Wyniki wyszukiwania - Biblioteka Nauki

1

Numerical Simulation of Flow Field in Air-Jet Loom Main Nozzle

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He S. , Qian Y. , Xue W. , Cheng L.

Autex Research Journal

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2019

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tom Vol. 19, no. 2

181--190

EN

To improve airflow injection capacity of the main nozzle and decrease backflow phenomenon, a new main nozzle structure with two throats is designed. Negative pressure value and negative pressure zone length are first proposed evaluating the strength of backflow phenomenon. Commercial computational fluid dynamic (CFD) code “Fluent” is performed to simulate the flow field inside and outside the main nozzle. Exit velocity increases about 10 m/s in new main nozzle. Airflow core length of the new main nozzle is 35% higher than that of commonly used main nozzle. Smaller negative pressure value and shorter negative pressure zone length mean a weaker backflow phenomenon in the new main nozzle. Bigger air drag force indicates stronger weft insertion ability in the new main nozzle.

2

Numerical Simulation of Fiber Motion in the Condensing Zone of Lateral Compact Spinning with Pneumatic Groove

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Lyu J. , Cheng L. , Xu B. , Hua Z.

Autex Research Journal

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2022

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tom Vol. 22, no. 1

35--41

EN

Lateral compact spinning with pneumatic groove is a spinning process to gather fibers by common actions of airflow and mechanical forces. Compared with ring spinning, it can more effectively reduce yarn hairiness and enhance yarn strength. However, fiber motion in the agglomeration area is complex. And, it is important to establish a new fiber model to accurately describing the fiber motion. The objectives of this research were to create a new fiber model to simulate the agglomeration process, to analyze yarn properties of the lateral compact spinning with pneumatic groove, and to compare with other spinning yarns through a series of tests. The new fiber model was based on the finite element method implemented in MATLAB and was to show the fiber motion during the agglomeration area. The simulation generated results were close to the real motion of fibers in spinning. In the lateral compact spinning with pneumatic groove, fiber bundle through the agglomeration area can be gathered, and the output of the fiber bundle was nearly to cylinder before yarn twisted. The experiments demonstrated that the lateral compact spinning with pneumatic groove can improve the yarn properties: increase the yarn twist, enhance the yarn strength, and reduce the yarn hairiness.

3

Is China's Textile Industry Still a Labour-Intensive Industry?

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Zhang J. , He L. , Cheng L.

Fibres & Textiles in Eastern Europe

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2021

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tom Vol. 29, no. 1 (145)

13--16

EN

Is China's textile industry (CTI) still a laboor-intensive one? To answer this question, this study measures the capital-labour intensity and technology intensity of CTI and its subsectors during 2006-2018, then applies factor intensity classification and cluster analysis to identify their industrial attributes. The results show that CTI and its sub-sectors are still the labour- and non-technology-intensive. All the indexes of capital-labour intensity and technology intensity of CTI and its sub-sectors are below 100, lower than the average of industry sectors, indicating that they are not separate from the category of labour-intensive industry and still heavily dependent on labour. And cluster analysis verifies the industrial classification results. So CTI still needs to keep on increasing its capital intensity and technology intensity to achieve the goal of industrial transformation and upgrading in the future.

PL

Czy chiński przemysł tekstylny nadal wymaga dużego nakładu pracy? Aby odpowiedzieć na to pytanie zbadano kapitałochłonność i intensywność technologiczną chińskiego przemysłu tekstylnego i jego podsektorów w latach 2006-2018, a następnie zastosowano klasyfikację intensywności czynników i analizę skupień w celu określenia ich atrybutów przemysłowych. Wyniki pokazały, że chiński przemysł tekstylny i jego podsektory nadal są pracochłonne i nie wymagają dużej ilości technologii. Wszystkie wskaźniki kapitałochłonności i technologiczno-pracochłonności chińskiego przemysłu tekstylnego i jego podsektorów kształtują się poniżej 100, czyli są niższe od średniej dla sektorów przemysłu, co wskazuje, że nie są one oddzielone od kategorii przemysłu pracochłonnego. Analiza skupień weryfikuje wyniki klasyfikacji przemysłowej. Chiński przemysł tekstylny nadal musi zwiększać swoją kapitałochłonność i intensywność technologii, aby osiągnąć cel, jakim jest transformacja przemysłowa i modernizacja w przyszłości.