Patent Application
20100092743
The present disclosure relates to methods for printing absorbent fibrous web substrates, and more particularly, methods for printing a series of different graphics on a plurality of absorbent fibrous web substrates as well as products including such substrates.
Some consumers may prefer absorbent fibrous web substrates with a number of different graphic designs printed thereon and provided in a single package. Various methods and apparatuses may be used to print different graphics on an advancing web of material used in the manufacture of facial tissue, bath tissue, and paper towels. However, such methods and apparatuses are limited. Existing methods often provide lower quality print and may require slower manufacture speeds and more expensive equipment. Therefore, existing methods may not provide low cost flexibility to vary the type of graphics to be printed on these web substrates.
In particular, one such process is flexographic printing that relies on the use of printing plates disposed on print cylinders. This type of process may restrict the number of different images that may be printed on the finished product, as well as restrict the ability to vary the distance between repeating images. Most flexographic printing plates have a fixed length. Printing cylinders, that have the plates mounted thereon, are also of a fixed diameter and circumference. Increasing the diameter of the printing cylinder to accommodate a larger number of plates, becomes impractical after a certain point. In addition, a printing plate does not allow the printing system to offer a multitude of different images. In order to change images, one must replace the printing plate or cylinder with another plate or cylinder, respectively, having different images. This change requires shutting down the equipment, substituting one plate or cylinder for another, and making a number of mechanical adjustments. Furthermore, these printing processes do not allow different images to be varied in size, location and registration as the pattern is repeated.
The disadvantages of the prior processes are minimized or avoided by the invention herein. Process advantages are provided, by feeding the fibrous web substrate onto a rotating central impression cylinder having an outer surface and arranging a plurality of printing stations adjacent to the outer surface of the central impression cylinder, wherein each printing station comprises an endless belt with one or more printing plates disposed thereon or integral with the endless belt. By advancing the endless belt to move each printing plate into contact with the fibrous web substrate, a plurality of different graphics may be printed on the substrate, thus maximizing the repeat of a series of graphics or images or otherwise varying these graphics.
Embodiments of the methods and substrates disclosed herein utilize flexographic printing to provide a series of n fibrous web substrates having different graphics printed thereon.
Embodiments herein relate to an absorbent tissue product comprising a fibrous web substrate comprising a plurality of graphics, G1-Gn, wherein the graphics comprise a LREPEAT SUBSTRATE of at least about 58 inches and an ink color disposed on the substrate in a non-random arrangement of dots wherein the color to color MD registration of the graphics is less than about 1.5 mm.
Embodiments herein further relate to a method for printing a fibrous web substrate comprising the steps of:
The following term may be useful in understanding the present disclosure:
“Sanitary tissue product” or “tissue product” as used herein means a wiping implement for post-urinary and/or post-bowel movement cleaning (toilet tissue products), for otorhinolaryngological discharges (facial tissue products) and/or multi-functional absorbent and cleaning uses (absorbent towels such as paper towel products and/or wipe products). The sanitary tissue products of the present invention may comprise one or more fibrous web substrates and/or finished fibrous web substrates, traditionally, but not necessarily, comprising cellulose fibers. In one embodiment, the tissue products of the present invention include tissue-towel paper products.
A “tissue-towel paper 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 tissue paper, pattern densified tissue paper, starch substrates, and high bulk, uncompacted tissue paper. Non-limiting examples of tissue-towel paper products include paper towels, facial tissue, bath tissue, table napkins, and the like. “Ply” or “Plies”, as used herein, means an individual fibrous web substrate or sheet of fibrous web substrate, optionally to be disposed in a substantially contiguous, face-to-face relationship with other plies, forming a multi-ply fibrous web substrate. It is also contemplated that a single fibrous web substrate can effectively form two “plies” or multiple “plies”, for example, by being folded on itself. In one embodiment, the ply has an end use as a tissue-towel paper product. A ply may comprise one or more wet-laid layers, air-laid layers, and/or combinations thereof. If more than one layer is used, it is not necessary for each layer to be made from the same fibrous web substrate. Further, the layers may or may not be homogenous within a layer. The actual makeup of a tissue paper ply is generally determined by the desired benefits of the final tissue-towel paper product, as would be known to one of skill in the art. The fibrous web substrate may comprise one or more plies of non-woven materials in addition to the wet-laid and/or air-laid plies.
