Fluid-activated endothermic thermal regulation system for disposable diapers

Overview

This technology is a fluid-activated endothermic thermal regulation system designed to address overheating in disposable diapers. The system integrates microencapsulated, food-grade polyol formulations—specifically tailored erythritol and xylitol blends—directly into the diaper's Acquisition/Distribution Layer (ADL). When warm urine contacts the treated layer, the polyols rapidly dissolve, and the resulting endothermic reaction absorbs latent thermal energy from the fluid and surrounding microclimate. This produces a reliable, localized temperature drop of 1.5–3 degrees C at the skin interface under real-use conditions, including wet, humid, and fully clothed environments.

The solution targets the root cause of diaper microclimate overheating by delivering active cooling exactly when and where it is needed. It maintains zero compromise on absorbency or skin contact, uses food-safe ingredients, and integrates via existing converting equipment, adding under two cents per unit to manufacturing costs.

Technical specifications

Key features:

• Microencapsulated, food-grade polyol formulations (erythritol and xylitol blends) that remain dormant until liquid insult occurs
• Activation triggered by warm urine at approximately 37 degrees C passing through the topsheet and contacting the treated ADL
• High negative heats of solution enable rapid absorption of thermal energy and localized cooling
• Designed for direct integration into the ADL during diaper assembly using existing converting equipment
• No compromise on absorbency or skin contact
• Estimated added cost of under two cents per unit

Development phases:

• Phase 1: Lab optimization—microencapsulation tuning and binder-slurry viscosity testing (TRL 4)
• Phase 2: Substrate and core integration—subsurface ADL coating and lab-scale EDANA fluid testing (TRL 5)
• Phase 3: Thermal and skin microclimate validation—thermal manikin testing under wet, humid, and swaddled conditions
• Phase 4: Safety and regulatory clearance—ISO 10993 extractable/leachable screening, cytotoxicity, and irritation assays
• Phase 5: High-speed pilot and line scale-up—converting trials at 300–500 m/min and commercial BOM locking (TRL 6–7)

Technology readiness level

The technology is currently at laboratory proof-of-concept stage (TRL 4). A five-phase validation plan is in place to advance the system through substrate integration, thermal and skin microclimate validation, safety and regulatory clearance, and high-speed pilot line scale-up to commercial readiness (TRL 7).