Coronaviruses belong to the Coronavirus genus of Coronaviridae in the systematic classification. The coronavirus is a positive-stranded single-stranded RNA virus with a coat and a diameter of about 80-120 nm. Its genetic material is the largest one in all RNA viruses, and only infects humans, mice, pigs, cats, dogs, and avian vertebrates. A variant of coronavirus is the causative agent of atypical pneumonia and belongs to the RNA virus. In December 2019, Wuhan discovered unexplained pneumonia. In January 2020, the expert group concluded that the pathogen of an unexplained viral pneumonia case in Wuhan was initially determined to be a COVID-19.
First, the lungs are affected, manifested in consolidation in the lungs, a large amount of exudation, infiltration of inflammatory cytokines, and a large amount of infiltration of inflammatory cells. At the same time, many secretions were seen in the small bronchus, which blocked the small airway and affected the gas exchange. Virus particles can also be seen in the lungs under the electron microscope. At the same time, using a nucleic acid detection method, found viral nucleic acid.
The immune system is more affected. Clinically, we can see that there are very few correlations between leukocytosis, lymphopenia, and the progression of the disease or even death.
The main routes of transmission of the new coronavirus are respiratory droplet transmission and contact transmission. Transmission routes of aerosol and feces-mouth have yet to be further clarified. Epidemiological investigations have shown that many cases can be traced to close contact with confirmed cases.
Refers to the infection caused by the patient's sneezing, coughing, talking droplets, and exhaled gas inhaled directly.
Refers to droplets mixed in the air to form an aerosol, which causes infection after inhalation.
Refers to droplets deposited on the surface of the article, contacting the contaminated hands, and then contacting the oral cavity, nasal cavity, eyes, and other mucous membranes, causing infection.
Because the main transmission route of the new coronavirus is the respiratory droplet transmission and contact transmission, wearing a face mask is an important means to prevent the new coronavirus.
The widespread use of medical masks in China started with the SARS virus in 2003. At that time, gauze masks were used. From the appearance, the entire mask was designed as an approximate standard rectangle, and the wearing method was to tie the strap behind the head.
With the development of society, the materials of medical surgical masks have been greatly innovated. The design of the entire mask is lighter, more breathable, elastic, and richer. It breaks the traditional single white and is more convenient to wear.
Medical protective masks have national standards. Therefore, SARS medical protective masks have not been used in large quantities. In the past, many medical protective masks stored by medical institutions were white 8210 models. At present, 2 models produced by the US 3M company, the 1860 model is the most classic bowl-shaped structure, the 9132 model is a folded structure.
These two models of masks have been greatly improved in shape design, designed for human facial structure, making the masks fit and breathable, and the materials are also different from before. Made of materials to achieve the best results.
Materials needed: non-woven fabric, bridge of the nose, ear hook.
Materials required: non-woven fabric, bridge of the nose, ear hook, filter paper.
The 3 ply face mask is made of two layers of fiber non-woven fabric, which is professionally used in medical and health, and an additional layer is added to filter and spray filter cloth with anti-bacteria of 99.999%.
It can be applied to electronic manufacturing, dust-free workshops, catering services, food processing, schools, riding locomotives, spray processing, stamping hardware, health centers, hand processing industry, hospitals, beauty, pharmaceutical, factories, environmental clean Electronic factories, iron and steel factories, printing plants and other uses.
The 3 ply face mask is very breathable; it can filter toxic gas; it can keep warm; it can absorb water; it can be waterproof; it has elasticity; it won't be messy; it feels very good and quite soft.
The respirator is a kind of sanitary product, generally refers to a device that is worn on the nose and mouth to filter the air entering the nose and mouth, to block harmful gases, odors, and droplets from entering and exiting the wearer's mouth and nose. Masks have a certain filtering effect on the air entering the lungs. When respiratory infectious diseases are prevalent and when working in a polluted environment such as dust, wearing a mask has a very good effect.
The threat of COVID-19 has made people pay more and more attention to personal hygiene protection, and masks have almost become the necessary protective products for human hands. We should consciously wear masks on the following occasions.
When a colleague or classmate has a cold or pneumonia in the same office or class. At this time, personal hygiene must be strengthened.
When it is oily, and these substances are attached to the electrostatic non-woven fabric, the electrical properties will be reduced and the fine dust will penetrate, so for the filter material that prevents oil and gas sol.
Special electrostatic treatment is required to achieve the purpose of preventing fine dust.
Besides, NIOSH also divides each type of filter material into 95 (95%), 99 (99%), 100 (99.97%) according to the filtration efficiency, so that the three types of materials also have three filtration efficiency, so there are nine levels in total Masks.
