Mat material and method for manufacturing the same

Abstract

A lightweight mat material having excellent sound absorption and thermal insulation properties comprises a mixture of glass fibers and sheath-core composite fibers, wherein the melting temperature of the sheath portion is lower than the melting temperature of the core portion. The glass fibers are fused with the sheath portions of the composite fibers by melting on at least one surface of the sheet-shaped mat material.

1 . A mat material comprising a mixture of:
 an inorganic fiber and   a sheath-core composite fiber, wherein the melting temperature of a thermoplastic resin at least substantially comprising a sheath portion of the composite fiber is lower than the melting temperature of a thermoplastic resin at least substantially comprising a core portion of the composite fiber,   wherein the mat material is formed in substantially a sheet-shape and the inorganic fiber is melt-fused with the sheath portion of the composite fiber on at least one surface of mat material.   
     
     
         2 . The mat material according to  claim 1 , wherein the inorganic fiber has an outer diameter of 3 to 9 μm. 
     
     
         3 . The mat material according to  claim 2 , wherein the outer diameter of the inorganic fiber is between 4 to 6 μm. 
     
     
         4 . The mat material according to  claim 1 , wherein the inorganic fiber comprises at least substantially glass fiber. 
     
     
         5 . The mat material according to  claim 1 , wherein the sheath-core composite fiber has a linear mass density of 1 to 4 decitex. 
     
     
         6 . The mat material according to  claim 5 , wherein the sheath-core composite fiber has a linear mass density of 2.5-3.5 decitex. 
     
     
         7 . The mat material according to  claim 6 , wherein the inorganic fiber and the sheath-core composite fiber are mixed at a mass ratio of 20 to 80(%):80 to 20(%) when the total mass of the mat material is assumed to be 100%. 
     
     
         8 . The mat material according to  claim 1 , wherein the sheath portion of the sheath-core composite fiber at least substantially comprises polyethylene terephthalate. 
     
     
         9 . The mat material according to  claim 8 , wherein the core portion of the sheath-core composite fiber at least substantially comprises at least one of polyethylene terephthalate and polyethylene. 
     
     
         10 . The mat material according to  claim 1 , wherein the mat material has an area density of between 390-410 g/m2. 
     
     
         11 . The mat material according to  claim 10 , wherein the inorganic fiber comprises at least substantially glass fiber having an outer diameter of 4 to 6 μm. 
     
     
         12 . The mat material according to  claim 11 , wherein the sheath-core composite fiber has a linear mass density of 1 to 4 decitex. 
     
     
         13 . The mat material according to  claim 12 , wherein the sheath portion of the sheath-core composite fiber at least substantially comprises polyethylene terephthalate. 
     
     
         14 . The mat material according to  claim 13 , wherein the core portion of the sheath-core composite fiber at least substantially comprises at least one of polyethylene terephthalate and polyethylene. 
     
     
         15 . The mat material according to  claim 14 , wherein the sheath-core composite fiber has a linear mass density of 2.5-3.5 decitex. 
     
     
         16 . The mat material according to  claim 15 , wherein the inorganic fiber and the sheath-core composite fiber are mixed at a mass ratio of 20 to 80(%):80 to 20(%) when the total mass of the mat material is assumed to be 100%. 
     
     
         17 . A method for manufacturing a mat material, comprising:
 mixing an inorganic fiber with a sheath-core composite fiber, wherein the melting temperature of a thermoplastic resin at least substantially comprising a sheath portion thereof is lower than the melting temperature of a thermoplastic resin at least substantially comprising a core portion thereof;   forming the mixed fibers substantially into a sheet-shape and intertwining the mixed fibers using a needle punch, thereby forming a nonwoven sheet material;   heating the nonwoven sheet material so to melt the sheath portion of the sheath-core composite fiber, whereby the inorganic fiber fuses with the melted sheath portion; and   cooling the nonwoven sheet material, thereby obtaining the mat material.   
     
     
         18 . The method according to  claim 17 , wherein:
 the step of forming the mixed fibers substantially into a sheet-shape further comprises forming a first layer of mixed fibers and disposing a second layer of mixed fibers on the first layer, and   the heating step is performed using a far-infrared heater.   
     
     
         19 . The method according to  claim 17 , wherein the inorganic fiber comprises at least substantially glass fiber having an outer diameter of 3 to 9 μm. 
     
     
         20 . The method according to  claim 17 , wherein the sheath-core composite fiber has a linear mass density of 1 to 4 decitex, the sheath portion of the sheath-core composite fiber at least substantially comprises polyethylene terephthalate and the core portion of the sheath-core composite fiber at least substantially comprises at least one of polyethylene terephthalate and polyethylene.