Method and apparatus for orienting magnetic flakes
The invention relates to a method of aligning magnetic flakes, which includes: coating a substrate with a carrier having the flakes dispersed therein, moving the substrate in a magnetic field so as to align the flakes along force lines of the magnetic field in the absence of an effect from a solidifying means, and at least partially solidifying the carrier using a solidifying means while further moving the substrate in the magnetic field so as to secure the magnetic flakes in the carrier while the magnetic field maintains alignment of the magnetic flakes. An apparatus is provided, which has a belt for moving a substrate along a magnet assembly for aligning magnetic flakes. The apparatus also includes a solidifying means, such as a UV- or e-beam source, and a cover above a portion of the magnet assembly for protecting the flakes from the effect of the solidifying means.
1. An apparatus comprising:
a rotatable roller including an outer surface and at least one magnet;
a belt on the outer surface of the rotatable roller,
wherein the belt provides a path for a substrate, and
wherein the at least one magnet creates a magnetic field that emanates into the substrate;
a solidifying means; and
a screen that protects a portion of the substrate from being affected by the solidifying means,
a portion of the screen being between the solidifying means and the rotatable roller.
2. The apparatus of claim 1 , wherein the rotatable roller comprises a cylindrical body.
3. The apparatus of claim 2 , wherein the cylindrical body comprises non-magnetic material.
4. The apparatus of claim 1 ,
wherein the belt moves the substrate in a first direction, and
wherein the solidifying means is in the first direction relative to the rotatable roller.
5. The apparatus of claim 1 , wherein a fluid carrier including magnetically-alignable flakes is disposed on the substrate.
6. The apparatus of claim 5 , wherein, after solidification of the fluid carrier, the magnetically-alignable flakes form an image of an object, indicia, or a logo.
7. The apparatus of claim 6 , wherein the image comprises a rolling object or a flip-flop.
8. The apparatus of claim 6 , wherein the image provides a dynamic optical effect when viewed at a varying viewing angle or at a varying illumination angle.
9. The apparatus of claim 8 , wherein the dynamic optical effect comprises color shifting or color changing.
10. The apparatus of claim 6 , wherein the image provides an illusive optical effect.
11. The apparatus of claim 10 , wherein the illusive optical effect is an illusion of depth exceeding a thickness of the substrate.
12. The apparatus of claim 5 , wherein the magnetically-alignable flakes comprise at least one of reflective flakes, absorptive flakes, or color-shifting flakes.
13. The apparatus of claim 1 ,
wherein the at least one magnet comprises a first magnet and a second magnet, and
wherein a first shape of the first magnet is different from a second shape of the second magnet.
14. The apparatus of claim 1 , wherein the solidifying means is located downstream from a beginning of the screen.
15. An apparatus comprising:
a drum comprising:
a cylindrical body of non-magnetic material, and
cavities,
wherein three or more first magnets and three or more second magnets are within the cavities and positioned flush with an outer surface of the cylindrical body,
wherein a first shape of the three or more first magnets is different from a second shape of the three or more second magnets, and
wherein the second shape is circular; and
a support for moving a substrate proximate to the drum.
16. The apparatus of claim 15 ,
wherein magnetically-alignable flakes are disposed on the substrate, and
wherein the three or more magnets create a magnetic field that emanates into the substrate.
17. The apparatus of claim 15 , wherein the three or more magnets include shaped permanently magnetized material.
18. An apparatus comprising:
a drum comprising:
a first circumferential band of a first plurality of magnets, only with a first shape, around the drum, and
a second circumferential band of a second plurality of magnets, only with a second shape, around the drum,.
wherein the second shape is different from the first shape; and
a support for moving a substrate proximate to the drum.
19. The apparatus of claim 18 , wherein the drum further comprises:
a cylindrical body of non-magnetic material.
20. The apparatus of claim 18 ,
wherein the first shape is cylindrical, and
wherein the second shape is prism-shaped.