There are many materials for the production of helmets. At present, the commonly used materials for the production of helmet shells at home and abroad are: ABS material, HDPE material, PC material, FRP material, etc.; the inner structure of the headgear is mainly produced by LDPE, PA and other materials; The top liner is made of HDPE or sponge composite nylon material, the sweat band is made of PVC film, acrylic or terry cloth sponge composite and other materials, and the acrylic and polyester tapes are the corresponding cap hoop connectors. Several main Safety Helmet products currently produced in various countries in the world are briefly described as follows: (according to international practice, the helmet shell material is classified)
1.ABS safety helmet
The full name of ABS plastic is acrylonitrile-butadiene-styrene resin, which is the abbreviation of Acrylonitrile Butadiene Styrene in English. This engineering plastic has heat resistance, high surface hardness, dimensional stability and good chemical resistance. At the same time, the electrical insulation performance is good, it is rarely affected by temperature and humidity, and it remains constant in a wide range of frequency changes. In addition, its chemical properties are also very good, and it has little effect on water, inorganic salts, alkalis and acids.
ABS material has good impact strength and does not drop rapidly at low temperatures. Of course, the materials suitable for the production of safety helmets generally mainly use ultra-high impact ABS materials, otherwise the impact test will be unqualified. (This material is widely used in other countries except for a small number of countries such as North America that do not use this material to produce helmets.)
2.HDPE safety helmet
HDPE plastic is a high density polyethylene material (High Density Polyethylene), which has high surface hardness and good heat resistance, electrical insulation and dimensional stability, and is widely used in the production of safety helmets. However, the compressive strength of this material is poor. If the internal structure of the cap shell and the wall thickness design of the product are not improved, the lateral pressure test is often unqualified. Therefore, the helmet brim of this material must be designed to strengthen the lateral pressure resistance. Otherwise, in Europe and Australia , Japanese and Chinese standards are difficult to pass. Because the North American standard does not have this item of side pressure. (HDPE helmets are widely used in the Americas, while in Japan, South Korea and other countries basically do not use HDPE to produce helmets.)
3. PC hard hat
PC plastic is a polycarbonate material (Polycarbonate), which is hard and tough, with high impact resistance, high dimensional stability, good electrical insulation properties and high temperature resistance. Due to the high price of the material, 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 require such high temperature-resistant PC helmets.
4. FRP helmet
FRP material is glass fiber reinforced plastic, referred to as Fiberglass Reinforced Plastics. This material has high fiber strength, excellent heat resistance and electrical insulation properties, as well as excellent acid and water resistance, flame retardant, small deformation and other characteristics.
5. Other helmets
In addition to the above 4 kinds of materials for the production of helmets, there are also the following types of helmets, which are mainly produced in China and are hardly seen in foreign helmet manufacturers and exhibitions.
(1) Tape safety helmet: use rubber and canvas to heat-press into a tape safety helmet.
(2) Cold-proof safety helmet: The plastic inner shell is used as the interlayer, and the cold-proof safety helmet made of sheep shearing and plush is used for the outer shell, which is suitable for winter protection.
(3) Bamboo woven safety helmet: a safety helmet made of bamboo poles.
(4) Rattan wicker helmet: This type of helmet is a helmet woven with rattan or wicker material, but the flame retardant effect is extremely poor.
(5) Aluminum safety helmet: Very few manufacturers use aluminum die-casting to produce aluminum safety helmets.
