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US 6,004,428 AGranted
Process for fiber recovery from bonded fiber webs
AssigneeBASF SE
InventorsKarl-Heinz Schumacher, Rainer Hummerich, Howard Peter Kirsch
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Abstract
A process for dissolving a binder off a fiber web bonded therewith includes treating the fiber web, which is bonded with a polymeric binder having carboxylate groups crosslinked via alkaline earth metal cations, with an aqueous solution of an alkali metal salt to form a sparingly soluble salt or complex between the anion of the alkali metal salt and the alkaline earth metal cations, and then removing the fiber freed of the binder.
Claims7
A process for dissolving a binder off a fiber web bonded therewith, which comprises
- treating the fiber web, which is bonded with a polymeric binder having carboxylate groups crosslinked via alkaline earth metal cations, with an aqueous solution of an alkali metal salt to form a sparingly soluble salt or complex between the anion of the alkali metal salt and the alkaline earth metal cations wherein the sparingly soluble salt or complex has a solubility of less than 0.5 g/L, and then
- removing the fiber from the binder.
Dependencies are inferred from the claim text.