The glass fiber tube is formed by infiltrating the glass fiber into a resin and solidifying it in a high-speed polymerization device integrated with photoelectric heat, and is drawn and pulled. Because of the variety of resins used, it is called polyester fiberglass, epoxy glass reinforced plastic, and phenolic glass reinforced plastic. It has the characteristics of light and hard, non-conductive, high mechanical strength, anti-aging, high temperature resistance and corrosion resistance.
       First, the main features of fiberglass tube:
 
       1. Good corrosion resistance. Since the main raw material of FRP is composed of polymer unsaturated polyester resin and glass fiber, it can effectively resist the corrosion of acid, alkali, salt and other media and untreated domestic sewage, corrosive soil, chemical wastewater and many chemical liquids. The erosion, in general, can maintain safe operation for a long time.
 
       2. Good anti-aging performance and heat resistance. The glass fiber tube can be used for a long time in the temperature range of -40 ° C to 70 ° C. The specially formulated high temperature resistant resin can work normally at temperatures above 200 ° C.

       3. Good antifreeze performance. Below minus 20 ° C, no cracking will occur after freezing in the tube.

       4. Light weight and high strength. The relative density is between 1.5 and 2.0, only 1/4~1/5 of carbon steel, but the tensile strength is close to or even higher than that of carbon steel, and the specific strength can be compared with high-grade alloy steel. As a result, it has achieved excellent results in aerospace, rockets, spacecraft, high-pressure vessels, and other applications that require reduced weight.

       5, can be designed well. Flexibility in designing a variety of structural products to meet the requirements of use, can make the product has a good integrity.

       6, good wear resistance. The water containing a large amount of mud and sand was loaded into a pipe to carry out a comparative test on the rotational wear. After 3 million rotations, the wear depth of the inner wall of the test tube is as follows: the steel pipe coated with tar and enamel is 0.53 mm, the steel pipe coated with epoxy resin and tar is 0.52 mm, and the surface hardened steel pipe is glass steel pipe. It is 0.21mm. Therefore, the FRP has good wear resistance.

       7, electrical insulation is good. FRP is a non-conductor. The electrical insulation of the pipe is excellent. The insulation resistance is 1012-1015Ω.cm. It is most suitable for transmission. The heat transfer coefficient of the telecom line dense area and the multi-mine area FRP is very small, only 0.23, which is the steel thousand. In five parts, the insulation performance of the pipeline is excellent.

       8. The frictional resistance is small and the conveying capacity is high. The inner wall of the glass tube is very smooth, and the roughness and friction are small. The roughness factor is 0.0084, while the concrete pipe has an n-value of 0.014 and a cast iron pipe of 0.013.
 
       Second, the production process of glass fiber tube
 
       There are three main types of fiberglass tube production processes: reciprocating filament winding, continuous filament winding, and centrifugal casting.

       Reciprocating fiber winding process (length-fixing method): In this process, the dipping tank reciprocates with the rotating mandrel, and the long-fiber glass wire is supplemented with a certain oblique angle with respect to the mandrel axis, and the auxiliary angle (ie The winding angle is controlled by the ratio of the moving speed of the dipping tank to the speed of the core mold, and the translational movement of the dipping tank is controlled by computerized machine-electricity. The number of winding layers is gradually increased until the wall thickness of the design is reached. After the winding is completed, the resin in the article is substantially cured. After curing, the mandrel is removed from the glass tube.
 
       Continuous filament winding process (continuous method): This process is a feeding station in which the tube is pre-impregnated with roving, chopped fiberglass fiber and resin sand mixture during the movement, and the tube is continuously advanced in the core mold. Made in the middle.

       Centrifugal casting process (length-fixing method): In this process, the cut glass fiber reinforced material and sand are fed into a steel mold fixed on the bearing, and a catalyst-added unsaturated resin is injected into one end of the steel mold. The impregnating reinforcing material, under the action of centrifugal force, the resin replaces the air in the fiber and the filler, thereby producing a non-porous dense composite material, and the inner wall of the tube forms a smooth, smooth and resin-rich inner surface layer due to the centrifugal force, the pipe material Curing at higher temperatures. The pipe manufactured by this method is also called a glass fiber reinforced plastic sand pipe.

       At present, the number of manufacturers using the reciprocating filament winding process in the world is much higher than that of the other two production process manufacturers. One of the reasons is that the glass steel pipe manufactured by the reciprocating filament winding process has wider application and better applicability.