US Patent 9469747 Mineral wool insulation

A method of manufacturing a mineral fiber thermal insulation product comprises the sequential steps of: Forming mineral fibers from a molten mineral mixture; spraying a substantially formaldehyde free binder solution on to the mineral fibers, the binder solution comprising: a reducing sugar, an acid precursor derivable from an inorganic salt and a source of nitrogen; Collecting the mineral fibers to which the binder solution has been applied to form a batt of mineral fibers; and Curing the batt comprising the mineral fibers and the binder which is in contact with the mineral fibers by passing the batt through a curing oven so as to provide a batt of mineral fibers held together by a substantially water insoluble cured binder.