A prototype printer for laser driven micro-transfer printing

This paper demonstrates a new mode of automated micro transfer printing called laser micro transfer printing (LμTP). As a process, micro-transfer printing provides a unique and critical manufacturing route to extracting active microstructures from growth substrates and deterministically assembling them into a variety of functional substrates ranging from polymers to glasses and ceramics and to metallic foils to support applications such as flexible, large-area electronics, concentrating photovoltaics and displays. Laser transfer printing extends micro-transfer printing technology by providing a non-contact approach that is insensitive to the preparation and properties of the receiving substrate. It does so by exploiting the difference in the thermo-mechanical responses of the microstructure and transfer printing stamp materials to drive the release of the microstructure or ‘ink’ from the stamp and its transfer to substrate. This paper describes the process and the physical phenomena that drive it. It focuses on the use of this knowledge to design and test a print head for the process. The print head is used to demonstrate the new printing capabilities that LμTP enables.     

染料废水的内电解脱色处理研究

采用铁屑内电解法对５大类１１种模拟染料废水和印染废水进行了内电解混凝处理，得出了内电解法处理染料废水的最佳工艺条件，探讨了脱色机理，并在实际印染废水处理工程中得到有效应用。研究表明，对中等色度和浓度的模拟染料废水，脱色率均在７７％以上，在实际印染废水处理工程中采用混凝和内电解联合处理工艺，脱色率可达９６％以上。     

Wireless acquisition of temperature data from embedded thin film sensors in cutting insert

This paper presents the results of wireless data acquisition experiments from embedded micro thin film sensors in cutting inserts for machining. A bluetooth module is used to acquire data and establish communication with a receiver PC over the serial port profile (SPP). A signal conditioning circuit is designed and developed to increase the signal-to-noise ratio of the embedded micro thin film sensors. Moreover, an averaging filter algorithm is implemented as a software interface. To characterize the wireless data acquisition (DAQ) system, laser heating and turning tests are conducted. Both tests show that the wireless DAQ system is able to provide desirable capabilities as well as the wired one for the embedded thin film sensors in cutting inserts.     

Hybrid hierarchical fabrication of three-dimensional scaffolds

Three-dimensional (3D) porous structures facilitating cell attachment, growth, and proliferation is critical to tissue engineering applications. Traditional solid freeform fabrication (SFF) methods have limited capabilities in the fabrication of high resolution micro-scale features to implement advanced biomedical functions. In this work, we present a hybrid scaffold fabrication approach by integrating electrohydrodynamic (EHD) printing technology with extrusion deposition together to fabricate hierarchical 3D scaffolds with well controlled structures at both macro and micro scale. We developed a hybrid fabrication platform and a robust fabrication process to achieve 3D hierarchical structures. The melting extrusion by pneumatic pressure was used to fabricate 3D scaffolds with filaments dimension of hundreds of microns using thermoplastic biopolymer polycaprolactone (PCL). An electrohydrodynamic (EHD) melt jet plotting process was developed to fabricate micro-scale features on the scaffolds with sub-10 μm resolution, which has great potential in advanced biomedical applications, such as cell alignment and cell guidance.     

Pulsed laser micro polishing: Surface prediction model

The objective of this work is to predict the final roughness of metal surfaces that have undergone pulsed laser micro polishing. The motivation for pulsed laser micro polishing is to reduce the surface roughness of parts whose surface texture can approach the feature size. Being able to predict the magnitude of the polishing and frequency (wavelength) content of the surface will assist in the design of optimal processing parameters with minimal experiments. Laser pulses are used to create shallow melt pools with a controlled size (e.g., depth) and duration in order to allow surface tension forces to “pull down” asperities with small radius of curvature. There is no ablation occurring in the process being modeled. The melt depth and duration are predicted with a transient, two-dimensional axisymmetric heat transfer model with temperature-dependent material properties. The surface of the melt pool is analytically modeled as oscillations of stationary capillary waves with damping resulting from the forces of surface tension and viscosity. Above a critical spatial frequency, f_cr, a significant reduction in the amplitude of the spatial Fourier components is expected. The work described in this paper extends the concept of critical frequency to a physics-based prediction methodology for predicting the spatial frequency content and surface roughness after polishing, given the features of the original surface, the material properties, and laser parameters. The proposed prediction methodology was validated using line polishing data for stainless steel 316L and area polishing results for pure nickel, Ti6Al4V, and Al-6061-T6. The predicted average surface roughnesses were within 12% of the values measured on the polished surfaces.     

