ARS | Publication request: QUALITATIVE AND QUANTITATIVE EVALUATION OF DAMAGE TO A COTTON FABRIC BY TUMBLE DRYING

Submitted to: Textile Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 24, 1999
Publication Date: N/A

Interpretive Summary: Drying machines for home laundries cause significant damage to textiles, as well as consuming substantial amounts of energy. This project investigated how and when this damage occurs and provided some recommendations on how damage and energy consumption might be minimized when cotton fabrics are dried. A home clothes dryer with a temperature probe was operated on top of a large scale, so the moisture loss could be recorded against time and temperature. Electron microscopy showed that much of the damage happens at three stages. The first type of damage occurs before the load is warm enough to remove much moisture. The second type is from the tumbling of the wet load under hot conditions while the majority of moisture was removed. The third time that substantial damage occurs is after the load is already dry and temperatures increase dramatically. Because dry cotton quickly absorbs water from the air to give a final level of about 4% moisture, energy is wasted by continuing to dry after that level is reached. Stopping the heating in the dryer at that moisture level would also avoid further damage to the cotton fibers. It was also suggested that the load in the dryer be warmed up prior to tumbling. This would help avoid the substantial damage that typically occurs before the dryer starts driving off the bulk of the moisture. Clothes dryers that incorporate these ideas should benefit the cotton growers and consumers. In turn, that should increase consumer satisfaction with cotton.

Technical Abstract: Abrasion and heat damage to a desized and scoured cotton fabric during drying in a household tumble dryer were evaluated by SEM (Scanning Electron Microscopy), and Weight and Tensile/Strain tests for breaking strength and elongation of fabric. Wet fabric dried with applied heat showed severe damage to the fiber. Wet fabric tumbled at room temperature showed less damage than one with applied heat. Dry fabric tumbled at high temperature, a treatment equivalent to over-drying in a dryer, showed different but still severe damage from the wet-conditioned fabric. Moisture loss patterns during drying as a function of time or temperature indicate possible ways to minimize dryer damage by reducing unnecessary tumble-drying time and energy input.