The relationships between several properties (e, g., swelling, solubility parameter and other properties of polypropylene film) in various organic solvents have been studied, and following results are obtained.
(1) Degree of swelling of film is closely related to solubility parameter is near to 9.3 or 8.9.
(2) Swelling behavior of film is also closely correlated with various of shrinkage (s) and birefringence
(Δn). Maximum degree of shrinkage and minimum birefringence take place, when a film is treated with solvents those solubility parameter approaches that of polypropylene.
(3) Birefringence decreases with increasing shrinkage of polypropylene by solvents. Relationship between birefringence and degree of shrinkage is linear.

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We composed an apparatus, with which the time required for a flame to propagate a definite distance on a fabric can be automatically recorded.
Using this apparatus, we measured flame propagation rates with cotton fabrics having various width and weigth, which were inclined at various angles, and the following results were obtained.
1.The flame propagation rate increases with increasing fabric width, and become nearly constant for the fabrics of width over 70mm. Therefore the sample of about 70mm width is appropriate to the rate of burning test for cotton fabric.
2.The flame propagation rate (V) of cotton fabrics can be represented by the following empirical expression :
V=A^*w^-aandA^*=A' (1+K'' sinθ), wherewis the weight of a sample per unit area, θ is the inclination angle of the sample, anda, A'andK'' are constants.
3.The rate of burning of a cotton fabric is influenced by presence of some adjacent object near the fabric ; what material the object is made of, how far the object is apart from the fabric, and whether the object is present over or under the fabric.

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To lay out the theoretical design of crepe fabrics, We analysed the character of hard twisted yarns and the form of hard twisted yarns were made on the detwisting moment and retractive force developed in twisted yarn when they were wetted, and got the following conclusions :
1) The strain of twisted yarn^εRis proportional to single twist coefficientS.T.C., and can be expressed as follows :
^εR=A (S.T.C) +B
whereAandBare the experimental constants that are related to the limits of twist coefficient and twisting tension.
2) The shrinkage of wetted crepe fabricf (s) is proportional to cover factor in the direction of warp and weftK₁, K₂and the strain of twisted yarn^εR, and can be expressed as follows :
f (s) =aK₂+bK₁+c^εR+d
wherea, b, canddare the experimental constants that are related tofineness of warp yarn and the arrangement of weft yarns.

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