Wyniki wyszukiwania - BazTech

1

Evaluation of Physical and Mechanical Properties of Cotton Warps Under a Cyclic Load of Stretch-Abrasion

Guo Min, Liu Jianli, Zhu Bo, Gao Weidong

Autex Research Journal

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2022

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Vol. 22, no. 1

135--141

EN

The fatigue behavior of cotton warps was studied by a newly weaving load simulator (WLS) developed in our laboratory. Reborn hairiness, strength retention, and elongation retention of sized warps were adopted to evaluate the physical and mechanical properties of sized warps under stretch-abrasion cyclic loading. The influences of different fatigue cycles on the above three indicators were also discussed. The results indicated that the fatigue behavior of the cotton warps accompanied by abrasion yields a three-parameter Weibull distribution. All the fitting plots show acceptable linearity. Moreover, there is a strong relationship of quadratic polynomial between the tensile properties and the fatigue cycle of the sized warps according to the scatter fitting (R2 > 91.08%). Similarly, there is also a good relationship of quadratic polynomial between the reborn hairiness index and the fatigue cycle of the sized warps (R2 > 94.51%). Finally, regardless of the strength retention, elongation retention, and reborn hairiness, the physical and mechanical properties of the cotton warps still change with the continuous increase of the fatigue cycle after 40% of the fatigue cycle, but it is not significant. The research was helpful to estimate the capacity of the warps to sustain failure.

2

Study on the Trajectory of Free-End Fiber in Jet Vortex Spinning Based on the Elastic Thin-Rod Finite Element Model of Flexible Fiber

Han Chenchen, Gao Weidong, Chen Lifen

Autex Research Journal

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2020

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Vol. 20, no. 1

43--48

EN

During the air flow twisting process of jet vortex spinning, the moving characteristics of flexible free-end fiber are complex. In this paper, the finite element model of the fiber is established based on elastic thin rod element. According to the air pressure and velocity distribution in the airflow twisting chamber of jet vortex spinning, this paper analyzes the undetermined coefficients of the finite element kinetic differential equation of the free-end fiber following the principle of mechanical equilibrium, energy conservation, mass conservation and momentum conservation. Based on numerical simulation, this paper gets the trajectory of the free-end fiber. Finally, the theoretical result of the free-end fiber trajectory by finite element simulating is tested by an experimental method. This paper has proposed a new method to study the movement of the fiber and learn about the process and principle of jet vortex spinning.

3

Numerical Simulation of the Condensing Effect of Different Suction Slots on Fiber Strands in a Compact Siro Spinning Machine with Lattice Apron

Han Chenchen, Gao Weidong, Chen Lifen

Autex Research Journal

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2020

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Vol. 20, no. 1

1--10

EN

Compact-siro spun with lattice apron combines compact spinning and siro spinning, and is widely put into practice. In this paper, compact-siro spun models with the parallel shaped slots, oblique parallel shaped slots and V-shaped slots were simulated. Based on the airflow data in the condensing zone, the geometrical model of single fiber is built, and then the trajectory of single fiber can be got. The morphological changes and movement process of fiber strands in the flow field of condensing zone were verified by the comparison experiments of yarn morphology, hairiness, tensile and evenness properties. The results showed that the V-shaped slot achieved the optimal agglomeration effect and yarn performance. The theory analysis gives foundation and explanation for the experiment, and also provides a theoretical basis for optimizing the properties of compact-siro yarn in production practice.

