Standardized Requirements For Testing Processes Of Fiberglass Reinforced Plastic (GRP/FRP) Pipe Winding Equipment
As the core equipment in the manufacture of composite material pipes, the performance stability of GRP/FRP pipe winding equipment directly determines the structural strength and service life of the product. Establishing a scientific and rigorous testing process is not only a key link in ensuring the quality of the equipment leaving the factory, but also a necessary means to ensure production continuity and product consistency. This process covers equipment body testing, process parameter verification, and finished product performance sampling inspection, spanning the entire lifecycle of design, manufacturing, and use, and must be implemented item by item under the guidance of professional standards.
Equipment body testing is first carried out during the manufacturing stage. A full inspection of the geometric accuracy of the mandrel should be conducted, including inner diameter tolerances, roundness, straightness, and surface roughness, to ensure that it meets the benchmark requirements for generating the winding pattern. The transmission system needs to undergo dynamic balancing tests and no-load test runs to test speed stability, vibration amplitude, and noise levels, eliminating fiber layer thickness unevenness caused by mechanical deviations. The slide travel mechanism should verify the straightness of the guide rails, transmission clearance, and repeatability accuracy to ensure that the axial movement trajectory is consistent with the CNC program. The electrical and control systems require checks on wiring reliability, signal response time, and sensor calibration status. Critical actuators such as servo motors and encoders should be used within their calibration validity period, and testing records should be maintained.
Process parameter verification is conducted before equipment commissioning and production changeover. First-piece trial production is used to test the fiber tension control range and stability, confirming that the impregnation tank temperature and resin viscosity match the design values to avoid dry spots or resin content fluctuations. The winding pattern is checked using the CNC system's playback function, measuring the deviation between the actual helix angle and number of layers and the set values. For thick-walled tubes, the continuity of the circumferential and helical winding transition zones needs to be checked. Curing regime verification should include temperature rise profile tracking and tube wall temperature uniformity testing to prevent internal stress cracks and incomplete curing defects.
Finished product performance sampling is an extension of the testing process and is typically conducted during trial production and the initial stages of mass production. Visual inspection focuses on surface flatness, absence of bubbles, no delamination, and exposed fibers; dimensional measurements verify that the outer diameter, wall thickness, and socket accuracy meet specifications. Pressure testing applies water or air pressure according to product grade, monitoring for leakage and deformation during pressure holding. Non-destructive testing, such as ultrasonic or X-ray testing, can identify internal porosity and delamination issues. All test data should be reported; any anomalies must be analyzed for root causes and corrective actions implemented, followed by retesting until (qualified).
The effective operation of the testing process depends on personnel qualifications and equipment management. Testing personnel must be professionally trained and certified, and testing instruments must be regularly calibrated and maintained in good working order. A testing log and traceability mechanism should be established to ensure complete and traceable testing information for each piece of equipment and each batch of products. By strictly implementing the above procedures, the reliability of GRP/FRP (fiberglass reinforced plastic) pipe winding equipment and the stability of the production process can be significantly improved, providing a solid guarantee for the manufacture of high-quality composite material pipes.
