Yarn Ends Research Articles

Manufacturing Process and Property Evaluation of Functional Composite Yarn-Dyed Woven Fabrics Made from Bamboo Charcoal/Stainless Steel and TPU

Recently, development of technology increases human life quality and gradually raises the value of health protection in human’s concept. Bamboo has multi-functional including far infrared radiation, deodorization and anion generation. Therefore, bamboo charcoal has been widely used in textile industry. Moreover, development of technology also increased the electromagnetic hazard in human’s daily life. This study aims to develop a manufacturing process of functional composite yarn-dyed woven fabrics. In the manufacturing process, the materials included pure cotton yarn, stainless steel fiber(called metallic yarn) and viscose rayon yarn containing bamboo charcoal (called bamboo charcoal yarn) were used for making the bamboo charcoal/stainless steel composite woven fabric. The composite woven fabrics were woven by using same warp yarn and two kinds of weft yarn that contained bamboo charcoal and stainless steel. The composite fabrics had two different structures. Those fabrics were changed the order of bamboo charcoal yarn and metallic yarn. The ratios of weft yarn were 1 end of bamboo charcoal yarn to 1 end of metallic yarn and 3 ends of bamboo charcoal yarn to 1 end of metallic yarn. Furthermore, the fabrication of composite fabrics that included plain, 2/2 twill and dobby were changed. The composite woven fabrics were finished and laminated by TPU film to enhance the waterproof and vapor permeable functions. The laminated composite fabrics were evaluated by far-infrared coefficient, anion generation rate, water vapor permeability, water resistance, surface electric resistance and electromagnetic shelter property to obtained optimal manufacturing process.

528 The Observation of Machined Surface Conditions of Unidirectional Glass Fiber Reinforced Plastics under small Depth of Cut Conditions

The mechanism for cutting unidirectional glass fiber reinforced plastic specimen, which were specially provided, was experimentally investigated to obtain a fine surface finish. The specimens were cut orthogonally under dry conditions using a lathe and grinder. The relationship between the direction of the glass yam and the topography of the cut surface was investigated. The cut end of glass yarn near the cut surface was observed microscopically, and fractographs of the glass fiber were inspected with a scanning electron microscope (SEM). The surface roughness was strongly dependent on the direction of the yarn. The appearance of the cut ends of glass yam near the cut surface could be classified into two types according to the direction of the yarn, i.e., hollow pits and swollen protuberances. The fracture of the glass fiber could be classified into four types : (A) interfacial debonding, (B) intermediate between type A and C. (C) cutting, and (D) tensile rupturing. The direction of the yarn for a comparatively good quality of the cut surface was from 5π/12radto 11π/12rad.

拘束噴流下におけるモノフィラメント糸の空気抗力

Air drag force on a nylon monofilament yarn in a confined jet was measured as a basic study for operating yarn by airflow, for example; for weft-insertion, for holding the yarn end, for adjusting yarn tension and for drawing yarn into a hollow spindle. The relative velocity of airflow around a yarn was expanded up to 300 m/s. Previously, this had been investigated up to 100 m/s. Both the supplying air pressure and combinations of nozzles and pipes changed diffusion of the flow in a pipe. Air drag force increased extremely if the primary stream acted on the yarn directly when the jet from the nozzle was directed at very high speed (around sonic velocity). Yarn was often stuck inside the pipe by the airflow when very thin pipes were used. When this occurred, air drag force was reduced to half. The air drag coefficient Cf for monofilament yarn has been arranged using the radius Reynolds number, Rea, for suction flow with lower than 100 m/s. The formula, Cf = KRea-n, has been applied for suction flow under 500 in Rea. Cf could be arranged in the same manner for annular jet or confined jet if airflow acted on a yarn in the pipe uniformly. This formula, then, is also available even for very high velocity over 100 m/s. According to these results, we were able to calculate air drag force on monofilament yam. We anticipate applying this to the other kinds of yarn, and expect air power savings and improvement in yarn operation.

