水辅注射成型工艺新进展

塑料模具制造商现正更多地关注塑料水辅注射成型技术(WIT),例如,德国Hoffmann公司专为Opel牌轿车制造了用于加工车门拉手的水辅注射成型模具,奥地利模具制造商JosefHaidlmair公司已经制造了一套用来注塑可折叠板条箱的模具,这种可折叠板条箱专设计应用于Schoeller Wavin系统方面,其侧面板是采用水辅注塑技术加工而成.     

聚丙烯成型工艺研究

聚丙烯(PP)作为塑料三大原料之一,其无毒无味且物理性均优于其他同类产品。在常温时,聚丙烯可用作耐腐蚀零件;而在110℃时,则可用作绝缘零件。基于其应用广泛性,不同等级PP制品所用的成型工艺各不相同,对聚丙烯注射成型及挤出成型的工艺进行了探究。     

聚碳酸酯的注射成型工艺

分析了聚碳酸酯的注射成型工艺特性，讨论了影响聚碳酸酯制品质量的工艺因素，包括模具与设备、制品与嵌件结构、原材料干燥、注射温度、注射速率、注塑压力、成型周期、模具温度、制品后处理等。总结了聚碳酸酯注射成型制品常见的缺陷及解决措施。     

台面框注塑成型工艺分析模具设计

通过分析台面框的结构工艺特点，设计了用于该零件的注塑模，确保生产符合技术要求的合格零件。     

注射成型工艺对内应力的影响与控制

内应力是影响塑料制品质量的主要因素,本文着重分析内应力与注射成型工艺条件的关系以及减少内应力的措施。     

模内装配——多重注射成型的发展方向

省却后加工步骤促使多重注塑工艺向前迈出了一大步,即通过搭扣配合、焊接和共注塑不相容材料等方式,在模具内组合装配各种独立的部件。模内贴标、薄膜装潢和织物层压技术都日渐成熟。因此,在模具内要完成这些工序而省去后加工的下一个技术又将是什么呢?     

塑料成型工艺及模具设计技术问答

内容简介：本书以问答的形式，全面介绍了常用塑料成型工艺及模具设计制造方面的知识和技能。全书共分塑料概论、塑件的设计、注射成型工艺与成型设备、注射模设计、压缩成型工艺与模具设计、传递成型工艺与模具设计、挤出成型工艺与模具设计、其他成型工艺与模具设计、     

光学塑料注射模具的设计制作与制品的成型工艺

从模具结构设计,模具材料及热处理选择,模具成型零件的加工工艺,塑料材料及成型及工艺选择,生产环境诸方面的述了生产优质光学塑料制品的方法和影响光学塑料制品的因素。     

硬质聚氯乙烯的注塑工艺

介绍了硬质PVC原料的注射成型技术,并探讨了原料,成型模具,成型设备对工艺的影响及成型工艺条件的控制。     

HDPE／EVA复合薄膜共挤出成型工艺及机头结构设计

介绍ＨＤＰＥ／ＥＶＡ复合薄膜的特点、用途、成型加工工艺及其挤出吹塑机头的结构设计。结果表明ＨＤＰＥ／ＥＶＡ复合薄膜作为冷冻食品包装袋其性能可靠、加工方便;采用共挤出吹塑复合薄膜的成型方法,具有生产设备简单、工艺流程短,成本低等优点;机头采用部分独立流动然后汇合的熔体流动方式,其结构紧凑、流道较短、熔体压力损失小,并有助于提高内外层膜间的粘合牢度     

一种实用的发黑工艺

详细介绍了一种实用的常温发黑工艺配方、各主要成分的作用和工艺参数的影响。阐述了该工艺的流程，溶液和发黑膜层的性能。     

New theoretical and practical aspects of the frying process

The deep‐frying process, normally carried out at 140–200 °C, is a very complex system due to the combination of heat and mass transfer between food and frying medium. The system becomes more complicated as the frying operation proceeds, because the composition of the food being fried and the frying medium is changing continuously due to the progressive deterioration of the frying medium. Apart from a variety of chemical reactions occurring, several changes take place in the frying food, such as gelatinisation of starch, denaturation of protein, and decrease of moisture. These changes bring about swelling of the product, formation of a crusty layer, and the appearance of a golden colour, good texture and taste. The precise control of the fryer enables these physical and chemical changes in the frying of food to convert it into a desirable finished product. This article discusses various types of reactions occurring in the food frying operation, possible mechanisms, a new realistic method – OSET index for measuring heat stability of frying oils – and the protective behaviour of substances that enhance the frying stability of oils.     

