Safety helmet is a kind of labor protection product used more in daily life to protect the user's head safety.
Because the application area is different, the dangers faced are also different, so helmets are divided into many types in practical applications. Today, I will explain five common types of helmets.
1. FRP safety helmet
In the past, glass fiber and unsaturated polyester resin were used as raw materials, and the safety helmet blank was made by hand paste, and then heated and solidified. It was named FRP safety helmet because of the glass fiber in it. However, because glass fiber is irritating to the skin and the efficiency of manual pasting is low, vinylon fiber is now used instead of glass fiber, and a certain temperature molding process is adopted without manual pasting. This kind of helmet is still called "glass reinforced plastic helmet", which is characterized in that the specific gravity is only 16-14 of steel, while the mechanical strength is close to that of steel, and the tensile, bending and compressive strengths can reach 39×10^8Pa or more. The thermal conductivity of this material is very low, and it has good high temperature resistance, low temperature resistance, electrical insulation, corrosion resistance and combustion resistance.
FRP helmets are mainly used in metallurgical high-temperature workplaces, oilfield drilling, forest harvesting, power supply lines, high-rise building construction and construction in cold areas.
2. Polycarbonate plastic safety helmet
Polycarbonate plastic is a thermoplastic engineering plastic. It has good impact resistance, electrical insulation, high temperature resistance (100~140℃) and low temperature performance. It can reach (59~6, 9)×10^7Pa. The flexural strength can reach 10×10^8Pa. The cap lining is made of polycarbonate plastic through an injection molding machine with a plastic lining (by injection molding). With tie.
This plastic safety helmet is suitable for oil field drilling, forest logging, power supply lines, construction and other operations.
3. ABS plastic safety helmet
ABS plastic is a combination of three components, acrylonitrile (A), butadiene (B) and styrene (S). It is a thermoplastic engineering plastic that is widely used at present. The cap shells of various styles are injection-molded with ABS plastic, which has the properties of good rigidity, not easy to deform, impact resistance, electrical insulation, heat resistance, chemical corrosion resistance, etc., and can withstand high temperature of 100°C. The disadvantage is that it is not resistant to combustion, low temperature resistance, and poor aging resistance.
This kind of plastic safety helmet is mainly suitable for indoor and normal temperature workplaces with high impact strength such as mining and machinery industry.
4. UHMWPE plastic safety helmet
Ultra-high molecular weight polyethylene plastic is a new thermoplastic engineering plastic. Its rigidity and mechanical strength are higher than polyethylene, high temperature resistance of 127℃ and low temperature of -70℃, electrical insulation and corrosion resistance are also better. But this material should not come into contact with gasoline, otherwise the performance will be affected. The cap shell is injection-molded with this plastic, and then equipped with a cap lining and a chin strap. The safety helmet made of ultra-high molecular polyethylene plastic is suitable for a wide range of applications in metallurgy, chemical industry, mining, construction, mechanical power, transportation, forestry It can be used for work types such as geology and other operations.
5. Modified polypropylene plastic safety helmet
Modified polypropylene plastic is a thermoplastic engineering plastic mainly composed of polypropylene and mixed with polyethylene and polybutadiene. The disadvantage is that it is easy to shrink and has poor aging resistance.
The helmet shell is injection-molded with a liner and chin strap. This helmet is mainly used in construction, metallurgy, forest power, mining, wells, transportation and other places of work.