The terms “fibrous web substrate” or “substrate” as used herein, mean an arrangement of fibers produced in any papermaking machine known in the art to create a ply of paper, in an embodiment an absorbent tissue product. “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 term “web substrate length” as used herein, means the length of the tissue product, taken in the MD, as sold to the consumer. For example, the web substrate length of a discrete napkin or placemat is the machine direction length of one napkin or placemat. The web substrate length of a roll of paper toweling or toilet tissue is the machine direction length of the entire roll, taken from the point of core attachment (if a core is present) or the inside end of the roll to the tail seal. In an embodiment the web substrate length for paper towel products or toilet tissue products comprises from about 400 inches to about 2,500 inches, and/or from about 500 inches to about 1,400 inches and/or from about 600 inches to about 1,200 inches.
The term “discrete sheet” means that portion of the fibrous web substrate which is discrete as defined by lines of termination. In an embodiment the discrete sheet may be a napkin or may be a single sheet of a rolled tissue or towel paper product with a plurality of discrete sheets. For example, a discrete sheet may have a length in the MD from about 4 inches to about 20 inches, and/or from about 8 inches to about 14 inches. “Basis Weight”, as used herein, is the weight per unit area of a sample of the fibrous web substrate reported in lbs/3000 ft2 or g/m2.
“Machine Direction” or “MD”, as used herein, means the direction parallel to the flow of the fibrous web substrate through the converting machine and/or product manufacturing equipment.
“Cross Machine Direction” or “CD”, as used herein, means the direction perpendicular to the machine direction in the same plane of the fibrous web substrate.
The term “graphic” refers to images or designs that are constituted by a figure (e.g., a line(s)), a symbol or character, a color difference or transition of at least two colors, letters, words, characters, symbols, icons, or the like. A graphic may include an image or design, created by printing, that can provide certain benefit(s) when an absorbent fibrous web substrate is viewed.
In one embodiment, the fibrous web substrate has a basis weight of from about 15 lbs/3000 ft2 to about 50 lbs/3000 ft2, and/or about 16 lbs/3000 ft2 to about 40 lbs/3000 ft2, and/or about 16 lbs/3000 ft2 to about 37 lbs/3000 ft2.
In one embodiment the fibrous web substrates may 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 include cellulosic fibers commonly known as pulp fibers. Exemplary layering embodiments and processes of layering are disclosed in U.S. Pat. Nos. 3,994,771 and 4,300,981. In an embodiment, the fibrous web substrate may comprise any tissue-towel paper product known in the industry. Embodiment of these substrates may be made according U.S. Pat. No. 4,191,609 issued Mar. 4, 1980 to Trokhan; U.S. Pat. No. 4,300,981 issued to Carstens on Nov. 17, 1981; U.S. Pat. No. 4,191,609 issued to Trokhan on Mar. 4, 1980; U.S. Pat. No. 4,514,345 issued to Johnson et al. on Apr. 30, 1985; U.S. Pat. No. 4,528,239 issued to Trokhan on Jul. 9, 1985; U.S. Pat. No. 4,529,480 issued to Trokhan on Jul. 16, 1985; U.S. Pat. No. 4,637,859 issued to Trokhan on Jan. 20, 1987; U.S. Pat. No. 5,245,025 issued to Trokhan et al. on Sep. 14, 1993; U.S. Pat. No. 5,275,700 issued to Trokhan on Jan. 4, 1994; U.S. Pat. No. 5,328,565 issued to Rasch et al. on Jul. 12, 1994; U.S. Pat. No. 5,334,289 issued to Trokhan et al. on Aug. 2, 1994; U.S. Pat. No. 5,364,504 issued to Smurkowski et al. on Nov. 15, 1995; U.S. Pat. No. 5,527,428 issued to Trokhan et al. on Jun. 18, 1996; U.S. Pat. No. 5,556,509 issued to Trokhan et al. on Sep. 17, 1996; U.S. Pat. No. 5,628,876 issued to Ayers et al. on May 13, 1997; U.S. Pat. No. 5,629,052 issued to Trokhan et al. on May 13, 1997; U.S. Pat. No. 5,637,194 issued to Ampulski et al. on Jun. 10, 1997; U.S. Pat. No. 5,411,636 issued to Hermans et al. on May 2, 1995; EP 677612 published in the name of Wendt et al. on Oct. 18, 1995, and U.S. Patent Application 2004/0192136A1 published in the name of Gusky et al. on Sep. 30, 2004.