Studies of electrospun regenerated SF/TSF nanofibers

The Bombyx mori silk fibroin/Tussah silk fibroin (SF/TSF) nanofibers with diameters between 300 and 3500 nm were prepared by electrospinning with the solvent HFIP. The average diameters of SF/TSF blend fibers increased from 404 to 1977 nm, with the increase of SF content in blend solutions, and the relationship between the average diameters of SF/TSF and SF content was proved to be linear correlation. Results from FTIR, TG-DTA and X-ray diffraction showed that the electrospun fibers were mainly β-sheet structure and, heterogeneous micro-structures. In particular, the presence of two different endothermic peaks at 300 and 360 °C in the TG-DTA curves may be ascribed to the thermal decomposition of SF and TSF. These results suggested that SF and TSF were still immiscible even dissolved in hexafluoroisopropanol (HFIP) after electrospinning and ethanol treatment. Moreover, the thermal decomposition temperature and enthalpy were improved with the blend of SF and TSF, else the SF/TSF nanofibers' moisture absorption was higher than the pure SF or TSF nanofibers. To study the cytocompatibility and cell behavior on the SF/TSF nanofibers, MSCs, VECs, and Neurons were seeded onto the nanofibers. Results indicated that the SF/TSF nanofibers promote cell attachment and spreading, suggesting that these nanofibers could be a candidate scaffold for blood vessel and nerve injury recovery.     

Economic process optimization strategies

The following deliberations are concerned with the application of economy criteria to the optimization of process-engineering plants. We are therefore not concerned here with criteria for investment decisions, i.e., decisions on the implementation orabandonment of an investment project, nor with criteria for the selection of the most profitable investment options from a series of alternatives. Instead, we are interested here in the question of how a plant, while at the planning stage, can best be designed, i.e., the most rational method of selecting process parameters, such as throughputs, pressures, temperatures, concentrations, etc. The problem of plant optimization only occurs, however, when there are design parameters which can be selected at will or can, at least, be varied within certain limits. This is however, virtually always the case. There is then a need for an optimization strategy in the form of an objective function which is either reduced to a minimum, where lowest possible production costs are the target, for instance, or advanced to a maximum, where high profitability is the aim. The inclusion of engineering economy functions, in the form, namely, of the net present value function and the internal rate of return function for definition of such objective functions, provides better defined information on the best possible choice of process parameters than was possible with methods previosly used, such as the annuity method, for instance. One obtains different values for the process parameters to be optimized, depending on the objective functionused, and therefore different investment costs and utility consumptions. These differences are delineated and quantified using a process-engineering example in the course of the following discussion. The example selected is a gas scrubber, the function of which is to remove and recover useful components from a flow of gas. The specific problem examined is one of heat recovery.     

高效实用的软锰矿浆脱硫新技术和工艺流程

本文介绍了高效实用的软锰矿浆脱硫的新技术和工艺流程以及硫酸锰副产品的回收。     

中低低变换工艺在我公司的应用

我公司年产合成氨120kt、尿素200kt化肥装置原料气变换工艺原采用两台中变炉并联的中变串低变工艺。2001年与齐鲁石化研究院合作,采用其饱和热水塔的中低低变换工艺新技术,按年产合成氨150kt、吨氨耗高压蒸汽720kg设计,对原来中变串低变工艺进行了改造,于2002年7月开车成功(期间经历半年停产改制),至今装置已稳定运行8个多月。1　改造简况1.1　工艺流程来自压缩机三段的半水煤气首先经油水分离器分离掉油和水,再经焦炭过滤器进一步除去油和水;然后分成两股,一股作为冷线用于调整中变炉入口温度,一股走中温换热器管间,与管内的中变气逆流…     

中低低变换工艺在我公司的应用

我公司新系统是由中国五环化学工程公司设计 ,年产 1 2 0ｋｔ合成氨、 2 0 0ｋｔ尿素。造气以煤为原料 ,气体净化采用 2 1ＭＰａ中低低变换新工艺 ,精制为甲烷化流程。这种净化工艺在国内同类企业中属首例。中变、低变催化剂均为衡阳化工研究所研制生产的 ,型号分别是Ｂ1 1 2、ＨＢ 3、ＨＢ 4。1 999年元月份一次开车成功投产后 ,中低低变换充分体现了能耗低、操作弹性大、流程短、系统阻力小等特点。但随着生产时间的延长 ,系统达到设计能力满负荷生产后 ,也暴露了许多问题 ,这些问题造成系统波动频繁 ,不能长周期高负荷稳定运行 ,给公司…     

Tantalum carbide coating via wet powder process: From slurry design to practical process tests

TaC coatings were deposited on graphite substrates via wet powder forming and sintering to potentially achieve both a highly reliable and low-cost process. Non-aqueous solvent mixtures of TaC slurries were optimized through characterization of raw materials and a novel design guide based on Hansen solubility parameters. The optimized TaC slurries enabled the formation of high-quality TaC powder compact films with ultrahigh powder packing densities of ≥70% (ca. 85% at maximum), which contributed to prevent defect formation in the TaC coatings after sintering. The TaC-coated components were tested in practical high-temperature processes, such as AlN and SiC bulk single crystal growth processes, and a SiC device fabrication process, which confirmed sufficiently low-levels of impurity incorporation and surface contamination from the TaC layers. The novel TaC-coated graphite components will contribute to higher quality and lower cost for bulk crystal growth, device fabrication, and epitaxial film growth processes of group-III nitrides and SiC.     

钡盐法除硫酸根的经济分析

分析了氯化钡法除硫酸根的经济条件。