medical masks consists of mask body and tighten belt, which masks face body is divided into inner, middle and outer layer and inner layer for close skin material (common health gauze or non-woven), middle to isolate filter layer (superfine melt-blown polypropylene fibre material layer), outer layer material for special antibacterial layer (non-woven or ultrathin polypropylene melt-blown material layer)
According to the performance characteristics and scope of application, medical masks can be divided into: medical protective masks, medical surgical masks, ordinary medical masks.
1. Medical protective masks
Medical protective mask is suitable for the medical personnel and related personnel of the airborne respiratory infectious disease protection, is a kind of closed self-priming filter type medical protective equipment, high protection grade, especially suitable for clinical activities by airborne or close contact in patients with respiratory tract infection disease transmission by droplets when worn.It can filter the particles in the air and block droplets, blood, body fluids, secretions, etc. It is a disposable product.Medical respirators block most pathogens such as bacteria and viruses. The WHO recommends respirators against particulate matter for medical workers to prevent viral infections in hospital air.
Medical protective masks meet the technical Requirements for Medical Protective Masks gb19083-2003, and important technical indicators include non-oily particle filtration efficiency and airflow resistance.Specific indicators are as follows: 
1) Filtration efficiency: The filtration efficiency of the aerodynamics median diameter (0.24±0.06) m sodium chloride aerosol was not less than 95% under the condition of air flow rate (85±2) L/min, that is, it conforms to N95 (or FFP2) and above grades.Diameter that blocks airborne transmission & LT;An infectious agent of 5 m or an infectious agent transmitted by droplets in close contact.
2) Suction resistance: The suction resistance shall not exceed 343.2Pa (35mmH2O) under the above flow rate conditions.
3) Spray the sample of the mask under the pressure of 10.9kPa (80mmHg), and no technical indicators such as penetration should appear on the inside of the mask.
4) A nose clip must be fitted on the mask. The nose clip is made of flexible material that can be bent. The length is & GT;8.5 cm.
5) The synthetic blood was sprayed into the mask sample at 10.7kPa (80mmHg) pressure, and no penetration should occur inside the mask.