In order to study sliver structure by fracturing method, suction air was applied to the slivers. Slivers were separated into fibers and small fiber assemblies. The size of separated fiber assemblies flying in a transport tube was sensitively measured by a photoelectric method. The effects of the kinds of sliver and suction air velocity on the sliver separation behavior were observed.
The distribution function of the number of fiber assemblies separated within a short period of time exhibits Poisson's distribution. The distribution of separation time interval shows an exponential curve. Power spectrum indicates a tendency of “pink noise” and the autocorrelation function decreases to zero after short period of time. From these results, it is concluded that the separation behavior within a short period of time is randomly independent of time. This suggests that fiber assemblies are arranged at random along a short length of sliver.
It was quantitatively shown that the size of fiber assemblies decreases with increasing drawing process. Comber roving consists of smaller fiber assemblies than card roving. As suction air velocity increases, large and medium size of fiber assemblies which could not be divided under the lower velocity are subdivided into smaller size. The aggregated structure of fibers in sliver is complex and is assumed to have a multiple structure of fiber assemblies.

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For dry relaxed cotton 1×1 rib knitted fabrics is investigated experimentally the effect of stitch length on the porosity P(%), the air permeability V(cc/cm²/sec), the thermal retaining property H(%), the bending length L(mm), the breaking strength S(kgf), the elongation E(%), and on the dimensional properties (U_c; =C_u; ×l_u;, U_w; =W_u; ×l_u;, U_s; =U_c; ×U_w;, U_c; /U_w; =C_u; /W_u; and the ratio t/l, where C_u; and W_u; are the course units/unit fabric length and wale units/unit width, l_u; is the stitch length in cm, t the fabric thickness in cm and l the loop length in cm). U_s; is approximately constant and independent of the stitch length. When the stitch length increases, U_w; , P(%), V(cc/cm²/sec) and E(%)'s in course, 22.5° and 45° directions increase, and U_c; , U_c; /U_w; , the ratio t/l, H(%), L(mm) and S(kgf) in each direction, and E(%)'s in wale and 67.5° directions decrease.

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The distribution curve of pill sizes, the total number and the total area of pills, and the mean area of pills are obtained from the image of a pilling smaple which is read into a computer with a TV camera. Then, how to determine the pilling grades of different samples by comparing their pilling feature values with those of the standard photographs in JIS L 1076 is discussed. The results obtained are as follows:
1. The region of the small size in the distribution curve of pill sizes, which is obtained from the image of sample, contain the components owing to the reflection from woven yarns and naps. It is considered that the distribution for the pill sizes larger than threshold Ta is assumed to be correct.
2. This threshold T_a; for the standard photographs is determined so that the total number of pills obtained by the image analysis may coincide with that obtained by the visual inspection of photograph. The values of T_a; are different with the groups of the standard photographs, but nearly constant for different grades in every group. The T_a; for the group whose distribution curve of pill size resembles that of a given sample can be used as T_a; for the given sample.
3. The pilling grades of a given sample can be determined by comparing its total number or total area of pills with that for the standard photographs of different grades in the group a distribution curve of which resembles that of the sample. However, the judgment of pilling grade by the two dimensional expression of pilling feature value is better than that by the single feature value, that is, the total number or area of pills.

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