Method and apparatus for inkjet printing nonwoven absorbent article components

Abstract

The present disclosure relates to methods and apparatuses including printheads arranged along a machine direction for printing regions of advancing substrate at desired contrasts, wherein apparatuses include at least one printhead configured to print a region of a nonwoven substrate. The printhead is operated at a firing frequency and the nonwoven substrate is advanced at a speed in the machine direction under the printhead. Drops of ink having a drop mass DM are ejected from the printhead onto the first surface of the nonwoven substrate to define a printed region having a print resolution extending the machine direction, MDR (dpi), and a print resolution extending in the cross direction, CDR (dpi). In turn, the printed region includes an ink basis weight, IBW (gsm), that is equal to or greater than about 0.5 grams per square meter (gsm) and an optical density that is equal to or greater than about 0.2.

What is claimed is: 
     
         1 . A method for printing graphics on nonwovens, the method comprising the steps of:
 providing a nonwoven substrate extending in a machine direction, the nonwoven substrate comprising a first surface and an opposing second surface and defining a width in a cross direction;   operating a printhead at a firing frequency that is equal to or less than about 20 kHz;   advancing the nonwoven substrate at a speed in the machine direction under the printhead;   ejecting drops of an ink from the printhead onto the first surface of the substrate to define a printed region comprising a print resolution extending the machine direction, MDR (dpi), and a print resolution extending in the cross direction, CDR (dpi), the drops comprising a drop volume, DV (pl), and the ink comprising a density, D (g/cc);   wherein the printed region comprises an ink basis weight, IBW (gsm), that is equal to or greater than about 0.5 (gsm); and   wherein IBW (gsm)=1.55×10 −6 ×[(MDR (dpi)]×[CDR (dpi)]×[DV (pl)]×[D (g/cc)], and wherein MDR (dpi) is equal to or less than about 80 (dpi).   
     
     
         2 . The method of  claim 1 , wherein the printed region comprises an optical density that is equal to or greater than about 0.2. 
     
     
         3 . The method of  claim 2 , wherein the drop volume is equal to or greater than about 10 (pl). 
     
     
         4 . The method of  claim 1 , wherein the printed region comprises a delta E* value that is equal to or greater than about 7. 
     
     
         5 . The method of  claim 1 , wherein the printhead comprises a maximum firing frequency that is equal to or less than about 20 kHz, and wherein the firing frequency is equal to or less than the maximum firing frequency. 
     
     
         6 . The method of  claim 1 , wherein the speed is equal to or greater than about 0.5 m/s. 
     
     
         7 . The method of  claim 1 , wherein CDR is equal to or less than about 400 (dpi). 
     
     
         8 . A disposable absorbent article comprising:
 a nonwoven substrate extending in a first direction and a second direction orthogonal to the first direction, the nonwoven substrate comprising a first surface and an opposing second surface;   an inkjet printed region on the first surface of the nonwoven substrate, the inkjet printed region comprising a first ink comprising a first color, the inkjet printed region comprising a print resolution extending the first direction, MDR (dpi), and a print resolution extending in the second direction, CDR (dpi);   wherein MDR (dpi) is equal to or less than about 80 (dpi) and wherein CDR (dpi) is at least about 128 (dpi); and   wherein the inkjet printed region comprises a delta E* of greater than about 7, wherein the delta E* is calculated based on L*, a*, b* values of the inkjet printed region relative to L*, a*, b* values of an unprinted region of the nonwoven substrate.   
     
     
         9 . The absorbent article of  claim 8 , wherein the inkjet printed region further comprising a second ink comprising a second color different from the first color. 
     
     
         10 . The absorbent article of  claim 8 , wherein the inkjet printed region comprises ink drops comprising a drop mass, DM (g), and wherein the inkjet printed region comprises an ink basis weight, IBW (gsm), that is equal to or greater than about 0.5 (gsm); and wherein IBW (gsm)=(1550)×[(MDR (dpi)]×[CDR (dpi)]×[DM (g)]. 
     
     
         11 . The absorbent article of  claim 8 , further comprising an anti-rub off coating. 
     
     
         12 . The absorbent article of  claim 8 , wherein the nonwoven substrate has a wet average ink adhesion rating of at least about 2.5 or greater. 
     
     
         13 . The absorbent article of  claim 8 , wherein the nonwoven substrate has a dry average ink adhesion rating of at least about 2.5 or greater. 
     
     
         14 . The absorbent article of  claim 8 , wherein the first ink is energy curable ink. 
     
     
         15 . The absorbent article of  claim 14 , wherein the energy curable ink is curable with ultra violet light. 
     
     
         16 . The absorbent article of  claim 8 , wherein energy curable ink is curable with is curable with an electron beam source. 
     
     
         17 . The absorbent article of  claim 8 , wherein the first ink is water based ink or solvent based ink.