Materials and Construction The main body consists of non-woven cloth, melt-blown fabric or filter material. The main material of the mask belt is usually non-woven fabric ( banding type ) or elastic ring ( hanging ear type ) . Melt blown cloth or filter material can provide better filtering functionality. The outer non-woven cloth material ( usually blue ) has water repellency and has a " lotus leaf effect "; the inner white layer is water-absorbent. The skin is better [2] .
Main technical requirements
Compared with disposable medical masks, the key technical requirements of these masks are look, construction and dimensions, nose clip, hide buckle, filtration efficiency, stress difference, parasitic signs, remaining ethylene oxide, skin irritation, and mobile along with toxicity, delayed hypersensitivity and other things, it is particularly vital to investigate the penetration of artificial blood. Two mL of artificial blood is 16 percent. Following the strain of 0 kPa is sprayed on the exterior of the mask, there should be no penetration on the inside of the mask. The BFE of the mask should be no longer than 95%, and the filtration efficiency for non-oily particles must be no longer than 30 percent. Additionally, investigations on fire retardant properties have been added. The mask material should be made of non-flammable materials, and the mask shouldn't burn more than 5 after leaving the flame. Microbiological indicators are equal to disposable medical masks [2] .
medical protective masks
Materials and Construction
This type of mask consists of a mask face and a mask buckle (the substance is usually a pressure belt ) . The face is divided into three layers: inner, middle and outer. The inner layer is constructed of non-woven fabric.
It's a certain degree of comfort; the middle layer is constructed from ultra-fine polypropylene fiber melt-blown material, which can provide better filtering performance; the outer layer is a coating of non-woven fabric and ultra-thin polypropylene melt-blown substance, which has a certain waterproof performance. Medical protective masks can't be equipped with breathing valves [3].
Main technical requirements
On the basis of medical masks, it's more requirements concerning airflow resistance, surface moisture resistance, and adhesion. Gas flow rate of 85 L / min at the instance, a mask to the filter efficiency of the non oily particles must fulfill the following requirements: 1 phase particle filtration efficacy ( Particulate Filtration Efficiency , that the PFE) ≥ 95% ( i.e., N95); two stage the PFE ≥ 99%; Grade 3, PFE ≥ 99. 97%. After the gas flow speed is 85 L/min , the inhalation resistance of the mask does not exceed 343. two Pa. The outer surface of the mask needs to be less than spray evaluation GB / T 4745 - 1997 in 3 predetermined levels. One of the microbiological indicators, the entire amount of bacterial colonies of this mask must be no longer than 200 cfu/g, E. coli, Pseudomonas aeruginosa, Staphylococcus aureus, hemolytic streptococcus, etc. shouldn't be detected, and the total number of fungal colonies shouldn't exceed 100 cfu/g; Masks indicated as sterile or sterile about the packaging should be sterile. The mask layout should provide good tightness, and the entire fit variable of the mask should not be less than 100 [3] .
Non -medical protective masks
Materials and Structure
Such masks incorporate daily security sprays and particulate respirator, the structure is usually 3 layers or 3 or even more layers, inner and outer layers is a nonwoven cloth, generally without the outer liquid barrier function. The filter coating can be broken up into coarse filter PET filter layer, higher efficacy PET filter layer, higher performance melt blown filter layer, electrostatic filter cotton, etc., and activated carbon layer may also be inserted in line with the function [4]. Non-medical protective masks could be equipped with breathing valves. The breathing valve is a one-way valve that simply lets the exhaled gas to exit the mask via it and prevents the inhaled gas from passing into the mask. When exhaling, the breathing valve opens, and the exhalation is directly out of your system, reducing the exhalation resistance and reducing the moisture in the mask, thus cutting down the wearer's breathing problem, keeping the face sterile, and prolonging the sporting time. The key technical index of the breathing valve is the cover fastness, which shouldn't be slipped, broken or deformed.
Main technical prerequisites
Daily protective masks are suitable for protective masks worn in everyday life to filter out particulate matter in air pollution environments. In 2018 , that the National Health Commission's Disease Prevention and Control Bureau"According to PM2. 5 , resulted in heavy pollution weather health education center message of pollutants,"indicated favored marked with heavy pollution weather GB / T 32610 - 2016 regular masks. Masks that meet the standards have great protective performance and may efficiently filter or block PM2 . 5 [5]. Protective face mask vancouver effect daily security respirators descending to a class, B class, C class, D grade. 4 stages, respectively the protective influence was ≥90 percent, ≥85 percent, ≥75%, ≧ 65%, are to be applied The air quality indicator is intense pollution, severe pollution and below, intense pollution and below, mild pollution and under. 
