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FRP Pipe Production Process

Jul 25, 2020

 FRP pipes are made of resin (food grade resin is used to transport drinking water), glass fiber, and quartz sand as raw materials. They are made by a special process. Today we briefly summarize the process flow:

   (1) Preparation process

  A, equipment debugging. First, carefully check whether the equipment operation and working parts are normal, especially carefully check whether the resin-curing agent two-component pump is clogged, and whether the ratio meets the design requirements; ensure the lining, winding, trimming, demoulding and other equipment Stable operation and working accuracy;

  B, clean the mold. The mold surface is required to be free of pits, dust, debris and other attachments. The mold surface must be smooth. If there is a problem, repair and maintain it in time;

  C, wrapped polyester film. In order to facilitate the demolding of the pipe, the surface of the mold should be covered with a layer of polyester film, the overlap width of the film is 1~2cm, and the thickness is between 40um. It is required that the film has no damage, no wrinkles, and both sides are smooth and clean. The quality of film products meets the requirements of GB 13950-1992.

       FRP pipe

   (2) Lining process

  A, lining resin preparation. According to the resin formula system made by the quality inspection department according to the working environment and temperature conditions at the time, the lining resin should be blended, and the amount of ingredients should be reasonably controlled according to the manufacturing schedule. When the on-site situation changes, the quality inspection department and the manufacturing department should adjust the formula in time and prepare the required resin according to the new formula;

  B. Preparation of reinforcement materials. According to the design requirements, transport the reinforcement materials needed to make the inner lining to the designated location, and cut and process some wide-format reinforcement materials to the design width;

  C. Production of lining layer. The inner lining is made according to the design requirements. Reasonable tension should be applied to each single layer during the laying process, and an appropriate amount of overlap should be applied to each other, and the combined pressure roller should be used to repeatedly roll out the bubbles to ensure that the fiber is completely saturated. And require each reinforced material layer to meet the designed resin content requirements;

  D, preliminary self-inspection. After laying each layer according to the design requirements, the operator is required to perform preliminary quality inspection: whether the inner lining reaches the design thickness, whether there is poor glue or glue hanging in some parts, whether there are white spots, bubbles, etc., if the above situation occurs Report and take measures in a timely manner;

  E, enter the far infrared deep curing process of the lining.

   (3) Far-infrared deep curing: FRP pipes must be subjected to far-infrared deep curing, the purpose is: to improve the curing degree of the lining layer, and improve the corrosion and temperature resistance of the pipeline;

   (4) Process quality inspection: before winding, reconfirm that the inner lining has no bubbles, pores, impurities, smooth surface, reasonable resin content, no white spots and poor local curing. It is necessary to carefully check whether the inner lining is qualified, and the unqualified ones are strictly prohibited to be wound on the machine.

  (5) Winding process: Input the designed parameters into the microcomputer, and after the lining is solidified, the microcomputer controls the reciprocating winding with alkali-free and twist-free glass fiber until the thickness of the winding layer. Apply an outer protective layer with 100% resin content to the specified thickness. The resin content of the winding layer is generally about 35%, and its thickness depends on the strength and rigidity of the pipeline design.

   (6) Infrared curing: The pipeline enters the curing stage. During the curing process, the mold should be kept rolling at an appropriate speed to make it evenly cured. During the curing process, attention should be paid to monitoring the temperature of the tube body and reasonably adjusting the curing plan.

   (7) Trimming and demoulding: when the Barcol hardness of the pipeline is greater than 30, trim the pipe port. Then use a hydraulic stripper to separate the pipe and the mold, and mark the middle part of the pipe as required.

(8) Pipeline hydraulic test and placement: each batch of pipelines shall be subjected to hydraulic test according to the regulations, filled with water, and evenly boosted to 1.5 times the design pressure of the pipeline, and kept for no less than 2 minutes, carefully check the surface and Pressure gauge. After the pressure test is qualified, the pipeline is supported at two points.