Laser-made microperforations in films
A laser system and method is used to micro-drill a web producing holes of approximately 85 μm or less. The laser system comprises a laser beam having a wavelength in the range of approximately 2 to 6 microns and the focal point of the laser beam being steered onto a surface of the moving web wherein the web is moving. The web is a film such as a flexible film or commercial packaging film. The laser beam wavelength and constant laser energy can be used to laser micro-drill the flexible film.
1 . A method of micro-drilling a moving web comprising:
providing a laser system for production of a laser beam having a wavelength in the range of 2 to 6 microns;
steering a focal point of the laser beam on a surface of the moving web concurrently with moving the web and producing one or more round holes in the moving web wherein the moving web has a thickness of approximately 20 to 150 μm, whereby the laser is pulsed at a duration of 1 μsec to 750 μsec producing round holes having a diameter in the range of approximately 85 μm or less; and
moving the web while producing holes.
2 . The method of claim 1 wherein the round holes have a repeating circular configuration.
3 . The method of claim 1 wherein the laser beam has a wavelength of 5 microns.
4 . The method of claim 1 wherein the round hole or holes have a diameter in the range of approximately 25 μm to 95 μm.
5 . The method of claim 1 wherein the round hole or holes have a diameter in the range of approximately 35 μm to 85 μm.
6 . The method of claim 1 wherein the moving web is a flexible material comprising a polymer film.
7 . A method of micro-drilling a film for use as a modified atmosphere packaging by using a laser system, the method comprising directing a focal point of a laser beam of the laser system onto a surface of the film to form round holes in the film, the round holes having a diameter less than approximately 85 μm while moving the film through the laser system wherein the moving film has a thickness of approximately 20 to 150 μm and whereby the laser is pulsed at a duration of 1 μsec to 750 μsec.
8 . The method of claim 7 wherein the laser beam has a wavelength in the range of 2 to 6 microns.
9 . The method of claim 8 wherein the round holes have a diameter in the range of approximately 35 μm to 85 μm.
10 . The method of claim 7 wherein the laser beam has a wavelength of 5 microns.
11 . The method of claim 7 wherein the diameter of the round holes is in the range of approximately 25 μm to 95 μm.
12 . A method of micro-drilling a flexible film with a laser system, the method comprising directing a focal point of a laser beam produced by an 2 to 6 micron wavelength laser onto a surface of the film to form round holes in the film, the round holes having a diameter approximately less than 85 μm while moving the film through the laser system wherein the moving film has a thickness of approximately 20 to 150 μm, whereby the laser is pulsed at a duration of 1 μsec to 750 μsec and wherein the flexible material is then incorporated into pet food bags.
13 . The method of claim 12 wherein the diameter of the round holes is in the range of approximately 25 μm to 95 μm.
14 . The method of claim 12 wherein the round holes have a diameter in the range of approximately 35 μm to 85 μm.
15 . The method of claim 12 where in the laser has a wavelength of 5 microns.
16 . A method of laser perforating a commercial packaging film with a mid-infrared wavelength laser beam at a constant laser energy while moving the commercial packaging film through a laser system at a commercial production speed to micro-drill round holes in the film having a diameter less than approximately 85 μm.
17 . The method of claim 16 wherein the wavelength of the laser beam is in the range of 4 to 10 microns.
18 . The method of claim 17 wherein the wavelength of the laser beam is 5 microns.
19 . The method of claim 16 wherein the diameter of at least a portion of the round holes is in the range of approximately 25 μm to approximately 95 μm.
20 . The method of claim 16 wherein the diameter of at least a portion of the round holes is in the range of approximately 35 μm to approximately 85 μm.
21 . The method of claim 16 and steering the laser beam with respect to the commercial packaging film moving through the laser system with a single axis galvanometer.
22 . A method of laser perforating a moving web comprising:
providing a laser system for production of a laser beam having a wavelength in the range of 2 microns to 6 microns;
steering a focal point of the laser beam on a surface of the moving web concurrently with moving the web and producing one or more round holes in the moving web wherein the round hole or holes have a diameter in the range of approximately 85 μm or less; and
moving the web at least approximately 200 feet per minute while producing the one or more round holes.
23 . The method of claim 22 wherein the moving web is a flexible film.
24 . The method of claim 22 wherein the round hole or holes have a diameter in the range of approximately 35 μm to 85 μm.
25 . A method of perforating a film for use as a modified atmosphere packaging by using a laser system, the method comprising directing a focal point of a laser beam of the laser system onto a surface of the film to form one or more round holes in the film, the one or more round holes having a diameter less than approximately 85 μm while moving the film through the laser system at a speed approximately 200 feet per minute or greater.
26 . The method of claim 25 wherein the laser beam has a wavelength in the range of 5 μm to 10 μm.