Today stone wool production at the ROCKWOOL factories is a highly sophisticated process.
Raw material and coke are automatically fed from the top of the cupola furnace. The melt runs out of the bottom of the furnace and onto the spinning machine, where the fibres are spun. Minor amounts of binder and oil are added, and the wool is collected on a belt conveyor in the spinning chamber. The structure and density of the wool are adjusted before it enters the curing oven. These properties are maintained after the binder has been cured.
The cured wool then proceeds to the cutting saws and packing equipment or is led to off-line equipment for special treatment.
The off-gases from the production - furnace, spinning chamber, curing oven - are cleaned in filters and after-burners before they enter the chimney. The waste inevitably created during the production is re-cycled.