Wet wipe and method for manufacturing wet wipe

Abstract

The purpose of the present disclosure is to provide a wet wipe which achieves both wet-strength and water-dissolvability. The wet wipe comprises the following configuration. This water-dissolving wet wipe comprises a multi-layer sheet provided with a first sheet and a second sheet, said wet wipe being characterized in that: the first sheet comprises a first hydrophilic fiber-containing layer and a first hydrophobic fiber-containing layer, and the second sheet comprises a second hydrophilic fiber-containing layer and a second hydrophobic fiber-containing layer; the multi-layer sheet has a plurality of junction parts at predetermined intervals; the plurality of junction parts occupy 0.5% to 12.0% of the surface area; the first sheet and the second sheet each have a separability of less than or equal to 100 seconds; the multi-layer sheet has a bending resistance of less than or equal to 150 mm; and the wet wipe has a tensile strength of greater than or equal to 1.0 N/25 mm.

1 . A wet tissue with water disintegratability, including a multilayer sheet comprising a first sheet and a second sheet,
 wherein the first sheet includes a first hydrophilic fiber-containing layer including hydrophilic fibers at 95 to 100 mass % and a first hydrophobic fiber-containing layer including hydrophobic fiber at 5 to 30 mass %, and the second sheet includes a second hydrophilic fiber-containing layer including hydrophilic fibers at 95 to 100 mass % and a second hydrophobic fiber-containing layer including hydrophobic fiber at 5 to 30 mass %,   the first hydrophobic fiber-containing layer being disposed adjacent to the second hydrophobic fiber-containing layer,   the multilayer sheet having a plurality of connected sections, disposed across spacings, where the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer are connected,   the spacings between the plurality of connected sections being 0.6 times or above the mean fiber length of the hydrophobic fibers of the first hydrophobic fiber-containing layer and 0.6 times or above the mean fiber length of the hydrophobic fibers of the second hydrophobic fiber-containing layer,   the plurality of connected sections having an area ratio of 0.5 to 12.0% with respect to the multilayer sheet,   each of the first sheet and second sheet, which is separated from the multilayer sheet, having a disintegratability of 100 seconds or less in a disintegration test,   the multilayer sheet having a bending resistance of 150 mm or less, and   the wet tissue having a tensile strength of 1.0N or greater per 25 mm width.   
     
     
         2 . The wet tissue according to  claim 1 , wherein a fiber density of the first hydrophobic fiber-containing layer is higher than a fiber density of the first hydrophilic fiber-containing layer, and/or a fiber density of the second hydrophobic fiber-containing layer is higher than a fiber density of the second hydrophilic fiber-containing layer. 
     
     
         3 . The wet tissue according to  claim 1 , wherein the first hydrophilic fiber-containing layer and the second hydrophilic fiber-containing layer are disposed on the surface layer of the multilayer sheet, the multilayer sheet having a ridge-furrow structure formed by spraying a high-pressure water jet on one or both surfaces of the multilayer sheet. 
     
     
         4 . The wet tissue according to  claim 1 , wherein each of the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer includes, as the hydrophobic fibers, heat-fusible fibers consisting of composite fibers that include a low-melting-point component and a high-melting-point component having a higher melting point than the low-melting-point component. 
     
     
         5 . The wet tissue according to  claim 4 , wherein each of the plurality of connected sections is an embossed section, and in the embossed section, at least some of the low-melting-point component of the hydrophobic fibers of the first hydrophobic fiber-containing layer are fused with the fibers in the second hydrophobic fiber-containing layer, and/or at least some of the low-melting-point component of the hydrophobic fibers of the second hydrophobic fiber-containing layer are fused with the fibers in the first hydrophobic fiber-containing layer. 
     
     
         6 . The wet tissue according to  claim 1 , wherein the hydrophobic fibers of the first hydrophobic fiber-containing layer and/or the hydrophobic fibers of the second hydrophobic fiber-containing layer have a mean fiber length of 6.5 mm or less. 
     
     
         7 . The wet tissue according to  claim 1 , wherein each of the plurality of connected sections has an area of 0.4 to 9 mm 2 . 
     
     
         8 . The wet tissue according to  claim 1 , wherein each of the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer includes hydrophilic fibers at 100 mass %, and each of the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer includes hydrophobic fibers at 5 to 30 mass % and hydrophilic fibers at 70 to 95 mass %. 
     
