Release webs and textured products
The present disclosure features processes and equipment for manufacturing materials that have a textured surface formed by applying a first texture to a curable coating, curing the coating, and then embossing a second, different texture over the first texture. The disclosure also features textured materials, including both release webs for use in replicative casting processes and finished products in sheet, board, plate or web form.
1. A release web comprising:
a substrate; and
a coating layer disposed on at least one surface of the substrate, the coating layer including a surface effect to be replicated during casting, wherein the surface effect comprises a first, predetermined micro- or nanoscale three-dimensional texture and a second, predetermined macro-scale three-dimensional texture;
wherein the first texture is coextensive with the second texture.
2. The release web of claim 1 wherein the first texture is a nanoscale texture.
3. The release web of claim 1 wherein the second texture is post-applied to the first texture in a manner that does not deleteriously affect the topography of the first texture.
4. The release web of claim 1 wherein the first texture is selected from the group consisting of lenticular lens textures, drag reduction textures, cube corner textures, diffraction gratings, hydrophobic surface textures, laser interference rainbow patterns, and combinations thereof.
5. The release web of claim 1 wherein the second texture has a feature depth of about 50 to 300 microns.
6. The release web of claim 1 wherein the first texture has a feature length of about 1 to 100 microns and a feature width of about 1 to 10 microns.
7. The release web of claim 1 wherein the first texture has a feature spacing of about 1 to 10 microns, and a feature depth or height of about 1 to 10 microns.
8. The release web of claim 1 wherein the coating layer comprises an acrylate.
9. The release web of claim 1 wherein the coating layer comprises polypropylene.
10. The release web of claim 1 wherein the substrate comprises paper or plastic.
11. A method comprising:
applying a coating to a flexible substrate;
imparting a first three-dimensional micro- or nanoscale texture to the coating; and
imparting a second three-dimensional macro-scale texture to the coating, in a manner that does not deleteriously affect the topography of the first texture, to form a release web having a textured surface.
12. The method of claim 11 wherein the coating is applied in liquid form and the method further comprises solidifying the coating prior to imparting the second texture to the coating.
13. The method of claim 12 wherein imparting the second three-dimensional texture comprises embossing the solidified coating.
14. The method of claim 12 wherein at least one of the textures is applied by nipping the solidified coating against the surface of an engraved roll.
15. The method of claim 13 wherein embossing is performed by nipping the solidified coating against a heated replicative surface.
16. The method of claim 15 wherein the replicative surface is heated to a temperature greater than the glass transition temperature of the cured coating.
17. The method of claim 15 wherein a pressure is applied at the nip of at least 1000 PLI.
18. The method of claim 11 wherein the first texture is selected from the group consisting of diffraction gratings, hydrophobic surface textures, laser interference rainbow patterns, lenticular lens textures, drag reduction textures, cube corner textures, and combinations thereof.
19. The method of claim 11 wherein the second texture is selected from the group consisting of leather, wood grain and combinations thereof.
20. The release web of claim 1 wherein the second texture is selected from the group consisting of leather, wood tick, wood grain and combinations thereof.