What Are the Considerations in GRC Decorative Panel Polishing? Key Techniques and Quality Control Points Explained

In the field of architectural decoration, GRC decorative panels have become the ideal choice for high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to their lightweight high strength and rich formability. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the decisive role of the grinding process in the final quality of GRC decorative panels. This article comprehensively analyzes the core points of the GRC decorative panel grinding process, from technical principles and key procedures to quality control, providing a professional reference for designers and owners.

I. Technical Positioning and Industry Value of the GRC Decorative Panel Grinding Process

The grinding process for GRC (Glass Fiber Reinforced Concrete) decorative panels is not simple surface treatment, but a key link that affects material performance, decorative effects, and engineering safety. High-quality GRC products must achieve three major goals through precise grinding: first, eliminating air bubbles, burrs, and mold marks produced during production, ensuring a surface flatness error ≤2mm; second, creating a fine texture through gradient grinding so that stone-imitation, metal-imitation, and other finishes meet design requirements; third, optimizing component edge curvature and joint seam precision, laying the foundation for "zero-error" splicing in subsequent installation. In the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), which Qinglong Group participated in formulating, the grinding process is explicitly listed as an important quality control node affecting product durability.

II. Core Technical Points of the GRC Decorative Panel Grinding Process

1. Tool Selection and Sandpaper Gradient Configuration: Based on the shape complexity and surface requirements of GRC components, grinding tools need to be scientifically matched. Flat components should preferably be rapidly leveled with pneumatic sanders combined with 80-grit coarse sand, while curved or special-shaped components require manual fine treatment with 120-240 grit sandpaper, and finally fine sand of 400 grit or above for finishing. The dedicated flexible grinding pad developed by Qinglong's production base for double-curved GRC components enables uniform grinding of areas with a minimum radius of curvature ≤300mm, avoiding fiber breakage caused by local stress concentration.

2. Standardized Control of the Grinding Process: A standardized grinding process should follow the "three-stage principle": the initial grinding stage focuses on treating surface defects after demolding, removing laitance and sharp edges; the intermediate grinding stage uses the cross-grinding method to eliminate consistent directional sanding marks and improve flatness; the fine grinding stage adopts circular grinding techniques, combined with dust removal equipment to achieve dust-free operation, ensuring surface dust residue ≤5mg/m². In the Dongguan Women and Children's Activity Center project, Qinglong achieved a surface smoothness of over 95% for GRC exterior wall panels through this process, winning the Silver Award of the First GRC Construction Engineering Innovation Award.

3. Process Treatment of Special Parts: For complex parts such as openwork reliefs and line joints, a combination of custom grinding heads and manual work is required. For example, for the groove parts of Roman columns, a cylindrical grinding head with a diameter of 10mm should be used to grind evenly along the arc direction to avoid the "step effect"; while cornice line joints need to reserve a 0.5mm grinding allowance to ensure a perfect fit during installation. In the Nanjing East Road Century Plaza renovation project, Qinglong controlled the splicing error of translucent GRC components within 0.3mm through such processes, winning the UHPC Construction Engineering Innovation Award.

III. Full-Process Quality Control System for GRC Decorative Panel Grinding

1. Raw Material Pretreatment Stage: Grinding results are closely related to the GRC substrate material. Qinglong uses self-developed low-alkali cement and crack-resistant fiber formulations to keep the 28-day flexural strength of products stable at above 20MPa, reducing the risk of grinding cracks caused by material brittleness at the source. Meanwhile, by adjusting the water-cement ratio and retarder dosage, the surface hardness of components is controlled between Shore D65-75, providing an ideal physical foundation for grinding.

2. Process Inspection and Data Traceability: Each GRC decorative panel must undergo three quality inspections: after initial grinding, a 2-meter straightedge is used to check flatness; after intermediate grinding, a gloss meter tests surface reflectivity; after fine grinding, 3D scanning obtains point cloud data, which is compared with the design model for deviation values. The RFID chip traceability system established by Qinglong can record information such as grinding operators, tool models, and time parameters in real time, enabling precise tracing of quality issues.

3. Environment and Personnel Control: The grinding workshop must maintain a constant temperature (20±5℃) and constant humidity (60±10%) environment to avoid surface shrinkage cracks caused by sudden temperature changes. Operators must undergo 100 hours of professional training and pass the assessment before taking up their posts. Qinglong's original "Grinding Process SOP Manual" specifies in detail the grinding parameters for different component types, raising the pass rate of novice operations to 92%.

As a national high-tech enterprise and a participant in formulating GRC industry standards, Qinglong Group always treats every process with a "meticulous and excellence-pursuing" attitude. The grinding of GRC decorative panels may seem simple, but it is in fact a fusion of materials science, mechanical engineering, and craftsmanship. In the future, with the development of UHPC/GRC composite technology, Qinglong will continue to optimize the grinding process, providing designers with broader creative space and contributing higher-quality solutions to the architectural decoration industry.