Large granite platforms serve as core benchmarks for precision measurement and machining. Their cutting, thickness setting, and polishing processes directly impact the platform’s accuracy, flatness, and service life. These two processes require not only superior technical skills but also a deep understanding of granite’s characteristics. The following will discuss the process principles, key operational points, and quality control.
1. Cutting and Thickening: Accurately Shaping the Platform’s Basic Form
Cutting and thickness setting is the first critical step in the production of large granite platforms. Its goal is to cut the raw material to the required thickness and provide a smooth foundation for subsequent polishing.
Rock Pretreatment
After mining, the rough material often has an uneven surface and weathered layers. Initially, a large diamond wire saw or circular saw is used for rough cutting to remove surface impurities and irregularities, giving the rough material a regular rectangular shape. During this process, the cutting direction and feed speed must be strictly controlled to prevent uneven cutting force from causing cracks within the rough material.
Positioning and Fixing
Place the pre-treated block on the cutting machine table and accurately position and secure it using a clamp. Refer to the design drawings for positioning, ensuring that the cutting direction of the block aligns with the desired length and width of the platform. Fixing is crucial; any movement of the block during the cutting process will directly result in deviations in the cut dimensions and affect the platform’s accuracy.
Multi-wire Cutting for Thickness
Multi-wire cutting technology uses multiple diamond wires to simultaneously cut the block. As the wires move, the grinding action of the diamond particles gradually reduces the block to the desired thickness. During the cutting process, coolant should be continuously sprayed into the cutting area. This not only reduces the wire temperature and prevents the diamond particles from falling off due to overheating, but also removes stone dust generated during cutting, preventing accumulation that could affect cutting accuracy. The operator should closely monitor the cutting process and adjust the wire tension and cutting speed appropriately based on the hardness of the block and the cutting progress to ensure a smooth cut surface.
2. Polishing Surface Treatment: Creating a Completely Smooth and Lustrous Finish
Polishing is the core process for achieving high precision and aesthetics on large granite platforms. Through multiple grinding and polishing steps, the platform surface achieves a mirror-like finish and high flatness.
Rough Grinding Stage
Use a large grinding head with silicon carbide abrasives to rough-grind the cut platform surface. The purpose of rough grinding is to remove knife marks and surface irregularities left by cutting, laying the foundation for subsequent fine grinding. The grinding head reciprocates across the platform surface with a constant pressure. The abrasive, under pressure and friction, gradually smoothes out any surface protrusions. During this process, cooling water is continuously added to prevent the abrasive from overheating and becoming ineffective, and to remove stone dust generated by grinding. After rough grinding, the platform surface should be free of visible knife marks, and the flatness should have been initially improved.
Fine Grinding Stage
Switch to aluminum oxide abrasives and use a finer grinding head for fine grinding. Fine grinding further refines the surface roughness and removes minor scratches left by rough grinding. During operation, the pressure and speed of the grinding head must be strictly controlled to ensure that the abrasive is applied evenly to the surface of the platform. After fine grinding, the surface flatness and finish are significantly improved, preparing it for subsequent polishing.
Polishing Stage
The platform surface is polished using tin oxide polishing paste and a natural wool felt grinding head. During the polishing process, the wool felt grinding head rotates, evenly applying the polishing paste to the surface. Through the chemical action of the polishing paste and the mechanical friction of the grinding head, a bright film is formed on the surface. During polishing, careful attention must be paid to the amount of polishing paste used and the polishing time. Too little or insufficient polishing time will not achieve the desired gloss. Too much or too long may cause scratches or an orange peel effect on the surface. After careful polishing, the large granite platform surface exhibits a mirror-like luster and a high level of flatness.
III. Quality Control: Key Throughout the Process
Quality control is an integral part of the entire process, from cutting to thickness determination to polishing and surface treatment. After each process is completed, the platform is inspected using advanced testing tools, such as laser interferometers for flatness and surface roughness meters for smoothness. If the test results do not meet design requirements, the cause must be promptly analyzed and appropriate remedial measures implemented, such as re-cutting or re-grinding. Only by strictly controlling the quality of each process can we ensure that the resulting large granite platform meets the requirements for high precision and stability.
Post time: Sep-09-2025