Numerical investigation of the influence of companion drops on drop-on-demand ink jetting

In this study we characterized and investigated the specific phenomenon of "companion drops" in the drop-ondemand(DOD) ink jetting process.A series of simulations based on a piezoelectric DOD printhead system is presented,adapting the volume-of-fluid(VOF) interface-capturing method to track the boundary evolution and model the interfacial physics.The results illustrate the causality between the generation of companion drops and droplet deviation behavior,as well as their close correlations with ink jetting straightness and printing accuracy.The characteristics of companion drops are summarized and compared with those of satellite drops.Also,a theoretical mechanism for the generation of companion drops is presented,and their effects and behaviors are analyzed and discussed.Finally,the effects of critical factors on the generation of companion drops are investigated and characterized based on variations in the printable pressure range.Recommendations are given for the suppression of companion drops and for the improvement of printing accuracy.

Preparation of PDOT:PSS Transparent Conductive Film Using Ink-Jet Printing

Flexible devices produced using organic materials have attracted the attention of many researchers. Important components of these flexible devices include transparent electrodes, which transmit visible light and possess conductivity. The present study improved the characteristics of a transparent conductive film that was made of poly(3, 4 ethylenedioxythiophene):poly(styrenesul-fonate) (PEDOT:PSS), an organic conductive material, and that had been prepared using ink-jet printing. To improve the resistance value and visible light transmittance of the film, the film substrate was first cleaned with ultraviolet/ozone treatment, and then the film was annealed after it was deposited on the substrate and dipped into a polar solvent. Consequently, the resistance value of the thin film decreased. However, the surface state of the film changed according to the treatment method and affected its visible light transmittance. Thus, the surface state of the film substrate, the annealing temperature after film deposition, and the dipping treatment with a polar solvent influenced the characteristics of a thin film.

Characteristics Improvement of PEDOT:PSS Transparent Conductive Film Prepared by Ink-Jet Printing

Recently, a high-performance and low-priced transparent conductive film has been expected to be developed because flexible devices produced using organic materials have been actively studied. An indium tin oxide (ITO) thin film, which has been generally used as a material for a transparent conductive film, has problems, such as fragility to bending stress and depletion of the resource. The present study used poly(3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), an organic electroconductive material, and examined the improvement in the resistance value and visible light transmittance of a transparent conductive film produced using the ink-jet method. In previous studies, we reported that, to improve the resistance value and visible light transmittance of a thin film, it was effective to clean the film substrate with ultraviolet/ozone (UV/O3) treatment, anneal the film after it was deposited on the substance, and dip the annealed film into a polar solvent. Focusing on the thin film processing between printing operations, the present study improved resistance value and visible light transmittance by examining both the application methods of a polar solvent and the annealing time between printing operations. As a result, the resistance value and visible light transmittance of a PEDOT:PSS thin film were 390.4 Ω and 86.6%, respectively. This film was obtained by applying a polar solvent and performing annealing for 30 min between printing operations. The printing was performed three times.

Application of nonlinear color matching model to four-color ink-jet printing

Through discussing the color matching technology and its application in printing industry the conventional approaches commonly used in color matching, and the difficulties in color matching, a nonlinear color matching model based on two step learning is established by finding a linear model by learning pure color data first and then a nonlinear modification model by learning mixed color data. Nonlinear multiple regression is used to fit the parameters of the modification model. Nonlinear modification function is discovered by BACON system by learning mixture data. Experiment results indicate that nonlinear color conversion by two step learning can further improve the accuracy when it is used for straightforward conversion from RGB to CMYK. An improved separation model based on GCR concept is proposed to solve the problem of gray balance and it can be used for three to four color conversion as well. The method proposed has better learning ability and faster printing speed than other historical approaches when it is applied to four color ink jet printing.

The Effect of Silica Particle Size on the Performance of Color Ink-jet Printing Paper

In this paper,the effects of four sorts of silica with the particle size range of 4～10μm on coated paper properties and printing performance were studied.The results showed that the smaller particle size silica can provide the coated paper with higher density and contrast, better definition and good printing performance.

