Anti-microbial carpet underlay and method of making

Abstract

A method for making antimicrobial rebonded carpet pad includes mixing zinc pyrithione with a polyol to form an antimicrobial polyol mixture concentrate, blending the antimicrobial polyol mixture concentrate with a binder stream, mixing the binder with foam particles and curing the binder. The percentage of zinc pyrithione mixed with the polyol and the addition ratio of the antimicrobial polyol mixture concentrate with the binder stream are selected to provide an overall concentration of zinc pyrithione in the binder of at least about 7500 ppm. The particles and binder are cured into a block and sliced to form carpet pad.

1 . A method for making rebonded carpet pad, comprising:
 mixing an antimicrobial compound with a polyol to form an antimicrobial polyol mixture concentrate;   blending the antimicrobial polyol mixture concentrate with a binder stream to form binder;   selecting a percentage of the antimicrobial compound mixed with the polyol and an addition ratio of the antimicrobial polyol mixture concentrate with the binder stream to provide an effective concentration of the antimicrobial compound in the binder;   mixing the binder with foam particles; and   forming the mixture of binder and foam particles into a pad;   wherein the antimicrobial compound is approximately uniformly dispersed in the binder, there is substantially no antimicrobial compound in the foam particles, and the antimicrobial compound in the binder renders the carpet pad as a whole effectively antimicrobial.   
     
     
         2 . The method of  claim 1 , wherein the antimicrobial compound comprises zinc pyrithione. 
     
     
         3 . The method of  claim 1 , wherein the antimicrobial compound is zinc pyrithione, and wherein the effective concentration of zinc pyrithione in the binder is at least about 7500 ppm. 
     
     
         4 . The method of  claim 3 , wherein mixing antimicrobial compound with a polyol to form an antimicrobial polyol mixture concentrate further comprises:
 mixing zinc pyrithione with a triol polyol to a 20% strength antimicrobial polyol mixture concentrate, and   blending the 20% strength antimicrobial polyol mixture concentrate with a binder stream at least a 3.90% addition level.   
     
     
         5 . The method of  claim 4 , further comprising blending the 20% strength antimicrobial polyol mixture concentrate with a binder stream at about a 3.90% to 6.5% addition level. 
     
     
         6 . The method of  claim 3 , wherein the ratio of binder to foam particles is about 1:10 and results in an overall concentration of zinc pyrithione in the carpet pad of at least about 750 ppm. 
     
     
         7 . The method of  claim 1 , wherein the antimicrobial compound is zinc pyrithione, and the overall concentration of zinc pyrithione in the carpet pad is between about 750 and about 850 ppm. 
     
     
         8 . The method of  claim 7 , wherein forming the mixture of binder and foam particles into a pad comprises shaping the mixture of binder and foam particles into a block, curing the binder, and slicing the block to form carpet pad of a substantially uniform thickness between about ⅜ and about ⅝ inch. 
     
     
         9 . The method of  claim 2 , further comprising laminating a film to at least one side of the carpet pad. 
     
     
         10 . The method of  claim 9 , wherein the film comprises an effective amount of an antimicrobial compound. 
     
     
         11 . The method of  claim 10 , wherein the antimicrobial compound of the film comprises zinc pyrithione, and wherein the minimum combined concentration of zinc pyrithione in the pad and the film is about 1600 ppm. 
     
     
         12 . The method of  claim 10 , wherein the film is an 0.45 to 0.5 mil monolayer blown film, the antimicrobial compound of the film comprises zinc pyrithione, the pad comprises a concentration of zinc pyrithione from about 750 to about 1250 ppm, and the film comprises a concentration of zinc pyrithione from about 500 to about 1500 ppm. 
     
     
         13 . The method of  claim 12 , further comprising:
 forming the 0.45 to 0.5 mil monolayer blown film; and   thermally laminating the film to at least one side of the pad.   
     
     
         14 . The method of  claim 2 , wherein blending the antimicrobial polyol mixture concentrate with the binder stream forms a binder comprising about ⅓ aromatic oil, about ⅓ triol polyol, and about ⅓ polymeric MDI. 
     
     
         15 . The method of  claim 2 , wherein blending the antimicrobial polyol mixture concentrate with binder stream comprises pumping the antimicrobial polyol mixture concentrate and binder stream from separate lines through a static mixer for discharge onto the foam particles. 
     
     
         16 . The method of  claim 15 , wherein the binder is not held after the polyol mixture concentrate is blended with the binder stream, but is sprayed from the discharge line directly onto the foam particles. 
     
     
         17 . The method of  claim 16 , wherein despite the fact that the antimicrobial is not uniformly distributed throughout the carpet pad, the carpet pad as a whole is effectively antimicrobial. 
     
     
         18 . A carpet underlay for use beneath carpeting comprising a pad, comprising:
 foam particles bound together with a binder comprising an effective amount of an antimicrobial compound;   wherein the antimicrobial compound is approximately uniformly dispersed in the binder, there is substantially no antimicrobial compound in the foam particles, and the antimicrobial compound in the binder renders the carpet pad as a whole effectively antimicrobial.   
     
     
         19 . The carpet underlay of  claim 18 , wherein the antimicrobial compound of the binder comprises zinc pyrithione. 
     
     
         20 . The carpet underlay of  claim 19 , wherein the binder comprises at least about 7500 ppm of the antimicrobial compound. 
     
     
         21 . The carpet underlay of  claim 19 , wherein the pad comprises between about 750 and about 850 ppm of the antimicrobial compound. 
     
     
         22 . The carpet underlay of  claim 19 , further comprising a film laminated to the pad. 
     
     
         23 . The carpet underlay of  claim 22 , wherein the film is a 0.45 to 0.5 mil monolayer blown film, and the film comprises an effective amount of an antimicrobial compound. 
     
     
         24 . The carpet underlay of  claim 22 , wherein the film comprises at least about 500 ppm of zinc pyrithione. 
     
     
         25 . The carpet underlay of  claim 18 , further comprising a film, wherein the film comprise an effective amount of antimicrobial compound. 
     
     
         26 . The carpet underlay of  claim 24 , wherein the concentration of zinc pyrithione in the pad plus the concentration of zinc pyrithione in the film comprises at least about 1600 ppm. 
     
     
         27 . A carpet underlay, comprising:
 a foam pad, and   a laminating film comprising an effective amount of an antimicrobial compound, wherein the laminating film is laminated to the foam pad, such that the film provides   effective antimicrobial protection to the foam pad.   
     
     
         28 . The carpet underlay of  claim 27 , wherein the antimicrobial compound comprises zinc pyrithione, and the laminating film comprises at least about 500 ppm of zinc pyrithione. 
     
     
         29 . The carpet underlay of  claim 27 , wherein the foam pad comprises foam particles bound together with a binder comprising an effective amount of an antimicrobial compound. 
     
     
         30 . The carpet underlay of  claim 29 , wherein the antimicrobial compound of the film is zinc pyrithione, the antimicrobial compound of the binder is zinc pyrithione, and the concentration of zinc pyrithione in the pad plus the concentration of zinc pyrithione in the film comprises at least 1600 ppm.