The structure of the bridge of the nose needs to be deformed well by external force, does not spring back under no force, and keeps the existing shape unchanged. The bridge of the nose is called the "spine" of the mask.
Types of nose strips
The nose strips used for masks are classified as follows by material:
Metal aluminum sheet
It is made of metal aluminum plate. The nose bridge made of this material has a good bending effect, but it is not easy to separate and recycle it from the discarded mask after use.
Polyolefin polymer coated galvanized fine steel wire
A layer of polyolefin polymer material is coated on the galvanized filament with a diameter of 0.45mm-0.55mm. At present, most facial mask factories in China adopt this type, and the production capacity is relatively high. The manufacturing principle is the same as that of wire and cable processing. It is understood that the current shortage of such mask materials is mainly concentrated on the galvanized and annealed fine iron wire, and the nose bridge has higher requirements for the softness and hardness of the iron wire.
Plastic nose strip
From the perspective of recycling and environmental protection, the nose strip made of metal wire and plastic is difficult to separate. Therefore, some manufacturers have developed a nose strip made of all plastic. This all-plastic head strip has the characteristics of a metal wire. It bends and deforms under the action of external force. After losing the external force, it cannot rebound and keep the original curved shape unchanged. However, the current production capacity is low, and the cost is much higher than that of synthetic materials.
Selection characteristics of nose bridge material
Plastic materials are indispensable for iron core and all-plastic nose strip. At present, the commonly used plastic materials are PE, PP, etc., and these materials have similar characteristics. From the comparison of toughness and extensibility, PE is better than PP. The production process of the nose bridge is extrusion and extrusion. In order to stabilize the product size and prevent rebound but not reduce its toughness, some material manufacturers will add some filler masterbatches to PE and PP.