Procedure for the production of magnetic plastic laminate
AssigneeS.I.P.A.P. Sas Di Demichelis Margherita & C.
InventorGiovanni Brussino
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Abstract
Procedure for the production of magnetic plastic laminate in which at least one of the paper fiber sheets impregnated with phenolic and melaminic resins, is first of all spread, using the silk screen process, with a cloth with a weave of from 9 to 24 threads per cm.sup.2, with a ferrous powder based paste with a percentage comprised of between 55%-80% and a binder with a percentage comprised of between 45%-20%; after drying the percentage of ferrous powders is comprised of between 75%-80%, the thickness of the paste of between 0.5 and 2.0 mm and the plastic laminate thus obtained is permanently magnetized through an electric charge thanks to the presence of the ferrous powders inside it.
Claims11
A process for producing a magnetic plastic laminate, said process comprising the steps of:
- impregnating at least three sheets of paper fiber with phenolic and melaminic resins and oven drying the impregnated paper fiber sheets;
- applying a paste on at least one of said dried impregnated paper fiber sheets, said paste comprising a ferrous powder in an amount of 55% to 80% and a binder in an amount of 45% to 20%, said binder being a resin;
- drying said paper fiber sheet having paste thereon, the thickness of the paste after drying being between 0.5 and 2.0 mm and the percentage of ferrous powder in the paste after drying being between 75% and 85%;
- inserting said paper fiber sheet having paste thereon between the other two dried impregnated paper fiber sheets and hot pressing the resultant layered structure to produce a laminate;
- and then
- applying an electrical charge to said laminate to permanently magnetize the laminate thereby producing a magnetic plastic laminate.
Dependencies are inferred from the claim text.