TESTING Table 2.1: Characteristics of the used woven cotton fabrics Weft yarn type
Warp yarn type
Ring-spun
Ring spun
100/1
4
4
Compact, Rieter-K44 (Com 4)
Ring spun
100/1
4
4
Compact, Toyota (RX-40)
Ring spun
100/1
4
4
Compact, Suessen (Fiomax-E1)
Weft yarn count, Ne
Weft yarn density, picks/inch
80
Ring spun
2.2 Laboratory testing The handle properties of cotton woven fabrics were measured objectively. All fabric samples were tested for their extensibility, bending rigidity, shear rigidity, compression and formability using FAST evaluation system.
Journal of the TEXTILE Association
108
163
100/1
All fabric samples were woven on the Rapier weaving machine with the following particulars: ◆ Machine model: Picanol Gamamax ◆ Shedding mechanism: Electronic dobby ◆ No. of Harness frames: 6 ◆ Machine width: 190 cm ◆ Machine running sped: 450 rpm ◆ Reed denting: 35 / inch ◆ Warp width: 168.4 cm
SiroFAST is a set of instruments (FAST-1, FAST-2, and FAST-3 instruments) and test method for measuring mechanical and dimensional properties of fabrics. These measurements allow the prediction of fabric performance in garment manufacture and the appearance of the garment during wear [38]. The instruments were developed by the Australian CSIRO Division of Wool Technology. The system was designed to be relatively inexpensive, reliable, accurate, robust and simple to operate. A simple method of interpreting the data to predict fabric performance is an integral port of the system. Fabric thickness, FAST-1 measures the thickness of a fabric under two fixed loads, T2 (2 g/cm2) and T100 (100 g/cm2). The difference in fabric thickness at the two loads is defined as fabric surface thickness. The surface thickness of the fabrics was calculated according to the following formulas.
224
Warp yarn density, Weft yarn Warp yarn Fabric width, ends/inch twist factor twist factor cm
4
4
Surface thickness (T) = T2- T100 in mm In this study, the results of fabric thickness at loads 2 g/cm2 and 100 g/cm2 were used to evaluate fabric compressibility according to the following formula: Fabric compressibility, % = Fabric extensibility, FAST-3 is an extensibility meter, providing a direct measure of fabric extension under selected loads. Warp, weft and bias directions are tested on woven fabrics strips. Warp and weft strips are subjected to three loads (5, 20, and 100 gf/cm). Bias strips are used to calculate shear rigidity and are subjected to only 5 gf/cm load [39]. In this study, fabric extensibility was evaluated in weft direction at load 100 gf/ cm. Shear rigidity, The percentage of fabric extension in the bias direction under a load of 5 g/cm (EB5) was obtained by a FAST-3 tester. The shear rigidity (G) is calculated as follows: G (N/m) = Formability, Formability is a term derived by Lindbergh, relating to the relationship between fabric properties and performance in garment manufacture. Lindberg [40] defined formability as its ability to cover surfaces of various curvatures that no wrinkles or folds are formed. Formability is a measure of the extent to which fabrics can be compressed in-plane before buckling and thus can be used to predict seam pucker. Formability, F, in mm2 is calculated from the following formula: F=
November - December 2015