Patent Application
20080230200
This invention pertains to the apparatus for producing images disposed upon a products, particularly papermaking belts that make a product which has a three an image disposed thereon that presents a three dimensional effect to the observer.
Absorbent paper products are a staple of everyday life. Absorbent paper products are used as consumer products for paper towels, toilet tissue, facial tissue, napkins, and the like. The large demand for such paper products has created a demand for improved aesthetics and functional benefits in absorbent paper products, and as a result, has driven the need for novel methods for providing these visual effects and benefits to absorbent paper products.
Visual effects may be provided on an absorbent paper product by a number of techniques. For example, a pattern may be embossed onto the surface of a paper web as it is being converted. Alternatively, a pattern may be molded directly onto the surface of a paper web using a patterned papermaking belt. Patterns provided onto the surface of paper products not only provide the consumer with a positive visual appearance both at the time of purchase and during use, but may also provide a number of functional advantages. For example, a highly textured surface as can be provided by embossing or by the use of textured belts may increase the softness, absorbency, or caliper of a paper product.
With the advent and growth of the computer imaging industry there has been a rapid saturation of consumers with three dimensional computer graphics, images, and effects. Without being limited by theory, it is thought that consumers perceive the use of such three dimensional effects as denoting a product or good that is technologically advanced, in addition to providing an interesting visual experience to the consumer. As a result, many consumers prefer goods that provide such a three dimensional effect.
Accordingly, there exists the need to provide a means for providing an absorbent paper product having an aesthetically pleasing surface pattern having a three dimensional effect.
The present invention relates to a papermaking belt for making a fibrous structure product. The papermaking belt has a machine direction, a cross machine direction orthogonal and co-planar with the machine direction, and a Z-direction mutually orthogonal to both the machine and cross machine directions. The papermaking belt comprises a framework and a reinforcing element. The framework has a structure formed by a first layer wherein the first layer comprises a plurality of deflection conduits that correspond to a resultant image and extend in the Z-direction, where the resultant image being the product of at least one image modification algorithm. Further, at least one of the image modification algorithms is a beta image modification algorithm such that the beta image modification algorithm is a three dimensional image modification algorithm.
In another embodiment, the present invention relates to a framework for a papermaking belt. The framework has a photosensitive resin that has been exposed to actinic radiation through a mask comprising an image. The image is the product of at least one image modification algorithm. The at least one image modification algorithm is a beta image modification algorithm. The beta image modification algorithm is a three dimensional image modification algorithm.
As used herein, “paper product” refers to any formed, fibrous structure products, traditionally, but not necessarily, comprising cellulose fibers. In one embodiment, the paper products of the present invention include tissue-towel paper products.
As used herein, “fibrous structure” or “fibrous structure product” refers to products comprising paper tissue or paper towel technology in general, including, but not limited to, conventional felt-pressed or conventional wet-pressed fibrous structure product, pattern densified fibrous structure product, starch substrates, and high bulk, uncompacted fibrous structure product. Non-limiting examples of tissue-towel paper products include disposable or reusable, toweling, facial tissue, bath tissue, table napkins, placemats, wipes, and the like.
As used herein, “image” refers to any figure, drawing, or other visual representation in any coordinate system. In one embodiment, an image can be a simple geometric figure which may be selected from, but not limited to: rectangles, squares, circles, triangles, ovals, polygons, quadrilaterals, and combinations thereof. In another embodiment, an image can be a random non-geometric shape.
As used herein, “resultant image” refers to the consequent image after an image modification algorithm has been applied to an image.
As used herein, “image modification algorithm,” also known to those of skill in the art as a “filter”, refers to an algorithm that performs one or more mathematical operations on the mathematical expression of the image. The modified (operated on) image is referred to as a resultant image. Exemplary mathematical operations that may be used as image modification algorithms include, but are not limited to, rotations, reflections and translations. For instance, a transformation performed in a two dimensional (sometimes referred to by those of skill in the art as “Euclidean”) plane can move every point of the image by a fixed distance in the same direction or even shift the origin of the coordinate system to a new point. For example, if v is a fixed vector, then the translation Tv(p) about another vector p can be described mathematically as:
T
v(p)=p+v
An image modification algorithm may have one or more adjustable parameters or variables that affect the extent to which the mathematical operation may affect the resultant image (such as p in the above example). As a result, one image modification algorithm may be adjusted to provide different resultant images by changing the parameters, such as p, selected for each image modification algorithm.
