Helmet is used to protect human head labor supplies, it is widely used. A lot of people are wondering , a little labor supplies helmets, how can withstand the pressure and protect the human head .
fire helmets structure:
First, the cap shell top should be strengthened. Can be made of light top or muscle structure . Cap shell made of non along with along or curling.
Second, the plastic cap liner should be madeafter the hoop structure, can freely adjust the headband size ( sub- pull adjustment buttons adjustment knob , etc. ) .
Third, no post hoop cap liner made ??under the chin with a "Y" , after the hoop , allowing made a single root.
Fourth, contact head forehead cap hoop , to breathable, absorb sweat.
Five , cap hoop around the liner , can be made into bars , or block, and leaving space for air circulation .
Six , helmet manufacturers must be strictly in accordance with the national standard GB2811-2007 for production .
Seven , Y class does not allow lateral pressure helmet , helmet just because Y class protection from top to bottom line impact of the damage caused , not by the side of the pressure protection .
PPE helmet pressure is mainly used three principles :
One , the buffer damping effect : cap shell and cap liner between 25 ~ 50mm gap , when the object hit the helmet , the cap shell deformation is not due to a direct impact to the head at the top .
Second, the dispersion of stress : cap shell is oval or hemispherical , smooth surface , when the object fall on the cap shell , the object can not stop immediately fall ; And cap shell hit points to withstand the force transmitted to the surroundings through the cap liner buffer to reduce the force of up to 2 /3 of the rest of the force through the cap liner gives the entire area of ??the skull to pass , so put the focus on the surface becomes a focal point , thus avoiding the impact of a point on the cap shell stress concentration , reducing the force per unit area .
Three , biomechanics : GB forth helmet must be able to absorb the 4900N. This is because the biological tests , the force in human cervical maximum limit , exceeding this limit will be harmed cervical spine , the light causing paralysis , severe life-threatening.