How to Control the Surface Flatness of Double-Curved GRC Panels?

The surface flatness of double-curved GRC panels is a core indicator of their manufacturing precision and visual quality. Especially for large-area continuous curved surfaces, any slight unevenness will be magnified under light and shadow, undermining the overall aesthetic. Through a trinity quality control system of "high-precision molds, standardized processes, and digital inspection", Qinglong Group ensures that the surface flatness of its double-curved GRC panels reaches an industry-leading level, earning high recognition from clients in projects such as Hainan Poly Peninsula No. 1.

The foundation of flatness control lies in the precision and stability of the molds. The mold surface of a double-curved mold must be smooth and accurate. Qinglong uses five-axis CNC machine tools to machine the master molds, achieving a precision of ±0.5mm. High-strength GRP or epoxy resin is selected as the mold material, providing sufficient rigidity to ensure no deformation during repeated use and production processes (such as spray impact and vacuum dewatering). The surface finish of the mold directly determines the smoothness of the finished panel surface, so after demolding, the mold must undergo fine grinding and multiple pore-sealing treatments.

Process control during production is key to ensuring flatness. The consistency of the GRC slurry, the spray pressure and angle, and the uniformity of fiber distribution all affect the surface condition after forming. Qinglong uses robotic-assisted spraying to ensure uniform and dense slurry coverage. After spraying is complete, a screed is immediately used for initial surface leveling, and vacuum dewatering technology is applied to expel excess water and air bubbles, making the panel surface denser and flatter. The curing stage is also crucial: the heating and cooling rates must be carefully controlled to prevent panel warping caused by thermal stress.

Finished product inspection is the final checkpoint. Qinglong uses two methods to verify flatness: first, traditional measurement with a 2-meter straightedge and feeler gauge, requiring a surface flatness deviation of no more than 3mm; second, for critical components, three-dimensional laser scanning technology is used to compare the finished product's point cloud data with the design model, generating comprehensive deviation color maps that visually display flatness errors in any area, with precision down to the millimeter level. This full-process precision control system, from mold to finished product, is a solid guarantee of the high quality of Qinglong's double-curved GRC panels.