การประเมินการรั่วเข้าและออกของหน้ากากอนามัย หน้ากากผ้าและหน้ากากกรองอากาศขณะสวมใส่ด้วยวิธีการสังเกตพฤติกรรมการเคลื่อนที่ของอนุภาคและการนับจำนวนอนุภาค

บทคัดย่อ

The aim of this paper to evaluate the inward and outward leakages of various types of surgical masks, fabric masks and respirators while wearing by observing the behavior of particle motion and the particle counting. Leak test with aerosol particles generated from Emery Oil. The particle size range is approximately 0.01 to 10 µm at a particle concentration of not less than 200 mg/m³. Using a test flow rate of approximately 6 L/min, the motion behavior of particles leaking out of the mask was observed by photographing and recording a video clip of approximately 10-15 seconds. The total inward leak assessment of masks was based on testing methods from OSHA Respiratory Protection Standard 29 CFR 1910.134 with a test mannequin head, which selected a face shape according to the size of an Asian person for testing. Each sample was tested with normal inhalation and exhalation for 60 seconds. There were 8 mask samples in this test: 1) surgical masks 2) fabric masks 3) Varogard masks normal strap 4) Varogard masks with shorter straps (Extra fit) 5) cloth masks overlaid with masks 6) cloth masks overlaid. Varogard Mask 7) N95 Mask and 8) Mask KN95 Thailand. The results of the leak test of the mask while wearing revealed that there are 2 main leak points in the mask, which are the nose bridge and the cheek area. It was found that the inward leakage through the mask is about 43.50%, cloth mask about 62.80%, Varogard mask, normal strap (Comfort fit) about 29.59%, Varogard mask, short strap (Extra fit) about 23.45%, cloth mask overlapped with a mask, about 23.67% Fabric mask overlaid with Varogard mask approximately 13.44%, N95 mask approximately 0.91% and KN95 Thailand mask approximately 7.30. It was found that the fit factor of hygienic masks, fabric masks, Varogard masks, normal straps, Varogard masks, shorter straps 1.5 cm, fabric masks stacked with hygienic masks. Fabric masks overlaid with Varogard masks, N95 masks and KN95 Thailand masks approximately 2.30, 1.60, 3.38, 4.26, 4.22, 7.45, 110.22 and 13.69, respectively. The overall efficiency of masks, fabric masks, Varogard masks, normal strap, Varogard mask, shorter strap      1.5 cm, fabric mask stacked with masks Cloth masks overlap the Varogard mask and N95 mask approximately 53.83%, -9.52%, 69.30%, 75.21%, 75.11%, 85.79%, 98.69% and 92.27%, respectively.

Keywords: Particle Counting, Leakage Tester, Surgical Mask, Leakage, Filtration Efficiency