Manufacturing techniques of the plastic-coated steel tube

under the room temperature

Pan Yanhong¹ ， Wang Shuyuan²

(1.Guangzhou Xintao Chemistry Science & Technology Co. Ltd.,Guangzhou 510660 China;

2.  South China University of Technology, Guangzhou 510640,China）
Abstract: The big caliber plastic-coated steel tube has a great need in the market recently, however the cost is very high with the existing technology. The development of the special paint makes the manufacture of the plastic-coated steel tube be possible under the room temperature. This technique requires less treatment on the surface of the tube and needlessness of heat treatment to the tube, in addition, there is no need of large machines. Tubes with caliber above Φ10-3800 can be painted both inside and outside, products reach the national standard. This techniques meets the demand of the of the steel tube of big caliber paint mold. The coat contains nontoxic and elastic paint which is of low water resistance and which schleps rust and guard against rust and which is of the virtue of keeping clean and unpoisonous, also it can depress the growth of the lichen and worm effectively.
Key words: plastic-coated steel tube; manufacturing techniques; room temperature; big caliber
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1．前言
　　钢管在传输介质时或置于大气、土壤等自然环境中，管壁都会经受不同程度的腐蚀，直接影响了管道的使用寿命。食品、饮用水管道、石油化工管道等诸多介质都不允许管壁腐蚀而影响传输介质受到污染，钢管壁防腐防护成为关键技术问题。涂塑钢管就应运而生，目前国内钢塑管是从衬塑走向了涂塑，涂塑材料大都采用塑料粉体材料，其中性能较好的是聚乙烯（PE）和环氧（EP）。但它们的施工要求高，工艺难度大，品质控制不易，设备投资大，严重影响涂塑钢管的推广与应用，而且国内目前只能生产口径小于ø250mm的涂塑钢管。在常规生产工艺中喷砂过程产生极大污染且对人体造成伤害，而加热过程能耗极大，造成大口径涂塑钢管无法生产。为有效解决大口径涂塑钢管生产难的问题，制作工艺专家组首先从涂层材料上着手，研制并应用了弹性体带锈防锈涂料，再引入防腐及卫生性能较好的防护涂料。采用了常温直接喷涂的方法，解决了大口径钢管涂塑生产难的问题。