试析注塑模具的结构与优化方法

为了有效缩短注塑模具开发周期,更进一步降低模具制造成本,提升模具质量,目前越来越多的模具企业开始使用计算机辅助技术(CAE/CAD)进行注塑模具结构优化。本文基于上述背景,从目前注塑成型的模具受力分析方法进行分析,并提出了注塑模具浇筑优化方法。     

汽车内饰转向护板注塑模设计

本文基于CAD/CAE技术对汽车内饰件转向护板注塑模具进行了设计。运用Pro/E软件对模具进行了三维设计,使用Moldflow对模具进行了CAE分析,优化了浇口位置,合理设计了排气槽,提高了设计效率,创新了塑料模具设计方式。根据产品结构,采用动模中心凸起布局,应用斜顶机构实现侧抽芯,简化了模具结构,提高了模具设计质量,降低了制造成本。     

基于Pro／E的电池盒盖注塑模CAD／CAE

介绍了基于Pro／E的电池盒盖的注塑模CAD／CAE方法。通过对塑件结构和特点的分析。确定了注塑模具的总体设计方案。着重介绍了注塑模浇注系统和侧抽分型机构的设计。利用Pro／E实现了该模具的3D设计,并进行了塑料流动分析。该模具的设计方法对同类产品的模具设计具有一定的借鉴作用。     

CAE技术在塑料设计优化领域的应用

以塑料设计优化领域中的CAE技术为研究对象,综述CAE技术的发展历程、技术原理、常用软件及其在塑料设计优化领域的运用优势,归纳CAE技术的特点及应用前景。通过介绍当前CAE技术在塑料模具设计、注塑成型、加工过程等方面的应用现状,为CAE技术在塑料工业领域的进一步发展提供理论参考。     

注塑模具概念设计的CAE应用

为研究注塑过程模拟技术捕助模具概念设计和工艺设计结合实例分析了 CAE在概念设计阶段的作用,及其进行模具流道系统和冷却系统设计方案的评估和优化的途径,提出了在模具概念设计阶段利用CAE技术捕助助塑工艺设计的方法。结果表明,该方法可以在模具概念设计阶段有效顶测填充模式的合理性、预测特定模具结构及其注塑材料注射成型可能存在的缺陷、确定合理的排气槽位置、对冷却系统的布局和设计合理性进行评价等,是缩短模具开发周期、提高设计品质的有效措施。     

塑料机器人一模多异腔注射模设计

以塑料机器人产品为载体,介绍异型组合产品的结构工艺性,确定该产品采用一模多异腔的成型方案。基于计算机辅助工程（CAE）数值模拟技术优化模具浇注系统的设计,解决流道填充不平衡的问题;同时在流道上增设特殊结构,解决注塑生产后产品的空间存放问题。根据产品的功能要求,在模具结构中设置抽芯机构,以解决产品成型后产生夹线的工艺问题。该模具在实际的生产过程中取得较好效果,为类似模具的设计提供相关的参考与借鉴。     

轿车骨架注塑模具结构的虚拟设计

立足于虚拟造型技术,利用CAE软件探讨了轿车骨架注塑模具结构虚拟设计的可行性。结果表明,通过虚拟设计制作的(乙烯/丙烯/二烯)共聚物改性聚丙烯轿车骨架用注塑模具结构设计合理,各部分动作顺畅,特别是浇注系统和冷却系统得到优化,能有效提高生产效率,缩短开发周期,降低生产成本。     

塑料行业的计算机网络辅助工业设计应用探讨

在简述了计算机辅助技术和注塑模具设计发展现状的基础上,分析了各个计算机辅助软件之间联系性差和数据的共享与整合能力弱等问题,提出了基于计算机网络辅助工业设计和注塑成型理论的CAD/CAE一体化系统,介绍了系统的总体结构与框架,分析了系统建立过程中涉及到的注塑模具初始设计、零件与结构的简化、数据访问、二次开发和云计算等关键技术,并以汽车B柱的注塑成型过程仿真为例,对CAD/CAE一体化系统仿真和优化的能力进行了检验。     

基于CAE技术的后壳体点浇口热流道模具设计

以后壳体塑件为例,详细阐述了基于CAE的点浇口热流道注塑模设计方法,分析了塑件的注塑成型工艺,对塑件的分型面、热流道浇注系统、顶出复位系统、冷却系统作了详细分析与介绍,阐述了模具的整体结构及工作过程。实际生产表明,设计的采用热流道注塑模能简化模具结构,减少废料的产生,从而缩短塑件注塑生产周期,提高生产效率,可为同类热流道模具的设计提供借鉴。     

电风扇壳体多重倒扣成型注塑模具设计

针对某款落地电风扇后壳的结构特点,对此塑料产品的分型面做了合理设计。由于该产品内侧存在多个形状各异、方向不同的倒扣难以脱模,因此设计了四组斜导柱抽芯机构和四组斜顶机构组合的单型腔注塑模具,从而保证成型的同时能够顺利脱模。该壳体作为大众消费品有较高外观质量要求,因此采用侧浇口进浇以保证产品外观质量。对产品进行注塑模具设计的同时,利用CAE技术对所设计的注塑模具进行了注塑成型过程的模流分析,提高了注塑模具的设计效率、优化了模具的设计结构和注射成型工艺参数的设置,降低了模具制造成本。经验证,该模具结构可靠,运动顺畅,产品注塑成型效果良好,为类似结构特点模具的设计提供了良好的借鉴。     

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。