Floor Covering Containing Polyvinyl Butyral and Method of Making the Same

1 . A method of manufacturing a backing for a floor covering, comprising:

providing a polymeric material mixture comprising polyvinyl butyral and a cell-forming material;

extruding the polymeric material mixture through a die;

calendering the extruded polymeric mixture to form a sheet; and

heating the sheet to activate the cell-forming material.

2 . The method of claim 1 , further comprising at least partially embedding a reinforcing material into the sheet.

3 . The method of claim 1 , further comprising adhering a reinforcing material to the sheet.

4 . The method of claim 1 , wherein extruding the polymeric material mixture comprises removing volatile organic compounds from the polymeric material mixture.

5 . A method of making a backing for a floor covering, comprising:

extruding a polymeric material mixture comprising recycled polyvinyl butyral and a cell-forming material;

calendering the extruded polymeric mixture to form a sheet; and

activating the cell-forming material to form a foamed sheet,

wherein at least one of the extruding, calendering, and heating are carried out at a temperature sufficient to release volatile organic compounds from the polymeric material mixture.

6 . The method of claim 5 , further comprising venting the volatile organic compounds away from the polymeric material mixture.

7 . The method of claim 5 , wherein the extruding is carried out at a temperature of from about 300° F. to about 350° F.

8 . The method of claim 5 , wherein the calendering is carried out at a temperature of from about 190° F. to about 350° F.

9 . The method of claim 5 , wherein the heating is carried out at a temperature of from about 300° F. to about 450° F.