Evaluation of Overall and Local Ventilation in Diapers

A device to evaluate the distribution of the ventilation in diapers by using a tracer gas method (steady state method) was developed to investigate the effect of the design- and material-factor of diapers on heat and water vapor transfer by ventilation. This device can also evaluate the quantitative local microclimate ventilation rate during rest or walking between the interior of the diaper and the ambient atmosphere. Using forced ventilation, it was shown that the devices’ measurement captured the actual ventilation in the diapers. For the overall ventilation values it was found that the air permeability of the diaper fabric affected the ventilation but did not dominate it. It means the ventilation was affected not only by the air permeability but also by the construction and design of clothing. Leg movement caused about 20% increase of ventilation compared to the static condition. The ventilation of the pants design diapers were less affected by the movement. For the local ventilation values, the ventilation of the front upper site contributed heavily to the overall ventilation. The repeatability of the microclimate ventilation values measured by the steady state method obtained in our present study was better than that of the transient method reported in our earlier paper. It was demonstrated that the device allowed the evaluation of diaper design for the purpose of improving the microclimate in the diaper.