Textile laminate with Integrated heating and humidity monitoring functions in protective clothing

This article presents a textile laminate system with heating and relative humidity measurement functions. The laminate was designed specifically for specialized protective clothing for workers. The goal was to design a method for manufacturing a layered textile laminate that incorporates a heating and measurement system without compromising the user’s comfort. The laminate should be characterized by appropriate thermal resistance values, increased durability of printed electrically conductive traces, and directional water vapor transmission from the underwear under varying conditions of relative humidity and moisture content within the garment structure. This goal was achieved by sequentially modifying the textile laminate layers to appropriately combine functions such as a moisture barrier, water vapor transmission, heating, and humidity measurement. Inkjet printing technology was used for that purpose. The system was powered by a 3.7-volt lithium-ion battery and utilized Wi-Fi communication. This article presents a measurement data acquisition system and a web-based application for monitoring and managing the thermal properties of the laminate. Environmental tests were conducted at various relative humidity levels to determine the system's effectiveness.

The main conclusions are as follows:

1. The heating module's efficiency is higher than 8°C/W as a function of heating power. A temperature increase of 8°C was achieved by supplying 0.5 to 0.16 W of power to a heating pad with a width of 2 to 6 mm. The maximum efficiency achieved for the heating module in the research is 47°C/1W of power.
2. The expanded uncertainty (U RH) of the humidity of the printed sensor on the knitting laminate substrate is less than 9%. The following was achieved: URH = 8.83%.
3. The relationship between the static temperature of the heating module and the supplied power is linear.

These interactive laminates fit into the concept of smart clothing, especially protective clothing for workers.