The substrates may be manufactured via a wet-laid making process where the resulting web is through-air-dried or conventionally dried. Optionally, the substrate may be foreshortened by creping or by wet microcontraction. Creping and/or wet microcontraction are disclosed in commonly assigned U.S. Pat. No. 6,048,938 issued to Neal et al. on Apr. 11, 2000; U.S. Pat. No. 5,942,085 issued to Neal et al. on Aug. 24, 1999; U.S. Pat. No. 5,865,950 issued to Vinson et al. on Feb. 2, 1999; U.S. Pat. No. 4,440,597 issued to Wells et al. on Apr. 3, 1984; U.S. Pat. No. 4,191,756 issued to Sawdai on May 4, 1980; and U.S. Pat. No. 6,187,138 issued to Neal et al. on Feb. 13, 2001. Conventionally pressed tissue paper and methods for making such paper are known in the art, for example U.S. Pat. No. 6,547,928 issued to Barnholtz et al. on Apr. 15, 2003. A suitable through air dried substrate may be made according to commonly assigned U.S. Pat. No. 4,191,609; U.S. Pat. No. 4,239,065, issued Dec. 16, 1980, Trokhan and U.S. Pat. No. 3,905,863, issued Sept. 16, 1975.
In one embodiment the tissue product is multi-ply, and the plies of the multi-ply fibrous web substrate may be the same substrate respectively or the plies may comprise different substrates combined to create desired consumer benefits. In one embodiment the fibrous web substrates comprise two plies of tissue substrate.
In one embodiment, the fibrous web substrate comprises a plurality of embossments. In one embodiment the embossment pattern is applied only to one ply. In another embodiment the fibrous web substrate is a two ply product wherein both plies comprise a plurality of embossments. In one embodiment the fibrous web structure comprises two or more plies of fibrous web substrate wherein at least one of the piles has a plurality of embossments thereon.
Suitable means of embossing include those disclosed in U.S. Pat. No. 3,323,983 issued to Palmer on Sep. 8, 1964; U.S. Pat. No. 5,468,323 issued to McNeil on Nov. 21, 1995; U.S. Pat. No. 5,693,406 issued to Wegele et al. on Dec. 2, 1997; U.S. Pat. No. 5,972,466 issued to Trokhan on Oct. 26, 1999; U.S. Pat. No. 6,030,690 issued to McNeil et al. on Feb. 29, 2000; and U.S. Pat. No. 6,086,715 issued to McNeil on Jul. 11, 2000.
The fibrous web substrate may be in any suitable form, such as in a roll form (e.g. wound about a core or may be wound without a core), in individual sheets, in connected, but perforated sheets, and/or in a folded or unfolded format.
Aspects of the present disclosure involve fibrous web substrates and methods for printing fibrous web substrates, and more particularly, for printing a series of different graphics during the manufacture of fibrous web substrates.
In existing conventional flexographic printing machines, such as shown in
Also, existing printing machines may include a series of flexographic printing units, such as those described in U.S. Pat. Nos. 4,856,429 and 5,003,873. For example,
An embodiment of the present invention relates to method of printing a fibrous web substrate, wherein a substrate is fed in the MD onto a rotating central impression cylinder of the printing apparatus having a plurality of printing stations disposed about the outer surface of the central impression cylinder. Each printing station may include n printing plates disposed on an endless belt and each is adapted to print a series of n graphics (G1-Gn) in the MD on the substrate. The printing stations may also be configured for halftone printing and configured to print different colors. In a second step, the substrate is moved past each printing station on the rotating central impression cylinder. In a third step, ink is transferred from the printing plates on the endless belts to the substrate. In an embodiment, the ink is transferred from each printing station to the substrate in a non-random arrangement of dot, e.g. substantially equally spaced dots of ink or rows of dots. For example, the ink will be disposed on the substrate in rows of dots resulting from or corresponding to the screen pattern over the print plate, wherein the screen pattern comprises a defined number of lines (or straight lines of dots) per inch. In an embodiment the rows of dots may be seen using about 20× to about 30× magnification with a microscope. The dots may be of various shapes and sizes, e.g. round, square, hexagon, elliptical, etc. In addition, the rows of dots from screen patterns of the anilox roll at each printing station may be printed at different screen angles so the graphics appear in different colors. In some embodiments, four printing stations are configured to print cyan, magenta, yellow, and black colors at screen angles of 15°, 75°, 0°or 90°, 45°, respectively. Thereafter, one or more, of the series of n absorbent fibrous web substrates are rolled, folded, stacked, and placed in a package.
