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硫化温度测定与经济效益 总被引:1,自引:0,他引:1
硫化温度测定与经济效益化工部北京橡胶工业研究设计院傅彦杰像轮胎一类多部件的橡胶厚制品,其理想的硫化工艺条件,是在一定压力和温度条件下,经过一定时间的加热而启模时,各部位均恰好达到正硫状态,即希望为适应各部位不同性能要求的各胶料之间获得良好的硫化匹配。... 相似文献
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采用ZLW16型智能硫化测温仪对厚壁圆桶形橡胶制品进行硫化温度的测定,可得出制品内部硫化温度的分布状态与各部位的硫化程度。测试结果表明该制品中心部位与外表面存在显著的差异。认为缩短现行硫化条件下的硫化时间、降低硫化温度、在硫化初期采用逐步升温的硫化方法、不同部位采用硫化速度不同的胶料均可减少这种差异。 相似文献
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合适的硫化工艺条件是保障橡胶制品质量的重要加工因素,轮胎硫化的均匀程度直接影响其使用性能,而轮胎硫化过程中内部温度的分布对橡胶轮胎的硫化程度起着决定性的作用。因此,正确地预测硫化过程中的温度历程对轮胎生产质量和效率的提高非常重要。本来橡胶厚制品硫化(工艺)时间的确定比较复杂,对于像轮胎这样的钢丝和橡胶交替迭合的厚制品则更甚。迄今国内外橡胶厚制品 相似文献
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力车外胎的理想硫化条件是使外胎各部位都达到正硫化状态。但在实际生产中,却很难做到。由于外胎是一种非等厚制品,且橡胶又是热的不良导体,由于各部位与热源的距 相似文献
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利用ANSYS热分析模块,得到圆柱形橡胶厚制品在传统工艺条件下的温度变化过程,并绘出制品不同位置胶料的硫化效应曲线。根据橡胶材料的硫化条件,计算得到其最小硫化效应及最大硫化效应,结果发现传统工艺条件下的制品在内层达到最小硫化效应时外层严重过硫。改变工艺条件,通过APDL参数化语言设计,实现由5级硫化温度与9级硫化加热时间组成的45组不同工艺条件的循环分析、结果存储及自动筛选,得到硫化质量满足要求且效率相对较高的工艺组别。结果表明,采用APDL参数化语言,进行数值模拟分析,能够实现橡胶厚制品硫化工艺条件的优化设计。 相似文献
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一、前言欲对巨型厚壁橡胶制品准确地选择其硫化温度和时间,往往是困难的。因为橡胶的导热性极差,当厚制品的中心部位胶料恰好处于正硫化时,而其表面的胶料则必定已经过硫化。因而导致制品的整体性能遭受严重的损害。有鉴于此,人们通常在热传导基本与温度无关的简单假设下(实际上是温度提高,则导热性增加),采用比较低的温度对厚壁制品进行硫化,以适应其内外温度存在差异所带来的不利影响,即传统的厚壁制品采用低温长时间的硫化方法。但这大都不能有一个量化的概念。某一大型橡胶制品厂生产一种巨型厚壁橡胶制品,尽管其已拥有众多… 相似文献
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研究了不同结构化控制剂搭配、硫化剂和减振填料用量对硅橡胶性能的影响,硫化时间、升温间隔对硅橡胶硫化效果的影响,脱模温度、放气量、工装设备对硅橡胶制品质量的影响。结果表明,采用高摩尔质量硅橡胶、气相法白炭黑,配合适量的结构化控制剂,可制备拉伸强度8 MPa以上、无结构化的硅橡胶;随着减振填料的大量填充,硅橡胶的力学性能呈下降趋势;随着硫化胶放气量的增加,大尺寸制品芯部有开裂的倾向。硅橡胶混炼胶用过氧化二异丙苯作硫化剂,采用分段升温、长时间硫化、保压降温工艺,可获得密实无缺陷的厚型制品。较佳工艺为:100份摩尔质量大于69×104g/mol的甲基乙烯基硅橡胶生胶、45份气相法白炭黑、6份羟基硅油、1份二甲基二乙氧基硅烷、1~2份DCP、2~5份氧化铁、10~40份减振填料,硫化时间选择厚制品157℃±1℃的传热时间,分段升温值15℃、升温间隔时间10~20 min、平均升温速率0.75℃~1℃/min,脱模温度根据制品厚度选择室温~80℃,放气量0.20%~0.27%,模具采用大间隙和小溢料槽。 相似文献
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Laksamon Raksaksri Saowaroj Chuayjuljit Phasawat Chaiwutthinan Anyaporn Boonmahitthisud 《乙烯基与添加剂工艺杂志》2019,25(Z2):E28-E38
This study aimed at preparing nanocomposite from epoxidized natural rubber with about 40 mol% epoxidation (ENR40), vinyl acetate ethylene copolymer (VAE) contained about 70 wt% acetate groups and nanosilica (nSiO2). Two parts by weight per hundred parts of rubber/resin of nSiO2 were assembled to 80/20 (w/w) ENR40/VAE blend via latex blending. The resulting nanocomposite latex was coagulated before compounding with curing agents in an internal mixer. Tetrabenzylthiuram disulphide was used as a non‐carcinogenic accelerator in three sulfur vulcanization/curing systems, namely conventional (CV), semi‐efficient (semi‐EV) and efficient (EV) systems. The rubber compounds were sheeted on a two‐roll mill and press‐cured using a compression molding machine. Influence of curing systems on cure characteristics, tensile properties, thermal stability, dynamic mechanical properties and oil resistance of the nanocomposites was investigated. The results revealed that the CV system exhibited the highest crosslink density, tensile properties and storage modulus, while the EV system exhibited the longest scorch and cure time and the highest thermal stability and oil resistance. Moreover, the percentage retention of the tensile properties after thermal aging for CV system was lower than that of semi‐EV and EV systems. However, the pristine ENR40 and 80/20 (w/w) ENR40/VAE blend were also prepared for comparison. J. VINYL ADDIT. TECHNOL., 25:E28–E38, 2019. © 2018 Society of Plastics Engineers 相似文献
