浸胶涤纶帘子布附胶量的改进措施探讨

分析了涤纶帘子布浸胶过程中附胶量的影响因素,提出了工艺和设备改进措施。结果表明:影响附胶量的主要因素为浸胶液浓度、挤压辊挤压力及浸胶时间;控制浸胶液质量分数17%,选择挤压力89~97kN,在第一浸胶槽增加胶液喷淋管及导向罗拉,加大帘子布倾斜度,从而提高浸胶时间,改进后的浸胶涤纶帘子布附胶量由原来的2.1%提高到3.3%,达到了GB/T 19390—2003标准要求。     

锦纶66浸胶帘子布收缩原因探析及解决措施

就影响锦纶66浸胶帘子布布头、布尾收缩的原因进行了分析,从机头布使用的原材料、织布、缝纫方法等方面入手,通过增加机头布纬密、使用新型机头布纱以及使用超低收缩缝纫线及缩水垫布等找到了解决锦纶66浸胶帘子布布头、布尾收缩的有效方法,实现了浸胶帘子布布头、布尾处幅宽同帘布主体幅宽基本一致的目标,杜绝了浸胶帘子布布头、布尾收缩而引起的近木轴处帘布卷姿不良、边劈等问题。锦纶66浸胶帘子布外观质量得到进一步提高,最大程度地满足了客户的质量要求。     

锦纶帘子布附胶量测试方法浅谈

锦纶浸胶帘子布作为轮胎理想的骨架材料,具有强度高、耐磨、耐疲劳性好及粘合性好等优良性能。然而浸胶前的白坯帘子布表面光滑且附有纺丝油剂,与人造丝和棉纤维相比,锦纶分子链上缺少与橡胶亲和的活性基因,因此很难实现与橡胶良好的粘合,只有经过浸胶,即将白坯帘子布通过盛放有胶液的浸胶槽,使其表面附上一层胶膜,才可以获得帘线与橡胶的良好粘合能力,具有实际使用价值。就是说橡胶与帘线粘合性好坏的一个因素是帘线的附胶量。在一定范围内粘合力随着附胶量增大而提高,但附胶量达到某个定值时,粘着力不再随其增大而提高,过高反而使帘布发硬…     

锦纶6帘子布浸胶液布氏粘度的优化选择

讨论了锦纶6帘子布浸胶液布氏粘度与温度、附胶量、粘着强度的关系。试验表明:浸胶液布氏粘 度随温度的升高而降低,而附胶量及粘着强度随布氏粘度的增大而增大。不同品种帘子布浸胶液的布氏粘 度分别为:930 dtex.／2,3.9-4.0 cPa·s,1 400 dtex／2,4.0-4.1 cPa·s,1 870 dtex,／2,4.1~4.2 cPa·s。     

胶液温度对浸胶帘子布附胶量及黏着强度的影响关系

通过对比实验，找出生产尼龙-6浸胶帘子布所用的胶液温度与胶液布氏黏度以及浸胶帘子布的附胶量、黏着强度之间的关系，确定了生产各品种浸胶帘子布的最佳胶液布氏黏度和使用胶乳的最佳温度。     

影响锦纶浸胶帘子布粘合强度因素探讨

介绍了影响锦纶浸胶帘子布粘合强度的影响因素，而粘合强度结果的准确性直接关系到浸胶帘子布等级的判定，甚至影响到产品质量，因此通过各种实验配方对比，分析几种原材料对粘合强度的影响及试验标准存在问题的探讨，提高轮胎企业对锦纶浸胶帘子布的检测质量。     

锦纶66浸胶帘子布胶斑产生原因的探讨

分析了锦纶66浸胶帘子布胶斑产生的原因,讨论了浸胶液质量、干燥区温度、湿度、风速和排风量对胶斑形成的影响。结果表明:锦纶66浸胶帘子布的浸胶液中,间苯二酚与甲醛反应越彻底,胶斑的生成量越少;采用乙烯基吡啶胶乳制成浸胶液,并添加氢氧化钠和氨水,控制其pH值为11.2±0.5,当干燥区温度为(150±1)℃,风速18 m/s,干燥A区相对湿度(24±15)%和排风量140 m3/min,干燥B区相对湿度(18±1)%和排风量25 m3/min,供风机风量为2 200 m3/min,风速为18 m/s,选择棱角形塔顶辊,安装可调式自动清胶器,抑制胶斑形成的效果显著。     