ラッシングエンドを利用したスパンデックスパッケージからの糸の引出し

ラッシングエンドを利用したスパンデックスパッケージからの糸の引出し

Tensile Behaviour of Staple Yarns

The tensile properties of staple yarns strongly depend on yarn structure. The differences in the yarn structure reflecting different distribution of fibres in the yarn and different fibre migration patterns result from different manufacture methods. The tensile behaviour of ring, open end, air jet and vortex yarns has been studied. The yarns were tested on a tensile tester. The images of the yarn before and after the break were recorded. On the basis of yarn images the distribution of number of fibres and fibre ends on the yarn length as well as the relative disposition of the fibres in yarn were determined. The models have been developed on the basis of these parameters to predict the tensile properties of staple yarns.

The Effect of Cotton Yarn Properties on Yarn End Breakage

In this work the effect of cotton yarn properties on yarn end breakage was investigated. The yarn nominal linear densities were 20, 25 and 36 tex and each of them, had three levels of twists. Following yarn properties were investigated: linear density, twists, tensile strength, elongation at break and irregularity. Standard methods were applied to determine these yarn properties and hronometric method for yarn end breakage was used. It was only the yarn linear density, among all yarn properties, that showed significant correlation with yarn end breakage (-0,75 to -0,96). It was shown that about 80% of all yarn end breakage are occurred in places with fineness lower than average cross section of the yarn that point out that the thin places of the yarn are inclined to breaking. Also, the mutuality effect of geometrical characteristics and physical-mechanical properties of the yarn on end breakage was investigated.

Breeding Transformed Cotton Expressing Enhanced Fiber Strength

ABSTRACT New cotton (Gossypium hirsutum L.) seeds that can produce fiber with enhanced strength would increase efficiency of the rotor form of open end yarn manufacture. We report results of 3-yr of breeding transgenic ‘Deltapine 50’ (DP 50) germplasm expressing enhanced fiber strength. The objective was to identify germplasm that could consistently express and transmit enhanced fiber strength to their progeny. Deltapine 50 cotton was transformed via particle bombardment of meristems by Monsanto. The intent of transformation was to insert a -glucuronidase (GUS) marker gene and a proprietary gene driven by a fiber specific promoter. The R4-R6 generations descendent from three GUS-positive, enhanced strength, R3 greenhouse plants were evaluated in the field from 1996-1998 near Florence, SC. Unusual frequencies of GUS-positive progeny were found upon self-pollination of GUS-positive plants, possibly reflecting altered fitness of transgenic gametes. Fiber strength of most GUS-positive plants was 30-70% greate...

Effect of Yarn Cross Section on Air Drag for Spandex Yarn

The effect of yarn cross section on the air drag coefficient and the characteristic length is examined for spandex yarn with non-circular cross section.Methods for estimating the air drag of spandex yarns in axisymmetric air flow are investigated. Results obtained are as follows:1) Although the drag coefficient for thin yarns is similar to that of a cylinder, the air drag coefficient of spandex yarn shows similarity to that of a flat plate because of remarkable irregularities in its cross section.2) The drag coefficient for a fixed- end yarn is the same as that for a flat plate. The drag coefficient for a free- end yarn is twice that of the fixed- end yarn. This value is useful in calculating yarn air drag.3) It is efficient and reasonable to use the effective diameter converted from the yarn perimeter length-without any consideration to its irregularity-as the characteristic length of the spandex yarn.

スパンデックス糸の空気抗力に及ぼす糸断面形状の影響

The effect of the yarn cross section on the air drag coefficient and the characteristic length was examined for the spandex yarn that doesn't have a circular cross section.The way to estimate the air drag of spandex yarns in axisymmetric air flow are investigated.Results obtained are as follows. (1) The air drag coefficient of the spandex yarn shows similar tendency to the effect of the flat plate rather than those of sylindrical curvature appeared in the thin yarn because it has remarkable irregularities in its cross section. (2) The drag coefficient for the fixed end yarn is the same value as that for flat plate.And the drag coefficient for the free end yarn is twice for that. (3) It is effective and actually reasonable for the characteristic length of the spandex yarn to use the diameter that is converted from the yarn perimeter length without any consideration to its irregularity.

