Stone column processing technology

Stone pillars are decorative cylindrical structures made from marble or granite, either solid or hollow. Depending on the type of stone used, they can be categorized into marble and granite pillars. These pillars come in various styles, such as Roman columns, plum columns, twisted columns, railing columns, engraved columns, multi-prism columns, and single-color or multi-color columns. Based on their cross-sectional dimensions, they can also be classified into equal-diameter columns, tapered columns, and drum-shaped columns. Unlike curved panels, which only wrap around the outer surface of a cylinder, stone pillars are full cylinders or assembled units made from solid or hollow cores.

The First Section of Standard Cylindrical Processing Technology

First, Types of Standard Cylinders

The standard cylinder described here refers to a circular column with straight or curved surfaces, but with a circular cross-section that may be uniform or varying. This includes equal-diameter columns, conical columns, two-drum columns with smaller diameters at the ends, and balusters. The diameter and height of these cylinders depend largely on the size of the raw stone block. The minimum diameter is typically around 100mm, while the maximum can reach up to 2000mm. The overall height is generally under 5000mm, though some special designs may exceed this limit. A standard stone column usually consists of a base, the main body (the cylinder), and a capital at the top.

Second, Processing of Standard Cylinders

(1) Grinding and Polishing of the Cylinder

Grinding and polishing of the cylinder is typically done using a lathe equipped with a pneumatic or hydraulic grinding head. The abrasive tools on the head can be quickly replaced. For this process, ring-shaped abrasives are commonly used, which come into contact with the cylinder surface and provide a smooth finish. An example of this technique can be seen in the cylindrical machining lathe used by companies like OMAC in Italy.

Since the force applied during grinding is much less than the resistance encountered during cutting, only one center hole is needed when mounting the cylinder for grinding. The type and grade of abrasive used vary depending on the material being processed. For granite, five different grades of abrasives are typically used, while marble may require a more flexible approach with specialized grinding materials.

For complex shapes like balusters or vases, where the contours change significantly, it's often more practical to use manual grinding equipment. This allows for greater control and precision in finishing these intricate pieces.

(2) End Cutting and Trimming

After the cylinder has been polished, the two end faces are cut using a diamond saw blade to ensure the final length meets the required specifications. It's important to make sure the angle of the cut is slightly less than 90 degrees so that the joint appears neat and seamless during installation.

(3) Cleaning, Inspection, and Packaging

Once cleaned, inspected, and dried, the finished cylinders are ready for packaging. The packaging process involves two steps: first, wrapping the cylinder in a 0.5mm thick plastic film, and then securing it within a wooden frame. Care must be taken during packing and transportation to avoid any damage to the delicate surface of the stone.