影响压延钢丝帘布空气含量的因素分析

分析了压延过程中对钢丝帘布质量产生影响的混炼胶门尼粘度、压延辊特性(轴交叉和辊弯曲)、压延速度、供胶温度和压延温度等因素。提高压延钢丝帘布质量可有效改善轮胎质量，减少轮胎使用过程中的前期损坏。探讨了提高压延帘布质量的一些途径，确定了合理的工艺条件：胶料门尼粘度[ML(1 4)100℃]80—90；压延温度、供胶温度80—90℃；压延速度宜低。     

天然橡胶对子午线轮胎钢丝粘合胶压延粘辊的影响研究

胶料粘辊是钢丝帘布压延过程中常见的问题,天然橡胶(NR)对钢丝粘合胶的压延粘辊有较大影响。本工作研究表明,生胶的常规指标(如塑性初值、塑性保持率和门尼粘度等)和终炼胶的主要硫化特性(如门尼粘度、F_L和F_max等)均不足以表征其压延粘辊性能。橡胶加工分析仪(RPA)的测试发现,终炼胶的储能模量(G′)与压延粘辊直接相关,G′偏低是导致胶料压延粘辊的根本原因,而NR的热氧稳定性对G′有较大影响,建议采用RPA在160℃下评估生胶的热氧稳定性。     

橡胶机械的维护与检修技术讲座 第8讲 压延联动线使用、维护保养和检修（上）

1 前言压延机及其联动装置是完成橡胶制品生产的重要设备之一,属于精度、自动化程度较高的机械设备,主要用于各种织物(或钢丝)帘布贴胶、布类擦胶及胶料压片、贴合、压型等作业。普通压延机主要由辊筒、辊筒轴承、机架、机座、调距装置、温度调节装置、润滑系统、传动装置和控制系统所组成。其附属装置主要有挡胶和刮胶边装置、扩布与扩边装置、切胶边装置、划气泡装置、测厚装置和供胶装置等。精密压延机除了具备普通压延机上的重要零部件和装置外,还有提高压延精度的辊筒轴交叉装置、预负荷装置、反弯曲装置、热水循环自动控制辊温装置…     

压延胶帘布厚度不均原因分析及解决措施

分析压延胶帘布厚度不均的原因并提出相应解决措施。压延胶帘布厚度不均的原因是辊筒轴线交叉值不合适、辊筒周向表面凹凸异常、辊筒预弯压力过大、辊筒压力波动、辊距不均匀、胶料混炼不均等。通过采取相应措施,压延胶帘布厚度不均问题得到有效解决。     

钢丝帘布压延质量与压延机压力辊位置的关系

通过对不同规格钢丝帘线、相同钢丝帘线不同压延厚度及不同胶料进行压延并测试帘布性能，指出不同规格钢丝帘线对压力辊位置的敏感程度不同；相同钢丝帘线不同压延厚度时，压延厚度越大，对压力辊的位置越敏感，因此需要调整压力辊位置及压力设定值；不同胶料压延时，胶料硬度和门尼粘度增大，压力辊与3^#辊间隙应小一些，而且压延压力应大一些。     

钢丝压延工艺对轮胎质量的影响

钢丝压延是子午线轮胎生产中的重要工序之一,钢丝帘布质量的好坏,直接影响下一道工序的操作质量及轮胎的使用寿命。覆胶钢丝帘布是通过钢丝帘线上锭子、帘线导向排列、整经、供胶、压延、贴聚乙烯垫布、牵引冷却及储布卷取等工艺过程制造出的。本文就Ｓ型四辊压延生产线...     

锦纶66帘布压延工艺控制及常见质量问题解决措施

介绍轮胎用锦纶66帘布压延过程及其工艺控制、压延帘布常见质量问题及其解决措施。严格控制热炼胶塑性值和供胶温度、保证原帘布干燥、导开帘布松紧一致、帘布对中、供胶和递布稳定、帘布压延张力和压延速度合理和均衡、压延机辊温和帘布冷却辊温稳定、压延机积胶量适当、压延帘布卷取协调性好,以及严格工艺操作,可以有效解决压延帘布幅宽和厚度不合格、扒皮、露白、罗股、劈缝、跳线、出兜、压坏和褶子等质量问题。     

橡塑整芯输送带生产工艺及配方的改进

对橡胶整芯阻燃输送带的生产工艺路线进行了改进。用两面一次贴胶代替了原来的出型和成型工艺,使生产工艺大大简化。为与此新工艺路线相配合,还重新设计了新的胶料配方,新配方胶料可通过一次混炼制得,比原配方胶料制备过程大大简化。另外,还具体介绍了采用新工艺路线生产整芯带的混炼和压延工艺。     

压延帘布扒皮掉胶质量缺陷分析及解决措施

对压延帘布扒皮掉胶质量问题进行分析,并提出了解决措施。通过严格控制压延机干燥辊温度、压延主机辊筒温度、压延主机辊筒间堆积胶量、压延帘布胶质量稳定性、压延机主机辊筒辊距、压延机主机辊筒预弯压力,以及严格按照帘布压延工艺标准操作,解决了压延帘布扒皮掉胶问题,大大提高了生产效率,降低了生产成本。     

一种新型的压延机热贴设计

对传统热贴合工艺的设备及工艺流程进行了改进,增加了导辊装置和贴胶装置及引片装置。改进了工艺流程。改造后的热贴合方式可完全在一台压延机上完成整个压延、贴合工序,提高了资源利用率和生产效率,降低了生产成本。     

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。