Production of sheet material for use as gaskets

Abstract

Abstract A process for producing in indefinitely long lengths a composite sheet for use as a gasket material, the sheet comprising surface coatings of fibre reinforced elastomer bonded to both faces of a metal core, is characterised by simultaneously forming a curable dough-like fibre reinforced elastomer composition into a sheet and applying the sheet to one face of the metal core of indefinite length in a single continuous operation. This is done by feeding the metal core and, on one face of the metal core the dough-like composition, which contains fibre, elastomer, curatives, fillers an a solvent system including a volatile solvent for the elastomer and a non-solvent liquid through a nip between two calender rolls to spread the elastomer composition over the metal core and apply it thereto to form one coating, subsequently passing the coated metal core to a drying device to remove the solvent system from the composition, passing the dry, but uncured, coated metal core together with further dough-like composition on the other face of the core through a second nip between the two calender rolls to spread the composition over the other face of the core and apply it thereto to form a second coating. The non-solvent liquid prevents adhesion of the composition to the rolls. After this the core with its second coating is passed to a drying device to remove the solvent system from the second coating, the core with its coatings is passed through a further nip between two calender rolls to consolidate the coatings and enhance the bond between the coatings and the core and finally the coated core is passed into an oven to cure the composition. When the metal core is a plain metal sheet as is preferred, the core is coated with an adhesive before the doughlike composition is applied to it and the adhesive is partly soluble in the solvent system.

Inventors

• 👤 John Geoffrey Qualtrough
• 👤 Harry Thornley

Bibliographic Details