This paper presents the mathematical model of a cross-lapper elaborated to satisfy the needs of computer simulation of its motion. An algorithm for calculating the optimal driving moment profile to provide motion according to the given functions of velocity and acceleration has been described Some results of the calculations are shown on graphs.

View full abstract

This work investigates the changes in bending properties in laundering of plain weft-knit silk fabrics, as compared with cotton and polyester. The effects of variations of linear density and stitch density of fabric samples on bending properties due to repeated laundering are examined. It is shown that both bending rigidity and hysteresis of the various yarns show different behaviour of the fibres in laundering. Silk is characterized by higher flexibility for bending in both principal directions than cotton and polyester, in laundering. Differences between technical face and technical back bending are also shown. Linear density of silk yarns affects bending rigidity more than cotton.

View full abstract

Designs that have been stored in early days are often used as a reference when textile designs are created. To effectively use these resources, an well-organized design database must be constructed and a useful searching method must be studied. As to design searching method, searching methods that deal with human subjective information is requested. As a technique for these searching methods, one method to characterize visual feature of textile designs is proposed. In this study, a correspondence was examined between the subjectivity like “strong impact” for textile designs and spatial frequencies that are objective visual features for them. In this examination, genetic algorithm was introduced in order to increase the efficiency of processing time.
It was presumed that the subjective impressions of “strong impact” were related to lower components of spatial frequencies of textile design images. In this result, the textile designs that impress human when human compare designs are similar to the textile designs that are made up of lower spatial frequency components. As to design searches from subjective impressions of “strong impact, ” lower spatial frequency components that are objective visual features are available for one of subjective searching item.

View full abstract

Double covered yarn is produced by a double covering machine equipped with hundreds pairs of upper and lower hollow spindles. Drawing Spandex to be a core yarn of covered yarn into the hollow spindles is so complicated that its automation is especially desired. So, we developed an automatic drawing-in apparatus that could draw Spandex in both upper and lower hollow spindles simultaneously. Results obtained are as follows: (1) The automatic drawing-in apparatus is comprised of both an injector and an ejector. Spandex was drawn into the lower spindle by the injection flow driven by the injector and was drawn from the upper spindle by the suction flow driven by the ejector.
(2) The auto-doffing apparatus developed for a model covering machine performed draw-in. It could draw-in 20 D Spandex that was widely used and was too thin to be easily drawn-in even by a manual doffing operation. So, this confirmed that the developed auto-doffing apparatus had practical utility in the drawing-in operation. (3) The rates of success of Spandex drawing-in are influenced by the supplied air pressures for the injector and ejector and the feed rate of Spandex. High rate of success could be accomplished by the proper adjustment of those conditions.

View full abstract