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Print ArticleWith five production lines currently in service and a sixth now under construction, Cosentino S.A. figures to be the largest manufacturer of engineered stone slabs in the world.
With five production lines currently in service and a sixth now under construction, Cosentino S.A., manufacturer of Silestone quartz surfacing, figures to be the largest manufacturer of engineered stone slabs in the world. Covering the world through five major distribution centers (Spain, USA, UK, Central Europe and Latin America), the company’s current production capacity is 700,000 square meters of engineered stone per year. Its North American distributor, CosentinoUSA, established in 1988, has doubled in size every year since its founding, and accounts for 25-30 percent of total sales for the company. Spain and Italy are currently Cosentino’s largest markets.
The production facility, which is located in the Andulacia region of southern Spain, is housed in a complex of buildings totaling nearly 1 million square feet of space. In addition to Silestone manufacturing, Cosentino processes marble slabs for distribution through wholesalers, and fabricates marble for the custom market. Four hundred employees work around the clock in three shifts to keep a steady flow of product to a world market hungry for engineered stone materials.
A third generation processor of marble slabs, Cosentino became interested in the concept of engineered stone manufacturing as a way to utilize marble scrap. In 1989 the company purchased an engineered stone production line from Breton SpA, and began turning out engineered stone made with marble chips. It quickly became apparent that using marble chips as a filler delivered less than acceptable performance characteristics, and Cosentino switched to quartz as the primary ingredient for its slabs. Today the company purchases quartz chips from quarries located in several countries, in color grades ranging from slightly brown to perfectly clear.
When quartz particles reach the plant they are loaded into a hopper where they are separated according to size and color, and stored in silos. At the time of manufacture the quartz crystals are combined with silica and resin (resin content ranges between 6 and 10 percent of the total mixture) in a vat that resembles a large bread mixer. The resulting mixture has the look and feel of moist sand. It is dumped into a metal form resting on a table lined with release paper, where it is molded into the shape of a thick slab. This is in preparation for entering the vibro-compactor.
There’s A Whole Lotta Shakin’ Goin’ On
Even though the vibro-compactor is physically the least imposing piece of equipment in the production line, it is the most important. It is here that the elements of vibration and pressure combine to turn a pile of damp sand into a compact slab. The compaction process begins as the loosely molded mixture is conveyed into the unit, which lowers itself onto the slab. When the machine is activated the floor shakes as the vibro-compactor noisily lives up to its very descriptive name. The commotion continues for slightly less than two minutes.
Emerging from the opposite end of the vibro-compactor is one lean and mean engineered stone slab, although it still lacks bonding strength. For that it must undergo 30 minutes in a heat press, which activates and subsequently cures the resin binder. After leaving the press, the slab is stacked vertically on a rack, where it finishes its cure cycle for a minimum of 24 hours before undergoing the sanding and finishing process.
The polishing line uses consecutively coarser grits of diamond abrasive mounted on large steel drums which pass back and forth over the engineered stone slab as it moves down the line. The polishers are enclosed in large, rectangular steel tubs which are flooded with water to keep the diamond abrasives cool and to flush off sludge. At the end of the polishing line the slabs are inspected for defects and color consistency with a colorometer, and graded according to quality. Finally, they are loaded onto A-frame racks, ready for shipment.
Cosentino currently operates five Silestone manufacturing lines and has a sixth on order from Breton. According to Roberto Contreras, president of CosentinoUSA, the issue of production capacity figures to play a prominent role in the future of an industry that is growing exponentially, yet only has the ability to expand at a finite rate.
