Helmet is to prevent physical damage to the head impact protection products

 Helmet is to prevent physical damage to the head impact protection products . By the cap shell , cap liner , and rear lower cheek with hoop components. Hemispherical cap shell , firm, smooth and have a certain flexibility , impact and puncture combat substance mainly composed of the cap shell to withstand the kinetic energy . Cap shell and leave some space between the cap liner can be buffered , dispersing instantaneous impact, so as to avoid or mitigate the direct damage to the head . Absorption of the impact properties, puncture resistance , lateral stiffness , electrical insulation , flame resistance is a helmet basic technical performance requirements.

Helmet can withstand the pressure is mainly used three principles : 1. Buffer damping effect : cap shell and cap liner between 25 ~ 50mm gap , when the object hit the Fire helmet , the cap shell deformation is not due to a direct impact to the head at the top . 2 . Dispersing stress : cap shell is oval or hemispherical , smooth surface , when the object fall on the cap shell , the object can not stay immediately fall ; And cap shell hit points to withstand the force transmitted to the surroundings through the cap lining cushioning 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 force to a point on the cap shell stress concentration and reduce the force per unit area . 3 . 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.