一方向ＧＦＲＰ材を切削加工した場合の加工表面品位への繊維方向の影響

In order to clarify the cutting mechanism of FRP, the quality of cut surface finish of unidirectional glass fiber reinforced plastics was investigated by changing the direction of glass yarn against the cutting direction. Cutting was operated under two-dimensional dry cutting conditions. The cut surface finish state of glass yarn end was discussed by taking the cut plastic surface state without any glassfiber as a standard surface. The following results were obtained by changing the both rake angle and depth of cut:(1) The cut end states of glass yarn near the cut surface were classified into two modes with changing the direction of glass yarn, such as the hollow pit and the swollen proturberance (uncut glassfibers).(2) The maximum hollow pit depth was almost twenty times of the maximum swollen proturberance height on changing the direction of glass yarn.(3) The change in rake angle of cutting tool did not affect the surface finish state.(4) The surface finish state became worse with increasing the depth of cut.

A study of the response of open end and ring spun yarns to zinc chloride and sodium hydroxide

AbstractAn investigation of the swelling behavior of open end and ring spun yarns in slack condition in 64.5% (w/w) aqueous zinc chloride and sodium hydroxide 22% (w/w) for different intervals ranging from 30 to 90 min is reported. The results show that the response of the yarns to the swelling agents is different in that the products treated with zinc chloride are found to possess higher strength and higher bending rigidities but low elongation. Swelling of yarns with sodium hydroxide has resulted in large increase in elongation. The other properties, namely, coefficient of friction and abrasion resistance, are found to be slightly higher than that of the yarns treated with sodium hydroxide. Degree of set of open end yarns is significantly higher than that of the ring spun yarns. Coefficient of friction and abrasion resistance of the zinc chloride treated yarn samples are found to be slightly higher than that of the sodium hydroxide treated samples.

一方向ＧＦＲＰ材の研削加工表面品位について（研削加工方法の影響）

As the first step to clarify the grinding mechanism of FRP, the quality of ground surface finish of unidirectional glass fiber reinforced plastics was investigated. It was shown in the previous paper [1] that the aspects of the cut end of glass yarn near the ground surface were classified into two modes by the direction of glass yarn, such as, the hollow pit and the swollen proturberance (uncut glass yarn). The present paper describes the investigation on how to produce the same quality ground surface finish irrespective of the change of glass yarn direction in the specimen and how the grinding method affects the quality of ground surface finish.The following results were obtained.(1) It was difficult to achieve the same quality of ground surface finish when the glass yarn direction was changed.(2) On the spark-out grinding, the length of uncut glass yarn decreased with increasing the number of spark-out grinding.(3) On the orthogonal plunge cut grinding, the length of uncut glass yarn increased with increasing the number of plunge cut.(4) None of these grinding methods could reduced the depthe of hollow pits.