紫外-微臭氧处理饮用水中有机优先污染物

城市自来水水质下降,研究开发给水深度处理技术刻不容缓。本文采用新型紫外—微臭氧工艺处理自来水中常见的三氯甲烷、四氯化碳、邻－二氯苯、对－二氯苯、1,2,4－三氯苯和六氯苯等6种优先污染物。处理结果表明,与紫外—臭氧工艺相比,本项技术作为自来水深度净化手段,具有效果基本相等,设备大幅度简化,运行费用低廉,更易于推广的优点。光化学氧化,紫外微臭氧,优先污染物,饮用水处理     

A review of process development steps for new material systems in three dimensional printing (3DP)

Three dimensional printing (3DP) is a method for direct digital manufacturing that provides capabilities for creating a wide range of part geometries (including internal channels) in a broad variety of materials, including just about anything that is available as a spreadable powder. Taking advantage of the full variety of materials requires development of specific implementations of 3DP. This paper organizes the process of 3DP implementation into five steps (powder formulation, binder method selection, binder formulation and testing, printing process specification, and post-processing specification) and presents a review of the literature relevant to each step in 3DP implementation.     

印刷行业VOCs排放特征研究

采用生产工艺调研,现场采样及实验分析相结合的方法,研究了生产工艺、原辅材料、治理技术及生产管理对制鞋行业VOCs排放的影响,研究了印刷行业VOCs的排放特征。研究表明：印刷行业VOCs主要来源于印刷用油墨及其稀释剂、润版液、清洗剂、胶黏剂等含溶剂产品的使用。印刷工艺和油墨种类是决定印刷企业总VOCs排放浓度的关键因素,水性油墨可显著降低VOCs的含量。目前印刷行业多为无组织排放,治理设施普及率低,存在生产管理不完善等情况。通过研究印刷行业VOCs的排放特征,为制定地区空气质量保障方案做充分的准备,具有十分重要的意义。     

印染废水吸附处理研究现状

随着染料纺织工业迅速发展,产生的印染废水成了水系环境的主要污染源之一,而染料品种的日益增加,及产品结构和印染工艺的不断改变,使得印染废水的水质也发生了变化,处理难度也随之加大。本文主要介绍不同的吸附处理法的优缺点及它们对不同污染因素的吸附效率。通过对几类吸附方法的比较,发现新兴的秸秆纤维素类生物吸附剂,既可以有效的解决农业固体废弃物的处理问题,又能低成本高效率的处理印染废水,对我国建立发展可持续发展,环境友好型社会具有重要的意义。     

EG-510PCB印制板复合复位模设计

此文分析了加工EG-510PCB印制板模具的设计方案。用大间隙的复位冲裁间隙和固定弹顶装置来解决八拼板零件的复位问题,满足了模具使用上的要求。并采用一次成形的复合复位模结构,既保证了产品的质量,又提高了生产效率,同时降低了生产成本。     

曝气生物滤池反冲洗特性的研究

曝气生物滤池集生物膜的强氧化降解能力和滤料截留效能于一体,是一种适合大规模回用、高效、低耗的污水再生工艺,也是升级改造的良好选择。反冲洗是曝气生物滤池运行中的一个关键步骤,合理优化反冲洗过程有助于改善其整体运行性能。根据反冲洗废水浊度变化确立了合理的反冲洗方式,并给出相关的反冲洗强度和反冲洗历时参数,以期为曝气生物滤池处理印染废水的设计和运行提供参考。     

印染废水处理回用工艺现状研究

印染废水产生量大、有机物含量高、具有一定的毒害性,因此印染废水的回用是降低印染废水污染和印染用水消耗的重要途径,印染废水回用包括原废水和二级生化出水的处理回用。印染废水主要回用于印染生产过程,在以印染原废水处理回用时,典型工艺是生化处理+膜分离组合工艺;在以印染废水处理后的二级生化出水进行处理回用时,其典型工艺分别是超滤+反渗透组合工艺,工艺出水可回用于印染漂洗、染色等生产过程,实现废水厂内循环利用。     

光固化3D打印废塑料来源、处置技术和环境影响

光固化技术因其在3D打印行业中具有打印精度高且技术成熟的优势,在工业应用和学术研究方面都受到国内外的广泛关注.随着光固化3D打印技术蓬勃发展,相应而来的废弃物（光固化3D打印废塑料）作为一种新型有机固废,其增长速度不可估量,对环境带来的影响难以预计.基于现有研究,对光固化3D打印废塑料来源、处置技术和环境影响的最新研究进展进行总结分析.结果表明,光固化3D打印废塑料为共价交联热固性塑料,具有较高的活化能,内部化学结构存在对光敏感的显色基团,其原料、形成过程和目前的处置方法均可能对环境或生物体等带来潜在危害.基于此,针对光固化3D打印废塑料未来处置方式的可能性,提出展望和建议,可为光固化3D打印产业清洁发展提供助力.     

