Method of making tissue sheets with textured woven fabrics having highlighted design elements

Abstract

A method of making tissue sheets is disclosed in which three-dimensional woven papermaking fabrics, such as throughdrying fabrics, are provided with woven highlight areas, particularly woven highlight areas containing design elements which make the design elements more visible in the resulting tissue product.

Description

BACKGROUND OF THE INVENTION [0001] Throughdrying is a well known method of drying tissue sheets, such as those useful for facial tissue, bath tissue, paper towels and the like. In general, the method involves supporting a wet web on a throughdrying fabric and passing hot air through the web / fabric structure to dry the web with minimal compaction. Throughdrying fabrics have evolved into more three-dimensional structures in order to provide texture and bulk to the tissue sheet, which is often perceived as advantageous by consumers. Examples of such relatively three-dimensional throughdrying fabrics are disclosed, for example, in U.S. Pat. No. 5,429,686 to Chiu et al., U.S. Pat. No. 5,672,248 to Wendt et al., and U.S. Pat. No. 6,398,910 B1to Burazin et al., all of which are hereby incorporated by reference. [0002] Although such three-dimensional throughdrying fabrics have many advantages, the texture imparted to the dried tissue sheet can detract from the visibility of any decorative e...

AI Technical Summary

Benefits of technology

[0003] It has now been discovered that tissue sheets can be made by using a woven papermaking fabric, such as an air-laid forming fabric or throughdrying fabric, having a three-dimensional topography with “highlight areas” that surround or otherwise outline “design elements”. The highlight areas are imparted to the resulting tissue sheets such that the design elements are more clearly visible. In addition, the presence of the highlight areas enhances roll bulk for tissue products sold in roll form and increases the bulk of multi-ply tissue products by reducing nesting between adjacent plies.

[0013] As used herein, the term “highlight area” means a woven surface area that either has substantially less surface texture than the surrounding background surface area, or has a texture that is substantially different in character than the surrounding background surface area, or has no texture, so that the design elements are easily distinguishable by the user of the tissue sheet product. It can be particularly advantageous for the highlight areas to be “substantially flat”, meaning they have substantially no elevational differences or few elevational differences in order to enable the design elements to be easily seen. Suitably, such flat areas have z-directional elevation differences of about 0.5 millimeter or less. However, as stated above, the woven highlight areas alternatively can be textured, provided they have a texture that is significantly different in character than the surrounding textured background surface area. Specific examples include, without limitation, a textured background surface area having substantially machine direction ridges and valleys, while the highlight areas comprise relatively flat regions, cross-machine direction ridges or lines, concentric circles or a series of dots. The highlight area can be woven or embroidered, stitched, extruded or embossed. For tissue sheets, the highlight area can be the same or different color as the textured background surface or design element. The highlight area can be raised above the mid-plane of the textured background surface, or it can be depressed below the mid-plane of the textured background surface, or it can be at the same level as the mid-plane of the textured background surface. In each case, the design element can be raised above the surface of the highlight area or depressed below the surface of the highlight area.

[0016] Air-permeable highlight areas and design elements are particularly suitable for throughdrying fabrics. The flatness of the highlight areas can be enhanced by depositing an air-permeable material onto the woven highlight areas to fill in the low spots and / or build up the highlight area surface. Particularly suitable air-permeable materials include non-woven fibers and open-celled foam materials. The design elements can be created by extruding a material, such as a thermoplastic material, on top of the highlight areas in the form of the desired design element. Alternatively, design elements can be woven or embroidered, stitched, or embossed. Alternatively, the design elements can recessed within the highlight area and be created by selectively removing portions of the highlight area by cutting, embossing or grinding. In addition, the highlight areas can be created by sanding, grinding, or embossing selected raised areas of the woven fabric.

Problems solved by technology

Although such three-dimensional throughdrying fabrics have many advantages, the texture imparted to the dried tissue sheet can detract from the visibility of any decorative elements which may also be imparted to the tissue sheet.

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