Papermaking apparatus having semicontinuous pattern

Abstract: A secondary belt for papermaking. The belt has a framework of protuberances arranged in a semicontinuous pattern to provide a semicontinuous pattern of deflection conduits. The semicontinuous pattern is distinguished from the discrete and continuous patterns of the prior art. The protuberances may be generally parallel, or may provide individual cells within the deflection conduits between the protuberances. Also disclosed is the paper made on such a secondary belt.

Description: FIELD OF THE INVENTION The present invention relates to a macroscopically monoplanar apparatus, such as a belt, used for making cellulosic fibrous structures, such as paper. Particularly this invention relates to such apparatus used in a through-air drying process for making cellulosic fibrous structures, and more particularly to an apparatus having a particular pattern thereon which imparts properties to the paper in a like pattern. A filter belt for aqueous suspensions according to the preamble of claim 1 is known from FR-A-1 148 810. However, in this belt the protuberances forming a semicontinuous patterned framework run strictly parallel to the cross machine direction. BACKGROUND OF THE INVENTION Cellulosic fibrous structures, such as paper, are well known in the art. For example, cellulosic fibrous structures are a staple of every day life and are found in facial tissues, toilet tissue, and paper toweling. One advancement in the art of cellulosic fibrous structures is cellulosic fibrous structures having multiple regions. A cellulosic fibrous structure is considered to have multiple regions when one region of the cellulosic fibrous structure differs in either basis weight, density, or both from another region of the cellulosic fibrous structure. Multiple regions within a cellulosic fibrous structure can provide several advantages, such as economization of materials, increasing certain desirable properties and decreasing certain undesirable properties. However, the apparatus used to manufacture the multiple region cellulosic fibrous structure will greatly influence these properties. Specifically a secondary belt, or comparable other apparatus, can affect the properties imparted to the cellulosic fibrous structure. As used herein, a "secondary apparatus" or a "secondary belt" refers to an apparatus or a belt, respectively, having an embryonic web contacting surface and which is used to carry or otherwise process an embryonic web of cellulosic fibers after initial formation in the wet end of the papermaking machinery. A secondary belt may include, without limitation, a belt used for molding an embryonic web of the cellulosic fibrous structure, a through-air drying belt, a belt used to transfer the embryonic web to another component in the papermaking machinery, or a backing wire used in the wet end of the papermaking machinery (such as a twin-wire former) for purposes other than initial formation. An apparatus or belt according to the present invention does not include embossing rolls, which deform dry fibers after fiber-to-fiber bonding has taken place. Of course, a cellulosic fibrous structure according to the present invention may be later embossed, or may remain unembossed. As an example of how a secondary belt may input specific properties to a cellulosic fibrous structure, a wet molded and through-air dried cellulosic fibrous structure made on a secondary belt according to Figure 4 of commonly assigned U.S. Patent 4,514,345 issued April 30, 1985 to Johnson, et al. may experience less curling at the edges than a cellulosic fibrous structure made on a secondary belt according to commonly assigned U.S. Patent 4,528,239 issued July 9, 1985 to Trokhan. Conversely, a cellulosic fibrous structure made on a secondary belt according to the aforementioned Trokhan patent may have a greater burst strength than a cellulosic fibrous structure made on a secondary belt according to Figure 4 of the aforementioned Johnson, et al. patent. This difference in performance relative to properties such as absorbency and burst strength may be attributed to the pattern of the drying belt used in wet molding and the through-air drying process to make the respective cellulosic fibrous structures. A cellulosic fibrous structure made on a secondary belt according to Figure 4 of the aforementioned Johnson, et al. patent will have discrete high density regions and essentially continuous low density regions. Conversely, a cellulosic fibrous structure made on a secondary belt according to the aforementioned Trokhan patent will have continuous high density regions and discrete low density regions. This difference in the pattern of the regions influences other properties of the respective cellulosic fibrous structures as well. For example, a cellulosic fibrous structure made on a belt according to the aforementioned Trokhan patent may have a lower cross machine direction modulus of elasticity and may have greater cross machine direction extensibility than a cellulosic fibrous structure made on a belt according to the aforementioned Johnson, et al. patent. However, these properties are typically offset by less sheet shrinkage and edge curling in a cellulosic fibrous