Method for making a slurry containing particulate matter and fibers for a preformed insulation product

A method of making a preformed insulation product from a slurry containing particulate matter, binder and fibers comprising making a liquid binder, putting chopped strands of fibers into said liquid binder, agitating said liquid binder to separate at least some of said strands into individual fibers, forcing said liquid binder and fibers under pressure through a hollow tubular member against an inwardly closing helical vane to form a conically expanding spray of binder and fibers, breaking up any remaining strands of fibers into individual fibers, forming a falling curtain of separated particulate matter and directing said conically expanding spray of binder and fibers against said falling curtain of separated particulate matter to form a uniform slurry of particles, binder and fibers, putting said slurry into molds and heating said molds to a temperature and for a sufficient period of time to make a preformed insulation product.