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以某汽车仪表盘为例,设计了仪表盘的热流道顺序阀浇注系统.运用正交优化试验法结合Moldflow模拟分析软件,优化各浇口的最佳开启时间,从而有效地减少和消除了仪表盘表面的熔接痕.试模结果表明,汽车仪表盘表面无明显熔接痕;基于顺序阀的热流道浇注系统可以推广至其他复杂结构或对表面质量要求较高的塑料制品. 相似文献
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结合注塑模拟分析软件Moldflow和正交试验法,对不同工艺条件下的塑件成型过程进行模拟分析,确定塑件制品品质评价指标为制品体积收缩率、表面缩痕指数和最大翘曲量,运用模糊数学中的综合评判法,建立主要成型工艺影响因素的多指标综合评价数学模型;通过对综合目标值的极差分析,确定熔体温度、模具温度、注射时间、保压压力、保压时间等工艺参数对综合目标值的影响程度的大小,绘制因素水平影响趋势图,分析得出最优的工艺参数组合方案,并对该工艺组合方案进行模拟验证。 相似文献
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《塑料工业》2019,(10)
针对某汽车音响面板在注射成型过程中易发生翘曲变形的现象,在该塑件工艺分析和翘曲变形预测理论分析的基础上,利用UG和Moldflow构建了该塑件的三维模型和分析模型,设计了以翘曲变形值最小为实验目标和以充填时间A、熔体温度B、模具温度C、保压压力D和保压时间E为因子的正交实验方案,并运用Moldflow进行了注射成型工艺模拟实验。通过对实验结果进行极差和方差分析得出,对塑件的翘曲变形量影响程度从大到小依次为DBACE,保压压力占比65.76%,最优工艺参数为充填时间1.4 s、熔体温度250℃、模具温度60℃、保压压力64 MPa、保压时间11 s,其翘曲变形值为0.549 7 mm,比用推荐工艺参数的翘曲变形值减少了24.84%。实践表明,采用该优化工艺生产的塑件,翘曲变形小,无熔接痕,质量优良,易于装配。 相似文献
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《塑料科技》2021,(8)
针对某35%玻纤增强尼龙材料的挡油板,利用计算机辅助技术对其注塑成型过程进行模拟。基于推荐工艺参数计算得到挡油板的最大翘曲变形量为4.704 mm,缩痕指数为0.313 9%,不满足设计指标要求。设计正交试验,分析得到各工艺参数对其最大翘曲变形的影响程度排序为:保压时间保压压力熔体温度冷却时间模具温度;对缩痕指数的影响程度排序为:保压时间冷却时间模具温度保压压力熔体温度。综合分析得到优化的工艺参数组合为A_2B_4C_2D_1E_4,仿真结果显示,最大翘曲变形量及缩痕指数相比初始工艺结果分别降低40.1%、50.9%,且满足设计指标要求,实际试模状态也验证其应用于生产的可行性。 相似文献
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《现代塑料加工应用》2017,(3)
以汽车水室为例,将Taguchi试验设计与CAE模拟相结合,以翘曲变形量和顶出时的体积收缩率作为质量指标,分析模具温度、熔体温度、保压压力、保压时间和冷却时间对塑件质量的影响规律,通过均值分析找到各指标的优化工艺参数组合,并运用加权综合评分法,得出兼顾翘曲和收缩的最佳工艺参数组合。实际生产表明该方法能有效提高塑件产品质量。 相似文献
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以降低注塑件翘曲值为目标,采用正交试验法,得到注塑成型工艺参数对翘曲值的影响程度由强到弱依次为保压压力、熔体温度、注射时间、保压时间和冷却时间。对单个注塑成型工艺参数变动和多注塑成型工艺参数交互作用进行了分析。结果表明:延长注射时间或升高熔体温度,均可使翘曲值先增大后减小;增大保压压力或延长保压时间均可使翘曲值逐步缩小;延长冷却时间,翘曲值则先减小后增大;翘曲值在保压压力与熔体温度、注射时间与熔体温度的交互作用下发生显著变化,而保压时间与保压压力、保压时间与熔体温度的交互作用则对翘曲值的影响不明显。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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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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. 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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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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