山东淄博通宇聚酯试生产及流程改进

介绍瑞士伊文达四釜流程20万t/a聚酯项目的试车过程以及4年来的运行状况和工艺设备改进之处。该工程吸纳了专利公司的许多改进之处,形成了装置的工艺设备特点,一次投料试车成功;在110%的负荷下,PTA、EG、电的单耗分别为856kg/t、334kg/t、88kW·h/t。在工艺设备改进方面给同类厂家提供了参考。     

基于傅里叶特征谱和相关系数的织物疵点检测

为提高织物疵点自动检测的准确度,提出一种基于傅里叶特征谱和相关系数的织物疵点检测算法。以平纹、斜纹织物为研究对象,对织物图像进行傅里叶变换,得到织物图像的频谱图;定位频谱中的特征峰点,提取表征图像灰度、纹理的五个特征值;以正常织物为模板,计算待检图像特征值与模板图像特征值之间的相关系数,确定用于识别织物疵点的阈值,来实现织物疵点检测。实验结果表明:当阈值设定为0.80时,该算法能够实现稀密路、断经、吊经、纬缩、破洞等常见疵点的准确检测。     

基于轮廓波变换的织物疵点图像消噪新方法

为了实现织物疵点图像的有效消噪,使其更有利于特征提取和疵点检测,提出了基于轮廓波变换的织物疵点图像消噪新方法。综合考虑轮廓波方向子带能量的大小与织物疵点图像轮廓细节之间的关系,对Donoho多尺度分解阈值进行修正,改进了Donoho多尺度分解阈值对图像细节"过扼杀"的缺点。实验结果表明,对织物疵点图像进行基于轮廓波变换改进阈值消噪时,该方法更好地保留了织物疵点图像的轮廓细节,峰值信噪比显著提高。采用改进的轮廓波Donoho多尺度分解阈值消噪后的图像,可以更好地应用于织物疵点图像的特征提取和疵点识别。     

Recycled poly(ethylene terephthalate) and its short glass fibres composites: effects of hygrothermal aging on the thermo-mechanical behaviour

This paper reports on the effects of hygrothermal aging at 70 °C in water and at 80% relative humidity, on the thermo-mechanical properties, molar mass and microstructure of recycled poly(ethylene terephthalate) (rPET) and its short glass fibres composites.For all the investigated materials, the elastic mechanical properties (tensile and storage moduli) determined at low strain levels resulted practically unaffected by hygrothermal aging under the selected conditions. On the other hand, a marked reduction of the tensile strength and apparent fracture toughness has been observed for rPET matrix and its composites during hygrothermal aging, more markedly for materials immersed in water than for those aged at 80% RH. Both properties resulted to be related on the molar mass of the rPET matrix, that decreased during hygrothermal aging as a consequence of the hydrolysis process.The materials glass transition, evaluated as the temperature of the loss factor peak, increased during hygrothermal aging due to the progressively restricted mobility of the amorphous phase caused by a concurrent crystallinity increase. This crystallization process (chemicrystallization) is favoured by temperature, by the plasticizing effect of water and by the reduction of molar mass.Consistently with the mechanical measurements, the morphology of fracture surfaces exposed to hygrothermal aging in water revealed a reduction of plastic deformation of the rPET matrix and a weakening of the fibre-matrix interface for rPET composites.     

影响海岛法纺PET超细纤维剥离性的因素

采用海岛复合法纺制PET超细纤维,织物终产品的剥离性能的优劣是由纺丝过程中原料、设备、工艺等因素决定的,着重通过表界面原理定性分析指出解决方法和调整方向。     

热媒炉热效率分析及提高

分析指出了热媒炉热效率不高,主要是由于热媒炉盘管和烟气预热器等设备积灰较多以及油气比控制不精确等原因造成的,并提出了相应的对策,如热媒炉盘采用水洗,烟气预热器每天吹灰,油气比控制灵活调节等,取得了一定的效果。     

易水解聚酯的热性能

用PTA法合成了一系列易水解聚酯(EHDPET)。采用DSC和TGA技术系统分析了SIPE、IPA、脂肪族化合物(A)等各组分含量对其热性能的影响。结果表明:tg、tcc(冷结晶温度)随SIPE含量的增加而升高,tm、tmc(热结晶温度)则下降;IPA的加入使tg、tm、tmc均下降,而tcc升高;随脂肪族化合物(A)含量的增加,tcc、tg下降。随SIPE、脂肪族化合物(A)含量的增加,EHDPET的热稳定性变差。     

熔体直纺129dtex/144f涤纶细旦POY的生产工艺

介绍了在直接纺丝设备上,通过工艺调整与设备改进,成功开发129dtex/144f涤纶细旦POY的经验。     

电袋复合除尘器清灰系统的优化组合

目前，关于电袋复合除尘器清灰系统优化组合的研究很少，而清灰系统是其核心和关键，因此清灰系统的设计对除尘器来说十分重要。本文提出了电袋复合除尘器的清灰系统所面临的问题，并给出了解决方案，从而得出了清灰系统的优化组合。     

Shear rate dependence of viscosity and first normal stress difference of LCP/PET blends at solid and molten states of LCP

The liquid crystalline polymer (LCP) and polyethylene terephthalate (PET) were blended in an elastic melt extruder to make samples having 20, 40, 60, 80, and 100 wt % of LCP. Morphology of these samples was studied using scanning electron microscopy. The steady state shear viscosity (η), dynamic complex viscosity (η*) and first normal stress difference (N₁) were evaluated and compared at two temperatures: 265°C, at which LCP was in solid state, and 285°C, at which LCP was in molten state. The PET was in molten state at both the temperatures. The shear viscosity of the studied blends displayed its dependence on composition and shear rate. A maxima was observed in viscosity versus composition plot corresponding to 80/20 LCP/PET blend. The N₁ increased with LCP loading in PET and with the increased asymmetry of LCP droplets. The N₁ also varied with the shear stress in two stages; the first stage demonstrated elastic deformation, whereas second stage displayed dominant plastic deformation of LCP droplets. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2212–2218, 2007