English
The half face mask is the core component of a self-priming filtering gas mask, which achieves respiratory protection function through a sealed structure and a filter box. Its working principle is not complicated: the wearer overcomes component resistance through autonomous breathing, filters the external air through the filter box and filter cotton, and inhales it into the body, thereby achieving the goal of purifying the air. The Fangdun half face mask covers the mouth and nose area, and the mask body is molded from silicone or rubber material. It is equipped with an elastic headband and adjustable nose clip to meet the sealing needs of different face shapes.
But the key to determining the success or failure of protection lies in the correct selection of filter elements. There are two main types of pollutants generated during spray painting operations: one is dust particles generated by polishing, and the other is organic solvent vapors emitted during spray painting, such as benzene, toluene, formaldehyde, etc. This requires the protective system to simultaneously deal with particulate matter and organic vapors.
For particulate matter, different grades of filter cotton need to be selected based on whether they are oily or non oily. The Chinese standard KN series is suitable for filtering non oily particulate matter, such as coal dust, cement dust, etc; The KP series is suitable for filtering oily particles, such as paint mist and oil mist generated by spray painting. The KN95 standard requires a filtration efficiency of ≥ 95% for non oily particulate matter. In terms of international standards, NIOSH certified N95 is also applicable to non oily particulate matter, while P100 can filter 99.97% of both oily and non oily particulate matter.
For organic vapors, activated carbon filter cartridges must be selected. Filter cartridges are classified according to the type of protective gas into A type (protective against organic gases or vapors, colored brown), B type (protective against inorganic gases or vapors, colored gray), E type (protective against acidic gases such as sulfur dioxide, colored yellow), etc. The main hazard of spray painting operations comes from organic vapors, so A-type filter cartridges should be preferred, and comprehensive filter elements equipped with organic vapor filters can also be selected. For water-based paint based operations, particle protection is the main focus, and a half face mask with high-grade dust-proof filter cotton can be used.
When making a purchase, attention should also be paid to the product's certification label. Products that comply with the national standard GB 2890-2022 are usually labeled with the LA certification number; Products certified by NIOSH or CE will also have their certification level clearly indicated on the label. There are many "three no" products on the market, with thin filter elements, poor sealing, and ineffective protection. Suggest purchasing from legitimate channels and requesting an invoice or proof of purchase.
In addition, it is necessary to choose a suitable size of half mask according to the face shape. Fangdun half masks are divided into large and small sizes, and undergo a tightness test after wearing: cover the air inlet of the filter box with your palm and slowly inhale. If the mask slightly collapses inward and there is no air leakage at the edge, it indicates good sealing. It should be noted that facial beard and stubble can damage air tightness, and should be scraped off before wearing.