structure made on a belt according to the aforementioned Johnson, et al. patent. The caliper of certain cellulosic fibrous structures is closely related to the crepe pattern caused by the impact angle of the doctor blade. The doctor blade is used to remove the cellulosic fibrous structure from the surface of a heated Yankee drying drum and to crepe the cellulosic fibrous structure by foreshortening it in the machine direction. However, maintaining constant material properties (such as machine direction extensibility), which properties are influenced by the doctor blade is difficult. This difficulty is encountered because the doctor blade wears over time. Such wear is rarely constant over time, due to the taper of the blade and the stiffness of the blade changing as a third order power when wear occurs. Furthermore, the wear and changes which occur on one papermaking machine utilizing a particular doctor blade are often totally different than the wear and changes which occur on another papermaking machine using an identical doctor blade. As the doctor blade wears, and the impact angle between the doctor blade and the Yankee drying drum becomes smaller, the cellulosic fibrous structure typically becomes softer, but loses tensile strength. Also, as the impact angle becomes smaller due to wear, the cellulosic fibrous structure may have greater caliper. Conversely, as the impact angle between the doctor blade and the surface of the Yankee drying drum becomes greater, such as occurs when the bevel angle of the doctor blade is increased, the doctor blade will typically wear at a faster rate. But, the situation is even more complicated than described above. Not all secondary belts produce cellulosic fibrous structures which respond alike to changes in the impact angle of the doctor blade. For example, a cellulosic fibrous structure through air dried on a belt made generally in accordance with the teachings of commonly assigned U.S. Patent 3,301,746 issued January 31, 1967 to Sanford, et al. shows an increase in caliper as the doctor blade impact angle is decreased. However, the caliper generated on a cellulosic fibrous structure made on a secondary belt according to the aforementioned Sanford, et al. patent is not as great as the caliper of a like cellulosic fibrous structure made on a secondary belt according to the aforementioned Trokhan patent. But a disadvantage to the aforementioned Trokhan patent is that a cellulosic fibrous structure made thereon does not show a correlation to the doctor blade impact angle. Thus, one skilled in the art is forced to select between greater caliper generation and control of the caliper (and other properties) by adjusting the doctor blade. Furthermore, wear of the doctor blade and the associated changes in impact angle cause different effects in cellulosie fibrous structures, which effects depend upon the pattern of the protuberances in the secondary belt. A cellulosic fibrous structure made on a belt having discrete protuberances will increase in caliper as the doctor blade wears, if the blade impact angle is not adjusted to compensate. Conversely, a cellulosic fibrous structure made on a secondary belt having a continuous pattern of protuberances is less sensitive to such wear. It is not surprising that considerable effort has-been expended in the prior art to achieve constant material properties by adjusting the impact angle of the doctor blades. In one example, illustrated by commonly assigned U.S. Patent 4,919,756 issued April 24, 1990 to Sawdai, the doctor blade is continually adjusted to minimize the effects of doctor blade wear on the material properties of the cellulosic fibrous structure. However, adjusting the doctor blade requires more equipment, associated maintenance, and set-up time for the papermaking machinery than machinery which simply tolerates changes in the doctor blade impact angle. While, of course, it is desirable to produce paper having certain consumer desired properties, the art clearly shows a need for greater flexibility in the manufacturing process, and particularly a way to achieve greater flexibility by not having to adjust the doctor blade impact angle using complex machinery. More importantly, the prior art shows a need for a secondary belt which generates relatively high caliper yet responds to changes in the impact angle of the doctor blade with like changes in the caliper of the cellulosic fibrous structures dried thereon. As noted above, one way to achieve greater caliper is by adjusting the doctor blade. Another way to increase the caliper of a cellulosic fibrous structure having multiple regions is to increase its basis weight. However, this arrangement also increases the basis weight of other regions in which it may not be desirable to do so, requires greater utilization of fibers, and increases the cost to the consumer. With the present invention, a way has been found to decouple the relationship between the Z-direction extent of the protuberances and the caliper of the cellulosic fibrous structure. Furthermore, other properties of the cellulosic fibrous structure may benefit from having been made on a secondary belt according to the present invention. For example, another problem frequently encountered