As used herein, “resolution” refers the measure of sharpness of an image expressed as the total number of pixels, or points of color, per unit area (i.e. the number density of pixels) in the image.
As used herein, “raster image” also known to those of skill in the art as a “bitmap” refers to a data file or structure representing a grid of pixels in an image. Without wishing to be limited by theory, it is thought that the quality of a raster image is limited by the resolution and the type of information in each pixel (so called “color depth”). For example, an image sampled at 640×480 pixels (therefore containing 307,200 pixels) may not appear as clear as an image sampled at 1280×1024 (1,310,720 pixels) in the same area.
As used herein, “vector image” refers to images that may be comprised of one or more individual, scalable geometric objects, such as curves and polygons, which may be defined by a mathematical function. A non-limiting example of a vector image which can be described by a geometric object is a circle. One embodiment of a circle that may be defined by a geometric object may be expressed by the function:
f(r)=[(x−h)2+(y−k)2]1/2
where h and k are the x- and y-coordinates of the center of the circle in a Euclidian plane and r is the radius of the circle. Thus, a circle with radius of 5 units around the origin (x- and y-coordinates of 0) may be described as:
5=[x2+y2]1/2
Without wishing to be bound by theory, because a vector image may be defined mathematically, it is thought that it is possible to freely change any number of parameters without causing a loss of resolution as the image is modified or scaled to a larger size. For example, the circle with a radius of 5 units as described above can be scaled to a circle of radius 10 units by simply altering the radius (a parameter):
10=[x2+y2]1/2
Alternatively, the circle may be scaled and translated so that it has a radius of 6 units and is no longer centered about the origin, but centered about the x-coordinate −2 and the y-coordinate +3:
6=[(x+2)2+(y−3)2]1/2
A vector image may be distinguished from a raster image in that vector images represent an image through the use of geometric objects such as curves and polygons while raster images are represented using pixels.
As used herein, “vectorize” or “vectorizing” refers to the process of converting any raster image to a vector image. It is known in the art that raster images which have been vectorized can be rescaled without quality loss. A nonlimiting example of a method for converting a raster image to a vector image is to replace the pixels in a raster image with geometric objects to form a vector image. This conversion can be done manually or using a software package such as Adobe Illustrator™, CorelDRAW!™, and Adobe Streamline™. Without being limited by theory, many software packages trace lines around a raster image and assign geometric objects to the traced outline of the raster image. An example of a method for converting a raster image to a vector image is disclosed in U.S. Pat. No. 5,715,331.
As used herein, “industrially usable format” refers to any file type that can be used as a template for the creation of any article of manufacture. Nonlimiting examples of articles of manufacture include, but are not limited to: a patterned belt, emboss roll, or print roll. Examples of industrially usable formats include, but are not limited to: Computer Aided Design or CAD (*.dwg or *.dxf) format and Adobe Illustrator™ (*.ai) format.
As used herein, “fibrous structure” as used herein means an arrangement of fibers produced in any papermaking machine known in the art to create a ply of paper. “Fiber” means an elongate particulate having an apparent length greatly exceeding its apparent width. More specifically, and as used herein, fiber refers to such fibers suitable for a papermaking process. The present invention contemplates the use of a variety of paper making fibers, such as, natural fibers, synthetic fibers, as well as any other suitable fibers, starches, and combinations thereof. Paper making fibers useful in the present invention include cellulosic fibers commonly known as wood pulp fibers. Applicable wood pulps include chemical pulps, such as Kraft, sulfite and sulfate pulps; mechanical pulps including groundwood, thermomechanical pulp; chemithermomechanical pulp; chemically modified pulps, and the like. Chemical pulps, however, may be preferred in tissue towel embodiments since they are known to those of skill in the art to impart a superior tactical sense of softness to tissue sheets made therefrom.
Pulps derived from deciduous trees (hardwood) and/or coniferous trees (softwood) can be utilized herein. Such hardwood and softwood fibers can be blended or deposited in layers to provide a stratified web. Exemplary layering embodiments and processes of layering are disclosed in U.S. Pat. Nos. 3,994,771 and 4,300,981.
