挤压造粒机切粒不合格的分析处理

针对全密度聚乙烯装置挤压造粒机生产的聚乙烯颗粒不合格的现象及轴承振动烈度接近上限值的问题,通过分析确定检修方案,解决问题.     

挤压造粒机切粒不合格的分析处理

针对全密度聚乙烯装置挤压造粒机生产的聚乙烯颗粒不合格的现象及轴承振动烈度接近上限值的问题,通过分析确定检修方案,解决问题。     

挤压造粒机组安装施工技术

挤压造粒机组在聚乙烯装置和聚丙烯装置中属于核心设备,结构复杂,安装施工工序多,找正难度大,本文从挤压造粒机的工作原理入手,详细叙述了挤压造粒机组的安装、找正方法,对挤压造粒机组现场安装施工有一定的指导意义。     

挤压造粒机组安装施工技术

挤压造粒机组在聚乙烯装置和聚丙烯装置中属于核心设备,结构复杂,安装施工工序多,找正难度大,本文从挤压造粒机的工作原理入手,详细叙述了挤压造粒机组的安装、找正方法,对挤压造粒机组现场安装施工有一定的指导意义。     

LCM400挤压造粒机组在聚乙烯装置中的应用

挤压造粒机组的可靠稳定运行对保证聚乙烯装置长周期、稳定生产起关键作用。介绍了LCM400型挤压造粒机组的主要技术参数、结构特点及主要部件材质选择，并与CIM410型挤压造粒机进行比能耗和可靠性比较，结合其在聚乙烯装置的应用，指出该型机组存在的问题，并提出了相应的建议。     

首台国产大型PE挤压造粒机试运行

<正>2012年12月16日,齐鲁石化塑料厂新建25万t/a高密度聚乙烯装置,即该厂2号高密度装置挤压造粒机组空载试运获得成功。该装置使用的造粒机是我国自主研发的用于大型聚乙烯(PE)装置     

国产首台挤压造粒机成功在齐鲁石化塑料厂试运行

齐鲁石化塑料厂新建25万t/a高密度聚乙烯装置,即该厂2号高密度装置挤压造粒机组空载试运获得成功。该厂新建高密度聚乙烯装置,历时21月个施工,建设总投资8.77亿元,计划于2013年初投产使用,目前正处在设备试车等生产准备阶段。该装置使用的造粒机,是我国自主研发的、用于大型聚乙烯装置的首台挤压造粒机组。为做好     

延长挤压机切刀使用寿命的研究

目前线性低密度聚乙烯装置使用LCM450H型挤压造粒机,由日本神户制钢所生产,是国内最大的挤压造粒系统。在该机组中,切刀为易损部件,其使用情况与产品质量和装置成本有直接的关系。本文介绍了影响切粒机切刀使用寿命的因素及延长使用周期的方法。     

复混肥料对辊式挤压造粒机的研制

本文简要介绍了化肥挤压造粒机的概况,阐述了对辊式造粒机的工作原理和成型过程,并应用了J.R.Johanson有关轧辊的计算公式,设计了国内第一台干式高轧辊比压的挤压造粒机。经考核,本机设计合理,运转平稳可靠,其产品的抗压强度符合我国复混肥料专业标准的要求。     

大型双螺杆挤压造粒机结构特点及制造过程质量控制

介绍了目前国内外大型双螺杆挤压造粒机的发展现状、工作原理、结构特点及应用工况,并结合作者长期从事大型双螺杆挤压造粒机制造过程的质量控制经验,从业主使用角度,分析了大型双螺杆挤压造粒机制造过程的质量控制要点。     

中原聚乙烯生产现状及发展建议

介绍了中原乙烯聚乙烯装置的生产运行情况,并与国内外同类装置进行了比较,指出了聚乙烯装置的不足,对下一步发展提出了建议。     

注射成型机四孔斜排双曲肘合模机构的运动和力学特性分析

利用机构学的方法对注射成型机四孔斜排肘杆式合模机构进行了运动和力学特性分析。推导出模板行程、油缸行程、速度变化系数、锁模力和增力倍数等参数的计算公式,并介绍了初始角和临界角的计算方法,为注射成型机合模机构的设计提供了理论依据。     

新型液压轮胎硫化机后充气装置卸胎机构

介绍新型液压轮胎硫化机后充气装置卸胎机构。卸胎机构由气缸驱动转套带动转轴,转轴通过齿轮啮合实现整体传动,从而带动若干个（片）夹持器张开闭合,实现压紧、释放轮胎的动作;夹持器收缩后基本呈圆形,避免与胎圈干涉。卸胎机构运行稳定,重复动作精度高,成本低,适用于中小型轮胎硫化机。     

Chlorocarboxylation of polyethylene. II. Reaction mechanism of the process

Chlorocarboxylated polyethylene (CCPE) is produced by simultaneous reaction of chlorine and maleic anhydride (MA) with polyethylene (PE). Hydrogen atoms on the PE chain are substituted either by chlorine atoms or by maleic anhydride moieties. The reaction mechanism involves creation of an active site, i.e. a radical on the PE chain. There is competition between chlorine and MA molecules for the reaction with this macroradical. Chlorine reacts to give chlorinated polyethylene (CPE) type segments, while MA reacts as a single unit (as chloro derivative) without forming any graft copolymer. There is a marked reduction in the rate of chlorination of PE due to the presence of MA. This is probably due to the competitive nature of the process and the radical scavenging action of MA.     

