Introduction to dust mask classification and filtering mechanism
As to improve people's living standard, the city of fog, the environmental pollution problems are becoming more and more serious.
Now people go out, always wearing a mask, the mask type so much, what is a particulate respirators?
Under the mask factory house can simple introduce the concept of particulate matter.
Particles, particles of classification and recognition, understanding its harm to the body, is the first step on the choice of respiratory protective measures.
Particles called aerosols, also refers to the air suspension of solid, liquid or solid liquid mixed state of granular material, is a kind of form, air pollutants exist in different language environment, the influence of the idioms, also use smoke, smoke, dust, fog, smoke, dust and other words to describe, some concepts are vague, not conducive to the understanding of protection, sometimes easy to be misled.
In 2010, the international organization for standardization (
ISO16972 standards had been issued, which is a term used in respiratory protection field and define standards, with reference to the definition of the ISO standards for particulate matter, can the concept of unity.
Two filtering mechanism of 1, particulate respirators.
Used for filtering particle mineral fibers, with the material of natural fiber or synthetic fiber, fabric fiber particles from the air filter down to five, the mechanism of comprehensive work, they can be respectively is: 2.
Sedimentation: large particulate matter in the air by the gravity sedimentation on the filter material, from the air;
Face mask machine 3.
Inertial impact effect: when the air particulate matter in the bypass the block in front air filter material fiber, high quality particles affected by inertia will deviate from the airflow direction, hit the filtered down on filter material fibers;
Block: particles in the air and on the closest to the filter material flow, due to the radius of the particles is greater than the line and the distance between the filter material and filter material 'scratches' and stopped;
Diffusion: affected by the air molecular thermal motion, extremely small particles impact by air molecules, changing direction, presents the Brownian motion, random access to the filter material fiber filtered down;
Electrostatic interactions: if the filter material fibers with weak electrostatic, regardless of whether or not to bring a electrostatic air particulate matter itself, when they are close to the filter material fiber is easy to be filtered down by electrostatic attraction.
Electrostatic interactions can help filter material without any increase in airflow resistance under the premise of improving the efficiency of filtering.
Inertial impact and intercept action influence on big particles, particles are more easily affected by diffusion, combined results showed the presence of one of the most penetrating particle size, the aerodynamic diameter in 0.
Separate improve velocity can make inertial impact play a bigger role, make the diffusion effect is reduced, the MPPS will become smaller, efficiency drops, air resistance increase.
Make filter material fiber with electrostatic charge (
At the same time with positive and negative)
Can, without any increase in airflow resistance under the premise of improving the efficiency of filtering, especially for the MPPS filtration efficiency.