Microperforated polymeric film and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-9238203-B2
Application number	US-201013514336-A
Country	US
Kind code	B2
Filing date	Dec 14, 2010
Priority date	Dec 14, 2009
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

Described herein are microperforated polymeric films comprising: opposed first and second surfaces separated by a first certain distance ( 40 a ); and a plurality of channels perpendicular to the first and second surfaces, wherein a first opening ( 20 a - c ) of a channel intersects the first surface and a second opening ( 22 a - c ) of the channel intersects the second surface; wherein the diameter of the first opening is larger than the diameter of the second opening and the second openings on the second surface are spaced apart by a second certain distance ( 50 a ); wherein the ratio of the first certain distance to the second certain distance is at least 0.25; and further wherein the second surface has an open area of at least 10%. Also described are methods of making and using such microperforated polymeric films.

First claim

What is claimed is:

1. A method of forming a microperforated polymeric film comprising:
providing a polymeric film comprising opposed first and second surfaces and a plurality of cavities there between, wherein the plurality of cavities is open to the first surface and includes a cavity surface wherein the cavity surface intersects the first surface, wherein the polymeric film comprises a film thickness of 50 to 800 micrometers;
providing a liquid between a support surface and the first surface; and
exposing the second surface to a thermal treatment to perforate the polymeric film in the areas covering the plurality of cavities.

2. The method of claim 1 wherein a layer of gas separates the liquid from the apex of the cavity of at least some of the plurality of cavities.

3. The method of claim 1 , wherein the fluid is water.

4. The method of claim 1 , wherein the support surface is a chilled roller.

5. The method of claim 1 , wherein the thermal treatment is one of: flame, hot air, radiant heat, and combinations thereof.

6. The method of claim 1 , wherein the support surface comprises at least one of: a texture, a coating, and combinations thereof.

7. The method of claim 1 , wherein the diameter of the cavity surface is at least 100 micrometers.

8. The method of claim 1 , wherein the surface of the support surface is smooth.

Assignees

• Scheibner John B
• Hansen Brent R
• Slama David F
• 3M Innovative Properties Co

Inventors

• Scheibner John B
• Hansen Brent R
• Slama David F

Classifications

• Y10T428/24273

  including aperture · CPC title

• Y10T428/24322

  Composite web or sheet · CPC title

• B01D69/02

  characterised by their properties · CPC title

• B01D2325/021

  Pore shapes · CPC title

• B01D2325/02

  Details relating to pores or porosity of the membranes · CPC title