4

Yarn-Dyed Fabric Image Retrieval Using Colour Moments and the Perceptual Hash Algorithm

Li Zhongjian, Xiang Jun, Wang Lei, Zhang Ning, Pan Ruru, Gao Weidong

Fibres & Textiles in Eastern Europe

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2019

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Vol. 27, no. 5 (137)

39--46

EN

Due to the variety of yarn colours and arrangement, it is a challenging problem to retrieve a yarn-dyed fabric image. In this paper, yarn-dyed fabric samples are captured by the DigiEye system first, and then pattern images of the fabric images captured are simulated by pattern design software based on extracted structure parameters of the yarn-dyed fabric. For the simulated pattern image, an effective algorithm is proposed to retrieve these kinds of images by combining the colour moments method and perceptual hash algorithm. Then the pattern images retrieved are mapped back to the yarn-dyed fabric image so as to realise the yarn-dyed fabric image retrieval. In the algorithm proposed, the colour moments method is adopted to extract the colour features, and the perceptual hash algorithm is utilised to calculate the spatial features of the simulated pattern images. Then the two kinds of image features are used to compute the similarity between the input original image and each target image based on the Euclidean distance and Hamming distance. Relevant images can be retrieved in dependence on the similarity value, which is determined by calculating the optimum weighted value of the colour features’ similarity and spatial features’ similarity. In order to measure the retrieval efficiency of the method proposed, the accuracy rate and retrieval rate of image retrieval were computed in experiments using a PATTERN image database with 300 images. The experimental results show that the average accuracy rate of the method proposed is 85.30% and the retrieval rate - 53.51% when the weighted value of the colour feature similarity is fixed at 0.45 and the spatial feature similarity is 0.55. It is shown that the method presented is effective to retrieve pattern images of yarn-dyed fabric.

PL

Ze względu na różnorodność kolorów i rozmieszczenia przędz otrzymanie obrazu tkaniny wytworzonej z barwionych przędz jest trudnym zadaniem. W artykule próbki tkanin z barwionych przędz były najpierw analizowane przez system DigiEye, a następnie wykonane zostały symulacje obrazów z zastosowaniem oprogramowania do projektowania wzorów oparte na wyodrębnionych parametrach struktury tkaniny. W przypadku symulacji obrazu wzoru zaproponowano skuteczny algorytm do odzyskiwania tego rodzaju obrazów poprzez połączenie metody momentów koloru i percepcyjnego algorytmu z mieszaniem. W zaproponowanym algorytmie do wyodrębniania cech kolorów zastosowano metodę momentów barwnych, a do obliczenia cech przestrzennych symulowanych obrazów został wykorzystywany percepcyjny algorytm mieszania. Następnie użyto dwóch rodzajów cech obrazu do obliczenia podobieństwa między oryginalnym obrazem wejściowym a każdym obrazem docelowym w oparciu o odległość euklidesową i odległość Hamminga. Odpowiednie obrazy można odzyskać w zależności od wartości podobieństwa, która jest określana przez obliczenie optymalnej ważonej wartości podobieństwa cech koloru i podobieństwa cech przestrzennych. Aby zmierzyć skuteczność proponowanej metody w eksperymentach obliczono wskaźnik dokładności i szybkość pobierania obrazów, wykorzystując bazę danych obrazów PATTERN z 300 obrazami. Wyniki eksperymentalne pokazały, że średni współczynnik dokładności proponowanej metody wynosi 85,30%, a szybkość pobierania 53,51%, wartość podobieństwa cech kolorów wynosiła 0,45, a podobieństwo cech przestrzennych wynosiło 0,55. Wykazano, że prezentowana metoda jest skuteczna w przypadku otrzymywania obrazów wzorów tkanin z przędz barwionych.

5

Measuring the Geometrical Parameters of Slub Yarn Using a Computer Vision Based Image Sequencing Technique

Li Zhongjian, Xiang Jun, Wang Lei, Zhang Ning, Wang Jing-an, Pan Ruru, Gao Weidong

Fibres & Textiles in Eastern Europe

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2019

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Vol. 27, no. 3 (135)

26--35

EN

This article presents a computer vision method for measuring the geometrical parameters of slub yarn based on yarn sequence images captured from a moving slub yarn. An image segmentation method proposed by our earlier work was applied to segment sequence slub yarn images to obtain overlapping diameter data. Then an image stitching method was proposed to remove the overlapped data based on the normalised cross correlation (NCC) method. In order to detect the geometrical parameters of slub yarn, the frequency histogram, curve fitting , and spectrogram methods were adopted to analyse the sequence diameter data obtained. Four kinds of slub yarn with different geometrical parameters were tested using the method proposed and Uster method. The experimental results show that the detection results for slub amplitude, slub length, slub distance, and slub period obtained using the method proposed were consistent with the set values and Uster results.

