Process for the production of enamelled workpieces
AssigneesBayer Aktiengesellschaft, Miles Inc.
InventorsHermann Gruber, Eberhard Arning, Hans Hoffmann, Alain Viquesnel, Paul Zybell, Dieter Margotte, Keith Foster
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Abstract
A process is disclosed for the production of metal sheets enamelled with two layers, wherein the sheet is coated, before shaping, with a polymer suspension. The sheet is then dried and shaped, and optionally is coated with an enamel frit. The sheet is then fired at a temperature of 560 to 850 degrees C. The binder in the polymer suspension is preferably a material which burns completely at melting and stoving temperature.
Claims14
A process for the production of shaped workpieces of metal sheet enamelled with two layers, wherein one or both of said layers have been applied prior to shaping of the workpiece, comprising:
- 1) coating the sheet, before shaping, with at least one enamel polymer suspension, wherein the polymer suspension comprises a mixture of thermosetting binder system, solvent and a suspension aid, said thermosetting binder system comprises at least one acid-functional polymer and at least one epoxy-functional polymer, said acid-functional and epoxy-functional polymers are nitrogen- and halogen-free and burn at temperatures of 200 to 500 degrees C. and wherein the acid-functional polymer has a content of acid-functional groups between 0.5 and 30 weight % and the epoxy-functional polymer has a content of epoxy-functional groups between 0.5 and 30 weight %;
- 2) drying the coated sheet;
- 3) mechanically shaping the dried coated sheet thereby producing shaped sheet workpieces. 4) coating the shaped sheet workpieces with an enamel frit, if only one layer has been applied prior to shaping;
- and 5) firing the workpieces;
- thus obtained at temperatures of 560.degree. to 850.degree. C.
Dependencies are inferred from the claim text.