In one embodiment, the substrate traveling in the MD is fed onto a rotating central impression cylinder or drum of a flexographic printing apparatus. Printing stations are located around a portion of the outer circumference of the central impression cylinder. While disposed on the rotating central impression cylinder, the substrate moves past the printing stations, which in turn, print a series of n graphics (G1-Gn), which may repeat, on the substrate, wherein each of the n graphics is different from each other, wherein n can be a number of 2 or greater and in another embodiment, n can be a number of 5, 10, 12, or 24 or greater. Lines of termination may be added to the advancing substrate to form discrete sheets. Thus, a product may be manufactured by rolling, folding, stacking, and placing one or more, or a portion of, the series of n fibrous web substrates in a package.
In an embodiment, each printing station of the printing apparatus may include an endless belt drawn around a printing roller. A plurality of flexible printing plates may be disposed on the endless belt, wherein each flexible printing plate may include a different graphic pattern corresponding to a distinct graphic to be printed on the substrate. As the central impression cylinder rotates, the substrate is advanced into a nip between the central impression cylinder and each printing station. At the same time, rotation of the central impression cylinder advances the endless belt and associated printing plates into contact with the substrate. More particularly, a first printing plate moves into contact with the substrate to print a first associated graphic onto the substrate. As the central impression cylinder continues to rotate, the substrate continues to move past the printing station, and the endless belt advances a second printing plate into contact with the substrate to print a second associated graphic onto the substrate. The central impression cylinder continues to rotate and the endless belt continuously advances such that all n printing plates disposed on the endless belt print associated graphics onto the substrate. As a result, a series of n graphics (G1-Gn) is printed on the substrate, wherein each of the n graphics may be different from each other. Once all n graphics are printed on the substrate, the endless belt advances to the first printing plate into contact with the substrate again and continues to repeatedly print the series of graphics. As discussed below, the printing stations can be configured in various ways to print different colored graphics. For example, in one embodiment, the printing stations may be configured to print graphics on a substrate through a process of halftone process printing.
Referring back to
As previously mentioned, the printing stations 104 can be configured to print a series of different graphics, which may repeat, on the substrate. As shown in
It is to be appreciated that the printing stations 104 may include different types of endless belt 112 configurations. For example, some embodiments may include a dimensionally stable endless belt made from a polyester film. In a particular example, the endless belt may be about 0.25 mm thick and may be made from polyethylene terephthalate. The physical properties of the transversely and longitudinally stretched film material may be the same in all directions. Such uniformity may extend over a wide temperature and humidity range. In addition, the film belt material may have relatively high elongation and impact resistance in transverse and longitudinal directions. Further, the film material of the endless belt may also be chemically resistant to withstand oils, greases, printing inks, and the like. In some embodiments, the endless belts may be provided with perforations adjacent the longitudinal edges of the endless belt. In such a configuration, knobs or teeth protruding from the first and second print rollers may be adapted to engage the perforations to help prevent the endless belt from sliding on the printing rollers.
As shown in
In an embodiment, the location of the anilox roller 126 and the ink supply 124 may be at any position around the endless belt 112 and in contact with the printing plates, as long as the endless belt 112 advances each printing plate (1001-100n) to sequentially moved into contact with the anilox roller 126, which transfers ink onto the printing patterns (2001-200n). In another embodiment the location of the anilox roller 126 and the ink supply 124 is adjacent to the position at which the endless belt 112 and the printing plates are adjacent to the second printing roller 116.
