Vacuum technology used for stone slabs
Diresco in Belgium produces synthetic stone slabs from quartz granules and synthetic resin. Vacuum technology from Busch is used to ensure that the slabs are completely free from gas inclusions and cavities.
Marketed under the brand name Diresco Stone, the slabs are used primarily as work surfaces in kitchens, and as wall and floor tiles in bathrooms.Vacuum is supplied to the material presses of both production lines, ensuring top quality appearance and optimal structural integrity.
Diresco markets its products to well-known kitchen and furniture manufacturers and interior decorators throughout Europe and in Canada, USA and New Zealand.
All Diresco Stone products are manufactured at the main site in Opglabbeek in Belgium. Here, 65 employees work with highly automated equipment in a three-shift system producing synthetic stone slabs with a dimension of 3.2 to 1.4m each.
After the mixing of various quartz granules and blending with synthetic resin, the material is fed automatically into a mechanical press. To create an absolutely perfect surface, vacuum is applied to the pressing process. Even the smallest indentations and cavities can become visible after processing – the reduced pressure ensures that they cannot form.
Individual slabs are then hardened in an oven at 100 to 125°C. After cooling they are stored for at least 24 hours before further processing. Every slab is subjected to extensive quality control examinations before leaving the factory.
Vacuum technology plays a major part in the manufacture of these high-quality products, as even the smallest air or gas inclusions cannot be tolerated. The liquid ring vacuum pumps originally used for the vibrating press were unable to prevent the formation of all air, steam and styrene vapour inclusions. As a result, in 2006 the Diresco management decided to switch to Busch rotary vane technology. Two Busch R 5 rotary vane vacuum pumps with a pumping speed of 1600m³/h each were installed, substantially increasing product quality and reducing the duration of the pressing process.
Busch R 5 rotary vane vacuum pumps achieve an ultimate pressure of 0.1 mbar, which corresponds to a vacuum level of 99.99%.
In order to meet increasing product demand, the pressing process was further accelerated by the addition of a Panda vacuum booster before the parallel arrangement of rotary vane vacuum pumps.
Diresco was extremely satisfied with this solution, and when a new production line was introduced in 2009 an identical Busch vacuum system was installed.
Maintenance work is carried out by Busch under a service contract. There are only two services per year, although at times the vacuum pumps are in operation 24 hours a day. Servicing is confined to inspection, oil change and filter replacement. The smaller R 5 rotary vane vacuum pumps used in production handling units are inspected at the same time.
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