What Are the Processing Differences Between Single-Curved and Double-Curved GRC Panels? Processing Difference Comparison and Matching Solutions

Due to differences in curved-surface geometry, the processing of single-curvature GRC panels and double-curvature GRC panels involves significant differences in mold making, forming processes, and precision control. Precisely adapting the processing plan is key to ensuring the forming quality of components. Drawing on experience from curved-surface projects such as the Guangxi New Media Center and Hainan Poly Peninsula No. 1, Qinglong analyzes the core processing differences and practical strategies.

I. Core Differences in Mold Making

Mold making is the core point of difference in processing single-curvature and double-curvature GRC panels. For single-curvature GRC panels (single-curvature surfaces), mold making is relatively simple: GRP molds or steel molds can be used, formed through manual lofting plus mechanical grinding, with a mold processing cycle of 3-5 days per set. Joints are fixed with simple bolts, and a curvature radius tolerance of ≤±3mm is sufficient. For double-curvature GRC panels (bidirectional-curvature surfaces), the complex surface requires high-precision steel molds or CNC-machined GRP molds, using an integrated process of "3D scanning + parametric design + five-axis CNC machining", with a mold processing cycle as long as 10-15 days per set. Joints require dual fixing with locating pins and high-strength bolts, and the curvature radius tolerance must be ≤±2mm. In the Shanghai Qingpu R&D project, Qinglong controlled double-curvature mold precision within ±1mm.

II. Comparison of Forming Process Differences

Forming processes must be adjusted according to surface complexity to ensure forming results. Single-curvature GRC panels can be produced by spray-up forming or casting, with a relatively simple process: spraying pressure ≥0.3MPa, casting thickness controlled at 5-10mm per layer, and post-forming surface flatness ≤0.8mm/m. Double-curvature GRC panels, due to their variable surfaces, require high-pressure spray-up forming (pressure ≥0.5MPa) combined with manual auxiliary pressing to ensure the slurry fully conforms to the mold surface, avoiding air bubbles and slurry shortage. After forming, secondary repair is needed to ensure surface smoothness, with surface flatness ≤0.5mm/m. In addition, the curing period for double-curvature panels must be extended by 2-3 days compared to single-curvature panels to prevent surface deformation caused by improper curing. In the Nanning New Media Center project, Qinglong ensured the forming quality of double-curvature panels through differentiated curing.

III. Differences in Precision Control and Post-Processing

Precision control and post-processing must be adapted to surface characteristics. For precision control, single-curvature GRC panels are inspected using a 2m straightedge and the string-line method, focusing on single-curvature accuracy; double-curvature panels require panoramic inspection with a 3D laser scanner, generating point cloud data to compare against the design model, with areas exceeding tolerance promptly corrected to ensure every point meets design requirements. For post-processing, single-curvature panels are ground with conventional flat-surface grinding tools, focusing on edges and joints; double-curvature panels require specialized curved-surface grinding tools with refined grinding by zone to avoid damaging the surface form. Double-curvature panels with stone-like textures also require manual texture repair to ensure natural continuity. In the Panzhihua, Sichuan project, Qinglong achieved precise grinding of double-curvature panels using specialized tools.

IV. Adapting to Differences in Processing Cost and Efficiency

Processing cost and efficiency differ significantly due to process complexity. In terms of cost, single-curvature GRC panels have lower mold and processing costs, with the processing cost per square meter approximately 40%-60% of that of double-curvature panels; double-curvature panels carry higher costs due to high-precision molds and complex processes, but costs can be diluted through mass production. In terms of efficiency, single-curvature panels offer high production efficiency, with daily output up to 100-200㎡; double-curvature panels have lower production efficiency, with daily output of only 30-50㎡, requiring optimized production lines and increased staffing to improve efficiency. Through differentiated production management, Qinglong allocates resources reasonably according to surface type, achieving a balance between processing efficiency and cost.