锦纶浸胶帘子布评优工作结束

<正> 锦纶大、小胎浸胶帘子布评优会议于1990年5月20～22日在河南省平顶山锦纶帘子布厂召开。会议由纺织部化纤司主持。这次评比的品种是锦纶6和锦纶66的1400dtex/2浸胶帘子布和锦纶6的1400dtex/1浸胶帘子布。这次评优方法是以用户对化纤企业提供的浸胶帘子布(包括从日本、美国进口     

影响浸胶帘子布挺度的因素及挺度的检测方法

关于轮胎骨架材料浸胶帘子布挺度的物性指标及检测方法问题。在GB／T9101—2002《锦纶66浸胶帘子布》标准中并没有该项要求,但是,随着半钢子午线轮胎的快速发展．以及半钢子午线轮胎加工和使用性能的不断提高,相应浸胶帘子布挺度越来越受到轮胎生产厂家的广泛关注。     

尼龙66浸胶帘子布表面胶斑的影响因素探讨

使用一浴浸胶机生产尼龙66浸胶帘子布,从工艺和设备两方面分析生产过程中帘子布表面产生胶斑的原因,探讨挤压辊空气弹簧压强、无挤压辊的浸胶区结构、刮布线数量、单/双面吸嘴等因素对浸胶帘子布千米胶斑面积的影响。结果表明:在尼龙66浸胶帘子布生产中,减小挤压辊空气弹簧压强或使用无挤压辊的浸胶区结构、增加刮布线数量、使用双面吸嘴替代单面吸嘴,均有利于减小浸胶帘子布的千米胶斑面积;综合使用无挤压辊的浸胶区结构、刮布线6根和双面吸嘴,生产的尼龙66浸胶帘子布表面胶斑显著减少,千米胶斑面积仅为0.9 cm~2。     

化学纤维浸胶帘子线试验方法国家标准研究

通过广泛研究国内外的相关测试方法,在充分考虑了各类化纤浸胶帘子线特性的基础上,对浸胶帘子线的多个测试项目确定合理、统一的测试条件,开发制定了国家标准GB/T 36020-2018:研究开发了芳纶浸胶帘子线以及锦纶与芳纶并捻浸胶帘子线的附胶量测试方法;统一了胶料配方,确定了5种制样规格,确定了黏合强力测试条件,并在国内外...     

Pickup, critical and wind threshold velocities of particles

This work presents experimental results on pickup velocity measurements for a variety of particulate solids in gases and in liquids. Based on our previously published experimental results for pickup in gas flow in pipes a three-zone master-curve is defined by establishing simple relationships between modified Reynolds and Archimedes numbers. The zones are distinguished by cohesive forces (van der Waals): Zone I represents negligible cohesion forces, Zone II represents considerable cohesion forces that increase the required pickup velocity of individual particles, and Zone III represents significant cohesion forces that cause pickup of agglomerates. Previously published experiments by others encompassing about 121 measurements for a wide range of particle sizes, shapes and densities picked up by liquids, were added to our master-curve with excellent agreement. The cohesive forces did not affect the critical velocity in case of liquid-particle systems. Therefore, these experiments extend the line fitting the pickup velocity of big dry particles. In most cases, the critical shear velocity (reported for liquid-particle systems) had to be converted to the average pickup velocity. Furthermore, additional 16 measurements of pickup velocities (in air) conducted in big wind tunnels were added to the master-curve with excellent agreement. We can conclude that our simple master-curve is appropriate for threshold velocities defined in three fluid-particle systems with a maximum error of only ± 30%.     

Effect of particle characteristics on particle pickup velocity

Particle entrainment is investigated by measuring the velocity required to pick up particles from rest, also known as pickup velocity. Pickup velocity is a function of individual particle characteristics and interparticle forces. Although 5-200 μm particles are investigated, the work presented here focuses on the pickup of particles in a pile in the size range of 5-35 μm. These smaller particle sizes are more typical for pharmaceutical and biomedical applications, such as dry powder inhalers (DPIs). Pickup velocities varied from 3.9 to 16.9 m/s for the range of particle sizes investigated.There is a strong correlation between particle size and the dominating forces that determine the magnitude of the pickup velocity. Preliminary data investigating pickup velocity as a function of particle size indicate the existence of a minimum pickup velocity. For larger particle sizes, the mass of the particle demands a greater fluid velocity for entrainment, and for smaller particle sizes, greater fluid velocities are required to overcome particle-particle interactions. Pickup velocity remains relatively constant at very small particle diameters, specifically, less than 10 μm for glass spheres and 20 μm for nonspherical alumina powder. This can be attributed to the negligible changes in London-van der Waals forces due to a hypothesized decrease in interparticle spacing. At intermediate particle diameters, electrostatic forces are dominant.     

