The mechanism of strength reduction of sewing threads has been discussed in Part I of this paper. The effect of fabric tightness and certain thread properties like its size, coefficient of yarn‐metal friction, twist direction, number of piles, type of fibre and fibre denier on strength reduction has been studied and found to influence the severity of strength reduction of the thread.

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Reports on investigations into the mechanism of sewing thread strength reduction. Results indicate that structural damage, namely, structural openness and pull‐out of fibre ends from the surface are the major cause of strength reduction and that the fibre strength reduction is found to be only marginal compared to the thread strength reduction. Cotton threads exhibit higher strength loss owing to their poor abrasion resistance. Comparatively shorter fibres in cotton threads are also found to be responsible for the higher strength reduction.

Pneumatic splicing was examined for various yarns spun from different fibers on different spinning systems. The retention properties of the spliced yarns compared to normal yarn are discussed; the results indicate that wet splicing gives better property retention than dry splicing. Retention of yarn properties in decreasing order was for yarns spun from polyester, polyester-rich blends, viscose, cotton, and wool, respectively. Coarse yarn, particularly that spun on a ring spinning system, contributes the most to better spliced yarn properties.

Gelatinization temperatures of starch and hydroxyethyl starch was determined using Differential Scanning Calorimetry (DSC), hot stage microscopy and viscography. The gelatinization temperature based on peak temperature of DSC is incorrect. Viscograph overestimates the gelatinization temperature. Hot stage microscopy based on visual observation gives the correct gelatinization temperature. DSC gives the heat of gelatinization which is helpful in estimating heat requirement during cooking of starch. Hydroxyethylation of starch reduces gelatinization temperature and heat of gelatinization for starch.