Masks are in urgent need! Whether it is medical workers on the front line of the epidemic or ordinary people, the need for masks has never been more urgent. In order to maintain the supply of masks and protective clothing, industrial textile companies, under the call of the state, overcame various difficulties and started production in advance, working overtime and uninterrupted production. However, due to shortages of upstream raw materials, production equipment, personnel, etc. during the Spring Festival, the production speed of masks cannot keep up with the demand gap, and the supply of masks is still tight.
Masks with protective effects are crucial to epidemic prevention and control. This article also hopes to popularize some relevant content about the mask production process, core materials, and implementation standards, so that everyone can become more familiar with masks and make more reasonable choices. With a mask.
1. The core filter material of the mask: electrostatic melt-blown nonwoven fabric after electret treatment!
Most masks are mainly composed of three layers of non-woven fabrics. The inner and outer layers are mostly spunbond non-woven fabrics, and the middle layer is electret polypropylene melt-blown non-woven fabrics. Or nanofiber composite materials with higher filtration performance are the key core materials for masks to achieve barrier protection functions. The outer non-woven fabric of medical masks also has water-repellent and other requirements.
Electret-treated polypropylene melt-blown nonwoven fabric can use the Coulomb force of its charged fibers to capture fine particles (virus aerosols, etc.), and masks made with it have better respiratory resistance. Suitable and relatively comfortable to wear, it greatly improves filtration efficiency. Currently, most of the medical protective masks, medical surgical masks, civilian protective masks and industrial protective masks on the market use electret melt-blown nonwoven fabrics as their core filter materials.
2. Standard support: Comparative interpretation of the main technical requirements of China’s current mask standards
At present, the relevant standards for various types of masks in China mainly include:
Three items for medical masks – GB 19083-2010 “Technical Requirements for Medical Protective Masks”, YY 0469-2011 “Medical Surgical Masks”, YY/T 0969-2013 “Disposable Medical Masks”;
Civil Protective Masks 1 item – GB/T 32610-2016 “Technical Specifications for Daily Protective Masks”;
Industrial Protective Masks 1 item – GB 2626-2006 “Respiratory Protective Equipment Self-priming Filtering Anti-Particulate Respirators”,
The main technical requirements of the above standards are compared, as shown in the following table:
Summary table of the main technical requirements of China’s mask standards
Interpretation:
1. Medical protective masks that comply with the GB 19083-2010 standard do not have an exhalation valve, have good facial tightness, and have a filtration efficiency of non-oily particles ≥95%. They are required to pass the synthetic blood penetration test and have requirements for microbial indicators. The filtration efficiency in the standard is divided into three levels, level 1 is ≥95%, and level 3, the highest level, is ≥99.97%.
2. Medical surgical masks that comply with the YY 0469-2011 standard, commonly known as flat masks, have no requirements for facial tightness, and the filtration efficiency of non-oily particles is ≥30%;
3. Disposable medical masks that comply with YY/T 0969-2013 standards are used in general medical environments. The appearance and facial tightness of the masks are the same as medical surgical masks. There are no requirements for the filtration efficiency of non-oily particles;
4. Civil protective masks that comply with the GB/T 32610-2016 standard and have good facial tightness. They are available with or without a breathing valve. They are divided into four categories: A, B, C, and D according to the protective effect. Levels, among which, the filtration efficiency of non-oily particles and oily particles of level A masks are ≥95%, and the filtration efficiency of non-oily particles of level B, C, and D masks is ≥90%;
5. Comply with GB 2626- The 2006 standard industrial protective masks have good facial tightness. They are available with or without breathing valves. According to the filtering of non-oily particles, the filtration efficiency is divided into three levels: KN90, KN95, and KN100.
3. Mask comparison summary
1. At present, the so-called “N95″ masks in society are not very accurate. ” N95″ is the classification in the American standard. The filtering effect is basically the same as the KN95 level in GB 2626-2006, but it is not the classification level in our country’s standards. In China’s standard system, GB 19083-2010 standard medical masks are divided into level 1, level 2, and level 3. Among them, the non-oily particle filtration efficiency of level 1 is ≥95%, level 2 is ≥99%, and level 3 is ≥99.97 %; GB/T 32610-2016 standard civilian masks, the protective performance is divided into four levels: A, B, C, and D. Masks of each level are used in different air quality environments. Among them, level A filters non-oily particles and oily particles. The efficiency is ≥95%, and the non-oily particle filtration efficiency of B, C, and D-level masks is ≥90%; GB 2626-2006 standard industrial masks, KN90, KN95, and KN100 three-level products require non-oily particle filtration efficiency ≥90 %, ≥95%, ≥99.97%. Note: The three standards of GB 19083-2010, GB/T 32610-2016, and GB 2626-2006 have basically the same testing methods for non-oily particulate matter filtration efficiency and respiratory resistance.
2. When the filtration efficiency of non-oily particles is required to be ≥95%, level 1/2/3 in the GB 19083-2010 standard, level A in the GB/T 32610-2016 standard, and GB 2626- KN95 and above levels in the 2006 standard can meet the requirements. At the same time, the breathing resistance required by the GB/T 32610-2016 standard is lower than that required by other standards, making it more comfortable for ordinary people to wear.
3. From the perspective of design and functional requirements, the protective capabilities of masks range from high to low.The order is roughly as follows: Medical protective masks > Class A/KN95 masks > Class B/KN90 masks > Medical surgical masks > Disposable medical masks. It is not recommended to use ordinary thermal or decorative masks as protective masks.
</p