Additionally, fibers derived from non-wood pulp such as cotton linters, bagesse, and the like, can be used. Additionally, fibers derived from recycled paper, which may contain any or all of the pulp categories listed above, as well as other non-fibrous materials such as fillers and adhesives used to manufacture the original paper product may be used in the present web. In addition, fibers and/or filaments made from polymers, specifically hydroxyl polymers, may be used in the present invention. Non-limiting examples of suitable hydroxyl polymers include polyvinyl alcohol, starch, starch derivatives, chitosan, chitosan derivatives, cellulose derivatives, gums, arabinans, galactans, and combinations thereof. Additionally, other synthetic fibers such as rayon, lyocel, polyester, polyethylene, and polypropylene fibers can be used within the scope of the present invention. Further, such fibers may be latex bonded. Other materials are also intended to be within the scope of the present invention as long as they do not interfere or counter act any advantage presented by the instant invention.
As used herein, “Machine Direction” or “MD” means the direction parallel to the flow of the fibrous structure through a papermaking machine and/or product manufacturing equipment.
As used herein, “Cross Machine Direction” or “CD” means the direction perpendicular to, and coplanar with, the machine direction of the fibrous structure and/or fibrous structure product comprising the fibrous structure.
As used herein, “Z-direction” means the direction normal to a plane formed by machine direction and cross machine directions.
The first image 10 may then be modified using an alpha image modification algorithm 20. By convention herein, an alpha image modification algorithm 20 may be a two dimensional image modification algorithm. An alpha image modification algorithm 20 can be repeated any number of times with any combination or sequence of image modification algorithms to create a variety of resultant images. An alpha image modification 20 may be performed using any suitable software package. Nonlimiting examples of suitable software packages for performing two dimensional image modifications include: Adobe Photoshop™, Adobe Illustrator™, Adobe After Effects™, Cinema 4D™, Maya™, 3D Studio Max™, Lightwave 3D™, the like, and combinations thereof. Examples of two dimensional image modification algorithms include, but are not limited to: tile (which replicates a single object any number of times), kaleidoscope (which divides an image into smaller parts, replicates the smaller parts and then rotates the replicated parts), blur (which diffuses the pixels which comprise a raster image), the like and combinations thereof. The terms given as examples are those from the Apple Motion™ software package. It should be understood by those of skill in the art that the terms used to describe two dimensional image modification algorithms can be purely arbitrary when compared to the actual mathematical operation(s) that are used because similar image modification algorithms may have different names in different software packages.
The image that results from the first image 10 modification algorithm 20 may be further modified by applying a beta image modification algorithm 30. Alternatively, in one embodiment, the first image 10 may be modified by applying a beta image modification algorithm 30 without having been modified by an alpha image modification algorithm 20. By convention, a beta image modification algorithm 30 is a three dimensional image modification algorithm. It is believed that the image that results from an alpha image modification algorithm 20 may be modified by any number of additional alpha image modification algorithms 20 before being modified by a beta image modification algorithm 30. Without being limited by theory, it is thought that a beta image modification algorithm 30 can be visually differentiated from two-dimensional image modification algorithms because three-dimensional image modification algorithms create an apparent difference in scale or sense of depth. Further, in one embodiment, a beta image modification algorithm 30 applied to an image causes the resultant image have a “falloff effect” at the edges of the resultant image. A falloff effect may be described as having the appearance of the edges gradually dropping off in the z-direction. Examples of three dimensional imaging software packages include, but are not limited to: Cinema 4D™, Maya™, Apple Motion™, 3D Studio Max™, the like, and combinations thereof. Within Apple Motion™, examples of three dimensional image modification algorithms include, but are not limited to: black hole (which creates a hole in the image having a falloff effect at the resultant edges of the image around the circle), bulge (which creates a circle in the image and maps the pixels within the circle from a Cartesian coordinate system onto a polar coordinate system), disc warp (which chooses a section of an image, rotates that section, and then creates a falloff effect at the edges of that section), the like and combinations thereof.