Formation of Photosensitizing Crystalline C₆₀Particles by Ink-Jet Method

The crystalline fullerene C60 particles were formed and immobilized on poly(dimethylsiloxane) (PDMS) substrates under the various discharge conditions by an ink-jet method, and investigated for the reactive oxygen species (ROS) generation property under visible light irradiation. The particles were synthesized by discharging a toluene solution dissolved C60 and poly(methyl methacrylate) (PMMA) with the ink-jet spotting system. The ROS generation was evaluated by comparisons of the fluorescence intensities measured for the formed particles under green laser irradiation and in a dark room using fluorescent dyes, 2’,7’-dichlorofluorescein diacetate and dihydroethidium. The results of transmission electron microscope (TEM) observation showed that the formed particles consisted of crystalline C60. The optimal ink-jet discharge conditions for synthesizing the particles to generate more ROS were found. In the case of the optimal conditions, the structure in which the needle-like particles were three-dimensionally formed was confirmed. The surface area of the crystalline C60 particles was calculated using the SEM observation results, and it was suggested that when the needle-like finer particles were three-dimensionally formed under the optimal conditions, increasing the surface area lead to an increase in the ROS generation amount.

振荡频率对曼氏无针乌贼成体死亡率及生存状态的影响

为提高曼氏无针乌贼增殖放流运输过程的存活率,在实验室条件下研究了0、60、100、120、140和160 r/min振荡频率对成体曼氏无针乌贼死亡率、乳酸、糖原含量及酶活性的影响。结果显示,除160 r/min死亡率略有下降外,其他组随着频率的增高死亡率升高,频率120、140 r/min时死亡率最高为91.7%,显著高于0、60、100 r/min处理组。死亡时间主要分布在振荡后的4~8 h,频率越低乌贼出现死亡的时间越晚,160 r/min率先在2 h出现死亡个体。除个别组出现波动外,随着频率的增大,两种组织(肌肉、肝脏)的糖原含量降低,而乳酸含量增大,140 r/min处理组糖原、乳酸含量与对照组间差异显著。除60 r/min处理组外,随着频率的增加,肝脏组织中的谷丙转氨酶(ALT)、谷草转氨酶(GOT)活性降低,超氧化物歧化酶(SOD)活性增加,且120、140、160 r/min处理组3种酶活性与其他组间差异显著。碱性磷酸酶(ALP)活性随着频率的增加而升高,140和160r/min处理组与其他组间差异显著。乌贼死亡率与SOD、肌肉乳酸含量、ALP之间极显著正相关,与肌肉糖原含量、GOT和ALT活性、消化腺糖原含量之间极显著负相关。研究表明,频率显著影响乌贼的存活率,能量耗尽和肝脏损伤可能是乌贼运输过程高死亡率的主要原因,运输过程建议振荡频率小于100 r/min且运输时间小于3 h,尽量避免较大程度的晃动。本研究可为曼氏无针乌贼成体的增殖放流运输过程提供技术支撑。

基于压电喷墨技术3D打印纳米银墨水的固化工艺研究

为了改善喷墨3D打印纳米银墨水的导电性,研究热台固化、近红外固化和光热耦合固化对纳米银墨水固化后微观形貌和电导率的影响。通过压电喷墨打印纳米银墨水,并用热台和近红外灯对纳米银薄膜进行固化。结果表明:热台固化时,纳米银薄膜的电阻率随固化时间和固化温度的升高而降低,在固化时间25 min,固化温度140℃时下降至99μΩ·cm;近红外固化时,固化功率1000 W,固化时间4 min的条件下,电阻率为33.2μΩ·cm;光热耦合固化时,纳米银薄膜的电阻率随扫描功率和固化时间的增加而降低,基板加热温度160℃、扫描功率为1000 W、固化时间60 s的条件下,电阻率为3.75μΩ·cm。光热耦合固化烧结颈的生长速度明显优于热固化及光固化。

喷气涡流纺长片段竹节段彩纱的设计与生产

探讨有色超短纤维在喷气涡流纺花式纱开发中的应用及生产要点。采用有色粘胶超短纤维与本色竹浆纤维、椰炭改性涤纶纤维,在并条机上加装竹节装置,利用喷气涡流纺纱技术纺制成长片段竹节段彩纱。针对粘胶纤维长度相对较短的特点,工艺上尝试采用短流程、减小隔距、降低打击件速度等技术措施。结果表明:开发的喷气涡流纺段彩纱具有段彩片段长、生产效率高的特点,其在布面上色点朦胧,时而形成连续分布,时而散点分布,形成不同于传统段彩纱的独特风格。

深色服装白墨直喷印花技术的研究

喷墨印花是具有发展潜力的新型印花技术之一,因深色服装印花困难,当前市场上深色服装常采用的喷墨印花为先丝网印白墨打底,再喷墨印花,工艺复杂,而深色服装白墨直喷印花先进技术可以代替。文中介绍了深色服装白墨直喷印花技术的应用现状和发展,阐述了白彩同出喷墨印花生产工艺流程。具体分析了印前分色原理、应用软件和性能要求,印前预处理目的、工艺处方和工艺方法,打印用白墨、彩墨的组成和物理性能指标,打印工艺类型、特点、难点和方法,印后烘干与固色工艺等,为深色服装白墨直喷印花生产提供参考方案。

