Process for the manufacture of an insulating product based on mineral fibres

An insulating product comprising mineral fibers of aluminosilicate glass including aluminum oxide, Al2O3, in a fraction by weight of between 14% and 28%, and an organic binder that binds the mineral fibers, wherein said organic binder is obtained by crosslinking a sizing composition applied to the mineral fibers, said sizing composition comprising the following constituents within the limits defined below, expressed as fractions by weight with respect to the total weight of the composition:

• from 80% to 98% of water,
• from 2% to 20% of water-soluble poly(furfuryl alcohol), which is obtained by polycondensation of furfuryl alcohol, and
• less than 0.5% of furfuryl alcohol,
• wherein a sum of the fractions by weight of the poly(furfuryl alcohol) and of the water is at least 95%, and
• wherein the sizing composition applied to the mineral fibres has a pH in a range from 5 to 8.