Study on the Grinding Mechanism of Glass Fiber Reinforced Plastics

In order to clarify the grinding mechanism of polymer matrix composites, special test specimens were provided. The test specimen is such one that glass yarns are unidirectionally embedded at even interval on the middle plane of thick of a polymer matrix plate. The end face perpendicular to the plane on which glass yarns are lined up is ground in the direction at various angle from the direction of glass yarn. The aspects of the cut end of the glass yarn near the ground surface are observed microscopically, and relations between the angle of the direction of yarn and the topography of the ground surface are investigated. Following results are obtained. (1) The microscopically observed aspects of failure of the end of yarns near the ground surfaces are classified into two modes by the direction of yarn measured counterclockwise from the direction of grinding. In the range from 0 rad. to π/3 rad. of the angle, the failure of the end of yarn is comparatively deep, and spreads over the whole section of the yarn. In the range from π/2 rad. to π rad. of the angle, the failure of the end of the yarn is comparatively shallow, and random in the depth and the spread. (2) The topography is also classified into two types by the above angle. In the range from 0 rad. to π/3 rad. of the angle, the end of yarn forms a hollow pit, and in the range from π/2 rad. to π rad., the end of yarn forms a swollen proturberance. (3) The above facts are well understood by considering the digging up action of the grinding grain in the range from 0 rad. to π/3 rad., and the push down action of the grain in the range from π/2 rad. to π rad. in the grinding process.

Creation of Effective Flow Pattern for Retrieving Yarn End

Effective methods for retrieving yarn end from a bobbin was before studied, and an intensive turbulent flow along the bobbin surface was proved effective to retrieve the yarn end.In this paper, we try to set a cut (a cavity or a slit) in the suction hood for creating effective turbulent flow. The result shows that the suction hood with a slit (45 degree oblique to the flow direction and 2mm wide) would be effective to retrieve the yarn end. It will be helpful to solve the actual problem.

Penetration of Nylon Ballistic Panels by Fragment-Simulating Projectiles

The purpose of this report is to present evidence supporting the thesis that the major mode of penetration of nylon ballistic panels by fragment-simulating projectiles is a cutting, shearing mechanism: Shear forces required for yarn failure are usually less than tensile forces. Penetration is always at a slight angle, with the 90° edge of the FSP leading. Many yarn ends terminated in a smooth surface (in a tensile break the filaments break at random places along the yarn). Penetration of the cloth in certain experimental situations occur in a manner precluding tensile failure. The force required for nylon or Kevlar yarn failure is less for a rectangular leading surface than it is for a chisel-shaped leading surface.

Fluid-flow Phenomena in Friction Spinning

An investigation is reported in which dynamic similarity was used to calculate a large–scale water analogue of a friction–spinning torque system that operated with water as the fluid. Reynolds numbers similar to those in an actual machine were used, and the model was geometrically similar. The results showed that leakage flows in the annuli between the rotating perforated cylinders and the stationary inner suction cylinders were very important, as were the relative positions of the suction slots in these inner cylinders. Yarn diameter and rotational speed were also important. With a particular port positioning, it was possible to create cross–flows that could pass behind the yarn from one cylinder to the other. Such cross–flows may be important in carrying portions of fibre from the ingoing roller to the outgoing one and thus help wrap the fibre around the forming yarn end.

Stiffness of Fabrics Made by Open End Yarns

Open end yarns are structurally different in character from ring spun yarns. This difference in structure could affect the yarn properties and consequently the fabric properties. This paper attempts a comparison of the stiffness properties of open end yarn fabrics and similar ring spun yarn fabrics using the SITRA Electronic Stiffness Tester. The important conclusions are that although open end fabrics show a higher stiffness than similar ring spun fabrics, there are directions in which the stiffness of open end fabrics is lower. Also comparison has been made of the stiffness behaviour of a open end fabric pile with that of the ring spun fabric pile.

正誤表

正誤表

Creation of Effective Flow Pattern for Retrieving of Yarn End

Creation of Effective Flow Pattern for Retrieving of Yarn End

Stiffness of fabrics made by open end yarns.

Open end yarns are structurally different in character from ring spun yarns. This difference in structure could affect the yarn properties and consequently the fabric properties. This paper attempts a comparison of the stiffness propeties of open end yarn fabrics and similar ring spun yarn fabrics using the SITRA Electronic Stiffness Tester. The important conclusions are that although open end fabrics show a higher stiffness than similar ring spun fabrics, there are directions in which the stiffness of open end fabrics is lower. Also comparison has been made of the stiffness behaviour of a open end fabric pile with that of the ring spun fabric pile.