Granite slab surface finishing requirements are stringent to ensure high precision, high stability, and excellent performance. The following is a detailed explanation of these requirements:
I. Basic Requirements
Defect-Free Surface: The working surface of a granite slab must be free of cracks, dents, loose texture, wear marks, or other cosmetic defects that could affect its performance. These defects directly impact the slab’s precision and service life.
Natural Streaks and Color Spots: Natural, non-artificial streaks and color spots are permitted on the surface of a granite slab, but they should not affect the overall aesthetics or performance of the slab.
2. Machining Accuracy Requirements
Flatness: The flatness of a granite slab’s working surface is a key indicator of machining accuracy. It must meet the required tolerances to maintain high accuracy during measurement and positioning. Flatness is typically measured using high-precision measuring equipment such as interferometers and laser flatness meters.
Surface Roughness: The surface roughness of a granite slab’s working surface is also a crucial indicator of machining accuracy. It determines the contact area and friction between the slab and the workpiece, thus affecting measurement accuracy and stability. Surface roughness should be controlled based on the Ra value, typically requiring a range of 0.32 to 0.63 μm. The Ra value for the side surface roughness should be less than 10 μm.
3. Processing Methods and Process Requirements
Machine-cut surface: Cut and shaped using a circular saw, sand saw, or bridge saw, resulting in a rougher surface with noticeable machine-cut marks. This method is suitable for applications where surface precision is not a high priority.
Matt finish: A light polishing treatment using resin abrasives is applied to the surface, resulting in a very low mirror gloss, generally below 10°. This method is suitable for applications where glossiness is important but not critical.
Polish finish: A highly polished surface produces a high-gloss mirror effect. This method is suitable for applications where high gloss and precision are required.
Other processing methods, such as flamed, litchi-burnished, and longan-burnished finishes, are primarily used for decorative and beautification purposes and are not suitable for granite slabs requiring high precision.
During the machining process, the precision of the machining equipment and process parameters, such as grinding speed, grinding pressure, and grinding time, must be strictly controlled to ensure that the surface quality meets the requirements.
4. Post-Processing and Inspection Requirements
Cleaning and Drying: After machining, the granite slab must be thoroughly cleaned and dried to remove surface dirt and moisture, thereby preventing any impact on measurement accuracy and performance.
Protective Treatment: To enhance the weather resistance and service life of the granite slab, it must be treated with protective treatment. Commonly used protective agents include solvent-based and water-based protective liquids. Protective treatment should be performed on a clean and dry surface and in strict accordance with the product instructions.
Inspection and Acceptance: After machining, the granite slab must undergo a thorough inspection and acceptance. Inspection covers key indicators such as dimensional accuracy, flatness, and surface roughness. Acceptance must strictly adhere to relevant standards and requirements, ensuring that the slab’s quality meets the design and intended use requirements.
In summary, the requirements for granite slab surface processing involve multiple aspects, including basic requirements, processing accuracy requirements, processing methods and process requirements, and subsequent processing and inspection requirements. These requirements together constitute the quality determination system for granite slab surface processing, determining its performance and stability in accurate measurement and positioning.
Post time: Sep-12-2025