Material Of Helmet Parts
Helmet materials are generally divided into four types: composite materials, plastic raw materials, abs, glass steel, and carbon fiber. The most common life is abs engineering plastics. ABS engineering plastics, namely PC + ABS (engineering plastic alloy), are also a kind of plastic raw materials. The Chinese name in the industry is called a plastic alloy, and it is named PC + ABS, mainly because this composite material has an excellent heat resistance and weather resistance of PC resin, excellent stability, difficult to deform and impact resistance, Contains excellent processing fluidity of ABS resin and strong plasticity. Therefore, such as plastic helmets, which have high plasticity requirements and need to ensure strong stability and safety, this plastic alloy is the best choice.
Material of helmet parts will be using ABS and PC, and these two materials must do heat treatment before molding.
A helmet that can withstand pressure mainly uses three principles
1. Cushioning and damping effect
There is a gap of 25 ~ 50mm between the cap shell and the cap liner. When the object hits the helmet, the cap shell does not directly affect the top of the head due to the deformation of the force.
2. Dispersed stress effect
The cap shell is elliptical or hemispherical, and the surface is smooth. When an object falls on the cap shell, the object cannot stay and immediately slide down; and the force received by the impact point of the cap shell is transmitted to the surroundings, which is reduced by the buffer of the cap lining The force can reach more than 2/3, and the rest of the force is transmitted to the human skull through the entire area of the cap liner, which changes the focus point to the force surface, thereby avoiding the concentration of impact force at a certain point on the cap shell and reducing Force per unit area.
The national standard stipulates that the helmet must be able to absorb 4900N. This is because of the biological test, the maximum limit of the human cervical spine when it is stressed. If it exceeds this limit, the cervical spine will be injured, and the mild will cause paralysis, and the severe will be life-threatening.