According to the definition of GB 2811-2007 "Safety hat", safety hat refers to "the protection of the human head by falling objects and other factors caused by the injury of the hat." In terms of basic technical performance, the standard stipulates that the helmet is subjected to impact testing after high temperature, low temperature, immersion, and ultraviolet radiation pretreatment, and the force transmitted to the head die does not exceed 4900N, and the cap shell shall not have debris falling off. After the puncture test, the steel cone shall not contact the surface of the head mold, and the cap shell shall not have fragments falling off. In addition, the safety helmet should have anti-static, electrical insulation, flame retardant and low temperature resistance.
The protective principle of the helmet is closely related to its appearance. The cap shell is elliptical or hemispherical, with a smooth surface, and when the object falls on the cap shell, the object immediately slides off and does not stay on the cap. And because it is similar to a sphere, the force of the object hitting the cap shell is transmitted around it. According to statistics, the force reduced by the buffer of the hat lining can reach more than 2/3. The standard also stipulates that in the impact test of the safety helmet, the force transmitted to the head die does not exceed 4900N, and the cap shell must not have debris falling off.
Safety helmets are for motorcycle, light riding, electric vehicles and other vehicle drivers and passengers to provide security. Under normal circumstances, the weight of a hard hat is about 400 grams, and the weight of a safety helmet is more than 1000 grams, because the safety helmet adds additional accessories such as head protection and goggles, while the hard hat does not. At the same time, the safety helmet is 360 degrees without dead Angle to the upper front and side of the head for all-round protection