What Are the Key Considerations in the Grinding Process of GRC Decorative Panels? Analysis of Key Technical Points and Quality Control

In the field of architectural decoration, GRC decorative panels, with their advantages of light weight, high strength, and rich styling, have become the "finishing touch" of many landmark buildings. However, to achieve the fine surface texture and precise shapes of GRC decorative panels, the polishing process is truly the "unsung hero". As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group understands well the decisive role of the polishing process in product quality. Today, we will analyze the key technical points and quality control logic of the GRC decorative panel polishing process.

### I. The Core Value of the GRC Decorative Panel Polishing Process: The Transformation from "Rough Blank" to "Work of Art"

The polishing of GRC decorative panels is not a simple surface treatment, but a fine operation that runs through the entire production process. Its core goal is to eliminate air bubbles, pitted surfaces, and joint marks on component surfaces, while ensuring the smoothness of contour lines and the consistency of textures. Take, for example, a convention and exhibition center project undertaken by Qinglong Group: through precision polishing, hyperbolic components that originally had 0.5mm deviations were corrected to within ±0.2mm, perfectly presenting the "fluidity" aesthetic pursued by the designers. For real estate developers and construction company decision-makers, high-quality polishing directly affects the project's visual effect and delivery standards, and is a key step in avoiding later rework and controlling costs.

### II. Key Technical Points: Controlling Polishing Precision in Three Dimensions

**1. Tool Selection and Grit Sequence Design** The special nature of GRC materials requires polishing tools that balance efficiency and fineness. Qinglong Group adopts a "three-stage progressive polishing method": in the rough polishing stage, 80-120 grit diamond abrasive discs are used to quickly remove cement laitance and protrusions from component surfaces; in the medium polishing stage, 240-400 grit resin abrasive discs are used to remove rough polishing marks and initially shape the texture; in the fine polishing stage, 600-800 grit sponge sanding blocks are used to achieve a fine surface texture. It is worth noting that for gypsum-based materials such as GRG, dedicated flexible abrasives must be used to avoid surface powdering caused by over-polishing.

**2. Polishing Path and Force Control** For flat components, the "cross-hatch method" is used to ensure uniform polishing; for shaped components such as European moldings and Roman columns, custom profile polishing tools are needed, moving forward unidirectionally along the contour curves. Qinglong Group uses BIM technology to simulate polishing paths, keeping manual operation deviations within 0.3mm. In terms of force control, the principle of "light first, then heavier, progressing step by step" is followed to prevent excessive local force from causing uneven component thickness — this is especially important for UHPC/GRC composite panels, as over-polishing may expose the internal glass fibers and compromise structural strength.

**3. Environment and Timing Control** The timing of polishing GRC components must strictly follow the curing cycle; initial polishing is usually performed 24-48 hours after demolding, when the material strength has reached over 70%, which ensures polishing efficiency while avoiding component damage. Meanwhile, the polishing workshop must maintain a relative humidity of 50%-60% and a temperature of 15-25℃ to prevent dust from flying and affecting operators' health and the surface cleanliness of components. Qinglong Group's intelligent production base is equipped with dust collection systems and constant temperature and humidity control equipment, ensuring that the polishing environment meets ISO9001 quality standards.

### III. Quality Control System: Full-Process Traceability and Standardized Acceptance

Qinglong Group has established a "three-inspection" polishing quality control system: in the self-inspection stage, operators use a 2m straightedge and feeler gauges to check flatness, with deviations required to be ≤1mm/m; in the mutual inspection stage, 3D scanning technology generates point cloud models that are compared with the design drawings to ensure shape accuracy; in the final inspection, quality engineers use a gloss meter and a colorimeter to conduct sampling tests on surface gloss (required to be ≥85°) and texture consistency. In addition, every GRC decorative panel is embedded with an RFID chip that records information such as the polishing operator, tool model, and working hours, enabling full life-cycle quality traceability — this management model has become an industry benchmark, helping Qinglong become a strategic partner of renowned real estate groups such as Vanke and Poly.

### IV. Industry Experience Sharing: Common Misconceptions and Solutions in the Polishing Process

In many years of project practice, we have found that some manufacturers have the problem of "emphasizing production while neglecting polishing", resulting in defects such as sand holes and scratches on component surfaces. In this regard, Qinglong Group recommends control at the source: first, optimize the mix design by adjusting the sand-to-cement ratio and fiber content to reduce air bubble formation; second, adopt the vacuum vibration process to improve concrete density, fundamentally reducing polishing difficulty. For the "stone-like texture" concerns of designers, customized abrasive disc textures and later sealing treatments can make the surface effect of GRC decorative panels comparable to natural stone, while weighing only 1/4 of stone, greatly reducing installation loads.

As a participant in drafting national GRC industry standards, Qinglong Group always treats every process with a "meticulous and striving for excellence" attitude. Although the polishing process may seem minor, it directly affects the final presentation and market competitiveness of GRC decorative panels. In the future, we will continue to integrate our 28 years of full-chain experience to provide designers and owners with integrated solutions from detailed design to after-sales maintenance, allowing more buildings to shine with brilliance through the unique charm of GRC materials.