An aqueous dispersion used as needling aid for producing needle mineral fiber felts characterized by comprising: (a) at least one perfluoropolyether having general formula F-(R f) m -CF(CF 3)-R 2 where R f = CF(CF 3)-CF 2 -O, R 2 = -COO - H +, K +, Li +, Na + and mixtures thereof, index m being an integer number selected so that the average molecular weight is between 500 and 100.000, or CF 3 -CF 2 -CF 2 -O-(R f) n -CF(CF 3)-R 2 where: R f = CF(CF 3)-CF 2 -O, R 2 = -COO - H +, K +, Li +, Na + and mixtures thereof, index n being an integer number selected so that the average molecular weight is between 500 and 100.000. (b) at least one water-soluble polar aprotic solvent, (c) at least one alkali metal salt chosen among lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, sodium bicarbonate, lithium bicarbonate, potassium bicarbonate, lithium chloride, sodium chloride, potassium chloride, lithium bromide, sodium bromide, potassium bromide, lithium fluoride, sodium fluoride, potassium fluoride, lithium iodide, sodium iodide, potassium iodide, lithium oxide, sodium oxide, potassium oxide and preferably lithium hydroxide, potassium hydroxide, lithium carbonate, potassium carbonate, lithium bicarbonate, potassium bicarbonate, lithium chloride, potassium chloride, lithium bromide, potassium bromide, lithium fluoride, potassium fluoride, lithium iodide, potassium iodide, lithium oxide, potassium oxide and most preferably potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium chloride, potassium bromide, potassium fluoride, potassium iodide, potassium oxide and mixtures thereof, (d) and the balance being water. (a) at least one perfluoropolyether having general formula F-(R f) m -CF(CF 3)-R 2 where R f = CF(CF 3)-CF 2 -O, R 2 = -COO - H +, K +, Li +, Na + and mixtures thereof, index m being an integer number selected so that the average molecular weight is between 500 and 100.000, or CF 3 -CF 2 -CF 2 -O-(R f) n -CF(CF 3)-R 2 where: R f = CF(CF 3)-CF 2 -O, R 2 = -COO - H +, K +, Li +, Na + and mixtures thereof, index n being an integer number selected so that the average molecular weight is between 500 and 100.000. R f = CF(CF 3)-CF 2 -O, R 2 = -COO - H +, K +, Li +, Na + and mixtures thereof, index m being an integer number selected so that the average molecular weight is between 500 and 100.000, or R f = CF(CF 3)-CF 2 -O, R 2 = -COO - H +, K +, Li +, Na + and mixtures thereof, index n being an integer number selected so that the average molecular weight is between 500 and 100.000. (b) at least one water-soluble polar aprotic solvent, (c) at least one alkali metal salt chosen among lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, sodium bicarbonate, lithium bicarbonate, potassium bicarbonate, lithium chloride, sodium chloride, potassium chloride, lithium bromide, sodium bromide, potassium bromide, lithium fluoride, sodium fluoride, potassium fluoride, lithium iodide, sodium iodide, potassium iodide, lithium oxide, sodium oxide, potassium oxide and preferably lithium hydroxide, potassium hydroxide, lithium carbonate, potassium carbonate, lithium bicarbonate, potassium bicarbonate, lithium chloride, potassium chloride, lithium bromide, potassium bromide, lithium fluoride, potassium fluoride, lithium iodide, potassium iodide, lithium oxide, potassium oxide and most preferably potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium chloride, potassium bromide, potassium fluoride, potassium iodide, potassium oxide and mixtures thereof, (d) and the balance being water.