Wyniki wyszukiwania - BazTech

1

Optimization of Operational Parameters of Foam Sizing Process for Cotton Yarns Based on Plackett-Burman Experiment Design

Zhu B., Liu J., Gao W.

Autex Research Journal

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2018

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Vol. 18, no. 1

61--66

EN

This study was aimed at investigating the process optimization of foam sizing for cotton yarns. In this work, effects of major foam-sizing process factors including size concentration, blowing ratio, stirring speed, pre-wetting temperature, pre-drying temperature, squeezing pressure and drying temperature were studied on the hairiness (more than 3 mm) and abrasion resistance of foam-sized yarns. The combination of Plackett-Burman, steepest ascent path analysis and Box-Behnken design were adopted to optimize the foam-sizing process of cotton yarns. Results revealed that size concentration, blowing ratio and squeezing pressure were significant factors that affected the hairiness and abrasion resistance. Optimum hairiness and abrasion resistance were obtained when the cotton yarns were sized at size concentration of 19.33%, blowing ratio of 4.27 and squeezing pressure of 0.78kN. The theoretical values and the observed values were in reasonably good agreement and the deviation was less than 1%. Verifcation and repeated trial results showed that it has good reproducibility and imparts the foam sizing process of cotton yarns.

2

Dynamic Measurement of Foam-Sized Yarn Properties from Yarn Sequence Images

Zhu B., Li Z., Cao X., Liu J., Gao W.

Autex Research Journal

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2018

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Vol. 18, no. 3

314--322

EN

Unlike the normal sizing method, the foam sizing had been proven to be a low-add-on technology. To investigate the effect of foam sizing, film thickness, sized-yarn evenness, and size penetration rate were necessary to evaluate the performances of foam-sized yarns. However, the conventional image analysis of sized-yarn cross sections primarily relied on artificial testing with a low efficiency. This paper proposed a novel dynamic method to measure the sized-yarn properties including film thickness, sized-yarn evenness, and size penetration rate based on yarn sequence images captured from a moving yarn. A method of dynamic threshold module was adopted to obtain threshold for segmenting yarns in the sequence images. K-means clustering algorithm was applied to segment pixels of the images into yarn and background. To further remove burrs and noise in the images, two judgment templates were carried out to extract the information of yarn core. The film thickness, sized-yarn evenness, and size penetration rate were measured based on the yarn core of each frame in sequence images. In order to compare with the experimental results of the dynamic method, the yarn properties of the same samples were tested by static and artificial testing. Results revealed that the proposed method could efficiently and accurately detect the film thickness, sized-yarn evenness, and size penetration rate.

3

Flexible diamond-like carbon film prepared by hydrothermal electrochemical method

Tao Y., Yi D., Zhu B., Cao W.

Materials Science Poland

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2017

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Vol. 35, No. 3

447--453

EN

Diamond-like carbon (DLC) thin films were prepared by hydrothermal electrochemical method in one-step process. The structural characterization of these films was carried out by scanning electron microscopy (SEM), Raman spectroscopy, and infrared reflectance spectroscopy (IR). It was found that there was an increased sp2 carbon content but decreased sp3 carbon and hydrogen contents with an increase in current density. The flexibility and internal stresses of the DLC films were affected by hydrogen, sp3 amorphous carbon and ordered crystalline sp2 carbon contents. The highly flexible DLC films with high sp3 carbon and hydrogen contents were prepared at a current density of 0.001 mA/cm2.

4

Preparation, characterization and photocatalytic performances of materials based on CS2-modified titanate nanotubes

An H., Hu X., Zhu B., Song J., Zhao W., Zhang S., Huan W.

Materials Science Poland

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2013

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Vol. 31, No. 4

531--542

EN

CS2-modified titanate nanotubes (CS2/TiO2–NTs) are fabricated by reaction of CS2 and Ti–O2Na+ species on titanate nanotubes. Pb2+ ions are coated on the modified nanotubes by ion exchange (Pb/CS2/TiO2–NTs). The products are characterized by means of nitrogen adsorption-desorption isotherms at 77 K (BET method), transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS), X-ray diffraction (XRD), atomic absorption spectrometry (AAS), and diffuse reflectance spectroscopy (DRS). The photocatalytic performances of the products are evaluated by monitoring their catalytic activities for degradation of methyl orange under UV light irradiation. The effects of calcination temperature and atmosphere on the photocatalytic performance are investigated. The results reveal that the photocatalytic activities of CS2/TiO2–NTs and Pb/CS2/TiO2–NTs are far higher than that of primary nanotubes, and the optimum calcination temperature is 500 °C under N2 atmosphere. It is also discovered that physically adsorbed Pb2+ ions affect the photocatalytic activity of Pb/CS2/TiO2–NTs obviously. The photocatalytic activity of washed Pb/CS2/TiO2–NTs is higher than that of the unwashed one under the same thermal treatment and reaction conditions.

5

Improving floatability of taixi anthracite coal of mild oxidation by grinding

Xia W., Yang J., Zhao Y., Zhu B., Wang Y.

Physicochemical Problems of Mineral Processing

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2012

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Vol. 48, iss. 2

393-401

EN

Grinding is widely used in ore size reduction. In this investigation, grinding is proved to be advantageous in improving the floatability of anthracite coal of mild oxidation. FTIR was used to explain changes in the main functional chemical groups of anthracite coal of mild oxidation upon grinding. Improvements of the floatability of four size fractions, namely, +0.25 mm, 0.25-0.125 mm, 0.125-0.074 mm and -0.074 mm, were discussed respectively. The results show that the floatability of anthracite coal of mild oxidation can be improved by 30 minutes grinding. The anthracite coal of mild oxidation can obtain many fresh hydrophobic surfaces by scuffing. Besides, the anthracite coal of mild oxidation can be crushed and/or ground to form fines which also contain many fresh hydrophobic surfaces. Combustible matter recovery of anthracite coal of mild oxidation, ground by 30 minutes, can reach 72.14% with ash content of 8.63%, while combustible matter recovery of original coal is 56.65% with ash content of 9.90%.

6

Effect of reaction temperature on carbon films prepared by a hydrothermal electrochemical method

Tao Y., Yi D., Zhu B.

Materials Science Poland

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2012

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Vol. 30, No. 1

17--22

EN

Carbon films were synthesized under hydrothermal electrochemical conditions using sugar as the carbon source at temperature ranging from 170 C to 180 C. The reaction temperature affects the degree of sugar decomposition, the concentration of carbon ions, supersaturation and overpotential of the solution, thereby affecting the morphology, orientation, and crystallinity of the films. The graphitic content (sp2) increases with increasing the processing temperature and vice versa. The higher the synthesizing temperature the less the amount of amorphous carbon (sp3). The graphite in thin films prepared at 170 C and 175 C shows a (101) preferred orientation, whereas those prepared at 180 C show a fairly random orientation. The mechanism of this synthesizing process seems to consist of three stages.