Brief introduction and characteristics of various types of helmets

FRP helmets are manufactured using unsaturated special polyester resin combined with alkali-free high-strength glass fiber cloth, utilizing advanced technology and rigorous testing procedures. This composite material is highly resistant to corrosion and exhibits excellent performance against atmospheric conditions, water, and common concentrations of acids, bases, salts, as well as various oils and solvents. FRP has found widespread use in chemical protection and is gradually replacing traditional materials like carbon steel, stainless steel, wood, and non-ferrous metals. Additionally, it serves as an outstanding insulating material, ideal for manufacturing insulators. It maintains good dielectric properties even at high frequencies. Furthermore, FRP has low thermal conductivity, making it an effective thermal insulation material and a suitable choice for thermal protection and ablation resistance.

Plastic safety helmets typically feature an outer shell made from high-density polyethylene (HDPE), a highly crystalline and non-polar thermoplastic resin. HDPE originally had a milky white appearance and showed some translucency in thin sections. It offers excellent resistance to most industrial and household chemicals. Some chemical types may be corrosive, but HDPE is still widely used for packaging applications. Its electrical properties are exceptional, particularly its high dielectric strength, making it ideal for wire and cable insulation. Medium to high molecular weight grades provide excellent impact resistance, even at low temperatures as low as -40°F.

Polypropylene is another common material used in plastic safety helmets, primarily in the form of acrylic. It is a thermoplastic resin derived from the polymerization of propylene and comes in three isomeric forms: isotactic, syndiotactic, and atactic. Industrial-grade polypropylene mainly consists of isotactic structures, with some variants containing small amounts of ethylene. This material is non-toxic, odorless, lightweight, and offers better strength, stiffness, and heat resistance compared to low-density polyethylene. It also has high fatigue resistance and can withstand temperatures up to around 100°C. Polypropylene has good electrical insulation properties that remain unaffected by humidity, though it becomes brittle at low temperatures and is prone to aging over time. It is commonly used in general mechanical components, corrosion-resistant parts, and electrical insulation, making it a popular choice for hard hat production due to its resistance to common acids, bases, and organic solvents.

In addition to these synthetic materials, traditional items such as tape, paper glue, and bamboo have also been used in the past for making safety helmets. However, current national standards for safety helmet materials are becoming more standardized and professional. Many manufacturers are now developing advanced, high-tech materials to enhance the performance and safety of protective headgear.

China Labor Insurance Network