Method for making a cellulosic material fire-resistant
OwnerBo O. E. Tjannberginventor
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Abstract
This specification describes a method for making a cellulosic material fire-resistant. The material is well dried and then impregnated with an aqueous solution containing phosphoric acid and ammonium sulphate and/or ammonium phosphate. The solution may also contain borax, trisodiumphosphate, ammonia, sodium carbonate, and sodium chloride. The method is particularly suited for treating sawdust in the manufacturing of chipboards. After impregnating the dry sawdust with the solution under stirring the material is dried once more and glue is applied whereupon chipboards are formed from the composite material.
Claims15
A method of manufacturing fire-resistant wood-products comprising:
- impregnating disintegrated wood material with an aqueous solution containing at least 2% phosphoric acid and 1-10% ammonium sulphate, which may be partly or completely replaced by a third as big quantity of ammonium phosphate, the quantity of said solution being 35-70% of the total weight of said solution plus wood material,
- drying the impregnated wood material to a maximum moisture content of 5% by weight, supplying glue to the impregnated, dried wood material, and
- forming wood-products of the combined impregnated wood material and glue.
Method for making wood sawdust and/or chips fire resistant, comprising drying said wood sawdust and/or chips to a moisture content of no greater than 10% by weight, thereafter impregnating the dried wood sawdust and/or chips with an aqueous solution containing at least 2% phosphoric acid and 1-10% of ammonium phosphate, which may be partly or completely replaced by a third as big quantity of ammonium phosphate, wherein the quantity of said aqueous solution is 35-70% by weight of the total weight of said aqueous solution plus said wood sawdust and/or chips, and thereafter the impregnated wood sawdust and/or chips are dried to a maximum moisture content of 10% by weight, to render said wood sawdust and/or chips fire-resistant.
Dependencies are inferred from the claim text.