     
         9 . The wet tissue according to  claim 1 , wherein the hydrophilic fibers of the first hydrophilic fiber-containing layer and/or the hydrophilic fibers of the second hydrophilic fiber-containing layer include pulp and regenerated cellulose. 
     
     
         10 . The wet tissue according to  claim 1 , wherein the wet tissue has a fold structure formed by crepe treatment of the first sheet and/or second sheet. 
     
     
         11 . A method of producing the wet tissue according to  claim 1 , including the steps of:
 (1) forming the first sheet;   (2) forming the second sheet; and   (3) stacking the second sheet onto the first sheet with the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer facing each other, to form a stacked sheet, and connecting the stacked sheet to form a multilayer sheet having a plurality of connected sections.   
     
     
         12 . The method according to  claim 11 , wherein step (1) further includes the steps of:
 (1a) supplying an aqueous dispersion of a starting material for the first hydrophilic fiber-containing layer onto a support, and forming a web of the first hydrophilic fiber-containing layer on the support;   (1b) spraying the web of the first hydrophilic fiber-containing layer on the support with a high-pressure water jet from a high-pressure water jet nozzle to tangle the fibers, and form a first hydrophilic fiber-containing layer;   (1c) supplying an aqueous dispersion of a starting material for the first hydrophobic fiber-containing layer onto a support, and forming a web of the first hydrophobic fiber-containing layer on the support;   (1d) stacking the web of the first hydrophobic fiber-containing layer onto a surface of the first hydrophilic fiber-containing layer that has not been sprayed with the high-pressure water jet, and forming a water-including first sheet; and   (1e) drying the water-including first sheet.   
     
     
         13 . The method according to  claim 11 , wherein step (2) further includes the steps of:
 (2a) supplying an aqueous dispersion of a starting material for the second hydrophilic fiber-containing layer onto a support, and forming a web of the second hydrophilic fiber-containing layer on the support;   (2b) spraying the web of the second hydrophilic fiber-containing layer on the support with a high-pressure water jet from a high-pressure water jet nozzle to tangle the fibers, and form a second hydrophilic fiber-containing layer;   (2c) supplying an aqueous dispersion of a starting material for the second hydrophobic fiber-containing layer onto a support, and forming a web of the second hydrophobic fiber-containing layer on the support;   (2d) stacking the web of the second hydrophobic fiber-containing layer onto a surface of the second hydrophilic fiber-containing layer that has not been sprayed with the high-pressure water jet, and forming a water-including second sheet; and   (2e) drying the water-including second sheet.   
     
     
         14 . The method according to  claim 11 , wherein each of the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer include, as hydrophobic fibers, heat-fusible fibers consisting of composite fibers including a low-melting-point component and a high-melting-point component having a higher melting point than the low-melting-point component, in step (1), the water-including first sheet is dried at a temperature lower than the melting point of the low-melting-point component of the hydrophobic fibers in the first hydrophobic fiber-containing layer, and in step (2), the water-including second sheet is dried at a temperature lower than the melting point of the low-melting-point component of the hydrophobic fibers in the second hydrophobic fiber-containing layer. 
     
     
         15 . The method according to  claim 14 , wherein in step (3), the stacked sheet is embossed at a temperature at or above the melting point of the low-melting-point component of the hydrophobic fibers in the first hydrophobic fiber-containing layer and the low-melting-point component of the hydrophobic fibers in the second hydrophobic fiber-containing layer, and below the melting point of the high-melting-point component of the hydrophobic fibers in the first hydrophobic fiber-containing layer and the high-melting-point component of the hydrophobic fibers in the second hydrophobic fiber-containing layer, to form a multilayer sheet having a plurality of connected sections. 
     
     
         16 . The method according to  claim 12 , wherein in step (1e), the water-including first sheet is dried while contacting the first hydrophilic fiber-containing layer with a roll of a roll-type dryer. 
     
     
         17 . The method according to  claim 13 , wherein in step (2e), the water-including second sheet is dried while contacting the second hydrophilic fiber-containing layer with a roll of a roll-type dryer. 
     
     
         18 . The method according to  claim 11 , wherein step (1) further includes a step of crepe treatment of the first sheet, and/or step (2) further includes a step of crepe treatment of the second sheet.