Once the beta image modification algorithm 30 is applied, the resultant image may be converted from a raster image to a vector image 40 using any means known in the art. The vector image 40 may be converted to an industrially usable format 50. The industrially usable format 50 may then be used as a template to make a papermaking belt 52, embossing roll 55, or pattern for a print roll 58 as described infra. The process describing the construction of a papermaking belt is described in the “Papermaking Belt” section below. The resultant image can then be provided to a fibrous structure product 60.
The images produced according to the process of the present invention may be applied to the surface of the fibrous structure product by any means known in the art. For example, the rasterized and/or vectorized images as produced by the process described herein can be applied via the application of ink to the surface of a fibrous structure product. Suitable processes for applying ink to a roll and then from the roll to the fibrous structure product by printing include, but are not limited to lithography, letter press, gravure, screen printing, intaglio, and flexography. The method for transferring an image of the present invention to a print roll or other printing mechanism may be done using any method that is known in the art. An exemplary embodiment of using ink to create surface patterns on fibrous structure products is disclosed in U.S. Pat. No. 7,037,575.
Alternatively, the images may be imparted to a fibrous structure product by embossing. The present invention images may be transferred to an embossing roll using any means known in the art. Knob to knob embossing is well known in the art as illustrated by commonly assigned U.S. Pat. No. 3,414,459. The images may also be imparted to the fibrous structure product by nested embossing as illustrated by U.S. Pat. No. 4,320,162. In addition, the images may be imparted to the fibrous structure product by dual ply lamination embossing as illustrated by U.S. Pat. No. 5,468,323.
Patterned belts can also be used to apply images to fibrous structure products. Processes for using patterned belts to make fibrous structure products that have images disposed thereon include, but are not limited to those processes disclosed in U.S. Pat. No. 3,301,746, U.S. Pat. No. 3,974,025, U.S. Pat. No. 4,239,065, U.S. Pat. No. 4,528,239, and U.S. Pat. Application No. 60/855576.
The papermaking belt 100 has a machine direction, a cross machine direction, and a thickness extending in a Z-direction perpendicular to the plane formed by the machine and cross machine directions that may receive a slurry of fibers that form the fibrous structure product. Without being limited by theory, it is thought that deflection conduits within the framework mold the slurry of fibers as the fibrous structure product is formed. As a result, the arrangement of the deflection conduits within the framework may be used to impart an image as described herein onto the surface of the fibrous structure product. The papermaking belt 100 comprises two primary components: a framework 120 and a reinforcing element 130. The framework 120 may comprise any suitable material, including, without limitation, a resinous material (such as a photosensitive resin), a plastic, a metal, metal-impregnated polymers, a molded or extruded thermoplastic or pseudo-thermoplastic material, and in one embodiment comprises a cured polymeric photosensitive resin.
The reinforcing element 130 may comprise a woven fabric as is known in the art. The reinforcing element 130 may be fluid-permeable, fluid-impermeable, or partially fluid-permeable (meaning that some portions of the reinforcing element may be fluid-permeable while other portions thereof may not be). Examples of the reinforcing element include, but are not limited to, a woven element, a felt, a mesh wire, or combinations thereof.
The papermaking belt 100 according to the present invention may be made by curing a photosensitive resin through a mask. A mask may be made using any means known in the art. Nonlimiting examples of methods for making masks for photoradiation purposes are described in U.S. Pat. Nos. 3,877,810, 4,374,911, 6,783,898 and U.S. Pat. App. No. 2004/0126710 A1. In one embodiment, an image produced according to the present invention that is in an industrially usable format 50 may be used as a template to form the mask. In one embodiment, the industrially usable format 50 may be saved as an Encapsulated Postscript (or *.eps) file format and then opened using a software printing program such as, but not limited to, Wasatch SoftRIP™, that may take the resultant image from the *.eps file and repeat the resultant image over a user-specified length and width. The software printing program will then print the image onto a transparent surface to form a mask having first regions which are transparent to actinic radiation and second regions which are opaque to the actinic radiation. In one embodiment, the printing can be done in one step by transferring the ink to a transparent film using a printer such as, but not limited to a Hewlett Packard™ Design Jet 5000.
