微纳增材制造微圆柱结构的形貌分析与工艺优化研究

针对目前亚像素微扫描的LCD式光固化3D打印技术在微纳结构增材制造中存在的典型打印瑕疵,通过优化打印工艺和分析打印结构,以提高打印成型质量和生产效率。首先,通过对打印材料后处理工艺研究,设计单因素试验并打印平板模型,分析后固化时长对零件硬度、粗糙度及形貌影响规律。其次,结合打印工艺参数,设计正交试验并打印圆柱阵列模型,分析打印层厚、曝光时间、振动次数对微圆柱成型的影响规律。结果表明：后固化时间在5～10 min时,后固化效果最优,此时表面粗糙度Ra值约为29 nm,邵氏硬度在88 HD左右。打印工艺参数对微圆柱直径尺寸影响大小排序为：曝光时间>打印层厚>振动次数。在均衡打印质量和打印效率的前提下,打印参数优化后,打印直径50 μm,高度210 μm的微圆柱结构应采用打印层厚10 μm,曝光时间2 500 ms,振动次数64 x的打印工艺参数。     

电喷印喷头位移参数对三维成型精度的影响

电喷印技术是一种新型的微结构成型技术,其由于具有成型精度高、制造成本低、设备结构简单、打印材料广泛等特点,备受业界关注。而基于液态成形的电喷印技术对于三维图形的打印方法,对其实际图形及打印质量难以直接观测,因而快速有效的控制打印三维图形的精度和质量面临重大挑战。本研究提出了一种通过合理设置打印线间距和层间距,以控制打印三维图形的精度和表面质量的有效控制方法。同时,建立了线间距、层间距等工艺参数与最佳成型质量的理论模型,以打印线横截面层高作为评价指标,通过实验探究了喷头逐线逐面打印移动距离对三维图形沉积形貌的影响。研究结果分析、揭示了电喷印技术中上述工艺参数对三维图形的影响及其规律,并进行了三维实体成形试验。基于接触角、喷射流量等因素对线间距和层高的影响的模拟仿真,为基于电喷印技术的三维成型工艺提供指导意义。     

Ink feed control in a web-fed offset printing press

Automatic and robust ink feed control in a web-fed offset printing press is the objective of this work. To achieve this goal an integrating controller and a multiple neural models-based controller are combined. The neural networks-based printing process models are built and updated automatically without any interaction from the user. The multiple models-based controller is superior to the integrating controller as the process is running in the training region of the models. However, the multiple models-based controller may run into generalisation problems if the process starts operating in a new part of the input space. Such situations are automatically detected and the integrating controller temporary takes over the process control. The developed control configuration has successfully been used to automatically control the ink feed in the web-fed offset printing press according to the target amount of ink. Use of the developed tools led to higher print quality and lower ink and paper waste.     

The Application of Digital Printing System in College Education

Digital printing brings the tremendous impacts not only to the printing industry but also to the publishing industry. Colleges could establish a "Printing and Publishing Center" to adopt the development of digital printing technology. It is necessary to build up a printing and publishing system to apply the digital printing's characteristics to fulfill the functions of college education. This system must contain the functions of digital right management (DRM), Internet, and database management system (DBMS). It could print the partial chapters of one of more particular textbooks and publish the books by using the digital printing press in order to present the most updating information. It could fully use the benefits of print-on-demand, variable-data printing, and a short-run printing of digital printing. For the system, it could satisfy the needs of teachers and students in teaching and learning in college.     

柔性递纸机构的动态设计方法研究

作为单张纸胶印机的关键部件——递纸机构的力学性能将直接影响着印刷的速度和印品的质量。本文以北京市第二印刷机械厂八开高速胶印机的摆动式递纸机构为工程背景 ,基于有限元理论 ,将运动周期离散化 ,建立的动力学模型为一系列系数时变的微分方程 ,并用 Newm ark方法求解其位移与应力的动态响应 ,为分析解决高速胶印机的磨损、振动和噪声等现象提供依据 ,也为柔性递纸机构的设计提供参考。     

基于DSP的印刷机控制系统设计

针对套印刷机的特点,本文运用DSP、FPGA和PLC技术构建了印刷机控制硬件系统,并采用UML对系统软件需求与流程进行分析,实现了印刷机控制系统软件部分。实践表明：该套印印刷控制系统运行良好,完全满足设计要求。     

基于STM32的微型热敏打印机的设计和实现

基于STM32的微型热敏打印机控制系统以STM32F103C8单片机为控制器,以存储器、步进电机和热敏打印头为控制对象,上位机和单片机之间进行串口通信,串口调试软件发送命令和字符,就可以在热敏纸上直接打印相应的字符。该文阐述了系统的硬件组成及软件的实现过程,并给出系统测试结果。测试结果表明,该微型热敏打印机控制系统稳定可靠,打印字迹清晰,不仅可以打印英文、汉字,还可以打印条形码和二维码等。     

GlossmarkTM Technology:An Innovative Digital Watermark

GlossmarkTM technology is a digital watermark process that embeds a visually striking gloss image within a high quality color print without the need of special papers or toners. It utilizes the angular dependence of gloss to create a differential-gloss image through the modulation of halftone structures. Both the primary image and the embedded GlossmarkTM image can be distinctively viewed from different perspectives with little interference. The strong directional nature of the gloss and the subtle halftone modulation process make GlossmarkTM images very difficult to detect by a scanner and even more challenging to reproduce through scanning and printing. The GlossmarkTM technology is ideally suitable for document authentication and graphics enhancement. Its digital implementation provides a capability to embed variable data as digital watermarks into individual prints quickly and economically.     

胶印机印刷压力控制分析与研究

以不走肩铁型平版胶印机为研究对象,提出了滚筒包衬计算方法与滚筒中心距调节方法,得出胶版印刷中印刷压力影响因素主要表现为纸张表面质量和平滑度、印刷速度、滚筒橡皮布和衬垫的选用等;印刷压力的控制主要为调节包衬和中心距;对文中研究的不走肩铁型胶印机来说,在调节印刷压力时,齿轮啮合保证接近标准啮合状态等结论,为印刷压力的控制调节提供了一定的技术支持。