Method for making a hydroentangled nonwoven fabric and the fabric made thereby

Abstract

A process for making a single layer or multi-layer nonwoven material having improved cross-directional strength and feel, and the nonwoven material made thereby, is described. The process provides a nonwoven material including at least one layer formed of polymeric continuous filaments. The layer(s) are formed in a continuous sequential manner, i.e., a subsequent layer being formed on top of a preceding layer or layers. Thereafter, in the absence of any prebonding, the layer(s) are subjected to hydroentanglement. The basis weight of the nonwoven material is from about 17 to 150 gsm. The nonwoven material has improved properties based on treating the layer(s) by hydroentanglement. Varying the number of water jets and the pressure of the water allows variance in the properties obtained in the final product. Other physical properties can also be imparted to or changed in the nonwoven material by inclusion of an additive in a polymer melt during formation of the filaments, or by topical treatment following treatment of the layers of the nonwoven material by hydroentanglement.

It is claimed:  
     
         1 . Process of forming a nonwoven material comprising 
 providing continuous thermoplastic polymer filaments;    laying the continuous filaments upon a moving support to provide at least one layer on said support;    joining the continuous filaments of the at least one layer together by hydroentangling the filaments in absence of prebonding of the filaments forming said at least one layer,    wherein said hydroentangling is provided by subjecting said at least one layer to water emitted at a pressure of from about 20 to about 250 bar from a plurality of water jets with at least 25 water jets per linear inch of planar surface of said at least one layer.    
     
     
         2 . Process according to  claim 1  wherein said polymer is a polyolefin.  
     
     
         3 . Process according to  claim 2  wherein said polymer is polypropylene.  
     
     
         4 . Process according to  claim 1  wherein said polymer is a polyester.  
     
     
         5 . Process according to  claim 1  further comprising, following said hydroentangling, topically treating said at least one layer with an additive to impart to or change a physical property in said at least one layer.  
     
     
         6 . Process according to  claim 1  further comprising incorporating an additive in said continuous thermoplastic polymer filaments to impart to or change a physical property of said filaments.  
     
     
         7 . Process according to  claim 5  wherein said additive renders said nonwoven material at least in part lyophobic, lyophilic, fire retardant, antistatic, and/or absorbent.  
     
     
         8 . Process according to  claim 6  wherein said additive renders said nonwoven material at least in part lyophobic, lyophilic, fire retardant, antistatic, and/or absorbent.  
     
     
         9 . Process according to  claim 1  wherein said at least one layer is spunlaid or meltblown.  
     
     
         10 . Process according to  claim 1  wherein said water jets have nozzle orifices ranging from about 0.1 to about 0.2 mm in diameter.  
     
     
         11 . Process according to  claim 1  wherein said at least one layer is supported on a series of perforated godet rollers during said hydroentangling.  
     
     
         12 . Process according to  claim 1  wherein said continuous filaments are provided at a denier of from about 0.8-5 dpf.  
     
     
         13 . Process according to  claim 1  further comprising, following said hydroentangling, providing a pattern on said nonwoven material.  
     
     
         14 . A nonwoven material made according to the process claimed in any one of  claims 1  to  13 .