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1.
玻璃钢成型技术   总被引:2,自引:0,他引:2  
系统地介绍了玻璃钢的几种传统成型加工技术的特点及工艺过程,同时简要地阐述拉挤成型、树脂传递模塑、反应注射模塑、片状模塑、自动叠层等近年来出现的几种新技术、新工艺,并介绍了各成型工艺的工艺流程、适用范围及优缺点。  相似文献   

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聚酯成功地用于包装(特别是食品包装)已有很长一段历史。双轴取向Mylar聚酯薄膜1952年就已上市,碳酸饮料包装用的聚酯瓶也于1978年工业化生产。今天,在包装领域快速增长的部分之一是采用非晶聚酯(简称APET)片材热成型加工各种包装用品。据估计,目前美国APET用量为6000~7000万磅,预测今后5年内将  相似文献   

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塑料特种成型技术   总被引:1,自引:0,他引:1  
第二讲 特种挤出成型一、双螺杆反应挤出 反应挤出技术是利用双螺杆挤出机完成单体、预聚物的反应合成过程及聚合物的接枝、嵌段、共聚、交联、最终挤出成为塑料制品的一种新颖挤出工艺。用作反应挤出的双螺杆挤出机既是传统意义上的混炼塑化成型设备,又是化学合成的反应器,在挤出过程中完  相似文献   

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第三讲 特种注射成型 塑料注射成型技术朝反应性、复合、精密、节能、低噪音、易操作、小体积的方向发展。具体体现在以下四个注射工艺的工业化上:反应注射、复合注射、气辅注射、精密注射。一、反应注射成型 反应注射成型(RIM)起始于六十年代德国Bayer公司首创的聚氨酯加工技术。传统的热塑性塑料注射成型是固体物料在注射机内熔融为液体然后注入模内并在模内由液体  相似文献   

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塑料制品的旋转成型技术及其发展   总被引:4,自引:0,他引:4  
戴赞明 《湖南化工》1997,27(1):11-13
概述了旋转成型的基本原理、制品可大可小、无内应力等基本特征、摇滚式等5种设备类型和PE等原料种类,介绍了国内外发展情况和制品的应用范围。  相似文献   

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氧化铝粉体的压滤成型工艺初探   总被引:1,自引:0,他引:1  
研究了两种氧化铝粉体的压滤成型行为及其影响因素,无硬团聚体的粉料在分散良好时可以获得比干压成型(55%,300MPa)的较高的素坯密度(63%,45MPa)和小的气孔尺寸分布,硬团聚的粉体无论是压滤成型还是干压成型,素坯密度都远低于无团聚粉体,此外还讨论了引起密度差别的原因。  相似文献   

8.
陶瓷直接凝固注模(DCC)成型   总被引:6,自引:0,他引:6  
直接凝固注模式型(DCC)是一种陶瓷净尺寸胶态成型方法,DCC成型的坯体具有成型密度高,密度及组分分布均匀,不含或只含少量有机物等特点,本文了DCC成型的原理、成型过程及特点。  相似文献   

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本文从技术及应用角度系统地介绍了塑料注射成型、气体辅助注射成型、反应注射成型、挤出成型、吹塑成型和热成型CAE技术的概况、内涵及发展趋势。  相似文献   

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本文综述了目前国外已用于(RTM)成型加工的环氧树脂的概况。  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.  相似文献   

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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。  相似文献   

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