with cellulosic fibrous structures which try to minimize fiber utilization and present less expense to the consumer is pinholing. Pinholing occurs when regions of the cellulosic fibrous structure are deflected into the deflection conduits of the secondary belts and break through, so that an opening is present and light passes through the opening. Pinholing and transmission of light therethrough present a cellulosic fibrous structure having a less durable and lower quality appearance to the consumer, and is accordingly undesirable to the consumer. One cause of pinholing in a cellulosic fibrous structure made on a belt according to the aforementioned Trokhan patent is caliper generation resulting from protuberances which are too great in the Z-direction. By generating caliper in this manner, Z-direction deflection of the cellulosic fibrous structure occurs to an extent that pinholing results. Thus, one using the aforementioned Trokhan belt is forced to select between caliper generation and reduced pinholing. Other problems found in cellulosic fibrous structures made on a belt according to the aforementioned Trokhan belt of the prior art are cross machine direction shrinkage and curling of the edges of the cellulosic fibrous structure. Such shrinkage and curling are caused by structural movement during machine direction tensioning, such as inevitably occurs during winding and converting. Shrinkage requires a wider cellulosic fibrous structure for manufacture. Edge curling may cause fold over, leading to breakage of the web during manufacture. Both cause greater expense in the manufacturing process. Unfortunately, the amount of shrinkage is also closely related to the amount of cross machine direction extensibility the cellulosic fibrous structure will undergo before rupture. While relatively greater cross machine direction extensibility is highly desired, due to allowing the cellulosic fibrous structure to elastically deform without tearing or shredding in use, the penalty for such desired cross machine direction extensibility is paid for at the time of manufacture by encountering greater cross machine direction shrinkage and curling. Accordingly, it is an object of this invention to provide a secondary apparatus or belt which reduces occurrences of pinholing and shrinkage and curling of cellulosic fibrous structures during manufacture. It is an object of this invention to provide a secondary apparatus or belt which reduces occurrences of pinholing without requiring a corresponding reduction in the caliper of the cellulosic fibrous structure manufactured thereon. Furthermore, it is an object of the present invention to provide greater control over the caliper of the cellulosic fibrous structure with the impact angle of the doctor blade. BRIEF SUMMARY OF THE INVENTION The invention comprises a macroscopically monoplanar apparatus used in manufacturing a cellulosic fibrous structure and having two mutually orthogonal principal directions, namely a machine direction and a cross machine direction, said apparatus comprising a reinforcing structure and a semicontinuous patterned framework of protuberances joined to the reinforcing structure and extending outwardly therefrom to define deflection conduits between said protuberances. Now the invention - according to claim 1 - is characterised in that semicontinuous patterned framework of protuberances (20) forms a parallel pattern running diagonally relative to the machine and cross machine directions. BRIEF DESCRIPTION OF THE DRAWINGS While the Specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the same will be better understood by the following Specification taken in conjunction with the associated drawings in which like components are given the same reference numeral, and: Figure 1 is a top plan view of a secondary belt according to the present invention having parallel protuberances with parallel deflection conduits therebetween, the protuberances and deflection conduits being oriented at a diagonal relative to the machine direction and the cross machine direction; and Figure 2 is a vertical sectional view taken along lines 2-2 of Figure 1. DETAILED DESCRIPTION OF THE INVENTION The invention comprises an apparatus for manufacturing a cellulosic fibrous structure. The apparatus according to the present invention may be embodied in a variety of forms, such as rotating drums for continuous processing and preferably endless belts 10 for ordinary papermaking machinery as illustrated in Figure 1. Although these, and other,-embodiments of the present invention are suitable, except as noted below, the preferred embodiment of the endless belt 10 is the embodiment discussed below with the understanding that other embodiments may be readily carried out by one skilled in the art. The preferred endless belt 10 embodiment of an apparatus according to the present invention comprises two primary elements: a patterned framework of protuberances 20 and a reinforcing structure 30. The reinforcing structure 30 of the belt 10 has two opposed major surfaces. One major surface is the paper contacting side 32 and from which the protuberances 20 extend. The other major surface of the reinforcing structure 30 of the papermaking belt 10 is the