Multilayered sheet
AssigneeE. I. Du Pont de Nemours and Company
InventorDariusz Wlodzimierz Kawka
Life of this patent
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Abstract
This invention pertains to a layered sheet comprising an inherently flame resistant high strength fiber wet-laid nonwoven carrier having a first and second surface and an inorganic refractory layer adjacent to at least one surface of the carrier wherein the refractory layer has a dry area weight of from 15 to 50 gsm and the bond strength between the refractory layer and the surface of the paper is at least 0.25 lb/in, preferably at least 0.8 lb/in, wherein the carrier comprises from 70 to 90 weight percent of aramid fibers and from 10 to 30 weight percent of polymeric binder, is hydrophilic, has a thickness of from 0.025 to 0.175 mm and a density of from 0.25 to 1.1 g/cc.
Claims14
A layered sheet comprising a nonwoven paper carrier having a first and second surface and an inorganic refractory layer comprising 100 percent platelets of vermiculite adjacent to at least one surface of the nonwoven paper carrier
- wherein the refractory layer has a dry areal weight of from 15 to 50 gsm, the bond strength between the refractory layer and the surface of the nonwoven paper carrier is no less than 0.25 lb/in, and wherein the nonwoven paper carrier
- (i) comprises from 70 to 90 weight percent of aramid fibers and from 10 to 30 weight percent of polymeric binder,
- (ii) is hydrophilic
- (iii) has a wet tensile strength of at least 3 lb/in in a first direction and at least 2 lb/in in a second direction, the second direction being transverse to the first direction,
- (iv) has a dry tensile strength of at least 7 lb/in in a first direction and at least 5 lb/in in a second direction, the second direction being transverse to the first direction,
- (v) has an air permeability no greater than 100 Gurley Air Resistance (sec/100cc, 20 oz. cyl.).
- (vii) has a thickness of from 0.025 to 0.175 mm,
- (viii) has a density of from 0.25 to 1.1 g/cc, and
- (ix) has a basis weight of from 20 to 70 gsm and wherein the layered sheet is a component of a flame barrier for a thermal and acoustic blanket.
Dependencies are inferred from the claim text.