What Should the Curvature Error of GRC Shapes Be Kept Within? Curvature Accuracy and Qinglong Group's Shape Reproduction Technology

Controlling the curvature error of GRC shapes is a key technical step in realizing the design intent. Based on shape complexity, it can be divided into three grades: single-curved shapes with a curvature error of ≤±2mm/2m, double-curved shapes ≤±1.5mm/2m, and complex biomimetic shapes ≤±1mm/2m. In the "Dongguan Grass Weaving" facade project of the Dongguan Women and Children's Activity Center, Qinglong Group kept the curvature error of 386 woven shape panels stable within ±1.2mm through five-axis CNC precision mold machining (surface error ≤0.1mm) and digital measurement control, achieving perfect texture alignment and a smooth, natural visual effect.

Mold precision is the foundation of curvature control. For single-curved shapes, we use high-strength GRP molds with a service life of ≥300 uses and good surface retention; double-curved shapes must use tooling board or aluminum molds, machined by five-axis CNC to ensure smooth surface transitions. In the double-curved curtain wall project of the Nanning New Media Center, we implemented a mold pre-inspection system under which every mold undergoes three-coordinate measurement before use and may only be put into production after passing.

Quality control during production is equally important. Qinglong Group introduced a robotic spray-up process with fiber distribution uniformity of ≥95%, avoiding shape distortion caused by material inhomogeneity. During the curing stage, custom tooling fixtures are used to prevent deformation caused by thermal stress. In a petal-shaped GRC project for an art center in Shenzhen, we kept the coefficient of variation of product curvature within 3% through full-process temperature and humidity control.

On-site installation is the final checkpoint for achieving the intended curvature. We use a digital total station for three-dimensional positioning, with errors at key control points ≤±1mm. For extra-large curved shapes, dedicated support frames are set up to ensure shape stability during construction. Qinglong Group's curvature control system ensures high-precision transformation from drawings to finished products.