Views: 38 Author: Site Editor Publish Time: 2020-05-06 Origin: Site
Mask is worn around nose and mouth for filtering air export nose, in order to achieve blocking harmful gases, dust, droplets out of the wearer's nose and mouth appliances. The general medical surgical mask has a three-layer structure, the outer layer is resistant to liquid splashes, the middle layer is a barrier against bacteria, the inner layer absorbs moisture and moisture released by the wearer, and the nose is fixed by an aluminum strip. The working principle of a mask filtering particles is to use different interception methods for particles of different sizes, such as inertial impaction, interception, diffusion, and electrostatic attraction.
2-1. Classification by shape: Masks are divided into three types: flat type, folding type and cup shape according to the shape. Flat-type masks are easy to carry, but have poor adhesion; folding masks are easy to carry; cup-shaped breathing space is large, but not convenient to carry.
2-2. Classification by wearing style:
(1) Head-mounted: suitable for workshop workers who wear for a long time, which is troublesome to wear.
(2) Ear-worn type: easy to wear, suitable for frequent putting on and taking off.
(3) Neck-worn type: S-hook and some soft material connectors are used to convert the ear straps into a neck-band type suitable for long-term wear, which is more convenient for workshop workers wearing hard hats or protective clothing.
2-3. Classification by materials used:
(1) Gauze Face Masks: There are still some workshops that use gauze masks, but the GB1908 4-2003 standards they follow comply with lower requirements and do not meet the standards of GB2626-2019. It can only protect large particles of dust.
(2) Non-woven Face Masks: Most disposable protective masks are non-woven masks, which are mainly based on physical filtration supplemented by electrostatic adsorption.
(3) Cotton Face Masks: The cotton face mask only has a warming effect without filtering the small particles such as PM2.5.
(4) Paper Face Masks: suitable for food, beauty and other industries, with good air permeability, easy to use and comfortable, etc. The paper used follows GB / T 22927-2008 standard.
2-4．Classification by scope of application:
(1) Medical masks: There are three types in China: medical ordinary masks, medical surgical masks, and medical protective masks.
(2) Particulate protective masks: Industrial use complies with GB 2626-2019 standard, special labor protection equipment safety mark certification (LA certification), in 2015 from mandatory certification to voluntary certification. If it is used for anti-fog and haze, it needs to use the insert type, which must meet the GB / T 32610-2016 standard. Civil use complies with GB / T 32610-2016 standard.
(3) Warm cloth masks: Warm masks, suitable for winter wear, only need to meet the relevant standards of fabrics.
(4) Other special industries: such as chemical industry.
2-5. According to protection level (See the following chart):
Different countries and different industries have formulated different standards, which are divided into different protection levels according to different particle filtration efficiency. At present, the main standards of Chinese face masks include:
1. GB / T 32610-2016 《Daily Protective Face Mask Technical Specifications》
2. GB 2626-2006 or GB 2626-2019《Respiratory Protective Equipment, Self-priming Filter Anti-particulate Respirator》
3. YY 0469-2011《Medical Surgical Face Masks Technical Requirements》
4. YY/T 0969-2013《Medical Face Mask for One-time Use》
5. GB 19083-2010《Technical Requirements for Medical Protective Face Masks》
So currently it has divided into three categories: Daily Protection, Labor Protection, Medical Protection.