There are many materials for safety helmet production. At present, the common materials for safety helmet shell production at home and abroad are ABS material, HDPE material, PC material, FRP material, etc; The cap hoop of internal structure is mainly made of LDPE, PA and other materials; The top lining is made of HDPE or nylon sponge composite material, the sweat absorbing belt is made of PVC film, acrylic fiber or towel sponge composite material, and the acrylic fiber and tapestry belt are used as the corresponding cap hoop connectors. The main safety helmet products produced in the world are summarized as follows: (according to international practice, they are classified by safety helmet shell materials)
1. The full name of ABS plastic is acrylonitrile butadiene styrene resin, which is the abbreviation of acrylonitrile butadiene styrene. This engineering plastic has heat resistance, high surface hardness and stable size, Good chemical resistance. At the same time, the electrical insulation performance is good, which is rarely affected by temperature and humidity, and remains constant in a large frequency range. 1n addition, it has good chemical properties, and has little effect on water, inorganic salt, alkali and acid
the impact strength of ABS is good, and it will not decrease rapidly at low temperature. Of course, the materials suitable for the production of safety helmets are mainly ultra-high impact ABS materials, otherwise the impact test is unqualified. This kind of material is widely used in other countries except North America where it is not used in the production of safety helmets< HDPE safety helmet is made of high density polyethylene, which has high surface hardness, good heat resistance, electrical insulation and dimensional stability, and is widely used in safety helmet production. However, the compressive strength of this material is poor. 1f the design of the inner structure of the cap shell and the wall thickness of the product are not improved, the side pressure test is often unqualified. Therefore, the side pressure resistance design of the safety cap brim of this material must be strengthened, otherwise it is difficult to pass the European, Australian, Japanese and Chinese standards. As there is no side pressure in North American Standard, HDPE safety helmet is widely used in America, while HDPE safety helmet is not used in Japan, South Korea and other countries< PC safety helmet 3. PC plastic is polycarbonate material, which is hard and tough with high impact resistance, high dimensional stability, good electrical insulation and high temperature resistance. Because of its high price, it is rarely used in other countries except Japan. Of course, because some special materials in PC have good temperature resistance, many metal smelting industries need this kind of high temperature resistant PC helmet 4. FRP safety helmet FRP material is glass fiber reinforced plastics. This material has high fiber strength, excellent heat resistance and electrical insulation performance, excellent acid and water resistance, flame retardant, small deformation and other characteristics, and has safety helmet made of this material all over the world< Other safety helmets in addition to the above four kinds of materials, there are also the following kinds of safety helmets, which are mainly produced in China and rarely seen in foreign safety helmet manufacturers and exhibitions (1) safety helmet made of rubber and canvas (2) cold proof helmet: it is made of inner plastic shell as interlayer, and the outer shell is made of cashmere and cashmere. 1t is suitable for winter protection (3) bamboo safety helmet: safety helmet made from bamboo pole< (4) rattan wicker helmet: this kind of helmet is made of rattan or wicker material, but its flame retardant effect is very poor (5) aluminum safety helmet: a few factories produce aluminum safety helmet by die casting China labor insurance net