Composite reinforcement

Abstract

A composite reinforcement includes a first nonwoven mat. A laid scrim overlies the first nonwoven mat, the laid scrim including a first plurality of yarns substantially oriented in a first direction and a second plurality of yarns substantially oriented in a second direction different from the first direction. The second plurality of yarns includes at least one different material from the first plurality of yarns and each of the yarns in the second plurality of yarns includes a tension greater than a tension of each of the yarns in the first plurality of yarns. A second nonwoven mat overlies the laid scrim, and a binder laminates the first nonwoven mat, the laid scrim, and the second nonwoven mat together to form the composite reinforcement.

What is claimed is: 
     
         1 . A composite reinforcement comprising:
 a first nonwoven mat;   a laid scrim overlying the first nonwoven mat, wherein the laid scrim comprises a first plurality of yarns substantially oriented in a first direction and a second plurality of yarns substantially oriented in a second direction different from the first direction, wherein the second plurality of yarns comprises at least one different material from the first plurality of yarns and wherein each of the yarns in the second plurality of yarns comprises a tension greater than a tension of each of the yarns in the first plurality of yarns;   a second nonwoven mat overlying the laid scrim; and   a binder laminating the first nonwoven mat, the laid scrim, and the second nonwoven mat together to form the composite reinforcement.   
     
     
         2 . The composite reinforcement of  claim 1 , wherein the first nonwoven mat comprises polyester fibers. 
     
     
         3 . The composite reinforcement of  claim 1 , wherein the second nonwoven mat comprises fiberglass fibers. 
     
     
         4 . The composite reinforcement of  claim 1 , wherein the first plurality of yarns comprises fiberglass yarns. 
     
     
         5 . The composite reinforcement of  claim 1 , wherein the second plurality of yarns comprises polyester yarns and fiberglass yarns. 
     
     
         6 . The composite reinforcement of  claim 1 , wherein the first direction is a cross direction of the laid scrim and the second direction is a main direction of the laid scrim, and wherein the first plurality of yarns is substantially oriented in the cross direction and wherein the second plurality of yarns is substantially oriented in the main direction. 
     
     
         7 . The composite reinforcement of  claim 1 , wherein the binder penetrates at least a portion of the second nonwoven mat without saturating the second nonwoven mat. 
     
     
         8 . The composite reinforcement of  claim 1 , wherein the laid scrim comprises a greater concentration of binder than the first nonwoven mat or the second nonwoven mat. 
     
     
         9 . The composite reinforcement of  claim 1 , wherein the tension of each of the yarns of the second plurality of yarns comprises a tension between about 1.0 cN/tex and about 18 cN/tex. 
     
     
         10 . The composite reinforcement of  claim 1 , wherein the tension of at least some of the yarns in the second plurality of yarns is configured to be relieved by shrinkage of the at least some of the yarns, wherein the shrinkage occurs in a direction parallel to the second direction. 
     
     
         11 . The composite reinforcement of  claim 10 , wherein the shrinkage comprises a shortening of each of the at least some of the yarns in the second plurality of yarns, wherein the shortening comprises at least between 0.2% and about 15%. 
     
     
         12 . A composite reinforcement configured for incorporation into a roofing membrane, wherein the composite reinforcement comprises:
 a polyester nonwoven mat;   a laid scrim overlying the polyester nonwoven mat, wherein the laid scrim comprises a plurality of fiberglass yarns oriented in a cross direction of the laid scrim and a plurality of polyester yarns and fiberglass yarns oriented in a main direction of the laid scrim, and wherein each of the polyester yarns and fiberglass yarns oriented in the main direction comprises a tension greater than a tension of each of the fiberglass yarns oriented in the cross direction;   a fiberglass nonwoven mat overlying the laid scrim; and   a binder laminating the polyester nonwoven mat, the laid scrim, and the fiberglass nonwoven mat together to form the composite reinforcement.   
     
     
         13 . A method of forming a composite reinforcement, the method comprising:
 coating a laid scrim with a binder, wherein the laid scrim comprises a first plurality of yarns substantially oriented in a first direction and a second plurality of yarns substantially oriented in a second direction different from the first direction, wherein the second plurality of yarns comprises at least one different material from the first plurality of yarns and wherein each of the yarns in the second plurality of yarns comprises a tension greater than a tension of each of the yarns in the first plurality of yarns;   contacting the laid scrim with a first nonwoven mat and a second nonwoven mat, wherein the laid scrim overlies the first nonwoven mat and wherein the second nonwoven mat overlies the laid scrim; and   curing the binder to form the composite reinforcement.   
     
     
         14 . The method of  claim 13 , further comprising relieving the tension of at least some of the yarns in the second plurality of yarns, wherein the tension is configured to be relieved by shrinkage of the at least some of the yarns, wherein the shrinkage occurs in a direction parallel to the second direction. 
     
     
         15 . The method of  claim 14 , wherein the shrinkage comprises a shortening of each of the at least some of the yarns in the second plurality of yarns, wherein the shortening comprises at least between 0.2% and about 15%.