The regions in the mask which are transparent to the actinic radiation will form like regions in the photosensitive resin which cure and become the framework 130 of the papermaking belt 100. Conversely, the regions of the mask which are opaque to the actinic radiation will cause the resin in the corresponding positions to remain uncured. Uncured resin may be removed during the beltmaking process and does not form part of the papermaking belt 100. Because the mask will determine what the surface of the belt will look like, the mask may be patterned according to any image that may be created as discussed supra.
The belt of the present invention may be formed by a process comprising the following steps: First, providing a coating of a liquid curable material. In one embodiment, the liquid curable material comprises a first layer. In one embodiment the liquid curable material is a photosensitive resin. The coating can be applied by any means known in the art. In one embodiment the coat is provided by dispensing liquid curable material through a nozzle. The thickness of the coating can be controlled by, for example, a roll, a bar, a knife, or any other suitable means known in the art. In one embodiment the coating of liquid curable material is supported by a forming surface, the coating having a first thickness. Second, providing a source of actinic radiation to cure the liquid curable material. In one embodiment, the source of actinic radiation may be a lamp having a bulb capable of providing light at the appropriate wavelength to cure the liquid curable material. Third, providing a mask having a pre-selected pattern of transparent regions and opaque regions that correspond to an image produced according to the present invention therein and positioning the first mask between the coating of the curable material and the source of curing radiation so that the opaque regions of the first mask shield areas of the coating from the curing radiation while the transparent regions of the first mask cause other areas of the coating to be unshielded. Fourth, curing the unshielded areas of the coating by exposing the coating to the actinic radiation through the mask having an image thereon. The shielded areas of the coating uncured. Fifth, removing substantially all uncured liquid curable material from the partly-formed first layer to leave a hardened or semi-hardened material structure. Sixth, removing substantially all uncured liquid curable material from the cured layer to leave a hardened material or semi-hardened material structure that corresponds to the negative tone of the image described infra.
In one embodiment, a backing film may be provided and positioned between the forming surface and the coating of a liquid photosensitive resin, to protect the forming surface from being contaminated by the liquid resin. If the papermaking belt having a reinforcing element is desired, the process may further include steps of providing a suitable reinforcing element supported by the forming surface, the reinforcing element having a paper facing side and a machine facing side, and depositing a coating of a liquid photosensitive resin to the paper facing side of the reinforcing element.
The fibrous structure product may comprise a tissue-towel paper product known in the industry. Embodiment of these substrates may be made according U.S. Pat. Nos. 4,191,609, 4,300,981, 4,191,609, 4,514,345, 4,528,239, 4,529,480, 4,637,859, 5,245,025, 5,275,700, 5,328,565, 5,334,289, 5,364,504, 5,527,428, 5,556,509, 5,628,876, 5,629,052, 5,637,194, and 5,411,636; European Patent 677,612; U.S. Patent App. No. 2004/0192136A1 and U.S. Provisional Patent No. 60/855499.
In one embodiment, the fibrous structure product may be manufactured via a wet-laid paper making process. In other embodiments, the fibrous structure product may be manufactured via a through-air-dried paper making process or foreshortened by creping or by wet microcontraction. In some embodiments, the resultant plies of fibrous structure may be differential density fibrous structure plies, wet laid fibrous structure plies, air laid fibrous structure pliles, conventional fibrous structure plies, and combinations thereof. Creping and/or wet microcontraction are disclosed in U.S. Pat. Nos. 6,048,938, 5,942,085, 5,865,950, 4,440,597, 4,191,756, and 6,187,138.
In one embodiment, the fibrous structure product may be a paper towel product or a toilet tissue product having an image as produced by the process of the present invention disposed thereon. Paper towel products and toilet tissue products having images disposed thereon are described in U.S. Provisional Patent No. 60/855499.
One embodiment of creating an image in an industrially usable format that could be used for making a paper product with a three dimensional surface pattern according to the present invention includes the following components: An Apple Mac™ computer with the Apple Motion™ and Adobe Illustrator™ software packages installed.
The steps used to create a paper product with a three dimensional surface pattern the following steps are:
All publications, patent applications, and issued patents mentioned herein are hereby incorporated in their entirety by reference. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited dimension or value and a functionally equivalent range surrounding that dimension or value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
