the temperature less than -5 0C Wind has an effect on the lowering of temperature APPLICATION Cold stores and rooms Very cold laboratories Outdoor working in cold countries Unheated ware houses in winter

COLD PROTECTIVE CLOTHING CLIMATIC PARAMETERS Temperature of air Moisture in the air Location Wind velocity

COLD PROTECTIVE CLOTHING PHYSIOLOGICAL FUNCTIONS Keep body temperature at 37 C by providing thermal insulation not allowing the heat to go out of the system Muscles can get flexed or tensed Shivering effect FUNCTIONS To insulate the body against low temperature To allow diffusion of water vapor

COLD PROTECTIVE CLOTHING Thermal insulation of clothing Air acts as best insulator Air trapped by the textile fibres is very important as it will not allow the heat to go out Textile fibres are good conductors of heat Exchange of hot air with cold air from outside causes a person to feel cold

COLD PROTECTIVE CLOTHING Phase change materials  (PCM) are substances that absorb and release thermal energy during the process of melting and freezing. When a PCM freezes, it releases a large amount of energy in the form of latent heat at a relatively constant temperature. PHASE CHANGE MATERIAL (PCM) Person produce 100 W energy at rest and 600 W while doing some hard work Heat dissipated by evaporation of sweat, dry heat flow and respiration Concept is heat could be stored and activated again Some materials change phase i.e. from one state to another by absorbing energy and the temperature does not change during the time Materials which can absorb energy and release it are termed as PCM Quantity of energy stored and temperature change depends on the material