Various types and configurations of endless belts 112 and printing plates (1001-100n) may be used. For example, in some embodiments, the printing plates may be constructed from flexible photopolymer or rubber. The printing patterns (2001-200n) may be formed on the printing plates in various ways. For example, in some embodiments, the printing patterns are engraved into the printing plates. It should also be appreciated that the printing plates can be secured to the outer surface of the endless belt in various ways, such as with, for example, fasteners, adhesives, and tape. In some embodiments, the endless belts have printing patterns formed directly therein (e.g. the printing plates are integral to the endless belt). As previously mentioned, graphics are printed on the substrate when ink is transferred from the printing patterns to the substrate. As such, the CD width and MD length of the printed graphics can also be varied by varying the size of the printing patterns. For example, some embodiments can be configured to print graphics having a CD width of about 2.5 m or greater. In addition, some embodiments of printing stations can be configured with various numbers of printing plates or printing patterns, and as such, may accommodate different lengths of endless belts. For example, some printing stations can be configured to include an endless belt length of about 1.5 meters to about 4.5 meters or greater. The printing apparatus can also be configured to allow ease of removal and replacement of printing plates and/or endless belts, providing for relatively quick printing apparatus changeovers/reconfiguration for different print jobs.
In an embodiment, the printing apparatuses 100 may be configured to print a repeating series of n graphics (G1-Gn) on a substrate. In operation, the central impression cylinder 102 rotates in the direction shown for example in
In an embodiment, the graphics G1-Gn that form a LREPEAT SUBSTRATE in the MD result from the use of about 1 printing plate or from a plurality of printing plates. In an embodiment, LREPEAT SUBSTRATE is from about 58 inches to about 2,500 inches, or from about 59 inches to about 1,400 inches or from about 60 inches to about 1,400 inches. In another embodiment the LREPEAT SUBSTRATE is at least about 58 inches, or at least about 60 inches, or at least about 65 inches.
As previously mentioned, components of the printing stations 104 may be located relatively close to the outer surface 106 of the central impression cylinder 102 so as to create nips 110 between the printing stations 104, the substrate 108, and central impression cylinder 102. In particular, the first printing roller 114 and the endless belt 112 disposed thereon can be located relatively close to the central impression cylinder 102 in order to form a nip 110 between the printing plates (1001-100n) on the endless belt 112 and the outer surface 106 of the central impression cylinder 102. In an embodiment, the printing stations 104 can be configured such that the distance between the printing plates and the central impression cylinder can be adjusted, which in turn, allows for adjustable nip pressures at each printing station. During operation of the printing apparatus, the substrate 108 is advanced into nips 110 between the central impression cylinder 102 and the printing stations 104. As the substrate 108 passes through the nips 110, the adjustable nip pressures help maintain the substrate in a constant or fixed position relative to the outer surface 106 of central impression cylinder 102. As such, the present method and apparatus provide relatively precise and consistent print registration as opposed to less precise registration obtained from flexographic inline printing presses, even though both systems utilize endless belts for printing.
For example, Table 1 shows MD and CD registration print data measured from low basis weight films (e.g. 20 grams per square meter) printed on a “Flexographic CI Printing Press” similar to that depicted in
For rolled products such as paper towels and toilet paper, which have substantial web substrate lengths, registration of graphics is more difficult to maintain throughout the entire length of the substrate. Rolled products have, for example, web substrate lengths of about 400 inches to about 2,500 inches, and/or about 500 inches to about 1,400 inches, and/or from about 600 inches to about 1,200 inches. Thus, cumulative registration error may be greater throughout the entire length of these substrates. Registration of graphics is also further complicated by the fact that the amount of stretch in these substrates may be relatively high, especially in lower density through air dried substrates, and may vary throughout their entire length or between parent rolls. Often, in some embodiments, for these types of substrates, multicolor images are provided by using a separate image for each of four colors, e.g., yellow, magenta, cyan, and, black. The four colors, or different colors, are printed in register on the substrate to form a single image on the web. As such, multi-color printing requires precise color-to-color (e.g. ink-to-ink) registration to achieve good image quality. When the print on a substrate is in register, then generally the plates, used at different printing stations, for example each printing station using a different color (such as cyan, magenta, yellow and black in the case of four color) line up closely and accurately on the printing press to produce a more clearly defined graphic. In an embodiment, the color to color MD registration required for acceptable and well defined color at the edges of the graphics is less than or equal to about 1.0 millimeters or less than about 0.5 millimeters in both the MD and CD directions. In tissue and towel paper products, in an embodiment, the color to color MD registration is less than about 1.5 mm, and/or from about 0.05 mm to about 1.5 mm, and/or from about 0.04 to about 1.3 mm.
In tissue and towel paper products, in an embodiment, it may also be desirable to register the graphics with lines of termination, wherein, for example, within a range of from about 0.05 inches to about 0.5 inches and/or from about 0.1 inch to about 0.8 inch, over one or more discrete sheets or over the entire web substrate length.
