從實驗可以看出洩漏的位置大多從鼻翼兩側及臉龐兩側的位置洩漏至鼻孔處。實驗結果證實當呼吸速率增加，洩漏率與洩漏覆蓋率亦增加；而當密合度越好時，洩漏率與洩漏覆蓋率越小。不同口罩在同密合度時有不同洩漏覆蓋率，顯示與洩漏孔隙大小及其洩漏速率，及洩漏微粒粒徑分布有關係，應進一步研究探討其關係。
The purpose of this research is to estimate the fit of wearing mask. We studied the leaking status on the model head in different conditions such as different masks, breathing rate, and fit factor. We estimated the status of micro particle covered on the face of model head with mask in different conditions by the image analysis. Then we studied the relationship between the fit factor and the coverage rate(CR).
This research is based on the model head wearing different masks such as F550, 3M 8511, and 3M 8210. The breathing rate of 15, 30, and 55 L/min means the steady, medium, and heavy breathing rate respectively. The fit factors in this research are represented by 10, 30, 50, and 100. We used Collison nebulizer to produce the challenge particle of methylene blue in the test system. The associated model head is maintained in the conditions with different breathing rate for 90 minutes by the respiratory simulator. We filmed the deposition status on the face of model head and processed the image analysis.
The result showed that the CR of F550 and 3M 8511 is 20.0~26.0% as FF is 10. The CR of F550 and 3M 8511 is 3.0~10.0% when FF is 100. The CR of F550 and 3M 8511 is 1.28~22.0% when the breathing rate is 15 L/min. The CR of F550 and 3M 8511 is 9.45~27.0% when the breathing rate is 55 L/min. It means CR is decreased with increasing fit factor and CR is increased with increasing breathing rate.
The leaking coverage rate of 3M 8210 showed the similar
connection above but its coverage rate is smaller than 4. We think it has some connection with the leaking gap.
This research shows most leaking positions are between the both sides of nose wings and both sides of cheek to nostrils. This research proves the leaking rate and coverage rate are increased with increasing breathing rate. The leaking rate and coverage rate is smaller with the better fit factor. The different masks with the same fit factor still have different coverage rate. It shows that the leaking rate and the size of leaking gap have some connection with the distribution of the leaking particle. We should do the further discussion and research about it.
