Low density non-woven material useful with acoustic ceiling tile products

Abstract

A non-woven material, that can be formed into an acoustic ceiling tile, is provided. The material includes a substantially planar and self-supporting core of an inorganic base fiber and a synthetic thermal bonding fiber. The synthetic thermal bonding fiber preferably has an increased bonding surface area that improves adhesion and porosity to provide a base mat or core with a low density to provide sound absorption required by an acoustic ceiling tile.

1 . An acoustic ceiling tile comprising:
 a substantially planar, self-supporting non-woven core comprising an inorganic base fiber and a synthetic thermal bonding fiber;   the synthetic thermal bonding fiber having an average fiber length of about 3 mm or less, an average fiber diameter of about 30 microns or less, and a bonding surface area of about 0.5 m 2 /gram to about 15 m 2 /gram or greater; and   a density of the core of about 7 pcf to about 13 pcf or less;   wherein the acoustic ceiling tile exhibits a noise reduction coefficient of at least about 0.55.   
     
     
         2 . The acoustic ceiling tile of  claim 1 , wherein the synthetic thermal bonding fiber has a main body portion and a multitude of microfibrils extending from the main body portion, and wherein a combination of the main body portion and the plurality of microfibrils provide the bonding surface area. 
     
     
         3 . The acoustic ceiling tile of  claim 2 , wherein the microfibrils have a microfibril diameter ranging from about 0.1 microns to about 10 microns. 
     
     
         4 . The acoustic ceiling tile of  claim 2 , wherein synthetic thermal bonding fibers make up about 0.1 percent to about 50 percent by weight of the core. 
     
     
         5 . The acoustic ceiling tile of  claim 1 , wherein the synthetic thermal bonding fiber is formed from a material selected from the group consisting of polyacrylic, ethylene vinyl acetate, polyester, polyolefin, polyamide, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, polyvinyl alcohol, polyvinyl chloride, and mixtures thereof. 
     
     
         6 . The acoustic ceiling tile of  claim 1 , wherein the synthetic thermal bonding fiber has a melting point in a range from about 100° C. to about 250° C. 
     
     
         7 . The acoustic ceiling tile of  claim 1 , wherein the synthetic thermal bonding fiber is a bi-component fiber. 
     
     
         8 . The acoustic ceiling tile of  claim 7 , wherein a melting point of one component of the bi-component fiber is substantially higher than that of its other component. 
     
     
         9 . The acoustic ceiling tile of  claim 1 , wherein the core has a Class A fire rating according to ASTM E84 with a flame spread index less than about 25 and a smoke development index less than about 50. 
     
     
         10 . An acoustic ceiling tile comprising:
 a substantially planar and self-supporting non-woven core of inorganic base fibers and synthetic thermal bonding fibers;   a multitude of microbranches extending from outer surfaces of the synthetic thermal bonding fibers to provide an increased bonding surface area relative to length and diameter thereof if compared to an unbranched fiber of a similar size; and   a density of the core of about 7 pcf to about 13 pcf;   wherein the acoustic ceiling tile exhibits a noise reduction coefficient of at least about 0.55.   
     
     
         11 . The acoustic ceiling tile of  claim 10 , wherein the synthetic thermal bonding fibers have an average fiber length of about 3 mm or less, an average fiber diameter of about 30 microns or less, and the bonding surface area is about 0.5 m 2 /gram to about 15 m 2 /gram or greater. 
     
     
         12 . The acoustic ceiling tile of  claim 11 , wherein the synthetic thermal bonding fibers make up about 0.1 percent to about 50 percent by weight of the core. 
     
     
         13 . The acoustic ceiling tile of  claim 11 , wherein the synthetic thermal bonding fibers are substantially hydrophobic. 
     
     
         14 - 20 . (canceled)