Cloth-like tissue sheets having camouflaged texture

Abstract

Embossing regularly textured sheets with an appropriate regular, discrete embossing pattern to improve softness can result in a combined texture that creates an interference pattern that camouflages the original texture pattern and the embossing pattern. The resulting pattern is more appealing to the eye and is more random in appearance than the initial textured sheet or the embossing pattern individually. This result is particularly advantageous for paper towels.

We claim:  
     
         1 . A method of embossing a textured tissue sheet having a regular, distinct, overall texture pattern, said method comprising embossing the textured sheet to provide a regular, distinct, overall embossing pattern that is different than the texture pattern and results in an optical interference pattern.  
     
     
         2 . The method of  claim 1  wherein the texture pattern is a fabric pattern imprinted into the sheet while the sheet is being made.  
     
     
         3 . The method of  claim 1  wherein the texture pattern and the embossing pattern comprise rows of distinct elements, wherein the embossing pattern differs from the texture pattern with respect to the spacing of the elements within the rows.  
     
     
         4 . The method of  claim 1  wherein the texture pattern and the embossing pattern comprise rows of distinct elements, wherein the embossing pattern differs from the texture pattern with respect to the spacing of the rows elements.  
     
     
         5 . The method of  claim 1  wherein the texture pattern and the embossing pattern comprise rows of distinct elements, wherein the embossing pattern differs from the texture pattern with respect to the orientation of the rows of elements relative to the machine direction of the sheet.  
     
     
         6 . The method of  claim 1  wherein the sheet is airlaid.  
     
     
         7 . The method of  claim 6  wherein the texture pattern is a fabric imprint pattern.  
     
     
         8 . The method of  claim 1  wherein the sheet is wet laid and throughdried.  
     
     
         9 . The method of  claim 8  wherein the texture pattern is a fabric imprint pattern.  
     
     
         10 . The method of  claim 1  wherein the texture pattern is an embossing pattern.  
     
     
         11 . A method of embossing an airlaid tissue sheet having a regular, distinct, overall fabric texture pattern imparted to the sheet during manufacture, said method comprising embossing the textured sheet to provide a regular, distinct, overall embossing pattern that is different than the fabric texture pattern and which results in an optical interference pattern.  
     
     
         12 . A method of embossing a tissue sheet comprising embossing the tissue sheet to produce a regular, distinct, overall first texture pattern and thereafter embossing the sheet to provide a regular, distinct, overall second texture pattern that is different than the first texture pattern and which results in an optical interference pattern.  
     
     
         13 . A tissue sheet having at least two distinct, regular, overall texture patterns and an optical interference pattern.  
     
     
         14 . The tissue sheet of  claim 13  wherein the interference pattern comprises multiple parallel stripes.  
     
     
         15 . The tissue sheet of  claim 13  wherein the thickness of the stripes is from about 0.5 to about 3 centimeters.  
     
     
         16 . The tissue sheet of  claim 13  wherein the thickness of the stripes is from about 1 to about 2 centimeters.  
     
     
         17 . The tissue sheet of  claim 13  wherein the percent area of the tissue sheet occupied by the interference pattern is about 30 percent or greater.  
     
     
         18 . The tissue sheet of  claim 13  wherein the percent area of the tissue sheet occupied by the interference pattern is about 40 percent or greater.  
     
     
         19 . The tissue sheet of  claim 13  wherein the percent area of the tissue sheet occupied by the interference pattern is from about 30 to about 70 percent.  
     
     
         20 . The tissue sheet of  claim 13  wherein the percent area of the tissue sheet occupied by the interference pattern is from about 40 to about 60 percent.  
     
     
         21 . The tissue sheet of  claim 13  wherein the percent area of the tissue sheet occupied by the interference pattern is from about 45 to about 55 percent.  
     
     
         22 . A tissue sheet having a surface texture characterized by 24 or fewer primary polar spatial frequencies greater than 0.2 mm −1  where the primary polar spatial frequencies have Fourier magnitudes greater than 5 times the average Fourier magnitude for the tissue surface and are limited in number to those with Fourier magnitudes of 20 percent or more of the special frequency with the largest Fourier magnitude, such that no two of the primary Fourier magnitudes have absolute frequency differences less than 0.1 mm −1 .  
     
     
         23 . The tissue sheet of  claim 22  wherein the number of primary polar spatial frequencies is 12 or fewer.  
     
     
         24 . The tissue sheet of  claim 22  wherein the primary polar spatial frequencies are limited in number to those with magnitudes of 30 percent or more of the spatial frequency with the largest magnitude.  
     
     
         25 . The tissue sheet of  claim 22  wherein the primary polar spatial frequencies are limited in number to those with magnitudes of 40 percent or more of the spatial frequency with the largest magnitude.  
     
     
         26 . The tissue sheet of  claim 22 ,  23 ,  24  or  25  wherein the primary polar spatial frequencies all have Fourier magnitudes 10 or more times the average Fourier magnitude for the tissue surface.  
     
     
         27 . The tissue sheet of  claim 22 ,  23 ,  24  or  25  wherein the primary polar spatial frequencies all have Fourier magnitudes 20 or more times the average Fourier magnitude for the tissue surface.  
     
     
         28 . The tissue sheet of  claim 22  wherein no two of the primary Fourier magnitudes have absolute frequency differences of 0.075 mm −1  or less.  
     
     
         29 . The tissue sheet of  claim 22  wherein no two of the primary Fourier magnitudes have absolute frequency differences of 0.05 mm −1  or less.  
     
     
         30 . The tissue sheet of  claim 22  wherein the sheet is an airlaid sheet.