Mineral wool insulation

Abstract

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

1 . A method of manufacturing a mineral fibre thermal insulation product comprising the sequential steps of:
 forming mineral fibres from a molten mineral mixture;   spraying a substantially formaldehyde free binder solution on to the mineral fibres, the binder solution comprising: a reducing sugar, an acid precursor derivable from an inorganic salt and a source of nitrogen;   collecting the mineral fibres to which the binder solution has been applied to form a batt of mineral fibres; and   curing the batt comprising the mineral fibres and the binder by passing the batt through a curing oven so as to provide a batt of mineral fibres held together by a substantially water insoluble cured binder.   
     
     
         2 .- 44 . (canceled) 
     
     
         45 . The method of  claim 1  comprising at least one of the following features:
 in which wash water is sprayed on to the mineral fibres between their formation and their collection to form a batt, at least a part of the wash water having been sprayed on mineral fibres and subsequently returned to a wash water system to be reused as wash water. 
 in which the binder solution is sprayed on to the mineral fibres when the mineral fibres are at a temperature of between 30° C. and 150° C. 
 in which the binder solution has a pH of greater than 7 when sprayed on to the mineral fibres. 
 
     
     
         46 . The method of  claim 1  in which curing of the binder is carried out by passing the batt through at least one zone of a curing oven at a temperature within the range 230° C.-300° C. with an oven residence time in the range 30 seconds to 20 minutes. 
     
     
         47 . The method of  claim 1  comprising at least one of the following features:
 in which the acid precursor makes up between 5% and 25% by dry weight of the binder solution. 
 in which the acid precursor of the binder solution derivable from an inorganic salt comprises an ammonium salt. 
 in which the acid precursor of the binder solution derivable from an inorganic salt comprises an ammonium salt and in which the inorganic ammonium salt makes up between 5% and 25% by dry weight of the binder solution. 
 
     
     
         48 . The method of  claim 1  comprising at least one of the following features:
 in which the acid precursor derivable from an inorganic salt of the binder solution comprises a species selected from the group consisting of sulphates, phosphates, nitrates and carbonates. 
 in which the reducing sugar of the binder solution has a dextrose equivalent value of at least 0.85. 
 in which the reducing sugar of the binder solution consists essentially of dextrose. 
 in which the binder solution comprises a silicon containing compound. 
 
     
     
         49 . The method of  claim 1  in which the binder solution comprises a material selected from the group consisting of a polycarboxylic acid, a salt of a polycarboxylic acid, an anhydride of a polycarboxylic acid. 
     
     
         50 . The method of  claim 1  comprising at least one of the following features:
 in which the binder solution consists essentially of an aqueous solution of: a reducing sugar; at least one acid precursor derivable from an ammonium salt selected from the group consisting of ammonium sulphate salts, ammonium phosphate salts, and ammonium carbonate salts; and, optionally, excess ammonia. 
 in which the binder solution consists essentially of an aqueous solution of: a reducing sugar; at least one acid precursor derivable from an ammonium salt selected from the group consisting of ammonium sulphate salts and ammonium phosphate salts; and, optionally, excess ammonia, the binder solution having a pH which, in its conditions of use, prevents precipitation of sulphates or phosphates. 
 in which the binder solution consists essentially of an aqueous solution of: a reducing sugar; an acid precursor derivable from an ammonium salt; a carboxylic acid or a precursor thereof; and, optionally, excess ammonia. 
 
     
     
         51 . The method of  claim 1  comprising at least one of the following features:
 in which the binder solution when sprayed on to the mineral fibres comprises at least 5% solids. 
 in which the binder solution when sprayed on to the mineral fibres comprises less than 50% solids. 
 in which the ratio by dry weight of reducing sugar to inorganic acid precursor expressed as (dry weight of reducing sugar/dry weight of inorganic acid precursor) is in the range 2.5 to 13. 
 in which the binder solution comprises between 0.1% and 1% of a silane or silicon-containing coupling agent calculated as dissolved binder solids. 
 
