Low-Cost Customized Color-Blind Contact Lenses using 3D Printed Molds

Prominence of color perception in our day-to-day routine is unequivocally pronounced, yet visual ramifications due to color vision deficiency (CVD) or color blindness impede carriers of this disorder from functioning normally. To circumvent this deficiency, patients opt for tinted glasses/contact lenses to complement their color distinction capabilities. Red-green color blindness, the most prevalent form of CVD, can be alleviated using such glasses/lenses that filter out problematic wavelengths (540–580 nm). Nonetheless, nearly all contact lenses established by companies and developed by researchers are tinted throughout their entire surface, causing patients discomfort and needless attention as people can easily note their deficiency. Ideally, the tint within the lens should only cover the eye's pupil as it is responsible for perceiving light. Hence herein, CVD contact lenses are fabricated by solely tinting the midportion of commercial lenses utilizing two additively manufactured molds with 4 and 8 mm-diameter holes to emulate the humans’ average pupil size. The tinted lenses filter light effectively at 530–590 nm with their transmission dip being at 558 nm. The contact lenses show excellent wettability and water retention capabilities along with demonstrating superior wavelength-filtering properties to most of the commercial and research-based CVD wearables.     

Partial-Ductile Grinding and Reduced Polishing for Ophthalmic Glass Molds

Plastic lenses are manufactured by the classical replication technique where two glass molds are assembled in a jacket and liquid plastic is injected into it. The glass molds are fabricated conventionally by fracture mode grinding, followed by lapping, and Finally polishing. This paper presents an alternative fabrication process using partial-ductile grinding, followed by a short polishing in an industrial polishing machine. The partial-ductile surfaces were generated on a laboratory ultra-precision machine using Fine grit resinoid-bond diamond wheel and they were compared to the glass molds prepared by industry. The results showed that (i) as much as 100% ductile streaks (fully ductile grinding) can be obtained in the ultra-precision ground surface and (ii) a net saving of 55 seconds polishing time if only 60% of ductile streaks on the glass mold surface was used prior to polishing.     

铝材氧化-电泳混凝土构筑物的玻璃钢衬里防护

总结了铝材氧化电泳工艺混凝土建筑的玻璃钢衬里防腐蚀工程的方案设计，材料选择，施工工艺等经验。     

加工回转体零件的柔性制造系统

概述了柔性制造系统的组成、各部分功能以及维护等方面的内容,为了解认识FMS提供了背景知识,旨在推广FMS的应用范围.     

Simulation of Binder Infiltration in Additive Manufacturing of Sand Molds

This article proposes a computational fluid dynamics approach to simulate binder infiltration in 3D printing of sand molds using OpenFOAM facilitating the identification of suitable levers for application-specific material and process developments. A method for randomly generating powder bulks of designated powder size distributions (PSD) and procedures for automated analysis of the infiltration profile and volume are introduced. Simulation is utilized to investigate binder infiltration using different droplet spacings, representing different printheads’ resolutions. The apparent particle size at the exact location of the droplets’ impact, the droplets’ landing position in relation to the respective surface topography, and thus the statistical appearance of particle formations appear to be influencing the infiltration profile. High-speed camera observations show the plausibility of the predicted infiltration kinetics. An exemplary use case compares the predicted infiltration profiles to the compressive strength of specimens printed from silica sand with low binder contents. Simulation predicts an average infiltration of 250 μm that presumably achieves reliable bonding for layer thicknesses up to 365 μm. A decrease in strength with increasing layer thickness at constant binder contents can be found in the experiment – at layer thicknesses above 350 μm, only minor strengths are achieved.     

基于广义Maxwell模型的非球面光学镜片成型模拟

介绍了玻璃材料模压过程及其存在的问题,针对玻璃模压仿真过程中所表现粘弹性力学特性,提出了采用广义Maxwell模型来模拟,分析了模压过程中的热传递形式及其模型.采用MSC.MARC软件对玻璃L-BAL42圆柱模压实验进行仿真,结果表明,广义Maxwell模型能够较好地模拟实际模压中的粘弹性力学特性,在600℃时利用此模型得到的松弛曲线与理论上的松弛曲线十分吻合.通过对非球面光学镜片的模压成型过程进行模拟,发现玻璃的最大应力出现在与上下模接触处的侧边,随着温度的降低,最大应力变大、模压力逐渐升高,在上下模闭合时,模压力快速上升,通过分析得到了透镜边缘处最易破碎失效的结论,实际透镜模压结果证实了结论.最后对非球面的形状偏差进行了预测,表明随着中心距离的增加,偏差变大,偏差最大值超过了5μm.研究的结果对玻璃模压建模及非球面透镜的实际加工具有一定的指导意义.     

非球面玻璃透镜模压成型的有限元应力分析

针对玻璃镜片模压成型过程中无法获得精确的内部残余应力数据,本文提出使用有限元方法分析内应力变化历程及预测残余应力分布.该方法根据高温下玻璃性质近似于粘弹性材料,将五单元广义Maxwell 模型的蠕变响应并入有限元计算.采用高级非线性有限元程序MSC.Marc,分别对圆柱玻璃单轴压缩和非球面透镜模压成型进行了仿真,获得了玻璃镜片成型后的残余应力分布情况.在此基础上,文章重点分析了温度和模压速度对合模后镜片内部残余应力分布的影响.实验结果表明,最大应力出现在镜片的边缘区域;较低的温度和较高的模压速度都会增大最大残余应力值.     

Visualizing Residual Stresses in Plastic and Glass

Polariscopes can be used to visualize the residual stress patterns in transparent or translucent materials. Residual stresses contribute to the fracture stress of failed components. This article describes the construction and usage of a lab polariscope made for less than US$150.     