PL

W artykule przedstawiono komputerową metodę pomiaru parametrów geometrycznych przędzy fantazyjnej na podstawie sekwencjonowania obrazów. Metoda segmentacji obrazu zaproponowana we wcześniejszej pracy została zastosowana do obrazów przędzy fantazyjnej w celu uzyskania danych dotyczących pomiarów średnicy. Następnie, w celu usunięcia nakładających się danych, zaproponowano metodę obróbki obrazu opartą o znormalizowaną metodę korelacji krzyżowej (NCC). W celu wykrycia parametrów geometrycznych przędzy fantazyjnej zastosowano histogram częstotliwości oraz dopasowanie krzywej i metody spektrogramowe do analizy uzyskanych danych. Za pomocą proponowanej metody i metody Uster przeanalizowano cztery rodzaje przędz fantazyjnych o różnych parametrach geometrycznych. Wyniki eksperymentalne wykazały, że wyniki detekcji amplitudy, długości, odległości i okresu wzgrubień uzyskane przy użyciu proponowanej metody były zgodne z wartościami zadanymi i wynikami Uster.

6

Wicking Behaviors of Ring and Compact-Siro Ring Spun Yarns with Different Twists

Lu Yuzheng, Wang Yang, Gao Weidong

Autex Research Journal

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2019

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Vol. 19, no. 1

68--73

EN

In this study, the wicking properties of ring and compact-siro ring spun staple yarns were compared. The twist level, which is related to the structure of the staple yarns, was found to significantly influence the wicking property of the two kinds of yarn. Polyester staple fibers with 1.33 dtex × 38 mm were selected as the staple fiber material, and the effect of the twist level on the wicking property was investigated using the capillary rise method. The results show that with a decreasing twist coefficient, the wicking height increases with a decrease in yarn compactness. The compact-siro spun yarn showed better wicking properties owing to it special ply yarn structure. Furthermore, the tension property of the yarns decreased significantly with a decrease in the twist coefficient. Compact-siro spinning was carried out to obtain staple yarns with lower twist coefficients, and the yarns showed great improvement in terms of yarn strength, fiber straightness, and wicking properties. Thus, compact-siro spinning is an efficient method to improve the wicking properties of staple yarns.

7

Automatic Construction of Digital Woven Fabric by Using Sequential Yarn Images

Li Zhongjian, Yu Fei, Zhang Ning, Lu Yichen, Pan Ruru, Gao Weidong

Autex Research Journal

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2019

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Vol. 19, no. 2

147--156

EN

In this article, a computerized method is proposed for simulating digital woven fabric (DWF) based on sequential yarn images captured from a moving yarn. A mathematical model of woven fabric structure is established by assuming that the crimped shape of yarns in weave structure is elastica, and the cross-sections of yarn in sequence image and fabric are circular and ellipse, respectively. The sequential yarn images, which are preprocessed and stitched first by image processing methods, are resized based on the mathematical model. Then a light intensity curve, which consists of radial curve model and axial curve model, is used to simulate the gray texture distribution of interlacing points in radial and axial directions. Finally, a Boole Matrix model is used to control the woven pattern. In the experiment, a slub yarn and a normal yarn samples with same count are applied to simulate gray texture fabrics. Then the gray fabrics are transformed to color fabrics based on three color maps. The fabric simulations are confined to single fabrics of plain, 2/2 matt, and 1/3 twill weaves.