The current epidemic is in an extraordinary period, masks have become a hot spot, a few unscrupulous businessmen take the opportunity to sell unqualified mask products in the market. How can ordinary people not be fooled into buying qualified masks?
All qualified medical masks have the implementation of standards: (kloc-0/ of the outer packaging should be indicated)
GB19083-2010, medical protective masks
GB19083-2010 is a medical protective masks, belonging to the medical device with a medical device mark.
Protection level: high
YYY0469-2011, medical-surgical masks
YYY0469-2011 is medical-surgical masks, which are medical devices with medical device markings.
GB2626-2006, respiratory protection equipment
GB 2626-2006 is a commonly used particle protection mask, which cannot be used for medical treatment.
Protection level: medium
YY/T 0969-2013, disposable medical mask, is a disposable mask for general medical environment.
Protection level: low
The technical requirements of medical protective masks need to meet the technical requirements of GB19083-2010, which requires high filtration efficiency and filtration resistance, so the filter material must be N95 grade and above. Internal medicine surgical mask corresponds to YY 0469-2011; disposable medical supplies masks corresponding to the standard YY/t0969-2013, simply understood as the most common hospital use of masks standard.
Medical masks include two types: one is a medical surgical mask with three layers, and the other is a medical N95 mask with five layers. Both types of masks are made of nonwovens, most notably the intermediate meltblown nonwoven. Meltblown nonwovens block viruses and bacteria through the blocking action of the fibers and the electrostatic attraction of the fibers.
Thin medical masks are divided into three layers, the outer layer has a water-blocking effect (spunbonded nonwoven), which prevents water droplets from entering the mask; the middle layer has a filtration function (meltblown nonwoven), which consists of more than 99.999% filtered meltblown nonwoven fabrics welded by ultrasonic pressure. The filtration efficiency of the mask should not be less than 95%; the inner layer has a moisture absorption function (spunbonded nonwoven), and the inner layer near the mouth and nose is used to absorb moisture.
Compared with woven fabrics, nonwoven fabrics are nonwoven fabrics made of fibers. The advantages are breathability, filtration, water absorption, water resistance, good handfeel, soft and lightweight, but also has the disadvantage of not being washable.
The meltblown nonwoven fabric in the middle layer of the mask is usually 20 grams of material, and this layer is the most important! If we disinfect the used masks by boiling, alcohol spraying or UV light, theoretically we can eliminate the bacteria and viruses adhering to the masks, but high-temperature boiling and alcohol spraying will destroy the fibers of the meltblown nonwoven fabrics, and thus the effectiveness of the masks will be reduced.
The fiber barrier and electrostatic adsorption of meltblown nonwovens have a certain degree of saturation. When it reaches a certain level, it no longer has the function of adsorption of pathogens, so medical masks surgical masks generally need to be replaced after a few hours of continuous use.