Abstract
To clarify the possibility of cross contamination by the door opening and closing operation in a cleanroom at solid tablet manufacturing factories, the dynamic characteristics of the door opening and closing operation is measured with airflow visualization and 3-dimensional ultrasonic anemometer. A strong backflow is observed in the opening operation using an inside opening single swing door and in the closing operation using an outside opening single swing door. However, the backflow is not observed when using a single sliding door. Moreover, the backflow velocity when opening and closing the door did not depend on the initial differential pressure between rooms.