Polyethylene and polytetrafluoroethylene crystals: chain folding,entropy of fusion and lamellar thickness

Chain folding in polyethylene (PE) and in polytetrafluoroethylene (PTFE) crystallites is simulated on the computer in an attempt to determine if the large disparity in their lamellar thicknesses has its origin in any differences between their inherent abilities to fold. PE and PTFE chains of 6 to 15 carbon atoms are permitted to adopt each f their many rotational isomeric state (RIS) conformations, and each is checked for the presence of a chain fold. The conformational energetics of both polymers are used to calculate the probabilities of generating both randomly and adjacently re-entering chain folds. Depending on the RIS model adopted for PTFE, calculated probabilities for generating randomly re-entering folds are found to be comparable in PE and PTFE. Adjacently re-entering folds, however, are much more easily formed in PE than in PTFE. Despite the greater ease of folding PE chains, the relative energies required to create a unit area of chain fold are estimated to be nearly the same for both polymers in agreement with results obtained from the kinetic theory of chain folding. Consequently, in agreement with the recent proposal of Bassett and Davitt, it is concluded that the greater lamellar thickness of PTFE crystals is attributable exclusively to their lower entropy of fusion. An analysis of the possible reasons for the low entropy of fusion of PTFE is also presented.     

Relaxation of Rat Aorta by Farrerol Correlates with Potency to Reduce Intracellular Calcium of VSMCs

Farrerol, isolated from Rhododendron dauricum L., has been proven to be an important multifunctional physiologically active component, but its vasoactive mechanism is not clear. The present study was performed to observe the vasoactive effects of farrerol on rat aorta and to investigate the possible underlying mechanisms. Isolated aortic rings of rat were mounted in an organ bath system and the myogenic effects stimulated by farrerol were studied. Intracellular Ca²⁺ ([Ca²⁺]_in) was measured by molecular probe fluo-4-AM and the activities of L-type voltage-gated Ca²⁺ channels (LVGC) were studied with whole-cell patch clamp in cultured vascular smooth muscle cells (VSMCs). The results showed that farrerol significantly induced dose-dependent relaxation on aortic rings, while this vasorelaxation was not affected by N^G-nitro-l-arginine methylester ester or endothelium denudation. In endothelium-denuded aortas, farrerol also reduced Ca²⁺-induced contraction on the basis of the stable contraction induced by KCl or phenylephrine (PE) in Ca²⁺-free solution. Moreover, after incubation with verapamil, farrerol can induce relaxation in endothelium-denuded aortas precontracted by PE, and this effect can be enhanced by ruthenium red, but not by heparin. With laser scanning confocal microscopy method, the farrerol-induced decline of [Ca²⁺]_in in cultured VSMCs was observed. Furthermore, we found that farrerol could suppress Ca²⁺ influx via LVGC by patch clamp technology. These findings suggested that farrerol can regulate the vascular tension and could be developed as a practicable vasorelaxation drug.     

试样厚度对聚乙烯拉伸性能的影响

通过对不同厚度聚乙烯试样的拉伸试验进行分析.结果表明,试样厚度对聚乙烯的强度、应变、拉伸模量均有较大影响,对单位面积的屈服吸收能没有影响;现有塑料制品设计中,材料的拉伸性能和制品厚度为独立参数的做法存在隐患.     

辽化HDPE装置浆液外循环技术改造后釜内的聚合过程分析

通过对辽阳石油化纤公司高密度聚乙烯淤浆聚合装置外循环撤热技术改造前后生产GF7750M牌号产品时聚合过程的工程分析,发现了釜内聚合过程特征的变化,提出了聚乙烯蜡含量的明显上升是引起聚合物粘壁加剧的最直接原因,并通过分析得出了可能导致聚乙烯蜡含量上升的主要因素以及进一步提高装置生产能力的可能性和主要手段。     

Highly ion-conductive solid polymer electrolytes based on polyethylene non-woven matrix

Highly ion-conductive solid polymer electrolyte (SPE) based on polyethylene (PE) non-woven matrix is prepared by filling poly(ethylene glycol) (PEG)-based crosslinked electrolyte inside the pores of the non-woven matrix. The PE non-woven matrix not only shows good mechanical strength for SPE to be a free-standing film, but also has very porous structure for high ion conductivity. The ion conductivity of SPE based on PE non-woven matrix can be enhanced by adding sufficient non-volatile plasticizer such as poly(ethylene glycol) dimethyl ether (PEGDME) into ion conduction phase without sacrificing mechanical strength. SPE with 20 wt.% crosslinking agent and 80 wt.% non-volatile plasticizer shows 3.1 × 10⁻⁴ S cm⁻¹ at room temperature (20 °C), to our knowledge, which is the highest level for SPEs. It is also electrochemically stable up to 5.2 V and has high transference number about 0.52 due to the introduction of anion receptor as an additive. The interfacial resistance between Li electrode and SPE is low enough to perform charge/discharge test of unit cell consisting of LiCoO₂/SPE/Li at room temperature. The discharge capacity of the unit cell shows 87% of theoretical value with 86% Coulombic efficiency.     

ASPEN PLUS SIMULATION OF POLYETHYLENE GASIFICATION UNDER EQUILIBRIUM CONDITIONS

The gasification process of polyethylene (PE) was successfully modeled using a combination of various unit operation modules available in the Aspen Plus simulation package. The study presents significant insight into the effect of various process parameters on the polyethylene gasification process under equilibrium conditions that has not been reported elsewhere. The simulation tool was used to predict the product composition and temperature for varying cases of steam and airflow rates and pressure. Based on the simulation results, the behavior of the conversion process was characterized according to the combined and individual fractional efficiencies. Finally, the optimum conditions that would yield a maximum conversion for the PE gasification process have been identified and reported.