注塑成型工艺对包塑成型嵌件变形的影响

利用ANSYS Workbench软件对汽车接插件成型过程中嵌件受力变形进行分析,分析细针状嵌件在注塑成型过程中的变形情况。采用包塑成型的优化工艺方案,先设计一个工艺过渡件,对细针状嵌件进行定位,再将工艺过渡件以嵌件的形式进行注塑成型,并对其嵌件受力进行分析。实际生产表明,应用包塑成型重叠注塑工艺可以提高产品质量,使其满足使用要求。     

尼龙1010注塑制品工艺设计

从尼龙1010塑料注塑成型的主要设备、工艺条件以及尼龙1010塑料的特性等方面,对尼龙1010的注塑工艺流程进行全面的分析和研究,为尼龙1010注塑件的开发、提高制品质量提供了相关的数据。结合典型制品,运用计算机辅助设计技术,对工艺过程进行了设计。     

聚甲醛双齿轮成型加工工艺研究

主要讨论聚甲醛双齿轮的成型工艺技术，重点分析了选材，嵌件处理，注射成型工艺和制件热处理等工艺因素，带有一个铝合金组合嵌件且两副齿的轴相互垂直的双齿轮最初采用尼龙制造，由于尼龙的吸湿性，金属嵌件注塑前没有进行热处理，注塑工艺上没有采取适当措施等原因，造成了双齿轮的同轴度垂直度严重超差，达不到设计要求，通过采取合理选材，嵌件热处理和成型工艺优化及制件热处理等措施，生产出满足设计要求的制品。     

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。     

改善塑件磁性嵌件翘曲的模流分析

以剪刀架与磁性嵌件的注塑为分析实例,阐述了丙烯腈-丁二烯-苯乙烯共聚物(ABS)材料在嵌入磁性嵌件后注塑中产生的翘曲问题及解决方法;采用Moldflow软件对制品结构、模具结构和成型工艺参数3个方面的影响因素进行了对比分析。结果表明,通过对工艺参数的极差分析以及制品结构、浇口位置的改变分析所得到的数据发现,改变工艺参数翘曲优化程度为15%,改变制品结构翘曲优化程度为53.7%,改变浇口位置翘曲优化程度可达76.5%;改善浇口位置是解决翘曲因素最主要的方法,可以得到远小于翘曲要求的翘曲值。     

微车后灯外罩注塑工艺优化

灯具外罩通常用透明PMMA制作,外罩采用两次注塑成型,先做成嵌件,然后把嵌件放在另一副模具中注塑合成,通过对嵌件、外罩注塑成型工艺等的介绍,围绕外罩产品特点,进行产品重量的控制,用重量控制法达到产品质量。经生产实践验证,用重量控制法优化工艺能满足外罩成型要求,符合生产需要,操作简便可行,产品能得到用户的认同。     

激车后灯外罩注塑工艺优化

灯具外罩通常用透明PMMA制作，外罩采用两次注塑成型，先做成嵌件，然后把嵌件放在男一副模具中注塑合成，通过对嵌件、外罩注塑成型工艺等的介绍，围绕外罩产品特点，进行产品重量的控制，用重量控制法达到产品质量。经生产实践验证，用重量控制法优化工艺能满足外罩成型要求，符合生产需要操作简便可行，产品能得到用户的认同。     

带嵌件的注塑模具温度场数值模拟

冷却分析（模具温度场计算）是注塑成型计算机辅助工程的关键技术之一,在优化模具设计、提高制品质量方面具有重要作用,本研究提出了采用边界元法建立带嵌件的注塑模具温度场数值模拟的方法,并针对嵌件与模具接触面上的边界条件给定的关键问题,采用耦合边界元法对其转化,将嵌件与模具接触面上的边界条件转移到嵌件与塑件制品的接触面上,使得它的计算可以采用解析法替代原来的差分法,有效提高了分析计算的精度。     

适用于输配电行业的铜件镀银工艺

介绍了适用于输配电铜及铜合金件镀银工艺,其流程主要包括化学除油、盐酸活化、混酸酸洗、氰化镀铜、氰化镀银、电解钝化.说明了各工艺的操作条件及注意事项.给出了银镀层变色后的处理,不合格品的褪镀方法,以及镀层抗变色性能、结合力和显微硬度的测试方法.指出了该工艺对环保方面的要求.针对实际生产中遇到的漏镀和镀层有少量颗粒的问题,...     

玻璃纤维增强尼龙的注射成型工艺改进

分析玻璃纤维(GF)增强尼龙(PA)制件在注射成型生产中的主要参数设置,从影响注塑制件质量的材料、成型工艺、模具设计、制品设计着手,分析了GF增强PA注塑制件常见表观缺陷产生的原因并提出了相应的解决方法.     

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。