Low emission household tumble drying with evaluation of damage to textile materials

The process of domestic laundry drying represents an environmental and human health burden due to the use of electricity and other emissions into the air and water. EU28 households consume 143 PJ of energy to dry textiles in one year, emitting 6.6x106 T CO2 eq. into the atmosphere. The remaining emissions resulting from the machine laundry drying are insufficiently quantified. Here we highlight the emissions of fibers that occur during drying and during the use of textiles that have been subjected to machine drying. Namely, drying in a rotating drum causes thermal and mechanical loads on the laundry, which are reflected in damage to the fabric, degradation of the properties of the laundry and the release of a multitude of fibers. Of particular concern are synthetic fibers, which represent one of the main sources of contamination of microplastics, which poses a health risk. The proposed project aims to reduce all the above-mentioned negative impacts of household machine drying on textiles, environment and health. The project goal is to develop a new generation of household tumble dryer with improved energy and functional characteristics and significantly lower fiber emissions, which we call a low-emission tumble dryer. The development of the new tumble dryer will be based on experimental research using modern measuring equipment and mathematical and empirical modeling of key processes related to drying in a tumble dryer with a heat pump, electric heater and separate drum and fan drive. The main development challenges will be related to research and quantification of textile degradation processes during tumble drying in connection with motion patterns (kinematics) of laundry. The project is structured into several work packages and tasks, which lead through the preparation of specifications, design of the measuring station and basic characterization of the drying properties of textiles to the final goal, that is the manufacture and optimization of a prototype low-emission tumble dryer. The central part of the project is represented by experimental research of processes in the dryer, where it is planned to perform an extensive set of drying experiments to understand the effects of time regimes of heat pump, heater, fan and drum on energy and functional characteristics of the machine. At the same time, the analysis of laundry kinematics will be performed with the already mastered method, where laundry is recorded with a high-speed camera, and computer analysis of images for determination of laundry motion patterns and statistical parameters for their description. Also crucial is the experimental analysis of damage and emissions of machine-dried textiles, with an emphasis on changes in fabric appearance, dimensional and thermal stability, mechanical properties, changes in crystal structure and morphological damage to fabrics themselves. The project will also investigate the disinfection effects of the drying process and develop a method for their evaluation. The results of the experimental work will provide the basis for the design of models to describe the phenomena of degradation of laundry properties, microfiber release and integral energy characteristics of the machine depending on the operating parameters. Methods of multi-regression analysis and physical-mathematical models will be used. A method of numerical evaluation of textile wrinkling will also be developed. Based on the acquired knowledge and models, the operating modes (drying programs) for a wide range of textiles of different composition will be optimized and implemented in the prototype of a low-emission dryer. At the end of the project, the evaluation and optimization of the prototype will be carried out, as well as the dissemination and promotion of the project through publications in literature and presentation of the prototype at fairs.