Method of preparing a bitumen-backed floor covering
AssigneeInterface, Inc.
InventorAndrew Thompson
Life of this patent
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Abstract
A floor covering having a bitumen composition as a backing layer, such as carpet tiles, which bitumen composition comprises straight run bitumen and a mixture of high density and low density polyethylene polymers blended and dispersed in the straight run bitumen as a continuous phase in an amount of up to about 12% by weight and which bitumen composition contains a minimum of about 40% by weight of a mineral filler material, such as limestone, and the bitumen composition having improved dimensional stability, adhesion, static loading and electrical conductivity and having lower cost and processing advantages.
Claims18
A method of preparing a floor covering having a bitumen composition backing layer, the floor covering having a fibrous face surface and a back surface, the bitumen backing composition being bonded to the back surface, which method comprises:
- a) heating a straight run bitumen to a temperature of about 180.degree. C. to 200.degree. C.;
- b) adding a mixture consisting essentially of low density polyethylene and high density polyethylene, the low density polyethylene in greater concentration than the high density polyethylene, to the heated, straight run bitumen to form an admixture;
- c) mixing the admixture to provide a homogenous dispersion with the straight run bitumen as a dispersed phase in a continuous phase of the polyethylene to provide a bitumen composition having a softening point of about 110.degree. C. to 128.degree. C. and a penetration value of about 10 dmm to 15 dmm;
- d) heating the bitumen composition to a temperature of 160.degree. C. to 180.degree. C. at a coating application station;
- e) applying at the coating application station the heated bitumen composition as the backing layer to the back surface of a fibrous face floor surface covering to bond to the back surface;
- and
- f) recovering a floor covering having the bitumen composition as the backing layer with an exterior back surface.
A method of preparing a carpet tile floor covering having a bitumen composition backing layer and a fibrous face surface and a back surface which comprises:
- a) heating to an application temperature a bitumen composition which comprises:
- i) a dispersed phase of straight run bitumen;
- and
- ii) a continuous phase of a mixture consisting essentially of low density polyethylene and a high density polyethylene, the low density polyethylene concentration less than about 12 percent by weight of the composition;
- b) applying the heated bitumen composition as a backing layer to the back surface of the fibrous face surface;
- c) cooling the applied backing layer to bond the bitumen backing layer to the back surface;
- d) recovering a carpet tile floor covering having the bitumen composition as the backing layer.
Dependencies are inferred from the claim text.