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Studies into solvent resistance and aging properties of blends of natural rubber and epoxidized low molecular weight natural rubber were carried out. Vulcanization of the blends using the semi‐efficient vulcanization (semi‐EV) system was found to have curing advantages over conventional vulcanization (CV) and efficient vulcanization (EV) systems. The rheological properties (cure time, t90, and scorch time, t2), solvent resistances, and aging properties of the vulcanizates were found to improve as the level of epoxidized low molecular weight natural rubber in the blends increases. The mechanical properties of the blends were also found to be within the accepted level for NR vulcanizates. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1733–1739, 2005 相似文献
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《国际聚合物材料杂志》2012,61(3-4):597-615
Abstract The cure time of accelerated sulphur vulcanization of Epoxidized Natural Rubber (ENR 25) was studied while one grade of unmodified natural rubber– Standard Malaysian Rubber Light (SMR L) was used as a control. Five accelerators, viz. 2-mercaptoben-zothiazole (MBT), tetramethylthiuram disulphide (TMTD), zinc dimethyldithiocarbamate (ZDMC), N-tert-butyl-2-benzothiazylsulphenamide (TBBS) and diphenylguanidine (DPG) were used in the study and the vulcanization systems used were conventional vulcanization (CV), semi-efficient vulcanization (semi-EV) and efficient vulcanization (EV). Monsanto Moving-Die Rheometer (MDR 2000) was used to determined the cure time in the temperature range of 100-180°C. The results indicate that cure time decreases exponentially with increasing temperature for the two rubbers studied. At a fixed curing temperature, ENR 25 shows shorter cure time compared to that of SMR L. This has been attributed to the activation of the double bond by the adjacent epoxide group in ENR 25. Studies of the effect of varying amounts of M Bata a fixed sulphur concentration show that cure time decreases as the accelerator concentration increases. ENR 25 shows higher torque maximum than SMR L. This observation can be related to the oxirane group which is bulky and thus accounts for increased glass; transition temperature with increase in the level of epoxidation. Of the vulcanization systems, CV shows the highest torque maximum followed by semi-EV and than EV. This trend can be attributed to the amount of active sulphurating agent which increases with increasing accelerator concentration. It was also found that the influence of accelerator/sulphur ratio becomes less significant as vulcanization temperature increases. 相似文献
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根据活塞原理设计变温变压硫化装置,并应用该装置研究硫化温度及硫化压力对天然橡胶胶料基本物理性能的影响规律。结果表明本研究设计的模具可以实现变温变压硫化,并得出胶料硬度和弹性模量随硫化温度的升高先升高后下降、随硫化压力的增大呈增高趋势的结论。 相似文献
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研究了添加不同用量的助交联剂齐聚酯和三甲基丙烯酸三羟甲基丙烷酯(TMPTMA)氢化丁腈橡胶的硫化特性、力学性能,并对比了两种助交联剂对氢化丁腈橡胶的硫化特性、力学性能、老化性能、高温拉伸性能、耐磨性能和加工性能的影响。结果表明:随着齐聚酯和TMPTMA含量的增加,橡胶的扭矩增大,硫化时间缩短;拉伸强度基本不变,硬度、100%定伸应力、撕裂强度逐渐提高,拉断伸长率、回弹性减小。与添加齐聚酯的橡胶相比,添加TMPTMA橡胶的扭矩较大,硫化时间较短;对比添加齐聚酯和TMPTMA的橡胶,它们的力学性能、老化性能、高温拉伸性能和耐磨性能都非常接近,可见它们在硫化过程中的作用原理相似。由橡胶加工分析仪可知,添加TMPTMA橡胶的储能模量较小,损耗因子较大。 相似文献