RT Journal Article ID 0c8cc4231ee33e55 A1 Bhouri, N. A1 Badel, Eric A1 Nasrallah, Sassi Ben A1 Perre, Patrick T1 Shrinkage/Swelling Behavior of Knitted Fabrics during Relative Humidity Cycles Determined by X-ray Imaging JF Journal of Porous Media JO JPM YR 2009 FD 2009-04-17 VO 12 IS 5 SP 403 OP 415 AB The 2D deformation of knitted jersey ready-to-wear clothing made of cotton was measured during adsorption and desorption steps. A digital x-ray imaging system was coupled with a climatic chamber to control temperature and relative humidity during the cycle. Images of the samples were recorded at each different equilibrium state of the cycle. Finally, an image correlation process was used to compare the recorded images and to determine the 2D strain. The deformations along course (εcc) and wale (εww) directions and the shear (εwc) were measured for four identical samples. The repeatability of the results shows the reproducibility of the measurement process. These original experimental results establish a clear anisotropic shrinkage and swelling behavior between the wale and course directions. The anisotropic ratio (εcc/εww) rises up to 2 during the adsorption step. Moreover, they enlighten a hysteresis between the adsorption and desorption steps. It denotes the effect of the material's history and it is explained by geometrical considerations of the structure at the microscopic level and the relationship with the manufacturing process. Finally, the shear strain is explained at the microscopic level by electronic microscopy (ESEM) observations that show the fibers' twist dissymmetry between the two wings of the stitch. PB Begell House LK https://www.dl.begellhouse.com/journals/49dcde6d4c0809db,54e7056e0c6b6dd0,0c8cc4231ee33e55.html