A Diagram for Glass Transition and Plastic Deformation in Model Metallic Glasses

In this paper, we report a strain rate related glass transition in model SrCaYbMg（Li）Zn（Cu） metallic glasses at room temperature. A critical strain rate, equivalent to glass transition temperature, is found for the strain rate induced glassy state to liquid-like viscoplastic state translation. The results show that the observation time, equivalent to temperature and stress, is a key parameter for the transition between the glass and supercooled liquid states. A three-dimension glass transition diagram involved in time, temperature and stress in metallic glasses is established.     

增材制造硫系玻璃光学元件的前景分析与探讨

硫系玻璃作为红外光学系统的基础材料,在夜视枪瞄、车载夜视、星际生命探测等高端红外光学领域应用前景十分广阔。硫系玻璃的优点是折射率温度系数低,可避免光学系统的热失焦,实现系统色差自校正,并保证成像质量;缺点是色散系数大,实际应用时需要将其加工成面形复杂的元件。现有元件加工技术难以满足高精度、多品种、小批量硫系玻璃光学元件的加工需要。增材制造是一种迅速发展的新型制造技术,适于复杂结构器件的个性化定制。将增材制造技术用于硫系玻璃光学元件制备,对于解决硫系玻璃发展中遇到的瓶颈问题,促进硫系玻璃的快速发展具有重要意义。重点探讨了增材制造技术用于制造硫系玻璃光学元件的可行性并分析未来发展前景。     

模具制造中曲面与型体的形成和加工

阐述了在模具制造中,如何应用CAD/CAM系统来形成曲面和模型,并自动生成刀具轨迹,提高模具制造质量和效率.     

增材制造常用塑料的材质感性意象研究

目的 明确增材制造的手板模型常用的塑料材料,给工业设计师和生产制造工程师带来的感觉差异性,为材料选取提供合理意见.方法 运用感性工学理论,构建塑料材料物理特性和感性意象词汇群的对应关系.选择适合增材制造的自由曲面形态,采用语义差异法和李克特五级量表,对6种代表性材料样本进行感觉意象认知分析,通过SPSS统计感性意象词汇测量数据,运用独立T检验方法判断了两类人群感觉是否具有显著性差异,并分析材料物理特性对感受差异性的影响.结论 将抽象的感性意象词汇与材料的关键物理特性建立起感知联系,为专业人员手板模型制作过程的材料选择提供了参考.     

Size Distribution Characteristics of Particulates from Glass and Plastic Lvp's

An automated microscopic system was used to detect particulates from four different large-volume parenteral solutions in glass and plastic containers. Solutions from glass containers were found to contain a significantly greater number of particles; however, the mean diameter of particles from plastic containers was greater. Characteristics of the size distribution of particles from glass and plastic containers were also different. An overall (particle size 5-50μ) cleanliness factor was calculated. Cleanliness factors for glass containers were larger by 55.5% to 264.1% than those for plastic.     

车铣加工UG-CAM 制造技术研究与应用

应用TCL(Tool Command Language)开发了车铣加工中心BUNMOTECS192FT后处理模块,实现了该机床刀具中心点B轴随动的高级功能,利用UG-CAM数控编程技术,使用平头立铣刀,在车铣加工中心进行C、X、Y轴联动,完成了零件曲面加工刀轨设计,解决了T型铣刀加工曲面环槽干涉问题,通过将平头立铣刀轴与曲面法线倾斜一定角度,避开平头立铣刀底齿中心切削,达到零件精度要求。     

Glastic Composite Prototypes: A Materials Alternative for Recycling Plastic and Glass Waste

Multiple plastic compositions containing polyethylene, polystyrene, PVC, ABS, Nylon, polypropylene, with various particle morphologies and a narrow range of sizes and size distributions were mixed with similar size brown glass into glastic composites having glass compositions of 15, 30, and 45 wt%. These prototypes were molded in a form similar to standard clay bricks at 235°C and were compression tested to more than double the fracture stress of clay bricks at temperatures ranging from 20 to 50°C. These prototypes illustrate the prospects for utilizing waste plastics and glass in simple commercial materials applications and the relief of land fill problems which are now world-wide.     

Simple Tests for Projection Lenses

The construction of some simple test slides, and their use in the visual assessment of the aberrations of projection lensos, is descnbed here. The kinds of aberration, and their magnitudes, if significant in the visual image can be determined readily.     

Monitoring and Quality Improvement of Pharmaceutical Glass Container's Manufacturing Process

This paper introduces the complete development of an infrared temperature measurement system for the different critical points in the pharmaceutical glass-container manufacturing process using low-cost sensorial devices. The system is able to measure temperatures between 500degC and 1300degC for maximum rates approximating 150 containers per minute. The system directly detects the presence of a container through the measurement without requiring any proximity detectors. During the usage, the system has demonstrated high reliability and repeatability in its measurements, becoming an essential system for both the adjusting stage of the machine and the supervision of its operations.     

Damage Investigation in Drilling of Glass Fiber Reinforced Plastic Composite Laminates

Machining of fiber reinforced plastic is a process that is substantially different from metals. The inherent anisotropy in the material system makes the material removal mechanism quite complex. Drilling composite materials is necessary to ascertain the structural integrity of intricate composite products. Drilling of laminated structures results in extensive damage around the drilled hole. This study is an attempt to quantify and propose mathematical models for drilling-induced damage in terms of the cutting speed and the feed speed. Mathematical models have also been proposed for the resulting thrust force and the torque. Four different drill point geometries, namely 4-faceted, 8-faceted, parabolic, and Jodrill, are investigated in this study.