Laser methods to create easy tear off materials and articles made therefrom
A method of creating an easily torn material using laser etching, as well as articles produced therefrom is provided. As opposed to standard perforations, a laser is used to etch a line in a sheet of material. The line allows the material to be easily torn by a user, yet exhibits enough tensile strength to prevent tearing during regular use.
1. A method of making a tearable sheet comprising:
moving a sheet having a first major surface and an oppositely disposed second major surface relative to a working area of a laser while laser etching with the laser to produce a continuous laser-etched trench in the first major surface, the continuous laser-etched trench forming a continuous tear line of the sheet, and
forming with the laser a plurality of craters within the trench, each crater having an overall diameter less than a diameter of the trench adjacent to each crater, wherein at least one crater extends into but not through the sheet, where the at least one crater has a varying profile along a depth of the at least one crater such that the at least one crater has a first diameter at a portion of the trench closest to the first major surface and a second diameter less than the first diameter at a portion of the trench furthest from the first major surface.
2. The method of making a tearable sheet according to claim 1 , including the step of selecting the sheet from a material selected from the group comprising a paper material, a plastic material, a leather material, and a metal foil material.
3. The method of making a tearable sheet according to claim 1 , wherein said laser etching forms the continuous tear line without completely extending through the sheet to the second major surface.
4. The method of making a tearable sheet according to claim 1 , wherein the sheet is tearable by hand along the continuous tear line.
5. The method of making a tearable sheet according to claim 1 , wherein the laser has a field size of 20 inches or more.
6. The method of making a tearable sheet according to claim 1 , wherein during said laser etching the laser has a power output between 1,000 and 5,000 W, a scan speed between 10 and 50 m/s, and a spot size between 0.05 and 0.3 mm.
7. The method of making a tearable sheet according to claim 1 , wherein during said laser etching the laser has an EDPUT between 0.28 and 254.77 watts-sec/mm 3 .
8. The method of making a tearable sheet according to claim 1 , wherein the continuous tear line is wavy, curved, or zig-zag.
9. A method of making a tearable sheet comprising:
moving a sheet having a width, a first major surface and an oppositely disposed second major surface relative to a working area of a laser while laser etching with the laser to produce a continuous laser-etched trench in the first major surface, the continuous laser-etched trench forming a continuous tear line extending entirely across the width of the sheet; and
forming with the laser a plurality of craters within the trench each crater having an overall diameter less than a diameter of the trench adjacent to each crater, wherein a plurality of the craters extend into but not through the sheet, where each of the plurality of craters has a varying profile along a depth of each crater such that each crater has a first diameter at a portion of the trench closest to the first major surface and a second diameter less than the first diameter at a portion of the trench furthest from the first major surface.
10. The method of making a tearable sheet according to claim 9 , wherein the width of the sheet is at least 20 inches.
11. The method of making a tearable sheet according to claim 9 , wherein the sheet is made of at least one of a paper material, a plastic material, a leather material, and a metal foil material.
12. The method of making a tearable sheet according to claim 9 , wherein said laser etching forms the continuous tear line without completely extending through the sheet to the second major surface.
13. The method of making a tearable sheet according to claim 9 , wherein the sheet is tearable by hand along the continuous tear line.
14. The method of making a tearable sheet according to claim 9 , wherein the laser has a field size of 20 inches or more.
15. The method of making a tearable sheet according to claim 1 , wherein during said laser etching the laser has a power output between 1,000 and 5,000 W, a scan speed between 10 and 50 m/s, and a spot size between 0.05 and 0.3 mm.
16. The method of making a tearable sheet according to claim 9 , wherein during said laser etching the laser has an EDPUT between 0.28 and 254.77 watts-sec/mm 3 .
17. The method of making a tearable sheet according to claim 9 , wherein the continuous tear line is wavy, curved, or zig-zag.
18. The method of claim 1 , wherein the plurality of craters are linearly aligned within the trench.
19. The method of claim 1 , further comprising at least one crater that penetrates through the sheet.
20. The method of claim 1 , wherein the plurality of craters comprises a first crater having a first depth and a second crater having a second depth different from the first depth and wherein the first crater and the second crater do not extend through the sheet.
21. A method of making a tearable sheet, comprising:
forming a trench in a first surface of a material using a first laser operating parameter, and
forming a plurality of craters within the trench using a second laser operating parameter different from the first laser operating parameter each crater having an overall diameter less than a diameter of the trench adjacent to each crater, wherein each crater formed within the trench has a varying profile along a depth of each crater such that each crater has a first diameter at a portion of the trench closest to a first major surface and a second diameter less than the first diameter at a portion of the trench furthest from the first major surface.
22. The method of claim 21 , wherein the first laser operating parameter is selected from at least one of a first power, a first duty cycle, a first scan speed, a first frequency, a first control factor setting, a first jump speed, and a first objective lens size, and the second laser operating parameter is selected from at least one of a second power, a second duty cycle, a second scan speed, a second frequency, a second control factor setting, a second jump speed, and a second objective lens size.
23. The method of claim 21 , including the step of forming the trench with center and side portions, wherein the center has a depth greater than the side portions.
24. The method of claim 21 , wherein the trench and the plurality of craters are formed using a single laser.
25. The method of claim 21 , wherein the trench and the plurality of craters are formed without etching completely through the material.
26. The method of claim 21 , wherein the material is selected from at least one of a paper material, a plastic material, a leather material, and a metal foil material.