Jeans Pai Nai, Spotlight on Jeans Fashion
Moisture Management: Myths, Magic, and Misconceptions
Five specimens of each of the fabrics were tested for wicking. Variations from specimen to specimen within a fabric were quite small. This indicates that the prepared fabric samples were quite uniform in construction and in scouring/bleaching, and the test procedure used for characterizing wicking was reproducible.
Finishing
Five fabric constructions were treated with a series of finishes. DMDHEU- and melamine-treated samples were prepared to provide a stable structure that would limit swelling of the cotton fabrics during subsequent laundering.
The acrylic-treated samples were prepared to fill the interior of the cotton fiber with non-water absorbing materials so that the final product more nearly resembled the synthetic benchmark fabric system; i.e., a hydrophobic fiber with a hydrophilic surface and to reduce the internal absorption capacity.
Combinations of these treatments were aimed at achieving both ends. The first finish was a standard DMDHEU mixture that was dried to approximately 18% moisture and then steamed for several minutes.
Sorption Capacity and Thickness
The Gravimetric Absorbency Testing System (GATS) was used to measure the demand wettability of the test fabrics. This measure indicated the ability of the material to take up liquid spontaneously in the direction perpendicular to its plane, and then spread it laterally within the plane of the fabric. Demand wettability was measured by the amount of water driven from a water-filled reservoir. Water absorbed was supplied through a tube that connects to the test sample through a porous test plate.
The GATS sorption test measured the uptake of water, delivered uniformly across the whole fabric surface, through the thickness of the fabric. While a number of parameters can be determined during the GATS test, the key values reported here were the absorption rate, Q (g/min), and the absorption capacity, C (grams absorbed at equilibrium) for a sample of standard surface area. Once the sample has reached saturation and steady-state evaporation, the drying time, Td (min to dry) can be determined.
Calendering
In order to further reduce the thickness of the finished cotton samples, calendering was investigated as a mechanical finishing option. New samples of a more commercial nature were constructed and finished without curing (fabric 8, finishes 1, 2, 4, and ii). The samples were calendered at 10 kN and then cured using heat.
RESULTS
Wicking of Scoured/Bleached Fabric
Average values of the results are given in Fig. 1. The benchmark, Si, and S3 fabrics meet the criteria of 15 cm rise in less than 30 min for wicking (or 60/10 in. in 30 min).
The performances of samples Si and S3 were highly encouraging. These results indicated that there was a set of conditions, either construction parameters such as yarn size, twist, and fabric structure, scouring/bleaching specifications, or both, that resulted in a product equaling, or perhaps exceeding, the performance of commercially successful and widely adopted polyester fabric. The challenge lies in discovering these specifications and reproducing the fabric with similar superior performance.
Wicking of Finished Fabric
Wicking results for the finished fabrics are listed in Table IV and shown in Fig. 2. Comparing wicking results (Figs. 1-2) showed that the scoured samples performed significantly better than the finished samples.
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