The control of polished materials

The surface finish of a stone together with the size and petrographic variety represent its hallmarks.

The surface finishes are in constant evolution, but the polished surface finish has always been the finishing par excellence for many granite products. Above all, this finish is the one chosen for most of the commercialized boards and for the materials used primarily for interior and counter use, since the tones of the stone are emphasized and the pore is sealed, which facilitates maintenance.

In particular, a polished finish is achieved at the factory by means of rotary polishing machines equipped with abrasive segments, which will provide that mirror-gloss appearance.

In the factory, for the manufacture of polished finishes, a sequence of abrasives must be established, which may be different for each variety and quality. This polishing sequence must be available at the work station of the polishing line.

Subsequently, to measure the final finish, we must:

• Use an instrument for measurement called a glossometer
• Perform the readings always with the same procedure and measurement angle
• Brightness measurements will be carried out immediately after the mechanical treatment of the polishing and, whenever it is carried out, also after the application of chemical products such as resins or similar.
• It is also recommended to repeat the measurements for control every 10 boards.
• The key is to take measures that cover the beginning, middle and end of the board
• A gloss result of a good polish will be around 70 units.