Mineral fiber insulation having thermoplastic polymer binder and method of making the same

Abstract

A method of forming a fibrous insulation product includes forming at least one fibrous veil including first fibers and blowing a non-aqueous, formaldehyde-free, thermoplastic binder in powder, liquid or fibrous form into said veil during said forming step to form a mixture of the binder and the first fibers. When in fibrous form, the binder fibers have average length of less than or equal to about 15 mm. The mixture is collected on the forming belt and formed into an insulation batt, board or molding media.

1 . A method of forming a fibrous insulation product, comprising:
 forming at least one fibrous veil comprising first fibers;   blowing a non-aqueous, formaldehyde-free, thermoplastic binder in powder, liquid or fibrous form into said veil during said forming step to form a mixture of said binder and said first fibers, said fibrous form having average length of less than or equal to about 15 mm;   collecting said mixture on said forming belt; and   forming said mixture into an insulation batt, board or molding media.   
     
     
         2 . The method of  claim 1 , wherein said binder is blown into said veil in liquid form as a hot melt. 
     
     
         3 . The method of  claim 2 , wherein said hot melt comprises droplets having average diameters between about 0.5 to about 10 μm. 
     
     
         4 . The method of  claim 3 , wherein said diameters are between about 0.5 to about 6 μm. 
     
     
         5 . The method of  claim 1 , wherein said binder is blown into said veil in fibrous form. 
     
     
         6 . The method of  claim 5 , wherein said binder fibers have average diameters between about 0.2 to about 20 μm and average length between about 0.1 to about 15 mm. 
     
     
         7 . The method of  claim 6 , wherein said diameters are between about 0.5 to about 15 μm and said length is between about 0.1 to about 6 mm. 
     
     
         8 . The method of  claim 1 , wherein said binder is blown into said veil in powder form. 
     
     
         9 . The method of  claim 8 , wherein the average diameter of particles in said powder form is between about 0.2 to about 60 μm. 
     
     
         10 . The method of  claim 9 , wherein the diameter is between about 2 to about 30 μm. 
     
     
         11 . The method of  claim 1 , wherein said forming step comprises shaping said mixture and heating said shaped mixture to melt said binder, whereby said binder bonds said first fibers together after cooling. 
     
     
         12 . The method of  claim 1 , wherein said insulation batt, board or molding media comprises between about 1-20% by weight of said thermoplastic binder. 
     
     
         13 . The method of  claim 12 , wherein said insulation batt, board or molding media comprises between about 3-15% by weight of said thermoplastic binder. 
     
     
         14 . A system for forming a fibrous insulation product, comprising:
 at least one fiberizing apparatus for forming a fibrous veil comprising first fibers;   means for blowing a non-aqueous, formaldehyde-free, thermoplastic binder in powder, liquid or fibrous form into said veil to form a mixture of said binder and said first fibers, said fibrous form having average length of less than or equal to about 15 mm;   a forming belt disposed below said fiberizing apparatus for collecting said mixture; and   an oven for heating said mixture to a temperature at or above the melting temperature of said thermoplastic binder.   
     
     
         15 . The system of  claim 14 , wherein said blowing means comprises a hot melt gun. 
     
     
         16 . The system of  claim 15 , wherein said hot melt gun is configured to provide said binder in droplet form, said droplets having average diameters between about 0.5 to about 10 μm. 
     
     
         17 . The system of  claim 16 , wherein said diameters are between about 0.5 to about 6 μm. 
     
     
         18 . The system of  claim 15 , wherein said hot melt gun is configured to provide said binder in fibrous form. 
     
     
         19 . The system of  claim 18 , wherein said binder fibers have average diameters between about 0.2 to about 20 μm and average length between about 0.1 to about 15 mm. 
     
     
         20 . The system of  claim 19 , wherein said diameters are between about 0.5 to about 15 μm and said length is between about 0.1 to about 6 mm. 
     
     
         21 . The system of  claim 16 , wherein said binder is blown into said veil in powder form, the system further comprising a gas atomizer for forming said thermoplastic fiber in powder form. 
     
     
         22 . The system of  claim 21 , wherein the average diameter of particles in said powder form is between about 0.2 to about 60 μm. 
     
     
         23 . The system of  claim 22 , wherein the diameter is between about 2 to about 30 μm. 
     
     
         24 . The system of  claim 14 , wherein said insulation product comprises between about 1-20% by weight of said thermoplastic binder. 
     
     
         25 . The system  claim 24 , wherein said insulation product comprises between about 3-15% by weight of said thermoplastic binder. 
     
     
         26 . The system of  claim 14 , wherein said providing means comprises a plurality of applicator apparatus disposed around the outer surface of said veil. 
     
     
         27 . A method of forming a fibrous insulation product, comprising:
 forming at least one fibrous veil comprising first fibers;   directing from a hot melt applicator a non-aqueous, formaldehyde-free, thermoplastic binder into said veil to form a mixture of said binder and said first fibers;   collecting said mixture on said forming belt;   heating said mixture to a temperature above the melting temperature of said thermoplastic binder in an oven, wherein at least a majority of said thermoplastic binder is melted, whereby said melted thermoplastic binder forms meltbonds with said first fibers when cooled; and   forming said mixture into an insulation batt, board or molding media.   
     
     
         28 . A method of forming a fibrous insulation product, comprising:
 forming at least one fibrous veil comprising first fibers;   forming a non-aqueous, formaldehyde-free, thermoplastic powdered binder using a gas atomization process;   directing said thermoplastic powdered binder into said veil to form a mixture of said binder and said first fibers;   collecting said mixture on said forming belt;   heating said mixture to a temperature above the melting temperature of said thermoplastic binder in an oven, wherein at least a majority of said thermoplastic binder is melted, whereby said melted thermoplastic binder forms meltbonds with said first fibers when cooled; and   forming said mixture into an insulation batt, board or molding media.