Multi-ply dispersible nonwoven material

Abstract

The invention relates to a nonwoven material having sufficient strength to be used in a pre-moistened state but also having dispersibility properties which allow the product to be flushed. The material comprises at least two nonwoven webs, at least one of which is hydroentangled. Each of the individual webs has a basis weight of 20-100 gsm. The nonwoven webs are joined together by thermal or mechanical embossing, or a combination of these.

1 . A method of making a nonwoven fabric material, the method comprising:
 separately hydroentangling at least two nonwoven web layers, each individual nonwoven web layer having a basis weight of 20-100 gsm, and each individual nonwoven web layer comprising wood pulp and non-thermoplastic man-made fibers, the non-thermoplastic man-made fibers having a length of from 5 to 15 mm,   joining the at least two separately hydroentangled nonwoven web layers together by thermal embossing, mechanical embossing, or a combination thereof, to obtain the nonwoven fabric material.   
     
     
         2 . The method of  claim 1 , wherein the non-thermoplastic man-made fibers are selected from the group consisting of regenerated cellulose, lyocell, viscose rayon, polylactic acid and polyvinyl alcohol. 
     
     
         3 . The method of  claim 1 , further comprising drying the at least two nonwoven web layers prior to the joining. 
     
     
         4 . The method of  claim 1 , wherein the at least two separately hydroentangled nonwoven web layers are joined together by thermal embossing. 
     
     
         5 . The method of  claim 4 , wherein the temperature during the thermal embossing is 140° C. to 180° C. 
     
     
         6 . The method of  claim 4 , wherein the thermal embossing is carried out at a pressure in the range of 40 to 90 N/mm 2 . 
     
     
         7 . The method of  claim 1 , wherein the at least two separately hydroentangled nonwoven web layers are joined together by mechanical embossing. 
     
     
         8 . The method of  claim 1 , further comprising treating the nonwoven fabric material with a wetting liquid. 
     
     
         9 . The method of  claim 8 , wherein the wetting liquid further comprises one or more additional agents selected from the group consisting of emollients, viscosity modifiers, natural or synthetic oil and fats, surfactants, antimicrobial agents, particulates, alcohol, salts, organic solvents, pharmaceutical agents, odor control agents, detergents, silicones, fragrance, pH control agents, whitening agents and surface feel modifiers. 
     
     
         10 . The method of  claim 8 , wherein the wetting liquid is added in an amount not exceeding 2.5 times a weight of the nonwoven fabric material in a dried state per unit area. 
     
     
         11 . The method of  claim 1 , wherein a wet strength of the nonwoven fabric material is greater than 250 g/50 mm. 
     
     
         12 . The method of  claim 1 , wherein the joined web layers comprise a wet strength which is greater than that of the at least two individual web layers. 
     
     
         13 . The method of  claim 1 , wherein each individual web layer has a wet strength of 100 g/50 mm to 600 g/50 mm. 
     
     
         14 . The method of  claim 1 , wherein the nonwoven fabric material has a final basis weight of 40 to 120 gsm. 
     
     
         15 . The method of  claim 1 , wherein the at least two separately hydroentangled nonwoven web layers are wet-laid web layers. 
     
     
         16 . The method of  claim 1 , wherein the nonwoven fabric material comprises an embossing bonding area which is 5% to 33% of the nonwoven fabric material. 
     
     
         17 . The method of  claim 16 , wherein the embossing bonding area is from 20% to 33% of the nonwoven fabric material. 
     
     
         18 . The method of  claim 16 , wherein the embossing bonding area is from 5% to less than 20% of the nonwoven fabric material. 
     
     
         19 . The method of  claim 16 , wherein the embossing bonding area has a discontinuous pattern. 
     
     
         20 . The method of  claim 1 , wherein each individual nonwoven web layer comprises 50%-95% of the wood pulp and 5%-50% of the non-thermoplastic man-made fibers.