Films comprising an array of openings and methods of making the same

Abstract

Polymeric layer having first and second, generally opposed major surfaces, comprising an array of openings extending between the first and second major surfaces. The polymeric layers are useful, for example, as components in personal care garments such as diapers and feminine hygiene products. They can also be useful for filtering (including liquid filtering) and acoustic applications.

1 . A polymeric layer having first and second, generally opposed, parallel major surfaces, comprising an array of openings extending between the first and second major surfaces, wherein the openings each have a series of areas through the openings from the first and second major surfaces ranging from minimum to maximum areas, wherein there is a total area and a total open area for each of the first and second major surfaces, wherein the total open area for each of the first and second major surfaces is not greater than 50 percent of the total area of the respective major surface, and wherein for at least a majority of the openings, the minimum area is not at either major surface. 
     
     
         2 . The polymeric layer of  claim 1 , wherein the total open area for each of the first and second major surfaces is in a range from 0.1 percent to not greater than 50 percent of the total area of the respective major surface. 
     
     
         3 . The polymeric layer of  claim 1 , wherein the total open area for each of the first and second major surfaces is not greater than 1 percent of the total area of the respective major surface. 
     
     
         4 . The polymeric layer of  claim 1 , wherein the openings have at least two pointed ends. 
     
     
         5 . The polymeric layer of  claim 1  having in a range from 50,000 to 6,000,000 openings/m 2 . 
     
     
         6 . The polymeric layer of  claim 1 , wherein the openings have a length and a width, and a ratio of lengths to widths in a range from 1:1 to 1.9:1. 
     
     
         7 . The polymeric layer of  claim 1 , wherein the layer has a thickness up to 2 mm. 
     
     
         8 . The polymeric layer of  claim 1 , wherein at least some of the openings have a first side on the first major surface comprising a first polymeric material and a second, opposed side on the first major surface comprising a second, different polymeric material. 
     
     
         9 . A polymeric layer having first and second, generally opposed, parallel major surfaces, comprising an array of openings extending between the first and second major surfaces, wherein the openings each have a series of areas through the openings from the first and second major surfaces ranging from minimum to maximum areas, wherein for at least a majority of the openings, the area of each opening is not greater than is 5 mm 2 , and wherein for at least a majority of the openings, the minimum area is not at either major surface. 
     
     
         10 . The polymeric layer of  claim 9 , wherein at least some of the openings have at least two pointed ends. 
     
     
         11 . The polymeric layer of  claim 9  having in a range from 50,000 to 6,000,000 openings/m 2 . 
     
     
         12 . The polymeric layer of  claim 9 , wherein the openings have a length and a width, and a ratio of lengths to widths in a range from 1:1 to 1.9:1. 
     
     
         13 . The polymeric layer of  claim 9 , wherein the layer has a thickness up to 2 mm. 
     
     
         14 . The polymeric layer of  claim 9 , wherein the polymeric layer is a sheet having an average thickness in a range from 250 micrometers to 5 mm. 
     
     
         15 . The polymeric layer of  claim 9 , wherein at least some of the openings have a first side on the first major surface comprising a first polymeric material and a second, opposed side on the first major surface comprising a second, different polymeric material. 
     
     
         16 . A method of making a polymeric layer having openings therein, the method comprising at least one of passing through a nip or calendaring netting comprising an array of polymeric strands periodically joined together at bond regions throughout the array, wherein the netting has a thickness up to 2 mm, and wherein the polymeric strands do not cross each other. 
     
     
         17 . (canceled)