     
     
         52 . The method of  claim 1  comprising one of the following features:
 in which the thermal insulation product has a thermal conductivity λ in the range 0.02 W/mK to 0.05 W/mK. 
 in which the thermal insulation product comprises glass wool fibres and has a density in the range of 8 to 50 kg/m 3 . 
 in which the thermal insulation product comprises stone wool fibres and has a density in the range of 25 to 180 kg/m 3 . 
 
     
     
         53 . A mineral fibre thermal insulation product comprising mineral fibres and a binder, in which the binder is substantially formaldehyde free and comprises a reducing sugar; an acid precursor derivable from an inorganic salt and a source of nitrogen. 
     
     
         54 . The mineral fibre thermal insulation product of  claim 53  comprising at least one of the following features:
 in which the binder has a pH of greater than 6 when dissolved in water. 
 in which the acid precursor of the binder derivable from an inorganic salt comprises an ammonium salt. 
 in which the acid precursor derivable from an inorganic salt of the binder comprises a species selected from the group consisting of sulphates, phosphates, nitrates and carbonates. 
 
     
     
         55 . The mineral fibre thermal insulation product of  claim 53  comprising at least one of the following features:
 in which the reducing sugar of the binder has a dextrose equivalent value of at least 0.85. 
 in which the reducing sugar of the binder consists essentially of dextrose. 
 
     
     
         56 . The mineral fibre thermal insulation product of  claim 53  comprising at least one of the following features:
 in which the binder comprises a silicon containing compound. 
 in which the binder comprises a material selected from the group consisting of a polycarboxylic acid, a salt of a polycarboxylic acid, an anhydride of a polycarboxylic acid. 
 
     
     
         57 . The mineral fibre thermal insulation product of  claim 53  comprising at least one of the following features:
 in which the binder consists essentially of a reducing sugar; at least one acid precursor derivable from an ammonium salt selected from the group consisting of ammonium sulphate salts, ammonium phosphate salts, and ammonium carbonate salts; and, optionally, excess ammonia. 
 in which the binder consists essentially of a reducing sugar, an acid precursor derivable from an ammonium salt, a carboxylic acid or a precursor thereof and, optionally, excess ammonia. 
 
     
     
         58 . The mineral fibre thermal insulation product of  claim 53  comprising at least one of the following features:
 in which the ratio by dry weight of reducing sugar to inorganic acid precursor expressed as (dry weight of reducing sugar/dry weight of inorganic acid precursor) is in the range 2.5 to 13. 
 in which the binder comprises between 0.1% and 1% of a silane or silicon-containing coupling agent calculated as binder solids. 
 in which the binder comprises glucosylamine. 
 
     
     
         59 . A mineral fibre thermal insulation product obtainable by thermally curing a product in accordance with  claim 53 . 
     
     
         60 . A mineral fibre thermal insulation product comprising mineral fibres and a binder, in which the binder is substantially formaldehyde free and comprises Maillard reaction products and in which the insulation product comprises more than 500 mg/kg of species selected from the group consisting of sulphates, phosphates, nitrates and carbonates. 
     
     
         61 . The mineral fibre thermal insulation product of  claim 60  comprising one of the following features:
 in which the species selected from the group consisting of sulphates, phosphates, nitrates and carbonates is derived essentially from binder precursors. 
 in which the Maillard reaction products comprise melanoidins. 
 
     
     
         62 . The mineral fibre thermal insulation product of  claim 60  comprising one of the following features:
 in which the thermal insulation product has a thermal conductivity λ in the range 0.02 W/mK to 0.05 W/mK. 
 in which the thermal insulation product comprises glass wool fibres and has a density in the range of 8 to 50 kg/m 3 . 
 in which the thermal insulation product comprises stone wool fibres and has a density in the range of 25 to 180 kg/m 3 . 
 in which the thermal insulation product comprises between 1% and 20% binder by dry weight.