Webbing for occupant restraint belt

Abstract

A webbing for a seat belt comprises warp yarns and weft yarns made of synthetic filaments woven to extend perpendicular to each other. At least either of the warp yarns and the weft yarns are made of synthetic filaments having thermal adhesiveness, which include a bundle of first filaments and a second filaments. The second filament is attached to an outer surface of the first filament and has melting point lower than that of the first filament. The second filaments melt when heated at a temperature of 150° C. or more and a process time of 180 seconds or more so that the filament bodies are welded to each other. The webbing has a weight of 60 g/m or less, tensile strength of 25 kN or more, and retention rate after hexagonal bar abrasion of 70% or more. The occupant restraint belt is sufficiently stiff and has a reduced weight.

1 . A webbing material for an occupant restraint belt that restrains a vehicle occupant, comprising: 
 warp yarns and weft yarns woven together to form the webbing, the warp yarns and weft yarns being made of synthetic filaments such that the warp yarns and weft yarns extend perpendicular to each other,    wherein at least either of the warp yarns and the weft yarns are made of synthetic filaments with thermal adhesiveness, the synthetic filaments are formed by bundling a plurality of filament bodies,    wherein each of the filament bodies includes: 
 a first filament; and  
 a second filament attached to an outer surface of the first filament, the second filament having a melting point lower than a melting point of the first filament,  
   wherein the second filaments melt when heated to temperature of 150° C. or more and a process time of 180 seconds or more such that the filament bodies are welded to each other, and    wherein the webbing material has a weight of 60 g/m or less, tensile strength of 25 kN or more, and retention rate after hexagonal bar abrasion of 70% or more.    
   
   
       2 . The webbing material for an occupant restraint belt as claimed in  claim 1 , wherein a density of the weft yarns is 20 picks per inch or less.  
   
   
       3 . The webbing material for an occupant restraint belt as claimed in  claim 1 , wherein at least either of the warp yarns and the weft yarns comprise a material of twist yarns  
   
   
       4 . The webbing material for an occupant restraint belt as claimed in  claim 1 , wherein at least either of the warp yarns and the weft yarns comprise a material of entangled non-twist yarn.  
   
   
       5 . A seat belt, comprising: 
 a webbing material that is configured to restrain an occupant in a vehicle, the webbing including warp yarns and weft yarns woven together to form the webbing, the warp yarns and weft yarns being made of synthetic filaments such that the warp yarns and weft yarns extend perpendicular to each other,    wherein at least either of the warp yarns and the weft yarns are made of synthetic filaments with thermal adhesiveness, the synthetic filaments are formed by bundling a plurality of filament bodies,    wherein each of the filament bodies includes: 
 a first filament; and  
 a second filament attached to an outer surface of the first filament, the second filament having a melting point lower than a melting point of the first filament,  
   wherein the second filaments melt when heated to a temperature of 150° C. or more and a process time of  180  seconds or more such that the filament bodies are welded to each other, and    wherein the webbing material has a weight of 60 g/m or less, tensile strength of 25 kN or more, and retention rate after hexagonal bar abrasion of 70% or more.    
   
   
       6 . The seat belt as claimed in  claim 5 , wherein a density of the weft yarns is 20 picks per inch or less.  
   
   
       7 . The seat belt as claimed in  claim 5 , wherein at least either of the warp yarns and the weft yarns comprise a material of twist yarns.  
   
   
       8 . The seat belt as claimed in  claim 5 , wherein at least either of the warp yarns and the weft yarns comprise a material of entangled non-twist yarn.  
   
   
       9 . A seat belt apparatus comprising: 
 a seat belt comprising a webbing material;    a seat belt retractor capable of winding and unwinding the seat belt;    a buckle fixed to a vehicle; and    a tongue attached to the seat belt and latched to the seat belt buckle when the seat belt is worn by a vehicle occupant,    wherein the webbing material comprises warp yarns and weft yarns woven together to form the webbing, the warp yarns and weft yarns being made of synthetic filaments such that the warp yarns and weft yarns extend perpendicular to each other,    wherein at least either of the warp yarns and the weft yarns are made of synthetic filaments with thermal adhesiveness, the synthetic filaments are formed by bundling a plurality of filament bodies,    wherein each of the filament bodies includes: 
 a first filament; and  
 a second filament attached to an outer surface of the first filament, the second filament having a melting point lower than a melting point of the first filament,  
   wherein the second filaments melt when heated to a temperature of 150° C. or more and a process time of 180 seconds or more such that the filament bodies are welded to each other, and    wherein the webbing material has a weight of 60 g/m or less, tensile strength of 25 kN or more, and retention rate after hexagonal bar abrasion of 70% or more.    
   
   
       10 . The seat belt apparatus as claimed in  claim 9 , wherein a density of the weft yarns is 20 picks per inch or less.  
   
   
       11 . The seat belt apparatus as claimed in  claim 9 , wherein at least either of the warp yarns and the weft yarns comprise a material of twist yarns  
   
   
       12 . The seat belt apparatus as claimed in  claim 9 , wherein at least either of the warp yarns and the weft yarns comprise a material of entangled non-twist yarn.