The Natural Stone Production Process

Any natural building stone, whether Marble, Travertine, Granite, Onyx or others, must pass the following stages to be ready for the end customer: from quarry to project.
Six steps are required to process a world-class-quality natural stone. Paying attention to these six steps can result in the manufacturing of a high-quality stone. In this article, we study this process briefly.

1. Block selection from quarry

One of the important factors in having a perfect product is to select the correct block from the quarry.

When selecting a block from quarries, we shall pay attention to the following:

• Surface color or pattern of the block
• Stone block health (not having cracks or defects)
• Choosing the right cutting direction

Travertine Block | BOLQA Stone Group

2. Cutting the block into slabs

Before starting the cutting machine (whether it’s a gang saw, multi-wire, etc.), we must check the health condition of the diamond wire. The diamond wires must have enough diamond parts and tensile strength power (this may vary based on each stone).

Diamond multi wire machine

Natural stone cutting machine parts – Source: https://www.sciencedirect.com/science/article/abs/pii/S0925963516304745

The operator of the machine shall also watch for two important parameters;

1. When starting the cutting machine, the operator shall start it at a slow speed for 10 – 15 cm depth and eventually increase the speed.
2. The water current of the system, the wires must always have water pouring on them and on the stone. Not following these standards may result in stone slabs having different thicknesses all over the slab.

3. Applying Resin and net on the back of slabs

After the second step, when the block is turned into raw slabs, we must wash the slabs with clean water to remove any dust or mud from the cutting process.

Then, the slabs will be moved to an automatic or manual furnace to get warmed and ready for the resin and net application process.

The reason for this process is to increase the endurance of the slab.

The operator shall pay attention to choosing the “Not Good” side of the slab for applying resin and net and leaving the “Good” side for polishing or other finishes.

In the net applying process, we must pay attention to the following:

• Choosing a high-quality epoxy
• Choosing the correct net, Hemp and soft fabrics are preferred.
• According to the epoxy factory manual, apply the correct mixture of epoxy + its hardener element.

It’s important to ensure the slab’s surface is dry and completely clean without dust. The surface must also be between 38 and 40 Celsius. After preparing these conditions, the slab is ready to be coated with net and resin.

BOLQA Stone workers applying resin and net on the back of the slab

The operator must note that the epoxy must be applied all over the slab (one side). After netting is also done, the slab must remain in the furnace for a couple of hours to let the resin’s chemical process happen.

4. Pre polishing

After stage 3 is done, we start the pre-polishing process on the other side of the stone using a pre-polishing machine and emery abrasive. This will remove the uneven parts from the slab surface caused by the cutting machine.
After pre-polishing, the slabs will be placed back in the furnace. After the slab is warm and dry, the resin-applying process will start on its second side.
After the resins are applied, the slabs must remain in the furnace for a couple of hours, and then they must not be polished for 24 – 48 hours.

5. Polishing the slab

At this stage, we use the slab polishing machine. Usually, 16 to 24 stages of abrasion are applied to the slab surface. The abrasives are set from soft to hard numbers. The last abrasion stages must be acidic to complete the polishing process.

Important points at this stage are:

• Observing the selection of the abrasives from rough to soft.
• Transparent and polished slabs based on customer needs.
• Slabs must be without any scratches.
• Even polishing all over the surface of the manufactured stone.

6. Round cut and size the slab

At this stage, we use a Double-Column machine to make the slabs in particular sizes according to the client’s needs.

Double-column-machine

Critical parameters in this stage;

• Each rectangle should be exactly 90 degrees.
• High cutting accuracy so that the cut dimensions are equivalent to the length and width of the customer’s order. The maximum tolerance in dimensions should not exceed +/- 1 mm.
• Avoid surface or small edge scratches.

Its all about details… | BOLQA Stone Group