What is the standard testing method for KN95 protective masks?

The standard testing methods for KN95 protective masks mainly include the following aspects:

Filtration efficiency testing: One of the main functions of KN95 masks is to filter particles in the air, so their filtration efficiency is a crucial indicator. Testing organizations typically use typical test particles, such as 0.3-micron particles, to evaluate the mask's filtration efficiency. During the test, the mask is placed in a specific testing apparatus, and the number of particles passing through the mask is measured under a series of flow and pressure conditions to determine its filtration efficiency.

Breathing resistance testing: Breathing resistance refers to the degree to which the mask impedes airflow during breathing. The method for testing breathing resistance is by placing the mask in a testing apparatus, simulating the breathing process, and measuring the resistance of the mask during inhalation and exhalation. Lower breathing resistance means the mask is easier to breathe through, making it more comfortable for the wearer.

Seal testing: The seal of the mask refers to the degree of fit between the mask and the face. Masks with good sealing can effectively prevent external air from penetrating through the mask edges. Testing organizations typically use bubble detection methods or a gas tightness tester to assess the seal of the mask by observing whether bubbles are produced under different conditions or measuring the air tightness of the mask contact with the face to determine its sealing performance.

Material and structural inspection: The materials and structure of the mask are crucial to its protective performance. Testing organizations conduct inspections of the mask's material composition, layer structure, durability, etc., to ensure that the mask meets relevant standards requirements.

These are the common standard testing methods for KN95 protective masks. Through these testing methods, the filtration efficiency, breathing resistance, seal, material, and structural performance of the mask can be comprehensively evaluated to ensure that the quality and performance of the mask meet standard requirements, providing effective protection for users.