|
Most of manufacturers try to produce the most efficient filter for respirators with the lowest breathing resistance. Filter performance depends on low penetration, i.e., high efficiency (%), and low pressure drop (㎜H₂O). This study was performed to evaluate performance of respirator filters by quality factor (q_F) and suggest the direction for improvement of respirator filters of good quality in Korea. Two mechanical filters, S and K made in Korea, three filtering facepieces, S made in China, C made in Korea and M made in USA, which were widely used in the workplace, were selected and tested efficiency and pressure drop in accordance with flow rate, using with Automated Filter Tester Model 8110 (TSI, USA). The best quality factor within the same respirator filter categories was 0.0672 ㎝¹H₂O for mechanical filter S, 0.0698 ㎝¹H₂O for filtering facepiece M at flow rate of 32Lpm. Mechanical filter S would be the best suitable during heavy work since quality factors decrease less sharply than any others as increased flow rates. It was necessary for mechanical filter S to lower pressure drop without increasing efficiency, but mechanical filter K should be increased efficiency and decreased pressure drop. While filtering facepiece M had the best quality performance of three ones, S and C should get much higher efficiency and lower pressure for better performance.
|