In the Part 1, relations were found between fundamental physical properties and performance of lining fabrics. In this paper, changes of these physical properties caused by laundry and dry cleaning are measured, and relations between these changes and shrinkage of lining fabrics are examined. Fourteen kinds of lining fabrics are chosen from the samples used in the Part 1. They are almost same in weight but different in fiber contents and in fabric structures. As the washing method, AATCC 96-1960T method was applied for laundry and AATCC 108-1963T method for dry cleaning. The results are summarised as follows : (1) Shear rigidity G and shear hysterisis 2HG and 2HG5 were decreased by laundry and dry cleaning. (2) A washing method affects the bending hysterisis 2HB ; a laundry decreases but a dry cleaning increases 2HB. (3) Silk interlinings show the largest shrinkage by the laundry and differ in the changes of bending rigidity from polyester, cupra-and viscose-rayon. (4) The difference is found, by the washing, between the change of fundamental physical properties of interlinings and those of wash-and-wear men's suits fabrics. Shear rigidity and shear hysterisis of lining fabrics are decreased but those of men's suits fabrics are increased by the laundry. (5) It is considered that the change of fundamental physical properties of interling fabrics due to washing is caused by the change of fabrics structure due to fabric shrinkage and by the change of fabric surface due to removal of the finishing agents by dry cleaning solvents or water.

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If a ply yarn formed by twisting together i pieces of single yarns is loaded at P=iP, an external force P is applied onto each single yarn twisted in a ply yarn. When an external force is applied on a ply yarn, single yarns forming a ply yarn contact more tightly together. This article aims to calculate an internal stress applied on a single yarn by the Kirchhoff's equation, assuming that (1) an internal shearing stress can be ignored, (2) the effects of the constraint torsional moment are little, (3) the relation between internal stress and strain is subjected to the Hooke's law, and (4) the Hertz's contact theory are applicable to the portions applied by the contact pressure. After discussing an internal stress applied on a single yarn forming a ply yarn by using an elastic dynamics, equations have theoretically been derived to calculate a Young's modulus of a ply yarn.

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