喷气涡流纺新型纱线开发探析

为提升开发喷气涡流纺纱线的技术水平,介绍喷气涡流纺纱在我国的发展历程及存在问题,对比环锭纺、转杯纺、喷气涡流纺的优势、局限及技术特性;详细分析喷气涡流纺开发多种纤维混纺纱、包芯包覆纱、有色纱等特色纱线开发途径;总结发展喷气涡流纺需注意的问题。指出:喷气涡流纺纱尚无法替代环锭纺与转杯纺;开发喷气涡流纺纱线产品时,应避免同质化竞争,合理配置纺纱速度,不断优化纺纱工艺配置,努力拓宽喷气涡流纺纱线的应用领域。

二维材料纳米油墨的制备及喷墨打印研究进展

以石墨烯为代表的二维材料具有出色的综合性能,可用其制作功能纳米油墨,通过喷墨打印可加工得到光电功能器件,其在能源、环境、生命健康等领域具有广阔的应用前景。本文总结了几种典型二维材料的性能、其纳米油墨的制备及喷墨打印应用等,重点介绍了液相剥离和喷墨打印过程的调控。对比不同剥离方法及原理,并对喷墨打印相关理论如咖啡环效应、马兰戈尼效应等进行综述。指出可通过对二维材料剥离过程及其纳米油墨打印过程的精准调控,形成基于喷墨打印的先进微纳制造技术,实现不同功能微纳电子元件和器件的低成本加工,推动生物传感、柔性电子等领域的发展。

基于改进型U-Net的变色油墨血浆判别模型

目的:为了解决因主观判别尺度不一和计算响应过长,在血浆制备过程中易出现疑似溶血血浆误判输出和疑似非溶血血浆医学报废的现象,给患者的生命安全带来极大隐患或产生浪费的问题。方法:研制一种基于深度学习和变色油墨理念的限界法。利用改进型U-Net网络进行图像分割,引入改进型注意力机制、批量归一化和填充模块来解决空间映射关系中存在的估计均值偏移、计算效率低和感受野视场不足的问题,并利用自采样本数据集对该模型进行验证对比。结果:采用变色油墨限界法进行分类判别,在确保血浆样本识别精度为前提的同时,提升了血浆判别的计算效率、降低了判别时间,实验结果评价准确率为99.52%。结论:本研究模型的血浆判别精度优于其他判别模型,有望应用于临床。

大气压等离子体射流功能改性硅树脂的工艺研究

[目的]采用大气压等离子体射流(APPJ)技术在聚二甲基硅氧烷(PDMS)表面产生结构色的方法和机制鲜有报道。[方法]通过对处在拉伸状态的PDMS进行1 min的氩气等离子体处理,然后释放拉应力,获得了具有环形渐变结构色的PDMS。[结果]扫描电镜(SEM)照片揭示,APPJ处理后的PDMS表面生成了周期排列的纳米褶皱结构,且褶皱周期是逐渐变化的。X射线光电子能谱(XPS)分析表明,经APPJ处理的PDMS表面发生了进一步交联和氧化,生成了弹性模量比PDMS更高的氧化硅物质层。可见光吸收和反射光谱分析表明,具有结构色的PDMS对可见光表现出了更低的反射率,而其垂直方向的可见光透过率则无显著改变。[结论]通过APPJ技术能够简单、快速地对有机硅化合物表面进行改性而获得精细结构色,该工艺方法有望满足显示、传感、防伪、功能材料等领域的实际需求。

可见光-近红外伪装分散染料墨水的制备及其性能

针对当前分散染料墨水其喷墨印花织物仅能与背景环境“同色”而不能“同谱”,无法有效躲避现有侦察技术的问题,开发了一套可见光-近红外伪装分散染料墨水。通过模拟绿叶、土壤和枯叶的反射光谱特征,筛选了特定分散染料,探究了印花工艺对织物伪装及服用性能的影响,通过超细化加工制备了分散染料墨水并探究了其性能。结果表明:调控分散蓝60、分散深蓝SUBC 12、分散橙30、分散黄CPY 015、分散红CPM 011与炭黑复配比例及印花工艺制备的仿绿叶、土壤和枯叶印花织物,其伪装及服用性能良好;5种分散染料墨水的粒径均小于173.00 nm,离心、耐热、高温储存和常温储存稳定性均高于80%,过滤流速分别为200、375、188、428、167 g/min,喷墨印花性能良好。

