Fibrous Nonwoven Web with Uniform, Directionally-Oriented Projections and a Process and Apparatus for Making the Same

Abstract

A process and apparatus is used for making a fibrous nonwoven web with uniform, directionally-oriented projections by depositing fibrous material onto a first forming surface with holes positioned above a second forming surface with both forming surfaces traveling at different speeds to one another. As the fibers are deposited onto the first forming surface, a portion of the fibers are drawn down into the holes of the first forming surface forming the projections which contact the second forming surface. Due to the speed differential between the two forming surfaces the projections are uniformly skewed in the same direction. The resultant material is particularly suited for use as a wiping material which can be more abrasive in one direction but which is softer to the touch when wiped in the opposite direction thus making it a dual purpose material.

What is claimed is: 
     
         1 . A process for forming a fibrous nonwoven web with uniform, directionally-oriented projections comprising:
 providing a first forming surface defining a plurality of openings therein;   providing a second forming surface which is pervious to air;   overlaying said first forming surface atop said second forming surface;   causing said first forming surface to travel in a first direction at a first speed;   causing said second forming surface to travel in said first direction at a second speed to cause a speed differential between said first forming surface and said second forming surface;   depositing a plurality of fibers onto said first forming surface to form a fibrous nonwoven web;   causing a portion of said plurality of fibers to extend through said openings in said first forming surface and contact said second forming surface to form a plurality of fibrous projections in said fibrous nonwoven web; said speed differential causing said projections to have a uniform, directional orientation relative to said first direction of travel of said first forming surface; and   removing said fibrous nonwoven web with said uniform, directionally-oriented projections from said first forming surface.   
     
     
         2 . The process of  claim 1  which further includes providing a vacuum source beneath said second forming surface on a side of said second forming surface opposite said first forming surface to aid in a movement of said fibers through said openings in said first forming surface and contact said second forming surface. 
     
     
         3 . The process of  claim 1  which further includes causing said first and second forming surfaces to travel at a distance differential “y” as defined herein of between about 51 millimeters (2 inches) and about 152 millimeters (6 inches). 
     
     
         4 . The process of  claim 2  which further includes driving one of said first and second forming surfaces by frictional engagement with the other of said first and second forming surfaces. 
     
     
         5 . The process of  claim 2  which further includes driving said first forming surface in said first direction independently of said second forming surface. 
     
     
         6 . An apparatus for forming a fibrous nonwoven web with uniform, directionally-oriented projections comprising:
 a first forming surface defining a plurality of openings therein, said first forming surface being capable of moving in a first direction at a first speed;   a second forming surface which is pervious to air capable of moving in a first direction at a second speed, said second forming surface being positioned below said first forming surface, said second speed being different than said first speed;   a fiber deposition apparatus positioned above and distanced from a surface of said first forming surface opposite said second forming surface; and   a vacuum assist apparatus positioned below said second forming surface on a side of said second forming surface opposite said first forming surface.   
     
     
         7 . The apparatus of  claim 6  wherein said fiber deposition apparatus is a coform apparatus. 
     
     
         8 . The apparatus of  claim 6  wherein said first forming surface and said second forming surface are frictionally engaged with one another and one of said first and second forming surfaces is driven by the other of said first and second forming surfaces due to said frictional engagement between said first and second forming surfaces. 
     
     
         9 . The apparatus of  claim 6  wherein said first and second forming surfaces are driven in said first direction separately from one another. 
     
     
         10 . The apparatus of  claim 6  wherein said first forming surface comprises a flexible belt defining a plurality of holes therein and extending there through which are spaced apart by a land area in said belt, said land area being impervious to air emanating from said fiber deposition apparatus. 
     
     
         11 . A fibrous nonwoven web having a top surface, an opposed bottom surface, a length, a width and a thickness,
 a plurality of uniform, directionally-oriented projections emanating from said top surface of said web.   
     
     
         12 . The fibrous nonwoven web of  claim 11  wherein said web has a knap on said top surface due to said projections such that it is smoother to the touch when engaged in one direction as opposed to the opposite direction. 
     
     
         13 . The fibrous nonwoven web of  claim 11  wherein said projections each have a base portion with a vertical axis generally perpendicular to a plane formed by said top surface of said web and a head portion connected to said base portion, said vertical axis being located at a position in said base portion such that said base portion has a lateral dimension that is equally spaced on either side of said vertical axis, said head portion of said projection being asymmetrically located relative to said base portion and said vertical axis such that said head portion has a lateral dimension which is skewed with respect to said vertical axis so that more of said head portion is located on one side of said vertical axis than said base portion when viewing said head portion and said base portion from the same position. 
     
     
         14 . The fibrous nonwoven web of  claim 13  wherein said head portion forms an overhang area with respect to said base portion. 
     
     
         15 . A wipe comprising the fibrous nonwoven web of  claim 11 . 
     
     
         16 . A personal care absorbent article comprising the fibrous nonwoven web of  claim 11 . 
     
     
         17 . A personal care absorbent article comprising a body side liner and a garment-facing sheet with an absorbent core disposed between said body side liner and said garment facing sheet wherein said body side liner comprises the fibrous nonwoven web of  claim 11 . 
     
     
         18 . The personal care absorbent article of  claim 17  wherein said article is selected from the group consisting of a diaper, a sanitary napkin, a child training pant and an adult incontinence device.