Tunable acoustical absorbing composite batt

Abstract

A composite batt structure that forms an effective low frequency sound absorber for use in buildings, appliances, automotive vehicles, and the like. The composite structure uses a facer covering a batt comprised of carded and crosslapped mixture of fibers. The general acoustic behavior of the composite batt structure has a low frequency absorption maximum by varying the number of crosslaps or the proportions of the fiber mixture. This allows for the composite batt structure to be tunable or layered with different laps.

What is claimed is: 
     
         1 . A tunable acoustically absorbing article comprising:
 (a) a batt of acoustically absorbing material having two major surfaces comprising:
 (i) 10 to 70% by weight staple flash spun plexifilamentary fibers or staple melt spun fibrillated fibers, 
 (ii) 10 to 70% by weight staple fibers, 
 (iii) 5 to 30% by weight binding agent, 
 (iv) carded and crosslapped; and 
   (b) a facer adhered said batt on at least one major surface.   
     
     
         2 . The tunable acoustically absorbing article of  claim 1  that is crosslapped at least 4 laps. 
     
     
         3 . The tunable acoustically absorbing article of  claim 1  that is crosslapped at least 8 laps. 
     
     
         4 . The tunable acoustically absorbing article of  claim 1  where the staple flash spun plexifilamentary fibers or staple melt spun fibers are at least 30% by weight. 
     
     
         5 . The tunable acoustically absorbing article of  claim 4  that is crosslapped at least 4 laps. 
     
     
         6 . The tunable acoustically absorbing article of  claim 4  that is crosslapped at least 8 laps. 
     
     
         7 . The tunable acoustically absorbing article of  claim 1  where the staple flash spun plexifilamentary fibers or staple melt spun fibers are at least 50% by weight. 
     
     
         8 . The tunable acoustically absorbing article of  claim 7  that is crosslapped at least 4 laps. 
     
     
         9 . The tunable acoustically absorbing article of  claim 7  that is crosslapped at least 8 laps.