A mechanical model for the lateral compression of woven fabrics is derived from Van Wyk's compression law for fiber assemblies. The pressure ( P ) and thickness (v) relationship is P = a/ ( v -v')3. The parameter v' refers to the core of the fabric, which is incompressible over the pressure range 2-5000 gf/cm 2 . The parameter a refers to the compressible surface layers and is dependent on the mass of fibers in the surface layers and their orientation.A comparison is made of the results obtained with the KES-F fabric compression tester and the standard fabric thickness tester. The energy of compression is proportional to the cube root of the parameter a. The compressibility of the fabric is proportional to the energy of compression per unit volume of fabric. The changes that occur in the fabric surface layers during a typical fabric finishing process are investigated.The measurement of the lateral or thickness compression properties of fabrics forms an integral part of objective measurements currently being considered internationally for wool fabrics [ 12,17]. These objective measurements are intended to help maintain consistent quality in finished wool fabrics and to aid in product engineering of wool fabrics. An early paper [2] described the thickness-compression curve of fabrics. The effects of finishing treatments on the lateral compression curves of fabrics have been described [3,9,13], but the thickness-compression curves of fabrics have not been analyzed mechanically. An analysis of the mechanics of fabric compression may help in developing compression test methods and interpreting results. In this paper, we present a mechanical model that describes the compression curves measured on a large number of woven fabrics over the pressure range of 2-5000 gf/cm2. The model reduces the fabric to three layers -a relatively incompressible core layer in contact with a much more compressible surface layer on either side. The model is reconciled with both electron microscope evidence and optical measurements made on the fabrics.The model indicates that the DIN standard [6] for measuring fabric compression is very simply related to the compression test performed on the Kawabata evaluation system for fabrics . The change in the compression properties of wool fabrics in some commercial worsted fabric finishing processes is presented and interpreted in terms of the model.

Recently developed by CSIRO for quality control and assurance of fabrics, FAST, or fabric assurance by simple testing, consists of a series of instruments that are in expensive, robust, and simple to use, and their related test methods. FAST is specifically designed for use by tailors and worsted finishers; it measures fabric properties that are closely related to the ease of garment making-up and the durability of worsted finishing. FAST- I gives a direct reading of fabric thickness over a range of loads with micrometer resolution. FAST-2 measures the fabric bending length and its bending rigidity. FAST- 3 measures fabric extensibility at low loads. Fabric shear rigidity is calculated from the 45° bias extensibility. FAST-4 is a quick test for measuring fabric dimensional stability, including both relaxation shrinkage and hygral expansion.

Data on the linear viscoelastic relaxation of wool fibers for a range of relative hu midities below the gas transition ( Tg) are systematized by a humidity-time superposition method. The differences in the relaxation behavior in water where the fiber is above its Tg are pointed out. The analysis relates to the properties of the water sensitive, viscoelastic component of the wool fiber and consists of superimposing the relaxation curves for different humidities onto the curve for the dry state by multiplicative scaling and shifting on the logarithmic scale of the reduced time variable λ, that corrects for the influence of ageing. The change of the scaling and shift factor with the absorption mechanism of the water is discussed.

No abstract

We evaluated the usefulness of saponification, direct solvent extraction, and Soxhlet extraction as extraction methods to determine the amounts of tocopherols in soybeans. Soxhlet extraction yielded the highest analytical values for each tocopherol homolog and was the best method for quantifying tocopherols in soybeans. Coupling of simple Soxhlet extraction with HPLC provided a highly reproducible procedure to quantify tocopherols in soybeans. The percent mean recovery 6 standard deviation (n = 5) was 103.2 6 1.21, 109.8 6 4.18, 93.8 6 1.12, and 106.9 6 1.54% for a-, b-, g-, and d-tocopherol, respectively. The linearity test for quantification was carried out over the ranges of 0.4-10.0, 0.2-4.0, 2.0-16.0, and 0.4-10.0 mg/mL for a-, b-, g-, and dtocopherol, respectively. Regression analysis showed an excellent linear relationship (R 2 .0.998), and the results of the validation parameters were generally reliable and satisfactory.