子午线航空轮胎带束条挤出工艺技术研究

为满足子午线航空轮胎高内压、高速度、高载荷、大变形、抗冲击的的使用条件,在覆胶胎体帘线和特制波纹保护层之间,采用缠绕带束条的方法形成环形网状结构作为胎体带束层.带束条采用挤出法生产,本文详细论述带束条挤出法生产及其工艺技术控制过程,为提高航空轮胎缠绕带束层质量,优化产品结构奠定良好的基础.     

不同骨架材料对轮胎接地印痕的影响

试验研究采用锦纶帘线、芳纶帘线以及芳纶与锦纶复合帘线作胎体帘布层或带束层骨架材料对轮胎接地印痕的影响。结果表明：采用相同帘线作胎体帘布层骨架材料、不同帘线作带束层骨架材料时,带束层帘线刚性越大,轮胎接地印痕长轴冠中长度越小,短轴长度越大,矩形率越大;采用锦纶帘线作胎体帘布层和带束层骨架材料的轮胎接地印痕形状与采用复合帘线作胎体帘布层和带束层骨架材料的轮胎相似;使用相同原材料（除骨架材料外）、采用相同工艺和模具硫化的轮胎,在相同充气压力、负荷和下沉量下,接地印痕面积比较接近。     

现代子午线轮胎钢丝骨架材料及其发展趋势

现代轮胎制造技术的快速发展,推动着轮胎工业不断生产出更节能、更安全、成本更低、寿命更长的轮胎。作为极具竞争力的子午线轮胎骨架材料,钢丝帘线不断适应并引领着这种发展趋势。国外载重子午线轮胎胎体大多选用密集型钢丝帘线,有不用外缠丝的趋势;带束工作层大部分采用开放型高强度钢丝帘线;带束保护层多采用全渗胶型钢丝帘线;大部分厂家的轮胎胎圈加强层采用专门的钢丝帘线,也有轮胎厂家采用多层锦纶帘布。全钢轻载子午线轮胎胎体和带束层钢丝帘线的选择趋势与载重子午线轮胎基本相同。轿车子午线轮胎带束层主要采用开放型高强度钢丝帘线,部分轮胎厂家仍采用传统结构钢丝帘线。有的轮胎胎圈采用钢丝帘线替代胎圈钢丝。综观近年来胎体和带束层帘线的发展,其共同之处在于不断采用更高强度的高等级材料。由于作用不同,对带束层帘线而言,通过改善渗胶性能来避免腐蚀至关重要;对胎体帘线而言,无外缠丝的紧密型帘线由于不存在内层和外缠丝的磨损,因而具有较高的抗疲劳性能;对于保护层帘线,覆胶后具有高破断伸长率的抗冲击帘线则很好地满足了吸收冲击能的要求。子午线轮胎的骨架材料及其发展受到业内的关注。     

子午线轮胎中骨架结构的剖析研究

剖析全钢载重子午线轮胎、轻型载重子午线轮胎和轿车子午线轮胎3种进口品牌轮胎,分析了3种轮胎的骨架结构设计特点。结果表明：11R22.5全钢载重子午线轮胎采用3层带束层和1层胎体层,35×12.50R20LT轻型载重子午线轮胎采用2层冠带层、2层带束层和3层胎体层,225/65R17轿车子午线轮胎采用1层冠带层、2层带束层和2层胎体层。剖析知名品牌子午线轮胎的骨架材料和结构设计特点,对轮胎设计与性能提升积累数据与经验具有重要意义。     

航空轮胎的发展概况（一）

介绍航空斜交轮胎和航空子午线轮胎的发展概况。航空斜交轮胎技术的主要发展方向：降低断面高度,优化胎面形状和花纹结构,采用胎面增强结构,提高胎体强度。航空子午线轮胎普遍采用尼龙帘线作骨架材料,芳纶帘线是理想的骨架材料,聚酮帘线和复合帘线发展前景良好。航空子午线轮胎胎面、带束层、胎体、胎侧和胎圈结构必须不断优化,以适应高性能飞机的发展。     

二段成型全地形车子午线轮胎的开发

介绍二段成型全地形车(UTV)子午线轮胎的开发。在对样胎配置进行分析的基础上,确定28×10R14 UTV子午线轮胎采用胎体+带束层+冠带层的结构,具体配置为:胎体骨架材料930dtex/2锦纶66帘线,胎体胎冠角20°;带束层骨架材料930dtex/2锦纶66帘线,带束层胎冠角65°;冠带层骨架材料1400dtex/2锦纶66帘线,一字缠绕,交叠5mm;钢丝圈Φ0.96mm钢丝,5×4排列;三角胶尺寸(高×宽) 35mm×5mm。成品UTV子午线轮胎性能达到相关要求,相对带束斜交轮胎,子午线轮胎外缘尺寸的稳定性和动平衡性能提高,原材料成本降低10.76%。     

子午线轮胎用钢丝帘线的发展方向

子午线结构是轮胎发展方向,钢丝帘线是制造子午线轮胎的骨架材料,轿车轮胎,轻型和重型载重轮胎的带束层,重型载重轮胎的胎体和带束层都要用钢丝帘线做骨架材料。本文结合近年出现的几种新结构钢丝帘线简要介绍钢丝帘线的发展方向。     

高耐切割性耐剥离性航空充气子午线轮胎

通过采用聚酮纤维帘线作为带束层保护层帘线,既可保持与芳族聚酰胺帘线相同的耐切割性,还可提高航空充气子午线轮胎带束层保护层与胎面之间的耐剥离性。     

半钢轿车子午线轮胎工厂生产工艺

子午线轮胎胎体帘线排列方式与斜交轮胎不同,不是交叉排列,是与轮胎断面平行与胎冠中心呈90°角或接近90°角排列,由帘线周向排列或接近周向排列的带束层箍在胎体上形成一条几乎不能伸张的刚性环形带.半钢子午线轮胎胎体骨架采用人造丝或其他纤维,带束层的骨架材料采用钢丝帘线,一般而言,轿车胎都是半钢子午线轮胎,卡车胎都是全钢子午...     

子午线轮胎带束层角度对轮胎印痕的影响

试验研究以芳纶为胎体、以芳纶与锦纶复合帘线为带束层骨架材料的子午线轮胎带束层角度对轮胎印痕的影响.试验结果表明:在同种条件下,随着带束层角度的变化,轮胎的接地印痕和受力分布发生变化;相应增大、减小内、外层带束层的角度,可减小接地印痕长短轴长度比值,印痕边缘趋于圆滑,轮胎接地面受力更加均匀.     

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。