20—THE INFLUENCE OF THE AIR PRESSURE AT THE ROTOR-CLEANING DEVICE OF ROTOR-SPINNING MACHINES ON THE PROPERTIES OF COTTON OPEN-END-SPUN YARNS

1985 ◽  
Vol 76 (5) ◽  
pp. 301-313 ◽  
Author(s):  
A. Barella ◽  
A. M. Manich ◽  
L. Castro ◽  
Patricia N. Marino ◽  
J. Carpintero
Keyword(s):  
Air Pressure ◽  
Rotor Spinning ◽  
Spun Yarns ◽  
Cleaning Device

Comparison of the airflow characteristics and yarn properties between conventional and dual-feed-opening rotor spinning units

2021 ◽  
pp. 004051752110417
Author(s):  
Qianqian Shi ◽  
Jiang Wang ◽  
Yuze Zhang ◽  
Qian Ding ◽  
Nicholus Tayari Akankwasa ◽  
...  
Keyword(s):  
Field Distribution ◽  
Air Pressure ◽  
Dynamics Simulation ◽  
Superior Performance ◽  
Rotor Spinning ◽  
Future Design ◽  
Yarn Properties ◽  
Spun Yarns ◽  
Airflow Field ◽  
Fancy Yarns

In order to explore the differences between conventional and dual-feed-opening rotor spinning units (RSUs), this work compares the airflow characteristics of two RSU models utilizing a computational fluid dynamics simulation model with the accuracy verified by airflow behavior observation and air pressure measurement. The effect of two different opening roller speeds on the airflow field distribution of a dual-feed-opening model is also investigated. In addition, the yarn properties of six pure and blended yarns corresponding to the two RSU models are evaluated. The results reveal that the distributions of airflow velocity vector and air pressure in the two RSU models show a strong similarity under the same boundary conditions. However, the dual-feed-opening model possesses a centrosymmetric and more balanced airflow field distribution compared to the conventional model. In addition, the dual-feed-opening yarns show a superior performance in comparison to the conventional yarns. Furthermore, for the dual-feed-opening model, there are equivalent contributions of two separated opening and fiber transmission systems to the airflow field distribution and yarn formation. Compared to the configuration with the same two opening roller speeds, the dual-feed-opening model configured with two different opening roller speeds obtains an improved blended yarn performance with having few effects on the airflow characteristics. This strength of the dual-feed-opening RSU could facilitate the production of blended and fancy yarns employing the fibers with diverse properties. This study could provide some guidelines for the manufacture of rotor-spun yarns and the future design of RSUs.

27—FACTORIAL STUDIES IN ROTOR-SPINNING PART III: ACRYLIC-FIBRE OPEN-END-SPUN YARNS

1984 ◽  
Vol 75 (4) ◽  
pp. 259-266 ◽  
Author(s):  
A. Barella ◽  
A. M. Manich ◽  
Patricia N. Marino ◽  
J. Garéfalo ◽  
L. Castro
Keyword(s):  
Rotor Spinning ◽  
Acrylic Fibre ◽  
Spun Yarns

Air-Jet Texturing of Spun Cotton Yarns for Improved Comfort

1992 ◽  
Vol 62 (1) ◽  
pp. 40-43 ◽  
Author(s):  
J. Srinivasan ◽  
A. K. Sengupta ◽  
V. K. Kothari
Keyword(s):  
Flexural Rigidity ◽  
Twist Angle ◽  
Air Pressure ◽  
Air Jet ◽  
Reduced Modulus ◽  
Spun Yarns ◽  
Cotton Yarns ◽  
Structural Configurations

We have studied air-jet texturing of spun yarns with different structural configurations. After texturing, the yarns have improved bulk and reduced modulus and flexural rigidity, rendering them more suitable for improved comfort applications. Increased bulk after texturing is accompanied by reduced strength. We have observed that after air-jet texturing, certain structures such as carded ring spun yarns and Siro spun yarns possess a higher level of bulk compared to other structures. Rotor spun yarns have lower bulk after texturing because of their tripartite structure, twist angle variations, and the alternating Z and S helices in their fiber belts. Yarns with reinforced structures like composite spun, wrap spun, and rotor spun are able to withstand higher overfeed and air pressure during texturing.

