Heat and mass transfer of adult incontinence briefs in computational simulations and objective measurements

This study aims to evaluate the heat and mass transfer of two kinds of multilayer adult incontinence briefs (diapers for short) in the dry condition and dynamic heat and moisture transfer processes in the wet condition in computational simulations and objective measurements. A commercial disposable brief (PROTEC) with polyethylene, superabsorbent polymers (SAP) and polypropylene, and another kind reusable brief (Reusable) with waterproof breathable fabric, full cotton inner pad and moisture management treatment nonwoven were evaluated. A software platform (S-smart system) with user friendly interfaces was employed in computational simulations. Wear trials were conducted by asking young female adults between 20 and 26 years old to wear incontinence briefs. Objective measurements revealed that there was significantly higher liquid moisture management capacity, water vapor permeability, thermal conductance and maximum value of heat flux in the Reusable than in PROTEC briefs. The simulation and wear trial results showed that there were significantly lower temperatures and humidity at the skin in the diaper area and diaper inner surface fabric in the Reusable briefs compared to the PROTEC ones. The good agreement between simulations and wear trials were observed. The 2D and 3D directly visualizes the changes of fabric temperature/humidity gradient and capacity of absorbing moisture etc. in each layer. The results indicate that the superior fabric's heat/moisture transporting properties, when incorporated into diapers, is the main mechanism for reducing heat and wetness of the diaper area. The results provide guidance for the optimal design of Eco-friendly diapers with reusable, breathable, biodegradable materials.