Hydrophobic fiberglass thermal insulation blanket

Abstract

A hydrophobic needle-felted insulation blanket having a textile-grade needle felted fiberglass blanket having a density in the range of 4 to 15 lb/ft3 (65 to 250 g/L) contains a uniform hydrophobic fluoropolymer disposed homogeneously throughout the textile grade needle felted fiberglass blanket without creating a higher density of hydrophobic fluoropolymer near edges of the textile-grade needle felted fiberglass blanket. The fluoropolymer has a melting point over 5500 Fahrenheit and decomposed residual hydrophilic compounds uniformly disposed through the textile grade needle felted fiberglass blanket. The finished hydrophobic needle-felted insulation blanket is (i) temperature stable up to 5500 Fahrenheit, (ii) moldable, (iii) silica dust free, and thereafter retains a selected shape and the finished blanket will not decompose, disintegrate, or lose structural integrity when submerged in water. The finished blanket comprises by weight: 60%-95% glass fiber 2%-30% hydrophobic flouropolymer, and non-decomposed hydrophilic opacifier.

What is claimed is: 
     
         1 . A hydrophobic needle-felted insulation blanket comprising:
 a. a textile-grade needle felted fiberglass blanket having a density in the range of 4 to 15 lb/ft 3  (65 to 250 g/L);   b. an uniform hydrophobic fluoropolymer disposed homogeneously throughout the textile-grade needle felted fiberglass blanket without creating a higher density of hydrophobic fluoropolymer near edges of the textile-grade needle felted fiberglass blanket, wherein the uniform hydrophobic fluoropolymer has a melting point over 550° Fahrenheit; and   c. a non-decomposed hydrophilic opacifier uniformly disposed through the textile-grade needle felted fiberglass blanket that reduces radiative heat flow through the finished blanket; and   wherein the finished hydrophobic needle-felted insulation blanket is (i) temperature stable up to 550° Fahrenheit, (ii) moldable, (iii) silica dust free, and thereafter retains a selected shape and the hydrophobic needle-felted insulation will not decompose, disintegrate, or lose structural integrity when submerged in water, and further the hydrophobic needle-felted insulation comprises by weight from 60%-95% glass fiber, 2%-30% hydrophobic flouropolymer, and 0.1-10% non-decomposed hydrophilic opacifier.   
     
     
         2 . The hydrophobic needle-felted insulation blanket of  claim 1 , wherein the finished hydrophobic needle-felted insulation blanket is free of any residual hydrophilic compounds, including glass fiber sizing, and the surfactants that had previously been used to emulsify the fluoropolymer. 
     
     
         3 . The hydrophobic needle-felted insulation blanket of  claim 1 , wherein the textile-grade needle felted fiberglass blanket comprises: fibers selected from the group consisting of E-glass fiber, C-glass fiber, T-glass fiber, S-glass fiber, textile-grade basalt fiber, carbon fiber, aramid fibers, and mixtures thereof; and wherein the diameters of the fibers are from 4 to 13 microns. 
     
     
         4 . The hydrophobic needle-felted insulation blanket of  claim 3 , wherein the finished blanket of has a thermal conductivity k measured as (Btu·in/hr-ft 2  F) of from about 0.26 at 75° Fahrenheit to about 1.18 at 1050° Fahrenheit. 
     
     
         5 . The hydrophobic needle-felted insulation blanket of  claim 1 , wherein the non-decomposed hydrophilic opacifier comprises particles selected from the group consisting of: carbon black, graphite, graphene, titanium dioxide, iron oxides, silicon carbide, zirconium dioxide, and mixtures thereof; and wherein the opacifier comprises 0.1% to 10% of the finished blanket by weight. 
     
     
         6 . The hydrophobic needle-felted insulation blanket of  claim 1 , comprising a super-hydrophobic topcoat disposed on at least one surface of the finished blanket; wherein the super-hydrophobic topcoat comprises:
 a. a 60%-99% by mass based on the total mass of the topcoat of second hydrophobic polymer consisting of polytetrafluoroethylene;   b. 0.1-10% by mass of silicone resin based on the total mass of the topcoat;   c. 0.1-10% by mass of an opacifer based on the total mass of the topcoat; and   d. 0.1 to 20% of hydrophobic inorganic particles by mass based on the total mass of the topcoat wherein the first and second hydrophobic polymers may be the same or different; and wherein the inorganic particles comprise particles selected from the group consisting of silica aerogel, fumed silica, precipitated silica, synthetic amorphous silica, and mixtures thereof.   
     
     
         7 . The hydrophobic needle-felted insulation blanket of  claim 6 , wherein the super-hydrophobic topcoat disposed on at least one surface of the finished hydrophobic needle-felted insulation blanket; wherein the inorganic particles have a particle size between 0.1 to 100 microns; wherein the inorganic particles have a specific surface area of 100 m 2 /g or greater; and wherein the inorganic particles comprise a hydrophobic surface and comprise from 1 to 25 wt % of the finished blanket by mass, wherein said hydrophobic surface treatment comprises dimethyl silyl, trimethylsilyl, or other alkylsilyl moieties. 
     
     
         8 . The hydrophobic needle-felted insulation blanket of  claim 3 , wherein the uniform hydrophobic fluoropolymer and the fibers are interspersed with one another with sufficient uniformity to form a flexible matrix and render the finished blanket hydrophobic at temperatures at least up to 600 F. 
     
     
         9 . The hydrophobic needle-felled insulation blanket of  claim 7 , wherein the hydrophobic surface comprises: a silicone, and wherein the silicone is di-alkyl silicone fluid in the form of aqueous emulsions with particle sizes from 100 nm to several μm; and the alkyl group has from 1 carbon atom to 8 carbon atoms selected from the group consisting of a methyl, a phenyl, a propyl, or a combination thereof. 
     
     
         10 . The hydrophobic needle-felted insulation blanket of  claim 3 , wherein the fibers comprise from 60% to 95% by mass of the finished hydrophobic needle-felted insulation blanket. 
     
     
         11 . The hydrophobic needle-felted insulation blanket of  claim 1 , wherein the uniform hydrophobic fluoropolymer comprises a compound selected from the group consisting of polytetrafluoroethylene, perfluoroalkoxy alkanes, fluorinated ethylene propylene, and mixtures thereof; 
     
     
         12 . The hydrophobic needle-felted insulation blanket of  claim 1 , wherein the uniform hydrophobic fluoropolymer is between 5% and 25% by mass of the finished blanket.