聚乙烯塑钢缠绕排水管热熔挤出焊接复合热收缩套连接研究与应用

发布时间：2019-02-16 18:13

【摘要】：近年来,聚乙烯管道被广泛应用于市政工程当中,其中,有相当一部分接头采用了热缩带连接或热熔挤出焊连接。这两种连接方式操作简单,连接速度快,连接效果良好,且成本较低,但两种连接方式分别使用时存在诸多缺陷,连接可靠性相对不足。本项目针对两种方法的复合应用进行研究,以期获得综合连接的优异效果。目前,在市政工程中很少有将两种方法联合使用的情况,因此热缩带和热熔挤出焊两种连接复合应用没有施工作业指南及验收标准,更没有系统和完整的技术规程,从文献资料中,也几乎没有将两种方法联合使用的研究成果,为此有必要进一步深入研究两种连接方式的复合操作工艺、复合连接效果、耐久性以及复合性能的检测及评判方法。本文依托中国水利水电七局的塑钢缠绕排水管接头连接研究项目,针对以上问题,从原材料试验分析、复合连接工艺设计、组合连接试件性能测试和全尺寸接头试验等方面对接头作了系统研究。主要内容和成果如下:(1)对PE接头材料作了基本的性能测试,在此基础上,确定了热缩带连接方法中加热喷枪火焰高度、喷枪行走速度与热缩带粘贴温度的关系,以及热缩带粘贴温度与粘结强度的关系。通过加热喷枪火焰高度、喷枪行走速度、热缩带粘贴温度与粘结强度的综合分析,提出热缩带连接加热工艺参数:热缩带连接方法加热火焰高度以15cm左右为宜,加热火焰行走速度以1 0cm/s～12.5cm/s为宜,控制温度在110℃～120℃较好。此外,管材表面油污,灰尘等杂质会显著降低热缩带的粘接效果;(2)通过组合连接和单独热熔连接两种类型的试件试验证明,组合连接试件的拉伸强度高于单独连接试件的强度。组合连接接头在热熔挤出焊焊接断裂之后并不立即破坏,热缩带通过塑性变形仍然能够给试件提供4MPa左右的强度,并且破坏前还会产生较大幅度的变形。无论是热熔挤出焊单独连接还是复合连接,焊缝宽度在4～6mm时达到最高强度;(3)热熔焊和热缩带复合连接的接头抗拉性能和断裂伸长率满足要求,通过单独热熔挤出焊连接试件和热熔挤出焊复合热缩套连接的试件的不透水性试验发现,两种接头在0.4Mpa的水压下均无渗水情况。热熔挤出焊受盐溶液和碱溶液影响较小,但对酸溶液敏感,酸溶液浸泡后强度下降达17.5%;(4)复合连接接头在受压变形过程中完好无损,证明了该连接的可靠性;压缩变形中,热缩带和PE管材的应变较大,钢带应变小,且从30°位置到90°位置逐渐增大,最大应变出现在接头的两侧。
[Abstract]:In recent years, polyethylene pipes have been widely used in municipal engineering. These two kinds of connection modes are simple in operation, fast in connection speed, good in connection effect and low in cost. However, there are many defects in the two connection modes when they are used separately, and the reliability of connection is relatively insufficient. In this project, the composite application of the two methods is studied in order to obtain the excellent effect of the integrated connection. At present, there are very few cases in which the two methods are used together in municipal engineering, so there is no construction operation guide and acceptance standard for the combined application of hot shrinkage zone and hot melt extrusion welding, let alone systematic and complete technical regulations. From the literature, there is hardly any research result of combining the two methods. Therefore, it is necessary to further study the composite operation technology of the two kinds of connection methods and the effect of composite connection. Testing and evaluating methods for durability and composite properties. This paper relies on the joint connection research project of plastic steel winding drainage pipe of the 7th Bureau of Water Conservancy and Hydropower of China. In view of the above problems, from the raw material test analysis, the composite connection process design, The performance tests and full-scale joint tests of combined joint specimens are studied systematically. The main contents and results are as follows: (1) the basic properties of PE joint materials are tested. On the basis of this, the relationship between the flame height, the walking speed and the bonding temperature of the hot necking belt is determined. And the relationship between bonding temperature and bond strength. Based on the comprehensive analysis of the flame height, the walking speed, the bonding temperature and the bonding strength of the spray gun, the paper puts forward the heating process parameters of the hot shrinkage belt connection: the suitable heating flame height is about 15cm. The suitable walking speed of heating flame is 1 0cm/s~12.5cm/s, and the control temperature is 110 鈩，

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