In recent years, with the heating up of real estate and the rise of decoration fever, stone decoration plays a crucial role in the decoration industry, and the quality of this product in stone decoration accounts for a considerable proportion, and customers have the highest quality requirements for this product. Improving the quality of hollow columns has always been the direction of stone manufacturers’ efforts.
The processing process of hollow columns generally includes material selection – cutting – shaping of hollow column arc plates – polishing, polishing – cutting chord length, height adjustment – final inspection, packaging, and warehousing.
1、 Material preparation stage
The selection of materials for hollow columns is the most important aspect of technological processing, and the quality of material selection directly affects the decorative effect. The selection of materials should be based on the material, color, and grain requirements on the production process processing sheet.
2、 Quality requirements
Select materials according to the customer’s feedback from the salesperson or the provided stone samples and quality inspection standards. The material used for the entire column is of the same color and pattern. The material used in the entire project should be consistent in color. If consistency cannot be maintained, the specific installation positions of each cylinder should be understood based on the engineering layout plan. Starting from the overall effect, a gradual color transition should be implemented.
Hollow columns usually have a higher grain direction, unless the customer requires the grain to have an arc length direction. The pattern of all cylinders in the entire project must be consistent, especially for cylinders installed in two or more parallel positions.
Cracks, color lines, stains, sand holes, holes, mold spots, color differences. In terms of quality, the stone defects mentioned above should be avoided as much as possible. But for many stones, there are more or fewer defects, and in unavoidable situations, the size of these defects should be comprehensively considered when using materials. If necessary, repair methods should be adopted to eliminate this defect. The appearance of the circular surface should meet the quality requirements of the hollow column product. When selecting raw materials, visual inspection and water pouring methods should be used to inspect the appearance quality of the stone raw materials.
The blank used for the shape of a hollow column circular arc plate should meet the following technical requirements: in the high direction, an additional machining allowance of 30-40 mm should be required, and in the chord length direction, the machining allowance should also be 30-40 mm. The two end faces in the height direction must be trimmed flat to facilitate strict and accurate alignment with the standard template.
3、 Modeling stage
Equipment: Computer wire-cutting machine
Process and processing technical requirements
Process 1: According to the technical requirements of the production and processing sheet, correctly rotate the prepared blank onto the processing table of the computer wire-cutting machine, ensuring that the height direction of the hollow column arc plate is as straight as possible with the diamond rope of the wire cutting machine.
Process 2: Shape production
Set the processing zero point according to the processing requirements of the process production order. Programming, simulating the machining program, and checking the correctness of the machining program. Start the machine tool and observe the machining process. After processing the first hollow column arc plate, immediately use the standard template provided by the technical department to check the accuracy of the arc degree, and the inspection error can be around 2mm; Use a standard guiding rule to check the straightness of the circular arc plate, and use a feeler gauge to check that the gap does not exceed 1mm. Then, check every 5 pieces.
Process 3: Lifting and unloading
For thin or poor material circular arc plates, they should be lifted and unloaded separately, or necessary protective measures should be taken for lifting and unloading.
4、 Polishing stage
Equipment: Automatic arc grinder, walking arc grinder, grinder, steam turbine.
Process and technical requirements
Process 1: rough grinding
When grinding by hand or grinding machine, the circular arc plate should be smoothly rotated on the workbench, and the standard template should be used to align with the reference planes at both ends of the height direction for marking and grinding. The range of the ground chord length should be greater than 15-20 mm compared to the actual chord length. During rough grinding, diamond steel discs or alloy cup-shaped grinding heads can be used to grind away the traces generated by the wire-cutting machine diamond rope on the circular arc surface. Now, 60 # coarse sandpaper is used to pass through it.
When rough grinding, cross grinding should be carried out, and the grinding time should be longer along the height direction. The movement trajectory should be parallel to the busbar direction of the hollow column, and the trajectory of the arc length direction should be parallel to the arc length direction. The standard template should be aligned while grinding, and the straightness of the busbar should be checked with a standard backup plate.
Process 2: Fine grinding, water grinding, polishing
Use 120 #, 220 #, 320 #, 400 #, 600 #, 800 #, 1800 #, 3500 #, 8500 # diamond grinding discs in sequence, or use 1 #, 2 #, 3 #, 4 #, 5 #, 6 #, 7 #, 8 #, and 10 # grinding heads for water grinding and polishing. During this process, it is possible to choose which grinding head to use based on the specific polishing situation.
Process 3: Use a standard template for process quality inspection to check the circularity of the circular arc plate. The inspection error is strictly controlled within ± 0.3 mm. Use a standard backup plate to check the straightness of the circular arc plate. Use a feeler gauge to check that the gap at the edge cannot exceed 0.5 mm, and the gap at the middle cannot exceed 1 mm.
Use hand touch to check the smoothness of the circular plate, and ensure that there is no obvious concavity or convexity along the arc length direction. Use a photometer to check the glossiness of the circular arc board. The glossiness requires that the straightness of marble and granite should be above 85 degrees. Visually inspect the appearance quality of circular arc plates.