有机硅改性聚丙烯酸酯预处理对涤棉织物喷墨印花性能的影响

为提升涤棉织物涂料喷墨印花工艺的印花性能,采用半连续种子乳液聚合法,以醋酸乙烯酯(VA)、丙烯酸丁酯(BA)和丙烯酸异辛酯(EHA)为共聚单体,丙烯酸羟乙酯(HEA)为功能单体,引入硅烷偶联剂(KH-1706),制备得到有机硅改性聚丙烯酸酯乳液(KH-1706/PVAc),并将其作为预处理液应用于涤棉织物;探究引入不同质量分数的KH-1706对乳液烘干后所得乳胶膜性能的影响,并分析以KH-1706/PVAc为预处理液对涤棉织物涂料喷墨印花性能的影响。结果表明:当引入KH-1706的质量分数为2%时,乳胶膜具有较好的热稳定性和耐水性,吸水率为16.8%;乳液运用于涤棉织物预处理后,有效抑制了墨滴在织物上的渗化,墨滴渗化面积为20.8 mm2;预处理后印花织物耐湿摩擦牢度提高半级,印花精细度提升约13%,并且复杂图案打印后仍具有较好的印花效果,表现出良好的综合印花性能。该研究可为提升涤棉织物涂料喷墨印花的印花性能提供理论参考。

基于空气耦合超声的宣纸润墨性检测技术

宣纸在中国书画艺术历史中占据不可小觑的地位,润墨性是鉴别宣纸质量的重要指标,所以对其润墨性的检测至关重要。现有检测方法易对宣纸造成损坏且受人为主观因素影响较大,为解决现有检测技术的缺陷,该文提出使用空气耦合超声技术对宣纸的润墨性进行检测,针对不同润墨性的宣纸进行C扫描成像,通过彩色直方图分析成像结果中的颜色分布关系,对宣纸润墨性进行评价。当采用400 kHz空耦探头、200 mm/s扫描速度时,C扫描结果均能对不同宣纸的润墨性做出表征,该方法克服传统检测中主观因素的影响,能够在对宣纸无损的情况下实现润墨性检测。通过上述结果表明,该方法可为宣纸的无损检测提供一些理论和实践参考。

聚乙烯醇基磷钼酸铵刺激响应防伪油墨的制备及性能研究

选取颜料为磷钼酸铵,连结料为聚乙烯醇,助剂为乙醇和乙二醇,一锅法制备了磷钼酸铵刺激响应防伪油墨。使用单因素优选实验法测试了黏度、初干性、变色灵敏度等因素,确定了磷钼酸铵刺激响应防伪油墨的最佳配比。根据国家标准方法对制备的防伪油墨进行耐性测试,发现所制备油墨耐性优良,符合国家标准。最后,对磷钼酸铵刺激响应防伪油墨应用能力进行了探讨,油墨墨迹在日光照射下会产生明显的颜色变化,可以应用于商品防伪、文件防伪等领域。

基于光谱融合的水性油墨印刷品颜色变化预测研究

目的利用近红外光谱及光谱融合策略,结合化学计量学方法,建立水性油墨的颜色预测模型,实现水性油墨印刷品颜色准确预测。方法采集不同酒精含量和不同调色墨含量的油墨的近红外光谱反射率和吸光度数据,并测得对应的印刷品的Lab值,然后建立单一光谱不同预处理过后的偏最小二乘(Partial Least Squares,PLS)模型,以及基于数据层融合和特征层融合的PLS模型,最终通过比较预测集决定系数和预测集均方根误差(Root Mean Square Error of Prediction,RMSEP)以及色差来评估模型的预测效果。结果单光谱建模,基于反射率建立的模型准确率高于基于吸光度建立的模型;数据层融合缺乏稳定性,对L和b值的预测有所提升,对a值的预测几乎不变;特征层融合建模效果明显好于单一光谱和数据层融合,对Lab的预测决定系数分别达到了0.9961、0.9939、0.9974;RMSEP值分别为0.1421、0.2126、0.2072;预测值与真实值的最大色差为0.6783。结论通过光谱特征融合技术能提高油墨颜色预测精度,准确预测出油墨颜色变化。

喷墨渗花瓷质砖渗透材料检验方法研究

笔者通过对渗透陶瓷墨水及助色剂等渗透材料检验方法的对比分析和研究,提出了一种新型渗透墨水检验方法——滴墨法,并探讨此方法在喷墨渗花瓷质砖生产企业对产品配方及工艺控制中的运用。结果发现,滴墨法可实现多种组成的面料与渗透墨水的组合发色,以及渗透材料的平行对比测试,从而快速精准地获得最优比例组合。