Process for applying high viscosity composition to a sheet with high bulk
View Patent ↗A process is disclosed for topically applying additive compositions to planar substrates, such as tissue webs. In one embodiment, the process is designed to apply relatively high viscous compositions to base sheets at high speeds in a manner that prevents the additive composition from penetrating into the sheet. The additive composition having the relatively high viscosity can be applied to the base sheet in one embodiment using an offset gravure printing process. The applicator roll includes a pattern of raised elements. The raised elements define a surface having at least one dimension that is less than 500 microns. The raised elements are also spaced closely together in order to prevent fiber buildup on the roll during relatively fast processing speeds.
1. A process for applying an additive composition to a surface of a substrate comprising:
applying an additive composition to a surface of a first roll;
transferring the additive composition from the surface of the first roll to a surface of a second roll, the surface of the second roll comprising a compressible material defining a pattern of raised elements, each of the raised elements having a surface in which at least one dimension of the surface is less than about 500 microns, all of the adjacent raised elements in the pattern being spaced apart a distance of less than about 500 microns measured from a center of one element to a center of an adjacent element; and
applying the additive composition from the surface of the second roll to a surface of a planar substrate, the planar substrate containing pulp fibers, the additive composition containing a polymeric material and having a viscosity of at least 500 cps, the additive composition covering at least 20% of the surface area of the surface of the planar substrate, the planar substrate moving at a speed of at least 500 ft/min during application of the additive composition.
2. A process as defined in claim 1 , wherein the raised elements have discrete shapes that have an effective diameter of less than about 500 microns.
3. A process as defined in claim 2 , wherein the raised elements have a circular shape.