An embodiment herein relates to a method of registering lines of termination with printed graphics on a fibrous web substrate comprising the steps of:
The graphics and the lines of termination are disposed upon the fibrous web substrate relative to each other such that registration is created. In an embodiment the predetermined distance between the lines of termination and the graphics has a tolerance range within ±0.125 inches and in another example, a tolerance range within ±0.063 inches.
In an embodiment one or more methods of registering the printed graphics to emboss, to sheet perforations, and/or registering to slitters (log saws) may be utilized. For example, U.S. Pat. No. 6,983,686, issued Jan. 10, 2006, Vaughn et al., relates to a process of registering printed images to emboss patterns.
The printing stations 104 can be configured to accommodate different values of LREPEAT SUBSTRATE, LREPEAT PLATE and LPATTERN. For example, the repeat length may be configured to be substantially equal to the MD length of a printed component. For example, embodiments configured to print graphics on a substrate used to manufacture printed paper towels or toilet paper, LREPEAT PLATE may be about 3 inches to about 15 inches.
It should also be appreciated that in some embodiments LPATTERN may be equal to LREPEAT SUBSTRATE or LREPEAT PLATE, and in other embodiments, the LPATTERN may be less than LREPEAT SUBSTRATE or LREPEAT PLATE. As such, MD length defined by printed graphics may span the entire web substrate length of a product or may span a portion of the web substrate length of a product. It should also be appreciated that the patterns (2001-200n) may be located in different positions along the MD and/or CD directions of the printing plates (1001-100n). As such, graphics can be located in different positions along the MD length and CD width of a substrate. It should further be appreciated that one or more printing plates (1000-100n) may include more than one printing pattern (2001-200n). Thus, a plurality of graphics can be located in different positions along the MD length and CD width of a substrate.
The number, n, of graphics printed in a series on a substrate may be increased or decreased by increasing or decreasing, respectively, the number n of printing plates and associated printing patterns mounted on the endless belts. For example, each printing station may have from about 2 printing plates to about 10 or more printing plates in the MD direction. As such, for a given LREPEAT SUBSTRATE and LREPEAT PLATE, a relatively longer endless belt may be required to accommodate higher numbers of printing plates. Alternatively, a relatively shorter endless belt may be required to accommodate fewer printing plates. For example, a printing station may include 12 printing plates arranged to print four repeating series of three different graphics.
It should also be appreciated that the embodiments of the printing apparatuses can be configured with various CD widths. For example, in some embodiments, the CD width may be about 3 inches to about 120 inches. In still other embodiments, the CD width may be from about 90 inches to about 120 inches for parent rolls, from about 8 inches to about 14 inches for paper towels, and from about 3 inches to about 6 inches for toilet tissue. It should also be appreciated that the printing stations can also be configured to include various numbers and sizes of printing plates oriented along the CD width of the endless belt. For example, some embodiments can be configured with 5, 7, or more printing plates along the CD width of the endless belt.
As previously mentioned, embodiments of the printing apparatus can be configured to include various numbers of printing stations 104. For example, as shown in
The printing stations 104 may also be configured to print graphics on a substrate that may appear in a relatively large range of colors through various different processes, such as for example, halftone printing. Halftone printing utilizes equally spaced dots of ink to simulate a continuous tone. Various descriptions of halftone printing processes are discloses in U.S. Pat. Nos. 4,142,462; 5,205,211; 5,617,790; 7,126,724; as well as U.S. Patent Publication No. 20040160644 and PCT Publication No. W098/06006A1.
In one embodiment, the printing apparatus 100 shown in
In halftone printing, the dot axes may be oriented at different angles, which may be referred to as screen angles, relative to a reference axis 144. As shown in
In operation, the printing stations may print dots at predetermined screen angles to produce graphics having desired colors. The dots printed by the printing stations may also be overlaid and may produce a pattern. In one example, the patterns may form a plurality of rosettes. In one embodiment, the printing stations are configured to produce open rosettes. In another embodiment, the printing stations are configured to produce closed rosettes. The dots may also be printed such that portions of subsequently printed dots overlap portions of previously printed dots to produce desired color combinations.