backside 34, which contacts the machinery employed in a typical papermaking operation. Machinery employed in a typical papermaking operation include vacuum pickup shoes, rollers, etc., as are well known in the art and will not be further discussed herein. Generally, for a belt 10 according to the present invention, the "machine direction" of the belt 10 is the direction within the plane of the belt 10 parallel to the principal direction of travel of the cellulosic fibrous structure during manufacture. The machine direction is designated by arrows "MD" in Figure 1. The cross machine direction is generally orthogonal the machine direction and also lies within the plane of the belt 10. The Z-direction is orthogonal both the machine direction and cross machine direction and generally normal to the plane of the belt 10 at any position in the papermaking process. The machine direction, cross machine direction, and Z-direction form a Cartesian coordinate system. The belt 10 according to the present invention is essentially macroscopically monoplanar. As used herein a component is "macroscopically monoplanar" if such component has two very large dimensions in comparison to a relatively small third dimension. The belt 10 is essentially macroscopically monoplanar in recognition that deviations from absolute planarity are tolerable, but not preferred, so long as the deviations do not adversely affect the performance of the papermaking belt 10 in making cellulosic fibrous structures thereon. In a rotating drum embodiment of the present invention (not shown), the reinforcing structure 30 may comprise a generally cylindrical shell having a plurality of holes therethrough. In a papermaking belt 10 embodiment, the reinforcing structure 30 comprises a series of filaments, preferably woven in a rectangular pattern to define interstices therebetween. The interstices allow fluids, such as drying air, to pass through the belt 10 according to the present invention. The interstices form one of the groups of openings in the papermaking belt 10 according to the present invention, which openings are preferably smaller than those defined by the pattern of the framework. If desired, the reinforcing structure 30 may have vertically stacked machine direction filaments to provide increased stability and load bearing capability. By vertically stacking the machine direction filaments of the reinforcing structure 30, the overall durability and performance of a belt 10 according to the present invention is enhanced. The reinforcing structure 30 should not present significant obstruction to the flow of fluids, such as drying air therethrough and, therefore, should be highly permeable. The permeability of the reinforcing structure 30 may be measured by the airflow therethrough at a differential pressure of about 127,5 Pa (1.3 centimeters of water or 0.5 inches of water). A preferred reinforcing structure 30 having no framework of protuberances 20 attached thereto should have a permeability at this differential pressure of about 240 to 490 standard cubic meters per minute per square meter of belt 10 area (800 to 1,600 standard cubic feet per minute per square foot). Of course, it will be apparent that the permeability of the belt 10 will be reduced when the framework of protuberances 20 is attached to the reinforcing structure 30. A belt 10 having a framework of protuberances 20 preferably has an air permeability of about 90 to 180 standard cubic meters per minute per square meter (300 to 600 standard cubic feet per minute per square foot). In an alternative embodiment, the reinforcing structure 30 of a belt 10 according to the present invention may have a textured backside 34. The textured backside 34 has a surface topography with asperities to prevent the buildup of papermaking fibers on the backside 34 of the belt 10, reduces the differential pressure across the belt 10 as vacuum is applied thereto during the papermaking process, and increases the rise time of the differential pressure prior to the maximum differential pressure occurring. A particularly preferred reinforcing structure 30 for use with the present invention may be made in accordance with the teachings of commonly assigned U.S. Patent 5,098,522 issued March 24, 1992 to Smurkoski, et al. which patent shows how to make a particularly preferred reinforcing structure 30 suitable for use with a papermaking belt 10 in accordance with the present Invention and showing a process for making cellulosic fibrous structures using such a papermaking belt 10. The other primary component of the papermaking belt 10 according to the present invention is the patterned framework of protuberances 20. The protuberances 20 define deflection conduits 40 therebetween. The deflection conduits 40 allow water to be removed from the cellulosic fibrous structure by the application of differential fluid pressure, by evaporative mechanisms, or both when drying air passes through the cellulosic fibrous structure while on the papermaking belt 10 or a vacuum is applied through the belt 10. The deflection conduits 40 allow the cellulosic fibrous structure to deflect in the Z-direction and generate the caliper of and aesthetic patterns on the resulting cellulosic fibrous structure. The