PET熔体直纺夹套管的设计

介绍PET熔体输送的工艺流程,从初选管径、管道中的停留时间,熔体流动的压力降计算,熔体管道的局部压力降,减小管道应力的配管设计,管内其他部件的设计等方面。对PET熔体直纺夹套管的工艺设计进行了论述。     

影响PET直纺FDY满卷率的因素

从熔体输送和纺丝工艺条件分析、探讨影响PET直纺FDY满卷率的因素。控制熔体停留时间小 于30 min,熔体特性粘数(0.645±0.014)dL／g,稳定侧吹风条件并优化其他工艺,PET直纺FDY满卷率可达 90％以上。     

切粒机控制系统中PLC的应用

切粒机在PET装置中占有重要的地位,担负着PET熔体直纺过多产能的调节,多出来的熔体通过切粒机生产成切片,保证了熔体输送主管压力的平稳,从而维持了纺丝高品质平稳地运行。论述了PLC在水下切粒机系统中的各种应用,减少切粒机运行出现故障,为切粒机安全稳定运行打下坚实的基础。     

吸湿排汗抗菌POY135 dtex/72 F涤纶 长丝生产工艺探讨

银系PBT载体抗菌母粒通过低露点干空气加温干燥、螺杆挤压熔融、注射泵计量进入熔体管道和PET熔体进入高效动态混合器,混合均匀抗菌改性PET熔体输送至纺丝箱体计量、冷却、上油、卷绕等。采用"十"字形喷丝孔,纺制吸湿排汗抗菌POY涤纶长丝,研究纺丝工艺条件对吸排抗菌涤纶长丝指标的影响,经过试验,采用纺丝箱体281℃、风压30 Pa、卷绕速度2 875 m/min得到性能良好的吸排抗菌POY涤纶长丝。     

PET直纺超细POY纺丝生产线设计优化

从熔体输送及分配管道、纺丝组件、喷丝板、纺丝箱体、丝束冷却装置、卷绕系统的设计优化等方面,介绍了PET熔体直纺单丝线密度为0.39~0.58 dtex超细POY纺丝生产线的设计特点。通过优化降低了超细纤维的生产成本,提升了企业的竞争能力。     

PP/PET共混熔体的流变性能研究

以PP-g-AA作增容剂,研究了PP/PET共混熔体的流变行为。讨论了温度、剪切速率以及PET和增容剂含量对熔体表观粘度、非牛顿指数等方面的影响。结果表明,PP/PET共混物熔体表观粘度随剪切速率的增大而降低,随PET及增容剂含量的增加而下降,随温度的升高而下降。PET和增容剂的加入,在共混熔体中起到了增塑剂的作用。     

现代BOPET生产线熔融挤出系统配置技术

文章总结了现阶段BOPET生产线切片熔融挤出系统装置配置的技术趋势：PET切片熔融挤出以两台单螺杆挤出机串联方式配置,以提高熔体制备能力和改善熔体质量;熔体过滤器以烧结金属纤维作为过滤介质,以延长使用周期;熔体计量泵采用平面式并联齿轮泵或斜齿齿轮泵,以改善熔体输送的脉动;熔体管径设计主要控制熔体的停留时间,压力降不作为主要考虑因素。     

聚对苯二甲酸乙二醇酯流变性能及熔体热稳定性的研究

本文以国产长征PET F-65和日本三菱C型聚对苯二甲酸乙二醇酯(PET)树脂为重点,研究了PET熔体的热稳定性和流变性能。结果表明:PET熔体对水分十分敏感,微量水分能引起PET熔体在熔融的最初5min内降解。本文计算了上述两种树脂的熔体流动活化能,并通过流变性能的研究,寻找了改善国产PET树脂加工性能的途径。     

共混聚酯与纳米蒙脱土复合物的流变性能

采用RH2000型毛细管流变仪对熔融共混制备的聚对苯二甲酸乙二酯(PET)/聚对苯二甲酸丙二酯(PTT)与纳米蒙脱土(MMT)复合物的流变性能进行了研究.结果表明:PET/PTT共混熔体及PET/PTT/MMT复合物熔体均为假塑性流体;复合物熔体的零切黏度(η0)小于PET/PTT共混熔体的η0,MMT的加入起到增塑剂作用;复合物熔体的黏流活化能高于PET/PTT熔体的黏流活化能,说明对PET/PTT/MMT复合物熔体而言,更适合使用调节温度的方法来控制其流动性.     

再生PET瓶片纺黏针刺非织造布生产线设计优化

介绍了再生PET瓶片纺黏针刺非织造布生产线中切片筛选及输送、结晶及干燥、螺杆挤压机、熔体过滤器、纺丝、气流牵伸、摆丝成网、刺针等系统的设计特点。产品品质优于国家标准指标。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.