This topic surveys the basic procedure of data base system of the fabric structural design which can be linked with existing pattern design and garment design CAD systems. For this purpose, the theoretical and empirical equations related to the fabric structural design are analyzed and discussed. The fabric structural parameters such as weave density coefficient, cover factor and yarn density coefficient of various kinds of fabrics are calculated using the empirical equations. These calculated fabric structural parameters of many kinds of polyester, nylon, worsted and cotton fabrics are compared and discussed with weave pattern, weaving loom and materials according to weaving manufacturer. Furthermore the difference between fabric structural parameters calculated by empirical equations are analyzed with polyester, nylon, worsted and cotton fabrics, and these structural parameters are analyzed and discussed with weave and finishing shrinkages. Finally, the case study of the data base system for fabric structural design is presented with weave pattern, weaving loom and weaving manufacturer, and also presented with the application fields to the existing woven fabric and clothing CAD systems.

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A realizable k-ε turbulence model was adopted to study the airflow characteristics inside the two nozzles including the slotting-tube of Murata air-jet spinning (MJS). Actions of the two nozzles and the accepted principle of yarn formation were both discussed. The results show that some factors in the first nozzle, such as weak opposite swirling balloon in upstream of the jet orifice, vortex breakdown in downstream of the jet orifice and opposite direction airflows between the grooves and the twisting chamber, do good to produce longer wrapper fibers and form twist difference between the edge fibers and the core ones. The airflow in the second nozzle rotates in the opposite direction to that in the first nozzle, to untwist the swirling balloon that formed by the first nozzle. On the other hand, simulation results well supported the theoretical analysis of the principle of the yarn formation proposed by Stalder and Krause.

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It is important for researchers developing dyeing technology to improve the dyeing techniques of polyester micro fiber fabrics in terms of the time efficiency. The empirical observations have led to the deploying of the O-type dual-nozzle flow dyeing machine developed by Asia Kingdom Machinery Industry Co., Ltd. to serve such purpose. The economic advantages include reducing the liquid ratio to 1:8 and reducing the water volume required by 20∼40%. The electricity required by 48∼80% less compared to conventional upward or downward type dyeing machines. Therefore the CO₂ production is decreased by 60%, demonstrating energy efficiency and environmental friendliness. The nozzle pressure of a single nozzle machine is 1.6∼3.0 kg/cm², whereas by adjusting the flux passing front and back nozzles, the dual nozzle pressure is maintained in the range of 0.2∼1.6 kg/cm². The reduced pressure decreases the frequency of yarn hairness occurrence, thus improving the dyeing quality. The low liquid ratio results in dye exchange increase by 1.3∼1.66 fold, significantly increasing the uniformity. Despite 40 times fewer contacts between the nozzle and the fabrics (total 244 times) compared to conventional machines, similar results were observed.

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Woven fabric consists of two sets of yarn, called the warp and the weft. Warp yarn movements in the process of weaving cloth produce the yarn interlacement pattern. The more heald frames a dobby loom is equipped with, the more complicated designs of cloth can be woven. By introducing long-eye healds into a loom, we can reduce the number of heald frames.
In this paper, we propose a heuristic algorithm for minimizing, for a given design of cloth, the number of necessary heald frames. First, we show that the number of necessary heald frames equals the Boolean rank of a Boolean matrix associated with the design of cloth. Next, we transform the problem of calculating the Boolean rank to the graph coloring problem and apply a heuristic algorithm for the latter problem. Finally, we experimentally show that there are weave diagrams for which our algorithm decreases the number of required heald frames drastically.

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In order to improve the quality of sliver made from fine denier fibers, a pin drafting method was investigated. Especially, the study of fiber control in drafting zone, pin count and pitch between moving gill-faller bars was discussed in this paper. The experimental result showed that the pin count of 24 provided higher quality slivers than that of 18. In addition, the sliver quality was also changed with the pitch between moving gill-faller bars. The relationship between the mean fiber length in the sliver and the total distance of the front nip gauge as well as the faller pitch is the most important in the control of fibers during drafting, thus the quality of the drafted sliver can be improved by adjustment of the relationship.

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The path followed by and the tension generated along a yarn under a false-twist process using an enlarged model unit of a doubly stacked multi-disk spindle are measured and analyzed on the basis of a theory, an extension of authors’ earlier proposition. The geometrical quantities necessary to reproduce the yarn path, i.e. the inclination angle made by the yarn against a disk surface, the length along which the yarn runs on the disk, etc., are estimated from the CCD image of the yarn configuration. The twisting tension, the inter-disk yarn tension, and the untwisting tension of the running yarn are also detected. It is revealed that the theoretical analysis can successfully elucidate and predict the inter-disk yarn tension as well as the relation between the twisting tension and the untwisting tension only if the yarn configuration is observed. This study will give a novel and useful clue to the manufacturing technology related to false-twist processing using multi-disk spindles.

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