印钞废水处理工艺的研究

通过对印钞废水的水质分析以有对印钞废水进行实验小试的基础上，提出了4条并行的小试工艺路线，经实验比较，结果表明，化学沉淀＋水解酸化＋好氧工艺流程为处理印钞废水的可行工艺，处理后的污水可以达标排放。     

珠江三角洲印刷行业VOCs组分排放清单及关键活性组分

根据珠江三角洲地区印刷行业活动数据和不锈钢罐采样-气质联用技术,获取了印刷工艺VOCs成分谱,建立了该地区2010年印刷行业VOCs组分排放清单,研究了不同工艺排放的臭氧生成潜势. 结果表明:该地区2010年印刷行业VOCs排放总量达8591.26t,深圳、东莞、佛山排放量较大.凹印是印刷行业主要VOCs排放工艺,排放量达5762.01t;平印和凸印次之,分别为1954.01和37.82t.不同工艺排放的VOCs组分差异较大,平印工艺排放的VOCs成分中异丙醇含量最多(306.58t),其次为正庚烷(115.87t);苯和甲苯是凸印工艺排放的VOCs成分中含量最大的2种化合物,分别达5.58和4.83t;乙酸乙酯是凹印工艺排放的VOCs成分中的首要化合物,达2482.85t.凸印工艺排放的VOCs单位浓度臭氧潜势最大,达1.30μg/m3,平印和凹印较小,分别为0.89和0.72μg/m3,各工艺排放的含氧有机物对臭氧生成潜势的贡献均为最大.      

Life cycle assessment of offset printed matter with EDIP97: how important are emissions of chemicals?

Existing product life cycle assessment (LCA) studies on offset printed matter all point at paper as the overall dominating cause of environmental impacts. All studies focus on energy consumption and the dominating role of paper is primarily based on the energy-related impact categories: global warming, acidification and nutrient enrichment. Ecotoxicity and human toxicity, which are related to emissions of chemicals, etc., are only included to a limited degree or not at all. In this paper we include the impacts from chemicals emitted during the life cycle of sheet fed offset printed matter. This is done by making use of some of the newest knowledge about emissions from the production at the printing industry combined with knowledge about the composition of the printing materials used. In cases with available data also upstream emissions from the production of printing materials are included. The results show that inclusion of the chemical emission-related impacts makes the EDIP97 impact profile of sheet fed offset products much more varied, as well for the normalised profiles as for the profiles weighted by distance to political environmental targets. Especially the ecotoxicity impact potential related to the production stage may contribute significantly, and the use of paper no longer becomes the overall dominating factor driving the environmental impacts.     

An Investigation of Selective Coloring with 3-D Laser Printing

This paper reports on preliminary results involving an experimental rapid prototyping process known as 3-D laser printing. The system builds parts by repeatedly laser printing thermoplastic cross-sectional “slice” images of a part one on top of the next. With each new layer, the total build thickness increases until the part is complete. An interesting extension to this system involves the use of a color print engine to produce selectively colored parts. Conventional rapid prototyping processes generally do not allow this sort of selective coloring. Initial results indicate that the system has considerable potential and warrants continued investigation.     

3D打印技术在固体废弃物资源循环中的应用

打印材料是限制3D打印技术发展和推广应用的瓶颈问题,目前已经发现部分固体废弃物与3D打印的契合度很高,可以用于制备3D打印材料.本文综述了4类可以用于3D打印的固体废弃物,包括硅铝基废弃物、农林废弃物、废旧塑料和废旧金属,着重讨论了这4类废弃物制备3D打印材料的方法以及废弃物的添加对原打印材料造成的影响,同时分析了当前废弃物制备3D打印材料需要解决的问题,并对废弃物基3D打印材料的发展趋势进行了展望.     

微机与材料试验机的联机应用

此文以单向拉伸试验为例,介绍了微机与材料试验机的联机应用,做到自动采集与处理数据,绘制实际应力—应变曲线,打印出所需要的机械性能指标,同时也能控制材料试验机的动作。     

烟标印刷行业的清洁生产途径

清洁生产作为防止污染的最佳模式,是企业实现经济效益、社会效益和环境效益的重要途径.按照烟标印刷的工艺路线,从产品的设计、制版、印刷到印后加工,对每一环节进行分析,探讨了烟标印刷行业的清洁生产技术途径,改进措施及环境方面达到的效果.