Spatial control of sheet and film forming processes

The general problem of controlling both machine and cross-directional properties on sheet and film forming processes is treated. A flexible class of linear dynamic-stochastic models capable of characterizing the process and disturbance dynamics in these systems is suggested. Procedures are presented for identifying these models from data collected from common scanning type sensors. Linear-Quadratic-Gaussian (LQG) control theory is used to design multivariable controllers capable of jointly controlling the machine and cross-directional property variations using both lumped and spatially distributed actuators.     

The impact of solvent characteristics on performance and process stability of printed carbon resistive materials

Carbon conductive pastes deposited by screen printing are used in many commercial applications including sensors, PCB, batteries, and PV, and as such represent an important value-added coating. An experimental investigation was carried out into the role of the solvent on the drying characteristics, conductivity, and process consistency in screen printed carbon pastes. Four materials with solvent boiling points between 166 and 219°C were deposited at film thickness between 6 and 16 μm, and the sheet resistance and film thickness were measured after successive passes through an industrial dryer operating with an air temperature of 155°C. Sheet resistances of 14 Ω/sq. were obtained with the thicker films while thinner films produced a sheet resistance of 46 Ω/sq. Thinner films achieved a stable resistivity within a 2.5-min residence time, while the thicker films required a residence time in excess of 12.5 min to achieve a stable resistivity. As well as prolonging drying times, the higher boiling point increased the resistivity of the cured film. It is postulated that the lower resistance of the faster drying materials is a result of film stressing increasing inter particle contact. Process models indicate that multiple thin layers are a more efficient means of manufacture for the process parameters examined.     

Regulation of film thickness, surface roughness and porosity in thin film growth using deposition rate

This work focuses on distributed control of film thickness, surface roughness and porosity in a porous thin film deposition process using the deposition rate as the manipulated input. The deposition process includes adsorption and migration processes and it is modeled via kinetic Monte Carlo simulation on a triangular lattice with vacancies and overhangs allowed to develop inside the film. A distributed parameter (partial differential equation) dynamic model is derived to describe the evolution of the surface height profile of the thin film accounting for the effect of deposition rate. The dynamics of film porosity, evaluated as film site occupancy ratio, are described by an ordinary differential equation. The developed dynamic models are then used as the basis for the design of a model predictive control algorithm that includes penalty on the deviation of film thickness, surface roughness and film porosity from their respective set-point values. Simulation results demonstrate the applicability and effectiveness of the proposed modeling and control approach in the context of the deposition process under consideration.     

铝阳极氧化膜的研究进展

简述多孔氧化铝膜的性质、性能和目前在各领域的应用情况及前景.综述了用二次阳极氧化制备多孔有序氧化铝膜的方法,较为系统地介绍了预处理、电解液的种类、电解液的浓度、温度、氧化电压及超声波等因素在多孔氧化铝膜的制备过程中时其成膜成孔过程的影响.     

反渗透水处理系统微生物污染特性分析及对策

鉴于当前反渗透水处理系统运行中出现的许多微生物污染的事例,作者分析了反渗透膜微生物污染的特点、形成过程及危害,并提出了控制和预防微生物污染的具体措施.     

Impact of cooling method and incoming sheet quality on final part surface quality in thick sheet paint film thermoformed parts

Thick sheet, “dry paint” film parts were thermoformed using different cooling methods and sheet temperatures to determine whether these two parameters had a direct effect on the surface quality of the final part. Although some thermoformers have claimed that applying chilled air after forming “dry paint” film parts improves the gloss of the parts, the data from this study showed that application of chilled air did not have an effect on either the parts' initial gloss or their gloss after time‐dependent hazing. The critical factor in maintaining surface quality in these parts was the maximum temperature reached by the “dry paint” film during heating. In addition, analysis of the data taken on the sheet prior to forming versus that taken on the part after forming demonstrated the importance of validating the surface quality of the as‐received sheet prior to conducting process versus appearance experiments. On the basis of these findings, a recommendation is made for incoming sheet surface quality levels for both process development studies and production applications. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers     

多液滴同步冲击液膜时中间薄膜射流形成机理与动力学特征

采用耦合水平集-流体体积（coupled level set and volume of fluid）方法结合高斯随机分布扰动对多液滴同步冲击平面液膜飞溅过程进行了三维数值模拟,通过分析压力、速度等细微场量分布,揭示了中间薄膜射流的生成、破碎以及后期柱状射流的形成机理。此外,讨论了Weber数、液膜厚度、液滴间距对薄膜射流高度的作用规律。结果表明,在液相加入高斯分布扰动后可以充分反映液滴冲击飞溅特征;相邻液滴颈部区域射流接触后,接触区压力梯度骤然升高,与流体运动间断共同作用下形成向上运动的薄膜射流,随后在流体不稳定性与气相涡流作用下发生破碎;薄膜射流高度随Weber数和液膜厚度升高而增大,液滴间距减小时,射流高度增大。     

Estimation and control of surface roughness in thin film growth using kinetic Monte-Carlo models

In this work, we present an approach to estimation and control of surface roughness in thin film growth using kinetic Monte-Carlo (MC) models. We use the process of thin film growth in a stagnation flow geometry and consider atom adsorption, desorption and surface migration as the three processes that shape film micro-structure. A multiscale model that involves coupled partial differential equations (PDEs) for the modeling of the gas phase and a kinetic MC simulator, based on a high-order lattice, for the modeling of the film micro-structure, is used to simulate the process. A roughness estimator is constructed that allows computing estimates of the surface roughness at a time-scale comparable to the real-time evolution of the process using discrete on-line roughness measurements. The estimator involves a kinetic MC simulator based on a reduced-order lattice, an adaptive filter used to reduce roughness stochastic fluctuations and an error compensator used to reduce the error between the roughness estimates and the discrete roughness measurements. The roughness estimates are fed to a proportional-integral (PI) controller. Application of the proposed estimator/controller structure to the multiscale process model demonstrates successful regulation of the surface roughness at the desired value. The proposed approach is shown to be superior to PI control with direct use of the discrete roughness measurements. The reason is that the available measurement techniques do not provide measurements at a frequency that is comparable to the time-scale of evolution of the dominant film growth dynamics.     