The difference with the American standard is that its detection flow rate is 95L / min, and it is dusted with DOP oil. Classification according to filtration efficiency.
The first type is disposable medical masks, which are recommended for public use in non-person-intensive public places.
The second type is medical surgical masks. The protective effect is better than that of disposable medical masks. It is recommended to wear suspected cases, public transportation personnel, taxi drivers, sanitation workers, public service personnel, etc. during the post.
The third type is KN95 / N95 and above protective masks. It is mainly recommended for medical personnel to conduct on-site investigation, sampling, and testing. The public can also use it in crowded places or closed public places. However, due to its poor breathability and large respiratory resistance, it is not suitable for long-term wear, and the public is not recommended using it for excessive protection.
The fourth type is a medical protective mask, which has a protective effect of more than 95% and has an anti-penetration function. It is recommended to be worn by medical staff in fever clinics, isolation wards, and confirmed patients.
The first type is the KN95 protective mask, which can effectively protect 95% of foreign virus infections and is disposable when used.
The second type is n95 and n99. N95 is an international standard similar to kn95. When using n95 and n99, it will slightly prevent breathing and be produced by water droplets. The third type is ordinary medical masks, which can also achieve more than 95% protection against viruses.
The structure and organization of these two masks are similar, using special ultra-fine fiber filter materials, both sides are without cloth, and are formed by heat sealing. But the N99 and N95 masks differ in their filtration efficiency. The filtration efficiency of respirator n95 is 95%, while the filtration efficiency of respirator n99 is 99%.
Of course, the higher the filtering efficiency, the higher the efficiency of the mask against viruses. If you can choose, it is recommended to buy N99 masks. Of course, if the resources are limited, it is possible to buy any mask, as long as it is properly worn, it can prevent COVID-19.
The main difference between gas masks and face masks is that gas masks protect the face, eyes, nose, and mouth together. Face masks are mainly used to protect the mouth and nose, and gas masks have no way to protect the eyes.
If irritating objects are used when working in the chemical field, we need to protect our eyes, and we will choose a gas mask.
If there are no radioactive objects and only a few microscopic harmful gas, we can use face masks. If the gas masks and face masks are used to protect or prevent our safety, different protective products should be used on different occasions;
The gas mask first appeared in the First World War. It was a well-known Russian chemist Jielinsky who used the principle of wild boar to arch the ground and used the soft soil particles to adsorb and filter the poison gas. Material, and charcoal that can make the air clear, designed, and manufactured the world's first gas masks in the shape of wild boar.
Gas masks are mainly composed of components such as filter elements, cover bodies, eye windows, exhalation communication devices, and headbands. They each have their responsibilities and can cooperate in harmony.
Generally, according to its structure and working principle. It is divided into two categories: air filter masks and air supply masks.
The working principle of the air filter mask is to let the air containing harmful substances pass through the filter material of the mask to evolve and then be inhaled by people. The structure of a filter mask is divided into two parts. One is the main body of the mask, and the other is the filter material, including filter cotton for dust prevention and chemical filter box for anti-virus.
Air-supply mask refers to a special source of clean gas that is isolated from harmful substances. It is sent to the person's face through a tube and a mask for breathing through powerful effects such as air compressors and compressed gas cylinder devices. Using electrostatic filter material and special activated carbon to remove odor layer, anti-virus mask is used for the protection of particulate matter and organic odor, used in the petrochemical, chemical, metal smelting and processing manufacturing industries.
According to the protection principle, it can be divided into filtering gas mask and isolated gas mask.
The gas mask bong is a truly dedicated way to smoke the sweet herb. It consists of a bong connected to a gas mask. Bong can either be plastic, glass, acrylic, or metal. It has adjustable head straps in order to deliver an unescapable direct hit to the sealed-in head of the smoker.
Filter gas masks are the most common type of gas masks. Filter gas masks are mainly composed of a mask body and a filter element. The mask serves to seal and isolate the outside air and protect the nose, nose and face. The filter element is filled with activated carbon with activated carbon as the main component. Since activated carbon has many pores with different shapes and sizes, it can absorb dust, and on the pore surface of activated carbon, impregnated with copper, silver, chromium metal oxide The chemical agent can react with the poisonous gas after adsorption, so that the poisonous gas loses its toxicity.
The isolated gas mask isolates the breathing organs, eyes and face of the personnel from the outside air, and the gas mask relying on its own air supply consists of a face mask and an air supply system.
The structure and performance of the mask and filter gas mask are basically similar. The gas supply system can be divided into compressed air type, compressed oxygen type and chemical oxygen type according to the principle of gas supply. The disadvantages of isolated gas masks are short effective protection time, heavy equipment, complicated structure and use, and are generally suitable for environments with a large concentration of toxic substances in the air.