Abstract: A process for forming mineral fibers by internal centrifugation using a device including a basket and a fiberizing spinner suitable for rotating jointly about an axis of rotation, the basket including an annular wall pierced by orifices and the fiberizing spinner including an annular wall pierced by orifices, the process including 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. The factor F is greater than 2000, the factor F being defined by F=?adN/Q; wherein ?a is the viscosity of the material to be fiberized at the temperature Ta; d is the distance between the annular walls of the basket and of the fiberizing spinner; N is the number of orifices of the basket; and Q is the feed flow rate of the material to be fiberized.

Abstract: A process for forming mineral fibers by internal centrifugation using a device including a basket and a fiberizing spinner suitable for rotating jointly about an axis of rotation, the basket including an annular wall pierced by orifices and the fiberizing spinner including an annular wall pierced by orifices, the process including 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. The factor F is greater than 2000, the factor F being defined by F=?adN/Q; wherein ?a is the viscosity of the material to be fiberized at the temperature Ta; d is the distance between the annular walls of the basket and of the fiberizing spinner; N is the number of orifices of the basket; and Q is the feed flow rate of the material to be fiberized.