As discussed above, the printing stations 104 may be configured with n printing plates (1001-100n), wherein n may be 2 or greater and wherein the printing stations are configured to print different colors of ink. For the purposes of illustration with reference to the printing apparatus 100 shown in
In an embodiment during operation, the substrate 108 on the rotating central impression cylinder 102 moves past the printing stations (104a-104d), and printing plates 1001a, 1001b, 1001c, and 1001d to print ink on the substrate 108 to form a first graphic G1 on the substrate. In conjunction with the rotation of the central impression cylinder 102 and coordinated advancement of the endless belts 112 on the printing stations (104a-104d), printing plates 1002a, 1002b, 1002c, and 1002d print ink on the substrate to form a second graphic G2 on the substrate 108, wherein the first graphic G1 is adjacent the second graphic G2 in the MD (see for example
The printing apparatuses disclosed herein may also be configured to print at various speeds. For example, embodiments may be configured to print graphics on a substrate that allows the substrate to advance in the MD at a speed from about 1,500 to about 3,000 feet per minute.
For example, endless belts having multiple lanes of printing plates in the CD, and wherein the endless belts are from about 12 inches CD width to about 100 or even about 200 inches CD width, may accommodate manufacturing line speeds of about 300 to 2,500 feet per minute.
As previously mentioned, in some embodiments, the graphics G1-Gn on the absorbent fibrous web substrates are different from each other in terms of graphic design. Herein, “different in terms of graphic design” means that graphics are intended to be different when viewed by users or consumers with normal attentions. Thus, two graphics having a graphic difference(s) which are unintentionally caused due to a problem(s) or an error(s) in a manufacture process, for example, are not different from each other in terms of graphic design. The graphic design is determined by, for example, the color(s) used in the graphic (individual pure ink colors as well as built process colors), the sizes of the entire graphic (or components of the graphic), the positions of the graphic (or components of the graphic), the movements of the graphic (or components of the graphic), the geometrical shapes of the graphic (or components of the graphics), the number of colors in the graphic, the variations of the color combinations in the graphic, the number of graphics printed, the disappearance of color(s) in the graphic, and the contents of text messages in the graphic.
It should be appreciated that although a package may contain tissue or towel products which have the graphics G1-Gn different from each other, the package may also contain, if desired, one or more additional products which have a graphic that is the same as one the other graphics in the package. For example, the absorbent product may include at least n fibrous web substrates, in a series, which have the graphics G1-Gn different from each other, and can include an additional absorbent fibrous web substrate(s) each having the same graphic(s).
It should be appreciated that printed graphics may be permanent or active graphics. Active graphics are graphics that are configured to appear or disappear upon various types of triggering mechanisms or stimuli, such as for example, moisture (e.g. aquachromic ink graphics), temperature change (e.g. thermochromic ink graphics), pressure change, and/or light (e.g. photochromic ink graphics, UV or IR light).
It is also to be appreciated that the position of the graphics G1-Gn may be registered within a predetermined area of the absorbent fibrous web substrates such that each of the graphics G1-Gn appears in an intended position (or the predetermined area) in each absorbent fibrous web substrates without unintentional variation.
The graphics G1-Gn of the absorbent fibrous web substrates may also have a predetermined association. Herein, “association” refers to a relationship which can conceptually bond a plurality of graphics. The predetermined association may be formed by the graphic designs of the n graphics. The predetermined association may include a predetermined order and/or a common theme.
In some embodiments, the predetermined association includes a predetermined order, and the n fibrous web substrates are stacked or arranged in the package in accordance with the predetermined order. The predetermined order may include an order illustrating story, an order for daily activity, an order for educational training, an order for sequential indication, an order of usage instruction, an order illustrating child care tips, and an order of sales promotion. In some embodiments, each fibrous web substrate carries one step or stage in a predetermined order in the graphic, and the predetermined order is completed by the n graphics of the n fibrous web substrates. In embodiments where the graphics illustrate a story, the story may include a children's story and a cartoon story such as Aesop's Fables, nursery rhymes, and the like. In some embodiments, a product may include fibrous web substrates in a single package wherein each fibrous web substrate including graphics illustrating different stories or nursery rhymes. For example, a fibrous web substrate may include a graphic G1 illustrating a first nursery rhyme, such as Jack and Jill, and an adjacent fibrous web substrate in the package may include a graphic G2 illustrating a second nursery rhyme, such as the Cat and the Fiddle, and so on up to graphic Gn. In some embodiments, a product may include fibrous web substrates in a single package wherein each product may include portions of stories or nursery rhymes. For example and as discussed above with reference
In some embodiments, the predetermined association may include a common theme, and the n fibrous web substrates may be stacked or sequenced in the package in a randomly selected order. The common theme can be any theme which is consistently expressed in the n graphics. The common theme may include cartoon characters (e.g., one cartoon character is doing different activities such as playing, eating, taking a bath, and the like, or a plurality of different cartoon characters are doing same/different activities), transportation means (e.g., cars, trains, ship, planes, etc.), animals (e.g., dogs, cats, rabbits, etc.), fruits (e.g., bananas, oranges, apples, etc.), vegetables (e.g., carrots, pumpkins, potatoes, etc.), plants (e.g., tulips, morning glories, roses, etc.), and seasonal themes (e.g., snowmen, etc.).
