Hideo Morooka

Twisting Mechanisms of Open-End Rotor Spun Hybrid Yarns:

We have developed a mechanical hybrid yam spinning system that produces different kinds of yam on a modified open-end rotor spinning frame. In order to understand the characteristics of hybrid yam and produce novel yarns, it is necessary to investigate yarn formation and the twisting mechanism in the spinning rotor during yam production. Our results reveal that the rotor revolution generally results in combining the filament yam and the staple fiber strand. The fiber twist angle of the strand in a hybrid yarn is smaller than that of a rotor spun single yam with the same spinning conditions. Although a fed filament yam has a false twist inserted by increasing the filament over-feed, the filament yarn in the hybrid yarn has a smaller level of fiber twist angle in the same direction as the twist of the staple fiber strand due to untwisting of the false twist.

Light Transmittivity of an Extended Circular Plain Knitted Fabric

In order to improve the sheerness of pantyhose to enhance the beauty of womens legs. the design and development of a new yarn and product are proposed. An experimental covering machine with a hollow spindle is produced, and the relationship between the main mechanical parameters of the covering machine and the characteristics of the single covered yams are investigated. The transmittivity of circular plain knitted fabrics made from single covered yams is examined, and the relationships between the transmittivity of light, the covering level of the single covered yarns, and the extension of the knitted fabrics are discussed. The results show that pantyhose sheerness is greatly influenced by the characteristics of the yams and the extension of the knitted fabrics and cannot be defined only by yarn count. Since women appear to mistakenly define sheerness by thinking only of yarn count, it will be necessary to develop a more accurate definition or description of pantyhose sheerness.

Sheerness of Extended Circular Plain Knitted Fabrics

To improve the sheerness of pantyhose to enhance the beauty of womens legs, the design and development of a new yarn and product are proposed. The sheerness of circular plain knitted fabric made from single covered yarns is examined, and the relationships between color, covering level of single covered yarns, and degree of extension of knitted fabrics are discussed. The results show that the appearance and sheerness of pantyhose are greatly influenced by yarn characteristics, degree of extension, and color. Furthermore, sheerness cannot be defined only by light transmittivity. It is necessary to evaluate the lightness difference Δ L* of a uniform color space for a colorless sample and/or chroma ticity differences, Δa* and Δb* of a uniform color space for a colored sample.

Combination effects of open-end rotor spun hybrid yarns

We have developed a mechanical hybrid yarn spinning system that produces different yam types on a modified open-end rotor spinning frame. In order to improve yam properties and produce novel yams, we investigate the effects of combinations with typical hybrid yams by inserting two filament yarns with varying filament over-feeds. The results are a new rotor spun loop (RSL) yam made by combining two aspects of typical hybrid yarn production into one process, and an RSL yam where a filament yam, fed with a core filament over-feed (CFOF), is located in the center of one yarn and the other filament yam, fed with the effect filament over-feed (EFOF), makes a loop on the yarn surface. The stable conditions of RSL yam production are within a range of EFOF ≧ 4 (m/min) and -6.0 << CFOF << -4.0 (m/min).

Compressive Properties of Pantyhose Fabric

To clarify differences in the compressive properties of different kinds of pantyhose fabrics on the market in Japan, cylinder-elongation experiments and wear experiments are conducted, with Zokki, kohhen, sheer, wooly, and conjugate kinds of pantyhose are used as samples. Their compressive properties, which include compressive energy, compres sive resilience, and fabric thickness, differ remarkably according to the types and the sites of hose and posture while being worn.

Exploratory Work on the Spinning Condition of the Structure of Staple-core Twin-spun Yarns

In order to design and develop novel-spun yarns with good functionality, we investigated how to construct a core-sheath structure adapted from a multilayered structure of triplet-spun yarn and/or made from a twin-spun yarn with core-staple fibers using an experimental ring-spinning frame. The results were follows: (1) staple-core twin-spun yarn, a new yarn, could be made by applying the production method of triplet-spun yarn and/or combining the production methods of core-spun yarn and twin-spun yarn into one twisting process; (2) by adopting three rovings made from fibers of differing length and fineness, the resulting triplet-spun yarn had the core-sheath structure within an adequate spinning condition; (3) for the construction of core-sheath structure, it is important that there be a difference between spinning tensions at the center and the two sides of the drafted fiber strands or drafted strand lengths from the front roller nip to the point of yarn formation by controlling the distance of the supply rovings and the yarn’s twist factor.

Reflective Properties of Pantyhose Cloth as Analyzed by an Image Analysis System

In this paper, we attempt to clarify experimentally the reflective properties of fine knit fabrics in the leg sections of pantyhose using an adjustable-angle optical imaging device with a zoom videocamera and an image analyzer. Three knit fabrics differing in yam structure are the samples. We analyze the effects of various angles of both the incidence ray and its receptor on reflectiveness, and we also look at the position of samples relative to the incidence direction and its effect on the distribution and intensity of reflection points. With the results, we clarify the effects of respective yarn structures on the reflectiveness of the cloth.

Morphology of Cloth Surfaces of Pantyhose in Real Contact with a Rigid Plate

The touch of pantyhose on skin is affected by the morphology of the hose surface in real contact with the skin, and the morphology differs with different kinds of hose. This study clarifies peculiar differences in the morphology of the real contact of cloth surfaces of different hose types, using a slide as a rigid plate. The morphology of real contact between the surface of hose leg parts and a slide to which candle soot was applied beforehand is examined. Black spots of soot transferred to the hose surface after contact between the slide and the cloth are regarded as being in real contact, and the effects of contact pressure and elongation of hose on real contact are examined. The study investigates six kinds of hose, including support hose, sheers, and wooly hose, all with different real contact results.

A Geometric Analysis of the Stitch Form of a Circular Plain Knit Fabric Inserted Over a Cylinder

The particular stitch used in the legs of pantyhose is one important factor related to wear performance, for example, the way the fabric feels, its luster, etc. To obtain a fundamental knowledge of the stitch form, we analyzed geometrically the stitch form of a circular plain knit model inserted over a cylinder. We developed some formulas that can be used to calculate each of the partial loop lengths from some parameters, such as the radius of a cylinder, yarn diameter, number of courses, number of wales, covered height, and length of yarn in one course, etc., where one loop is divided into eight parts. The formulas include those in the general analysis and an analysis under extreme conditions. Some results from the numerical calculations are shown.

Apparent Thermal Conductivity of Power Stretch Knitted Fabrics for Women's Foundation Garments under Dry and Wet Conditions.

女性ファンデーション用パワーストレッチ編布を試料とし，乾·湿時における見かけの熱伝導率を計測し，交編糸の繊維素材，組織，加工との関係を明らかにした．パワーストレッチ編布の熱伝導率は，繊維の熱伝導率，繊維の体積分率，布の厚さおよび繊維の水分率に依存することがわかった．なお，各種加工の熱伝導率への寄与はみられなかった．また，吸湿時の熱コンダクタンスには編組織が，含水時の熱コンダクタンスには編布の見かけ密度および交編素材の吸湿性が影響することがわかった.