气力输送过程中炭黑粒子破碎率影响因素分析

分析气力输送过程中炭黑粒子破碎率的影响因素。炭黑品种及造粒方式、炭黑粒子压碎强度、输送距离、输送气速、输送方式、输送管道清扫对炭黑粒子破碎率的影响较大。综合考虑各方面因素,对气力输送系统优化提出建议:湿法造粒炭黑粒子破碎率明显小于干法造粒炭黑,应按造粒方式分别设定炭黑粒子破碎率指标,炭黑造粒应优选湿法造粒工艺;为了保证输送后炭黑粒子破碎率小于10%,炭黑粒子压碎强度应大于30 g,同时炭黑粒子压碎强度分布不宜过宽;在气力输送系统中采用比例调速阀,通过自动控制系统自动调节炭黑输送气速,以实现不同炭黑在最佳状态下输送;尽量减小管道清扫次数。     

炭黑气力输送中粒子破碎问题及对胶料的影响

分析炭黑粒子破碎率对炼胶工艺的影响及气力输送中炭黑粒子破碎的原因,指出炭黑比表面积、炭黑粒径分布、输送压力参数、输送方式、输送管材料和输送距离是影响炭黑破碎率的主要因素。通过对压送罐开启压力、主管压力、辅管压力、结束弯管压力和辅管开启压力进行优化,可相应减小输送时的炭黑破碎率;采用密相输送、选择摩擦因数较小的管道材料和尽量减小输送距离也可减小输送时的炭黑破碎率。     

炭黑气力输送中破碎率及气量控制的试验研究

近年来，随着气力输送行业的发展，人们对输送后物料的破碎率要求趋于苛刻。在炭黑密相气力输送试验的基础上，对炭黑输送中的破碎率进行了正交试验，并研究了输送气量控制、气速对破碎率的影响，认为气速是影响粒子破碎率的主要因素，在保证输送正常（不堵管）的情况下，降低输送气速，可大大地降低炭黑在气力输送中的破碎率。     

炭黑气力输送流动特性研究

对气力输送过程中炭黑的流动特性进行了试验研究.依据试验结果,分析了炭黑的粒径大小与输送管道阻力、输送压力与输送管道压力损失、气体流量与炭黑的质量流量、输送压力与炭黑粒子破碎率之间的关系,为炭黑气力输送系统的设计及其工艺参数的确定提供参考.     

优化密炼机上辅机系统 提高密炼机炼胶效率

探讨气力输送过程中各工艺辅助时间及成本和炭黑粒子破碎对密炼机炼胶效率的影响.通过采用相应输送管材和相应技术措施防止结垢,并优化工艺缩短炭黑投料和注油等辅助过程时间后,可大大提高密炼机混炼效率.针对密炼机投料过程中易产生堵塞的问题,采用圆形偏心料斗和软斜槽及管夹阀后,可大大减少堵塞,提高炼胶效率.     

炭黑气力输送系统分析研究

分析了不同炭黑气力输送系统的工作原理及主要优缺点，重点探讨了炭黑正压密相气力输送系统的设计流程、主要零部件的设计及选型，为正确选择和设计炭黑气力输送系统提供依据。     

炭黑在气力输送过程中破碎率的影响因素分析

介绍了在气力输送系统中炭黑的破碎机理,分析了炭黑破碎率的影响因素,指出炭黑品种,炭黑的堆积密度、压碎强度和不同粒径质量分布等物性,输送管道长度及其布置、输送压力和炭黑输送速度等工艺参数是影响炭黑破碎率的主要因素,并通过实验结果进行了论证.     

GK400密炼机上辅机自动配料及控制系统

介绍GK400密炼机上辅机自动配料及控制系统。该系统主要由加料系统、贮存系统、输送系统和称量系统组成。炭黑双管气力输送可保证输送气压和速度，内橡胶管可以降低炭黑因输送而导致的破碎。并能耐炭黑侵蚀，输送时袋滤器能有效控制炭黑的飞扬。称量系统可完成炭黑、油料和胶料的称量和加料。其控制系统采用微机＋PLC的结构，减小了系统的复杂程度。软件采用全中文界面，操作非常方便。     

炭黑气力输送形式的对比分析

为保证橡胶厂炼胶质量的均一稳定和炼胶车间的环境整洁,作为补强剂的炭黑采用气力输送方式是必然的。分析了不同炭黑气力输送形式的工作原理、性能特点及主要优缺点,重点探讨了炭黑正压密相气力输送形式的结构组成、设计流程、主要零部件的设计,为正确选择和设计炭黑气力输送系统提供依据。     

炭黑密相气力输送系统设计

随着橡胶工业的发展，以及气力输送特有的优点，气力输送系统越来越广泛地应用于输送炭黑的过程中。以炭黑气力输送系统为研究对象，详细介绍了系统设计的基本参数确定、气力输送形式的确定、压送罐客积的设计、输送管道的设计，并通过输送系统压力降的计算验证了设计参数的取值是合理的。     

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。