Advanced Materials Research Vols. 550-553

Abstract: Abstract Because of external driving, dynamic pre-cyclone separators have excellent operational performances in areas of pressure vary occasionally. In this work, a numerical model of the dynamic separator been built and the flow field is thoroughly studied. The distribution results of angular velocity show that an appropriate structure of pre-cyclone vanes is of great importance to get a relative uniform flow angular velocity field. A novel structure of pre-cyclone vanes under different separation requirements is developed and verified by a number of experiments.

Abstract: Based on the unified Reynolds equation model and fast Fourier transform (FFT) method, the lubrication performance of the piston pin bearing for high power density diesel engine was studied by numerical simulation. First of all, through the coupled solving of a unified Reynolds equation and elastic deformation equation, the orbit of journal center for piston pin bearing is investigated. The eccentricity ratio of the piston pin bearing in vertical direction of the piston stroke is smaller, however it is much larger in the downward direction of the piston stroke, which indicate that the below area of the piston pin bearing bears greater load and occurs larger deformation. This is consistent with the reality that the below area of the piston pin bearing is prone to damage and wear. Secondly, the influence of the different bearing clearances and width on the minimum oil film thickness is discussed, The results show that the minimum oil film thickness is increased, while the width of piston pin bearing is increased or the clearance of piston pin bearing is decreased.

Abstract: In this paper，a high temperature heat-pump dryer and a corresponding semi-enclosed test drying room for using the dryer are built up respectively. While the average dry bulb of the external environment is 25°C and the relative humidity is 55%, the performance of the dryer is obtained when the dryer is running continuously for five hours. The results show that: the electromagnetic valve-capillary institution has an obvious effect on the lower the dryer exhaust temperature. It makes the suction temperature of compressor dropped 10 °C~15 °C, which can reduce the exhaust temperature and prevent compressor’s overheating. When the exhaust temperature keep at 100~110 °C, it can not only guarantee the temperature of wind coming from the dryer is high, but also can make sure the drying system’s long-term stable operation.

Abstract: A new kind of red polymaleic acid dyes was designed and synthesized through diazotization-coupling reaction of a polymeric coupling component, which was prepared based on poly(maleic anhydride) and 1-amino-8-naphthol-3,6-disulfonic acid (H acid), and was then characterized by FTIR and 13C NMR. The dyes were evaluated on dyeing of cotton. Results showed that cotton dyed with the polymaleic acid dyes possessed high fixation and good fastness properties.

Abstract: The hydrophobicity characteristic of lignocellulosic fibers is an advantage for some paper or paperboard. In this work, the unbleached kraft pulp was treated by laccase and lauryl gallate (LG). The sizing degree, water retention value (WRV) and the wet strength of the treated fibers were studied. The optimal process conditions such as the beating degree of pulp, the drying time and drying temperature of the resulting paper for improving the sizing degree and wet strength were discussed. The results showed that the sizing degree of pulp with beating degree of 25 °SR could be increased by 4.6 times after laccase/LG treatment. The optimal drying time and temperature of the resulting handsheet was 30 min and 105°C for improving the sizing degree of pulp, respectively. The water retention value of pulp with beating degree of 25 °SR decreased. The wet/dry tensile index value of the treated pulp increased after laccase/LG treatment. The high drying temperature (above 105 °C) of handsheet helped to enhance the wet strength of pulp.

Abstract: In this project, the effect of different kinds of the knitted fabric structure in relation to the ultraviolet radiation (UVR) protection was studied. Different single jersey knitting structures were investigated such as plain, pineapple, lacoste and other combinations of different knitting stitches of knit, tuck and miss. The results showed that different knitted structure would provide different UVR protection behaviour.

Abstract: In this study, sulphur dye was used for dyeing 100% cotton knitted fabric and the effect of dye concentration and colour shade on ultraviolet protection factor (UPF) was discussed. The results indicated that the UVR absorbency of sulphur dye was not satisfactory. Generally speaking, the higher the dye concentration, the darker the shade of fabric. Nevertheless, it did not affect the UPF of fabric if the absorbency of the selected dye was ineffective.

Abstract: In this study, sulphur dye was used for dyeing 100% cotton knitted fabric and the effect of dye concentration and colour shade on ultraviolet protection factor (UPF) was discussed. The results indicated that the UVR absorbency of sulphur dye was not satisfactory. Generally speaking, the higher the dye concentration, the darker the shade of fabric. Nevertheless, it did not affect the UPF of fabric if the absorbency of the selected dye was ineffective.

Abstract: The aims of prehydrolysis are mainly removing pentose and decreasing viscosity in the preparation process of dissolving pulp. In this paper, the effect of prehydrolysis in the preparation process of poplar and bamboo dissolving pulp were investigated under different prehydrolysis conditions. The optimum prehydrolysis process conditions of poplar were obtained as followings: the liquid ratio of 1:6, the highest temperature of 160±2°C, heating time of 90min, holding time of 120min, H₂SO₄ of 1.0%, the P-factor was 1537. Under this condition, the results showed that the content of pentosan decreased from 24.10% to 7.85%. The optimum prehydrolysis process conditions of bamboo were obtained as followings: the liquid ratio of 1:8, the highest temperature of 160±2°C, heating time of 90min, holding time of 120min, H₂SO₄ of 1.0%, the P-factor was 1549.And the content of pentosan was also decreased from 19.64% to 6.76% by the prehydrolysis process.

Abstract: Hand towel is one kind of disposable tissue paper which has characteristic of soaking up water quickly and lower cost. It becomes increasingly popularity in families, at work, and public places. There are many kinds of raw materials to produce hand towel according to its level. Some researches showed that bleached chemical pulp could be partially used to the production of hand towel and some other household paper. In this study, some kinds of raw material which be used to produce hand towel were analyzed and trying to looking for new one. Poplar Extruding Mechanical Pulp (EMP) had characteristics of long fiber, high level of strength and brightness. Different ratio of poplar EMP and certain Bleached Kraft Pulp were tested to make hand towel. The effects of poplar EMP on whiteness, tensile strength, bulkiness, absorbability were discussed. The results showed that characteristic targets of hand towel made from poplar EMP and Bleached Kraft Pulp met the quality requirements of GBT22455-2009 and satisfied the high-end hand towel. The new hand towel had lower cost, higher stiffness and higher bulkiness. It was feasible from the technique and economy point.