Torque-Balanced Singles Knitting Yarns Spun by Unconventional Systems

1997 ◽  
Vol 67 (10) ◽  
pp. 739-746 ◽  
Author(s):  
X. M. Tao ◽  
W. K. Lo ◽  
Y. M. Lau
Keyword(s):  
Cotton Fibers ◽  
Burst Strength ◽  
Rotor Spinning ◽  
The Core ◽  
Modification Process ◽  
Knit Fabrics ◽  
Spun Yarns ◽  
And Performance ◽  
Single Jersey ◽  
Sheath Structure

This paper is the first part of a series reporting on the recent development of a yarn modification process to produce torque-balanced singles spun yarns. Taking advantage of the core-sheath structure of unconventionally spun yarns, we have developed a yarn modification process and applied it to singles yarns spun by rotor spinning, producing torque-free singles yarns from 100% cotton fibers. The spirality of the resultant single jersey knit fabrics is greatly reduced or, in some cases, completely eliminated. Properties and performance characteristics of both parent and modified yarns, as well as their resultant fabrics, are evaluated, including yarn tensile properties, surface properties, handle, air permeability, burst strength, and pilling resistance of the fabrics.

Characterization of the airflow field in the rotor spinning unit based on a novel experimental approach and numerical simulation

2020 ◽  
pp. 004051752095740
Author(s):  
Qianqian Shi ◽  
Nicholus Tayari Akankwasa ◽  
Yuze Zhang ◽  
Jiang Wang ◽  
Jun Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Approach ◽  
Operating Conditions ◽  
Air Pressure ◽  
Rotor Spinning ◽  
Model Unit ◽  
Transfer Channel ◽  
Rotor Wall ◽  
Airflow Field ◽  
Fundamental Research

It is very challenging to experimentally characterize and verify the airflow in the rotor spinning machine because the process takes place in an enclosure. In an attempt to portray the process, we present a methodology that combines a novel experimental approach and numerical techniques. We developed a model unit and used colored smoke to mimic the airflow behavior practically, measured the air pressure, and compared the results to the simulation data. Three state conditions, namely suction and rotation (the regular rotor spinning operation, (Case 1)), without rotation (Case 2), and without suction (Case 3), were adopted to investigate the formation mechanism of the airflow field in the rotor spinning unit based on two operating conditions. Results show that, in a regular state, the airstream accelerates rapidly in the transfer channel under the dominant action of air suction at the rotor outlet and crashes clockwise to the rotor wall with the joint action of two operating conditions. In the rotor, the airflow flows clockwise with the velocity distribution of a multi-ring gradient due to the dominant action of high-speed rotor rotation. Analytics from the air pressure indicate that while the air pressure in the rotor is mainly controlled by the action of the air suction mechanism, it is also affected by the superposition action of the rotation mechanism. This approach is groundbreaking for rotor spinning machine optimization and is anticipated to trigger more insights that will lead to fundamental research in the spinning industry and beyond.

scholarly journals Blending effect of rotor spun yarn with different blending methods

2019 ◽  
Vol 70 (05) ◽  
pp. 403-407
Author(s):  
RUI HUA YANG ◽  
QIAN QIAN DENG ◽  
CHUN PING XIE ◽  
WEI DONG GAO
Keyword(s):  
Mechanical System ◽  
Cross Sections ◽  
New Method ◽  
Cross Sectional ◽  
Blend Ratio ◽  
Rotor Spinning ◽  
Spun Yarn ◽  
Blending Method ◽  
Spun Yarns ◽  
Rotor Spun Yarn

Color blended rotor spun yarn mixing with different methods were spun. Three blending methods were used, one passage of drawing, three passages of drawing and rovings during multi-channel spinning. Multi-channel spinning is modified on rotor spinning machine, which is implemented by a novel mechanical system specially designed to incorporate three separate feed rollers side by side and controlled by servo motors with PLC. Using this new method, blend ratio of yarn can be controlled and realized by asynchronous drafted rovings. 37 type of color blend yarn were produced with different blending ratios. And each yarn was intercepted with 5 cross sections and a total of 185 cross-sectional images were taken. Hamilton index of different colored fibers were calculated of the each type of yarns. And sum of absolute values of Hamilton index were got to demonstrated fibers blending effect in yarns cross sections. All the Hamilton index of the yarns prepared by the three above mentioned methods were all around 5, much below 20. The results showed that regardless of blending method used, the blending effects of rotor spun yarns were all very good.

Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

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