Showing papers in "Journal of the Textile Machinery Society of Japan in 1968"

Thick and Thin Places in Fabrics during Weaving

Abstract: The purpose of this article is to clarify the relation between the causes for setting-on areas in fabrics and their scales. We have made several experiments to grasp the tendency of scales and analyzed them by using the equations on warp tension which were established in Part 1 and the equation on bending of the race which was introduced in this report.In the light of the results, we have tried to make clear the causes for setting-on areas and find the means to avoid them. We have reached the following conclusions:(1) To make setting-on areas small in scale, the moment of inertia of the tension roller system must be made as small as possible for the automatic bobbin changing cotton loom and the spring constant of the tension spring must be made as small as possible for the water jet loom.(2) The change of the loom speed when the loom starts or stops has great influence on the scales of setting-on areas.(3) On the automatic bobbin changing cotton loom, the scale of setting-on areas in fabrics is affected mainly by the change of the warp tension. On the water jet loom, it is affected mainly by the bending of the race.(4) To avoid setting-on areas due to fluctuations in the beating-up tension of warp just before or after the loom starts, we should do well to equalize this tension to the tension in its stationary running state. That is, compensate for the warp tension around the beat-up point so as to satisfy the following equation: where ∫ba; f(t)dt=∫ba; g(t)dt f(t): Warp tension curve in stationary running state. g(t): Warp tension curve in starting or stopping state. a, b: Beginning and end of beating-up.

How the Quality of Cotton Yarn Processed by a High Production Card is Affected by Its Cylinder, Taker-in and Doffer Speeds, Sliver Weight and Production Rate

Abstract: The effects of the cylinder speed (250 to 600rpm), taker-in speed (600 to 1, 500rpm), doffer speed (15 to 33rpm), sliver weight (4 to 8g/m) and production rate (16 to 34kg/hr) were investigated on a high production card with the following results:1) The optimum speeds of the cylinder and the taker-in are 400rpm and 1, 000rpm, respectively, from the viewpoint of yarn quality.2) Increasing the sliver weight up to 6g/m does not deteriorate the yarn.3) Increasing the production rate in proportion to the doffer speed does not deteriorate the yarn.4) Keeping the sliver weight at 6g/m and using a high speed web doffing unit may increase the production rate up to 57kg/hr without deteriorating the yarn.

Mechanical Properties Related to the Handle of Heavy Fabrics

Abstract: Some fundamental properties of heavy fabrics-bending, shearing, stretching, compression, etc.-were measured and then calculated to make a matrix and a vector indicating a pattern of such properties of heavy fabrics.This pattern has been found capable of differentiating between woollen and other fabrics in terms of characteristics concerning mechanical properties. A mechanical behavior related to fabric handle is believed to be almost completely covered by the properties measured in our experiment under review. It is, therefore, possible to correlate the mechanical properties of fabrics to their handle. Discussion of the surface characteristics of fabrics is omitted from this article.

Mechanical Properties of Fiber Reinforced Plastics

Abstract: We have investigated the effect of the laminating structure of glass cloth on the elastic anisotroly of FRP in which plain-woven glass cloth is embedded. The relationship between the manner of piling up glass cloth and the elastic anisotropy of FRP has been analyzed by using a mechanical model. The major results of our research are:A)The elastic anisotropy of FRP may disappear if equal numbers of sheets of cloth (a) (plainweave glass cloth) and cloth (b) (the same as cloth (a) but rotated 45°) are embedded.B) For FRP in which many sheets of glass cloth oriented parallel with one another are embedded, Young's modulus gets a maximum value in the directions of warp and weft of the cloth and declines to a minimum in the center direction.C) Placing cloth (b) on top of cloth (a) reduces Young's modulus in the yarn direction of cloth (a) in FRP, if sheets of cloth (a) and (b) to the number n each (2n sheets in all) are embedded, Young's modulus declines to 80% of that where 2n sheets of cloth (a) only are embedded.

Electronic-Controlled Tensile Tester

Abstract: A universal electronic testing machine has been experimentally produced and the characteristic of its control system has been analyzed with respect to the effect of nonlinear properties of transfer elements on the stability of the system.When the input signal is sinusoidal, there is no output signal produced if the input amplitude falls in the backlash zone, but when the input signal contains some random noise in it, the stable regions are changed.(1) Whenκ1; is assumed the equivalent gain of the neutral zone for the sinusoidal input, a formula κ1; =(TA; +TM;)[-(T2A; +T2M; )+√ ]/k[(TA; +TM; )2-radic; ]TA; TM; is obtained where D=(T2A; -T2M; ) 2+4(TA; TM; )2(TA; +TM; )KThe proportional gain K of the linear part is included in the denominator and numerator of the above formula. As a result, the increase of K value results in the increase of κ1; . So that, the increase of K extends the stable region for both sinusoidal input and random input. In other words, the increase of K has the same effect on the stability of the system as the increase of (Az; /a).(2) Decreasing of variance σn; 2 of the random noise extends the stable region.(3) Above conclusions lead us to the next method for increasing the stability of the system.When the value of Az; /a is large and the proportional gain K is fixed, it is recommended to place a saturation element in front of the neutral zone, and provide a filter to reduce the value of σz; /a.

Abrasion of Fabrics

Abstract: 目的 布の摩耗は単繊維の損耗が起こり, つぎに損耗繊維の切断が起こると考えられるが, 単繊維の損耗を伴わない切断もありうるので, 布を摩擦して得た摩耗布および繊維残渣を光学顕微鏡で詳細に観察し, 摩耗条件による繊維の切断過程の定性的知見を明確にする. 成果 1) 研摩紙による摩耗機構 単繊維の太さと研摩紙粒子との相対的大きさによって2通りの摩耗が考えられる. a. 単繊維が粒子間に入りこむことのできる場合, 摩耗は主に単繊維の引掛切断の累積による. b. 単繊維が粒子間に入りこむことのできない場合, 摩耗は主に単繊維の引っかき損耗による損耗単繊維切断の累積である. 2) 金属ブレードによる摩耗機構 押圧荷重が比較的大きい場合, 摩耗による破壊は主に引掛切断である.摩耗はこの引掛切断の累積である. 3) 金属平板による摩耗機構 摩耗は主に単繊維の凝着損耗に起因する単繊維損耗で, 最終的な単繊維切断は摩擦力の繊維軸方向に働く応力による引張切断であり, この切断の累積が布の摩耗となる.