Auto Industry Sand Blasting And Graniglia

A lot of industries are making use of shot blasting technology, and not to be left behind is the automation-hungry automobile manufacturing sector. While grit of various materials can be messy to work with, they can be recovered quite easily within a confined arena. They are labour-saving on a conveyor belt because they work quickly and do not need the precise placement of a grinding brush. Steel shot is normal but Graniglia is used for some applications. 

Learn more about abrasivi per sabbiatura

The Italian word Graniglia is used to describe a mixture of marble and powder as an abrasive for sandblasting, or an abrasivi per sabbiatura in Italian. What is used by the auto industry might be different from other applications, but the reason to use crushed marble would be that it is less abrasive than steel shot. It is more costly to sweep up marble powder, which can be quite fine, but the results seem to be worth it for the auto industry.

The safety and cleanliness of using marble for shot is aided by an airtight room that is typical of segmented assembly lines. The marble powder would linger in the air, but most would settle to the floor quite quickly and can be cleaned by both sweeping robots and maintenance personnel as necessary. The finest particles can be removed with purpose-built filters, but the crew would have to wear ventilated suits.

Marble is basically a form of calcium carbonate. It is harder than lime formations and so is excellent for shot blasting, but it is still chemically reactive in powder form. It is not entirely toxic to humans, but the dust should not be inhaled. A mask is a minimum while a suit is much better. As the blasting room would normally be isolated and entirely automated, entry by personnel would actually not be too frequent.
Marble is harder than many metals but also cracks when it strikes hard. The resulting blast is lighter and more complete than steel grit. The raw material might also be cheaper except for the fact it cannot be reused as many times. The lime powder likely is not used for welding, as these jobs are in a separate station. Using Graniglia would be an obvious choice in places with abundant supply.

Like other shot blasting operations, the advantage is quickly removing material to produce a consistently cleaned surface that is perfect for welding because of the now-stripped and rough surface. Graniglia might be easier to move than steel shot because of its lighter weight, meaning that there would be less wear on machines. A finer powder would also produce a finer sand blast. Marble forms very fine powder.