At present, the medical masks in China are mainly divided into three categories: the medical protective mask with the highest protection level, the surgical mask commonly used to create an operating environment, such as the operating room, and the disposable medical mask with ordinary level. ?
1. Medical protective mask
Medical protective mask has a good close fit with the wearer's face, which can filter particles in the air and block pollutants such as droplets, blood, body fluids, secretions, etc. The filtering efficiency of non-oily particles reaches over 95% (this sentence means that it can reach the level of N95), so it is a common personal protective article to deal with air infection. Common medical protective surfaces are arched and butterfly-shaped. ?
2. Medical surgical masks
Medical surgical masks are often used in operating rooms and other environments where there is a risk of body fluids and blood scattering. While preventing blood and body fluids from polluting the wearer through the masks, the filtering efficiency of bacteria is over 95%, but the filtering efficiency of particles is limited, and there are many rectangular designs. Therefore, medical surgical masks with a close fit to the face are commonly used in medical surgical masks, such as strap type and ear hanging type. ?
3. Ordinary medical masks
Medical masks without the letters "protection" and "surgery" in their names are ordinary medical masks. This level of masks does not require a barrier to blood and does not require tightness, so they can only be worn in ordinary medical environments. Most common medical masks are ear-hanging, and their appearance is similar to that of ear-hanging surgical masks.
Extended information
Material conditions of mask filter:
For a good filter material of protective mask, the following three conditions should be met: first, the filter efficiency is high when the mask is well fitted to the user's face; second, the breathing resistance is low; and third, the user feels comfortable. There are many kinds of filter materials for dust-proof masks, including ordinary fabrics, animal hair, non-woven fabrics and so on. What is very popular in the national standard is an activated carbon felt material.
The structure of gauze mask has a poor fit with human face. Many tiny particles that are harmful to us will enter the respiratory tract and lungs through the gap between the mask and face. Its filter material is usually some mechanical fabrics. The only way to achieve high dust resistance is to increase the thickness, and the negative effect of increasing the thickness is to make users feel great respiratory resistance and uncomfortable.
Non-woven fabrics after electrostatic treatment can not only block large dust particles, but also the electrostatic charge attached to its surface can adsorb fine dust through electrostatic attraction, thus achieving high dust blocking efficiency.
However, the thickness of the filter material is very thin, which greatly reduces the breathing resistance of users and makes them feel comfortable, thus achieving the three necessary conditions of good filter material mentioned above. With a good filter material and a scientifically designed mask structure, an efficient and high-quality mask is formed.