摄像机镜头显示屏注塑模设计

介绍摄像机镜头显示屏注塑模的设计方法。在对该塑料件结构分析的基础上,根据塑料件制造精度设计模具的型腔数目和分流道,综合考虑成型零件的特点设计了模具结构。结果表明,该模具结构合理,可以生产出符合技术要求的摄像机镜头显示屏。     

Effect of particle and fluid properties on the pickup velocity of fine particles

Systems involving fluid-particle flows are a key component of many industrial processes, but they are not well-understood. One important parameter to consider when designing a conveying system is pickup velocity, the minimum fluid velocity required for particle entrainment. Many theoretical and experimental analyses have been performed to better understand pickup velocity, but there is little consistency with regard to system conditions, fluid properties, and particle characteristics, which makes comparisons between these studies very difficult. Although the proper design of many conveying systems requires the utilization of expressions that are applicable across a broad range of operating parameters, most expressions are system specific, which means that they are not extendable to other conditions. Also, there is currently an absence of a universal expression to predict particle entrainment in both gases and liquids.In this work, the pickup velocity of glass spheres, crushed glass, and stainless steel spheres in water has been measured for particles less than 450 μm. The effects of particle size, particle shape, and particle density are discussed and compared to the pickup velocity trends previously determined for similar gas-phase systems. In addition, the experimental data are used to assess an existing force balance model previously developed for gas-phase systems.     

酰胺基改性聚酯的合成及性能测试

首先合成了含有酰胺键的组分T4T、T2T ,然后按一定物质的量比将T4T、T2T分别与EG反应制备含有酰胺键的改性聚酯。通过DSC密度法等测定改性聚酯的超分子结构 ,并测试了改性聚酯的吸湿率。结果发现 ,随着T4T含量的增加 ,聚酯的吸湿率明显增大。     

整车涂装车间干式喷房迷宫纸盒技术的应用研究

以迷宫纸盒的工程应用为出发点,介绍了其基本工作原理,并通过试验测试分析了纸盒的捕捉性能和工作效率,通过搭建试验线和流场仿真提出了在整车涂装车间中迷宫纸盒干式喷房系统的整体设计方法和要点,并对其运行经济效益进行了对比分析,为后续的工程应用提供了参考。     

Generalized master curve for threshold superficial velocities in particle-fluid systems

This paper presents our previous analyses of pickup gas velocity from a layer of particles in pipes and big wind tunnels, pickup liquid velocity, boundary saltation and minimum pressure velocities, and a new analysis of the minimum fluidization velocity and the terminal velocity. All these threshold velocities are defined as simple relations between the Reynolds and Archimedes numbers as modified by various effects. The Reynolds number is modified by taking into account the pipe diameter while the Archimedes number is modified by taking into account various properties that affect each threshold mechanism. Since all threshold velocities could be defined successfully by the same non-dimensional groups it was possible, at the first time, to present a Generalized Master Curve, which provides an overview of all the threshold velocities. This overview enabled, for example, to find quantitatively the relationships between all the threshold velocities to the terminal velocity and to compare the pickup and saltation velocities.     

Efficient Formation of Size-Selected Clusters upon Pickup of Dopants into Multiply Charged Helium Droplets

Properties of clusters often depend critically on the exact number of atomic or molecular building blocks, however, most methods of cluster formation lead to a broad, size distribution and cluster intensity anomalies that are often designated as magic numbers. Here we present a novel approach of breeding size-selected clusters via pickup of dopants into multiply charged helium nanodroplets. The size and charge state of the initially undoped droplets and the vapor pressure of the dopant in the pickup region, determines the size of the dopant cluster ions that are extracted from the host droplets, via evaporation of the helium matrix in a collision cell filled with room temperature helium or via surface collisions. Size distributions of the selected dopant cluster ions are determined utilizing a high-resolution time of flight mass spectrometer. The comparison of the experimental data, with simulations taking into consideration the pickup probability into a shrinking He droplet due to evaporation during the pickup process, provides a simple explanation for the emergence of size distributions that are narrower than Poisson.     

三洋新力电子照相机简介

概述了三洋/新力电子照相机的整机概念及其包括的摄像机、放像机与音频单元等组成部分的原理。