In another embodiment the fibrous web substrate may also comprise embossment patterns wherein the embossment patterns and the printed graphics, G1-Gn, of the fibrous web substrates, have a predetermined association, for example such as those described in US 2004/0258886 A1, published on Dec. 23, 2004, Maciag.
The printing apparatuses and methods disclosed herein may be used offline (i.e., the printing process is a not part of a manufacture process) or used as an online process. In the offline printing process, the printed substrate may exit the printing apparatus and be wound on a roll.
In an embodiment one or more methods of controlling tension, speed and modulus, in the fibrous web substrate are utilized. For example, U.S. Pat. No. 7,092,781, issued Aug. 15, 2006, Franz et al.; U.S. Pat. No. 7,035,706, issued Apr. 25, 2006, Franz; U.S. Pat. No. 6,845,282, issued Jan. 18, 2005, Franz; U.S. Pat. No. 6,993,964, issued Feb. 7, 2006, Franz et al.; and U.S. Pat. No. 6,991,144, issued Jan. 31, 2006, Franz et al.
The following provides a test method for detecting and analyzing graphics printed in accordance with the processes and apparatuses disclosed herein with a halftone printing process.
Carefully remove the printed substrate from the fibrous web substrate taking care not to deform the substrate's dimensions. Typically layers can be separated using a flash-freezing spray such as Cyto-Freeeze (Control Co. TX) or gently heating the fibrous web substrate to release the adhesives. Lay the specimen flat on a lab bench with the printed side facing up, and draw a reference line centered along the longitudinal length of the specimen. Identify a one square inch test area that includes a printed image where either 1) a color is constructed with overlapping print, where dots of at least one screen color can be discerned or 2) halftone printing where dots of the screen color can be discerned. Draw a first auxiliary line, perpendicular to the reference line, which passes through the test area. Next, place the substrate, printed side down, on the scanning surface of a flat bed scanner (for example an Epson Perfection V500 Photo scanner), close the lid and scan the identified test region at least 4800 dpi and 24-bit color depth in reflectance mode.
Examine the digital image within a graphics program such as Image J (National Institute of Health, USA). Rotate the digital image as necessary to align the first auxiliary line horizontally. Visually identify a linear arrangement of printed screen dots of a specific first color, for example 140 in
Next, an angle for a second distinct printed screen color is measured in like fashion. The second angle can be measured within the same test area, or if needed, a second test area can be chosen, scanned, and measured, following the same procedure outlined above.
Compare the angles of the two measured printed screen colors, calculating the difference between them to ±1.0 degree. Repeat the angle measurements, using corresponding test areas and colors for a least 3 fibrous web substrates. Report the average angle difference to ±1.0 degree.
Table 5 below shows exemplary data gathered using the test method described above by measuring the screen angles of ink dots printed on absorbent fibrous web substrates:
The following method is used to measure the color to color MD registration. First, the substrate samples are conditioned in a conditioned room at a temperature of 73° F.±4° F. (about 23° C.±2.2° C.) and a relative humidity of 50%±10% for 2 hours prior to the test. Further, all tests are conducted in such conditioned room. All measurements are made under constant tension in the MD and CD. Lay samples out flat on a clean, dry table-top surface, minimizing stretching the substrate. Provide a substrate sample having 20 cross-hair registration marks in the MD.
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 value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application, is incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
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.
This application claims the benefit of U.S. Non-Provisional application Ser. No. 12/249,153 filed Oct. 10, 2008.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12249153 | Oct 2008 | US |
| Child | 12268623 | US |
