The filling skewness of thick twill fabrics is closely related to the structure and mechanical properties of fabrics. An investigation has been made to integrately evaluate the filling skewness through fabric properties, i.e., tensile and shearing strength, by using a principal component analysis and finite element method. Following results have been obtained
(1) Among fabric structures, i.e., direction of twills, density, weave, number of twists of constituent yarns, etc., the fabric weave has a remarkable influence.
(2) The principal component analysis has shown that mechanical properties affecting the filling skewness are classified into two main factors ; (i) factors relating to the thickness change and compressive energy caused by the shearing deformation and factors relating to tensile properties, and (ii) factors relating to the tensile and compressive recovery properties.
(3) Assuming that the load extension curve obeys the linear elastic unloading, the recovery behaviour of an anisotropic fabric was proposed by a finite element method of the modulus at unloading and shearing rigidity. The theoretically calculated and experimentally measured degrees of the skewness agreed well for anisotropic fabrics. Therefore, it might be considered that the finite element method is useful to analyse the deformation of fabrics.

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The basic mechanical properties of fabrics for men's suits before and after dry-cleaning were measured by using the KES-FB fabric testing system, and changes of these properties and the fabric handle caused by 15 times repeated dry-cleaning were investigated.
The relationships between total hand value observed at the initial state used as the index of fabric quality evaluation, and the changes of these mechanical properties were also measured in each cycle of dry-cleaning.
Relaxation of fabrics was recognized at the first or second cycle of dry-cleaning and the fatigue phenomena of fabrics by repeated dry-cleaning were recognized in the reduced recovering ability of tensile, bending, shearing and compressive deformation, i.e., in the increase of bending and shearing hysteresis.
The correlation between the total hand value observed at the initial state and the property changes by the repeated dry-cleaning was noticed more remarkably in the winter suit fabrics than in the summer suits fabrics.
In the case of winter suit fabrics, ‘KOSHI’ (regidity) decreased and ‘NUMERI’ (smoothness) and ‘FUKURAMI’ (fullness) increased by the repeated cleaning, and in the case of the summer suit fabrics, ‘KOSHI’ (rigidity), ‘HARI’ (firmness) and ‘SHARI’ (roughness) decreased.
It was observed that the first or second cycle of dry-cleaning remarkably changed the mechanical properties. Subsequent cycles of the repeated dry-cleaning increase the changes of such mechanical properties to the initial changes.

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