Method for producing mineral fibres

A process for forming mineral wool by internal centrifugation using a device comprising a basket and a fiberizing spinner which are suitable for rotating jointly about an axis of rotation, the basket comprising an annular wall pierced by a plurality of orifices and the fiberizing spinner comprising an annular wall pierced by a plurality of orifices, said process comprising:

• feeding the basket with material to be fiberized at a temperature Ta;
• centrifuging the material to be fiberized by joint rotation of the basket and of the fiberizing spinner,
• wherein a factor F is greater than 2000, the factor F being defined by F=μadN/Q, wherein:
• μa is the viscosity, expressed in Pa·s, of the material to be fiberized at the temperature Ta;
• d is the distance, expressed in m, between the annular wall of the basket and the annular wall of the fiberizing spinner;
• N is the number of orifices of the basket;
• and
• Q is the feed flow rate, expressed in kg/s, of the material to be fiberized,
• wherein the orifices of the annular wall of the basket have a diameter of from 1.5 to 3 mm, and
• wherein the annular wall of the basket comprises from 220 to 1,000 orifices.