塑料异型材挤出模头模架CAD系统研究

塑料异型材挤出模头形状复杂,但其模架部分装配结构相对固定,以塑料异型材挤出模为研究对象,提出了整体式设计方案。以制图软件UG(Unigraphics NX)为平台,应用特征建模技术和装配建模技术,建立标准件并装配形成可配置的模架标准件组。以编程系统VC(microsoft visual C++)为开发工具,构建基于UG的异型材挤出模头标准模架计算机辅助设计(CAD)系统,通过人-机交互对模架进行数据调用与修改,应用引用集技术和参数关联设计技术(WAVE),根据模架标准件组自动成型板块,切割并切换标准件装配显示,形成符合设计要求的三维挤出模头模架装配模型,有效提高了挤出模设计效率。     

塑料异型材挤出定型模冷却水路系统快速设计研究

由于塑料异型材挤出定型模冷却水路结构复杂且多变,设计主要靠设计人员的经验,出错率较高且效率低下,因而很难满足目前异型材挤出模高效率、高质量的设计要求。针对此问题,对冷却水路系统结构问题进行分析,在UG平台下,将分组设计思想和整体设计思想相结合,将冷却水路轨迹点线进行草图分组,分别获取不同水路草图组的标识,同时初步创建了多节挤出定型模的冷却水路系统;采用最小距离算法,对初步创建的冷却水路进行干涉检查;通过用户自定义对象的关联技术实现冷却水路轨迹点线与冷却水路的关联,实现冷却水路的同步修改。在此基础上,开发了异型材挤出定型模冷却水路系统程序设计模块,应用于企业实际工作中,减少了工作量,使设计时间缩短至原设计时间的1/5,提高了异型材挤出定型模冷却水路系统设计的质量和效率。     

应用UG软件进行轮胎三维设计

以26.5-25 S形块状花纹工程机械轮胎为例,介绍以UG NX2软件进行的轮胎三维设计。使用UG软件的导入功能可将原AutoCAD的轮胎断面轮廓导入草图,草图中各曲线对应的尺寸变量则是参数化驱动的主要参数来源,通过使用UG的后参数化功能驱动这些参数可节省大量的重复劳动。建模后的轮胎三维模型除可用于外观和CAE等技术分析及模具制造外,生成的高质量图片还可用于前期的市场宣传。     

塑料挤出模CAD系统的研究

针对塑料挤出模结构,工艺流程复杂,设计周期长且质量低下等问题,提出一种计算机辅助设计(CAD)系统设计方案,目的是提高塑料挤出模设计水平。首先介绍了塑料挤出模基本构造及几何特点,并说明了三维参数化CAD系统总体设计框架。提出了基于UG软件的塑料挤出模CAD系统设计平台及关键技术,包括口模图形设计、口模板设计、外形与流道设计、分流支架、型芯与分流锥设计。最后就塑料挤出模具设计中的实际应用过程进一步说明该系统的具体参数设计过程。     

基于UG平台的塑料异型材挤出模标准件库的建立

针对塑料异型材挤出模中存在大量标准件这一特点,以UG软件为开发平台,利用VC++6 0面向对象的编程技术,在UG/OpenAPI开发平台上,创建参数化图库、设计用户界面、实现参数化尺寸驱动,总结了系统的主要功能和特点,建立了三维塑料异型材挤出模的标准件库。     

中望3D在塑胶玩具行业建模应用

正随着社会物质化生活水平不断提高,大众对玩具的需求也在提高。传统的手工制作方法,效率慢周期长且不利于大批量生产,运用三维CAD软件进行造型,开模,组装,逐渐成为塑胶玩具行业厂家的主流生产模式,因此需要一款灵活自由简单快捷的三维CAD设计软件操作来满足设计需求尤为重要。下面小编来介绍一下通过国内知名三维CAD软件中望3D如何来实现三维CAD建模设计一款玩具。我们知道,塑胶玩具对设计要求并不算高,大多数三维设计软件均能完成工作,但对产品造型创意和设计周期才是重点,因此对三维设计要求有强大的建模功能、灵活便捷的操作命令、浅而易懂的简易操作流程,小编在操作试用中发现中望3D对比其他三维软件在此方面较为出色:从草图到曲面实体造型,模具设计,CAM制造加     

塑料异型材挤出定型模CAD系统

针对塑料异型材挤出定型模分型繁琐、孔多易干涉、定型板块重复性设计等问题,提出了整体式设计和参数化设计方案。设计了1套智能分型算法,自动创建分型片体,构建分型板块,当调用标准件时自动修改相应参数,智能加载。基于UG平台,以VC为开发工具,应用UG/Open二次开发技术和MFC技术,通过人机交互界面进行参数化设计,开发了塑料异型材挤出定型模CAD系统,规范了定型模设计流程,提高了定型模设计效率。     

UG在自由曲面产品逆向工程与模具设计中的应用

详细介绍了逆向工程在复合材料头盔设计中的具体应用,包括逆向软件的选取、测绘方法、曲面重构、曲面评价及实体形成的具体思路,成功实现了在UG中头盔的三维自由曲面逆向设计。在三维实体模型的基础上,生成了模具三维结构设计图与二维工程图,为成型加工提供了数据,并提高了设计效率。     

塑料异型材挤出口模设计的数值模拟概述

从挤出口模设计原则出发,综述了数值模拟技术在塑料异型材口模流道的曲面构型,入口角和压缩比、降低或消除挤出胀大和挤出口模成型段的设计、熔体流动平衡和压力降的研究进展,以及口模设计的发展趋势.     

基于PRO／E的多级离心泵三维造型

应用工程绘图软件PRO/E对多级离心泵进行三维建模和装配设计,对各部件的建模不仅使用了实体拉伸、旋转、扫描、混合和曲面造型功能,还对特殊部件使用了拔模、钻孔和倒圆角的设计.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。