改进我国农膜现状的几点建议

回顾了我国农地膜的发展概况,扼要总结了农地膜多年来对我国农业发展和技术进步起到的重要作用,讨论了地膜生产和应用至今仍存在的问题,并就如何防止和减少地膜污染土壤、污染环境提出几点意见、对策和看法,供参考用。     

锐钛矿型TiO2溶胶的成膜特性及薄膜性能

使用具有锐钛矿晶粒的TiO2溶胶,在铜质基材、氧化铝陶瓷片、玻璃载玻片、聚碳酸酯(PC)板、聚氯乙烯(PVC)片、聚对苯二甲酸乙二醇酯(PET)膜、涂料涂层、纸片等多种基材表面涂膜。利用扫描电子显微镜观察了各种基材表面的TiO2薄膜形貌,并对以载玻片为基材的TiO2薄膜的光学性能和光催化性能进行了测试。结果表明TiO2溶胶在多种基材上都能较好地成膜;TiO2薄膜透明,不会遮盖基体材料;TiO2薄膜具有较好的光催化活性。     

Control and optimization of multiscale process systems

In this work, we present an overview of recently developed methods for control and optimization of complex process systems described by multiscale models. We primarily discuss methods developed in the context of our previous research work and use examples of thin film growth processes to motivate the development of these methods and illustrate their application.     

304不锈钢化学着黑色的研究

在INCO法的基础上,通过添加辅助成膜剂和添加剂对不锈钢化学着色液的配方进行改进,采用时间-电位差法控制着色过程,在304不锈钢表面得到了黑色膜(简称304黑钛板)。实验结果表明:304黑钛板具有良好的耐蚀性能、耐磨性能和加工性能。Tafel极化曲线表明:着色膜的形成提高了304不锈钢板的阳极极化作用以及电化学稳定性。SEM和EDS分析结果表明:黑色膜均匀、致密,主要由Fe,Cr,Ni,Mn,Ce,C,O,P等元素组成。此外,初步探讨了304不锈钢表面黑色膜的成膜机理。     

PET聚酯非纤应用及进展

PET聚酯材料主要用于纤维生产，但它在非纤领域的应用越来越多，用量也不断增长。详述了PET聚酯瓶、聚酯薄膜、工程塑料以及PET片材等的主要应用情况，并介绍了聚酯非纤应用的最新研究和开发进展。     

New production technologies and applications of poly(vinyl alcohol) film

The following aspects of the manufacture, properties and applications of biaxially oriented poly(vinyl alcohol) (PV-OH) films are discussed: selection of starting PV-OH; method of production by successive biaxial orientation: technical aspects of production; characteristics and applications of the film. Biaxially oriented PV-OH films have good antistatic properties, good thermal resistance, oil and solvent resistance, and excellent gas barrier properties, and are used in food packaging applications. The following aspects of the manufacture, properties and applications of poly(vinyl alcohol) film produced by a blown film technique are discussed: selection of starting PV-OH; process for the production of hot-water-soluble (HWS) film; technical aspects of film production; characteristics and applications of the film. Blown films, which are hot-water-soluble, are produced in tubular form, for conversion into disposable laundry bags.     

厚度不均匀对PET薄膜分切的影响

介绍了PET薄膜厚度直观的量化指标,并从厚度偏薄和偏厚2个方面阐述了厚度均匀性对PET薄膜分切的影响。     

乳化型水性固化剂的固化行为与成膜机理探讨

乳化型水性固化剂在成膜过程中兼具乳化与固化功能,直接影响了水性涂料的固化成膜和涂层性能。比较了水性环氧树脂涂料与溶剂型环氧树脂涂料的成膜过程,探讨了双组分水性环氧树脂涂料的成膜机理,分析了影响水性环氧树脂涂料成膜的因素;环氧乳液的粒径、固化剂与环氧树脂的相容性以及水从环氧乳液中的挥发速率等都会影响水性环氧树脂涂料的成膜过程,进而影响涂膜的物理化学性能。     

环保型单组分塑料涂料产品质量控制

介绍了环保型单组分塑料涂料原材料进厂的质量控制,涂料产品生产和产品施工过程中的质量控制,并对常见涂膜病态进行分析及解决。     

自由降膜传热传质数值模拟技术研究进展

自由降膜过程在许多工业领域,特别是在石油化工工业中有着非常广泛的应用。近年来,随着计算机技术的发展,采用理论分析、数值模拟和实验相结合的技术手段,对降膜传热传质过程进行了深入的研究,为优化降膜传热传质过程和新型设备的开发提供了理论基础。     

水乳型胶粘剂成膜过程的研究进展

对水乳型胶粘剂成膜过程、影响成膜的主要因素及成膜理论进行了综述,指出了水乳型胶粘剂成膜过程中需要进一步研究和开发的领域,     

高强度钢板及其在汽车制造中的应用

阐述了高强度钢板的定义与分类；综述了汽车用高强度钢的研究与发展；介绍了高强度钢板在汽车制造中的应用；分析了汽车用高强度钢板在冲压成形过程中的主要问题及其冲压成形对模具材料的要求。