protuberances 20 are arranged in a semicontinuous pattern. As used herein, a pattern of protuberances 20 is considered to be "semicontinuous" if a plurality of the protuberances 20 extends substantially throughout one dimension of the apparatus, and each protuberance 20 in the plurality is spaced apart from adjacent protuberances 20. The protuberances 20 in the semicontinuous pattern are generally parallel as illustrated in Figure 1 and run diagonally relative to the machine and cross machine directions. Of course, the direction of the protuberance 20 alignment discussed above refers to the principal alignment of the protuberances 20. Within each alignment, the protuberance 20 may have segments aligned at other directions, but aggregate to yield the particular alignment of the entire protuberance 20. Protuberances 20 arranged in a framework having a semicontinuous pattern are to be distinguished from a pattern of discrete protuberances 20, in which any one protuberance 20 does not extend substantially throughout a principal direction of the papermaking belt 10. An example of discrete protuberances 20 is found at Figure 4 of commonly assigned U.S. Patent 4,514,345 issued April 30, 1985 to Johnson, et al. Similarly, a pattern of semicontinuous protuberances 20 is to be distinguished from protuberances 20 forming an essentially continuous pattern. An essentially continuous pattern extends substantially throughout both the machine direction and cross machine direction of the papermaking belt 10, although not necessarily in a straight line fashion. Alternatively, a pattern may be continuous because the framework forms at least one essentially unbroken net-like pattern. Examples of protuberances 20 forming an essentially continuous pattern is illustrated by Figures 2-3 of the aforementioned U.S. Patent 4,514,345 issued to Johnson, et al or by the aforementioned U.S. Patent 4,528,239 issued to Trokhan. As illustrated in Figure 2, the framework of semicontinuous protuberances 20 according to the present invention is joined to the reinforcing structure 30 and extends outwardly from the paper contacting side 32 thereof in the Z-direction. The protuberances 20 may have straight sidewalls, tapered sidewalls, and be made of any material suitable to withstand the temperatures, pressures, and deformations which occur during the papermaking process. Particularly preferred protuberances 20 are made of photosensitive resins. The photosensitive resin, or other material used to form the pattern of semicontinuous protuberances 20, may be applied and joined to the reinforcing structure 30 in any suitable manner. A particularly preferred manner of attachment and joining is applying liquid photosensitive resin to surround and envelop the reinforcing structure 30, cure the portions of the liquid photosensitive resin which are to form the semicontinuous pattern of the protuberances 20, and wash away the balance of the resin in an uncured state. Suitable processes for manufacturing a papermaking belt 10 in accordance with the present invention are disclosed in the aforementioned U.S. Patent 4,514,345 issued to Johnson, et al., commonly assigned U.S. Patent 4,528,239 issued July 9, 1985 to Trokhan, and the aforementioned U.S. Patent 5,098,522 issued to Smurkoski, et al., each of which patents shows a particularly preferred manner of forming the protuberances 20 and joining the protuberances 20 to the reinforcing structure 30. As is evident from a reading of any of the three aforementioned patents, the pattern of the protuberances 20 is determined by transparencies in a mask through which an activating wave length of light is passed. The activating light cures portions of the photosensitive resin opposite the transparencies. Conversely, the portions of the photosensitive resin opposite the opaque regions of the mask are washed away, leaving the paper contacting side 32 of the reinforcing surface exposed in such areas. Thus, to form a particularly preferred embodiment of a papermaking belt 10 according to the present invention, the mask must be formulated with transparent regions having a semicontinuous pattern as described above. Such a mask will form a like pattern of protuberances 20 on the papermaking belt 10. For the embodiment described herein, protuberances 20 forming a semicontinuous pattern should have characteristics which produce desired properties of the cellulosic fibrous structures. The geometry of the protuberances 20 significantly influences the properties of the resulting cellulosic fibrous structure made on the secondary belt 10. For example, the protuberances 20 may produce hinge lines in the cellulosic fibrous structure, which hinge lines impart softness or burst strength thereto. Furthermore, the semicontinuous pattern of protuberances 20 will yield a like semicontinuous pattern of high and low density regions in the cellulosic fibrous structure made on this belt 10. Such a pattern in the resulting cellulosic fibrous structure occurs for two reasons. First, the regions of the cellulosic fibrous structure coincident the semicontinuous deflection conduits 40 will be dedensified by the air flow therethrough or will be dedensified by the application of a vacuum to the deflection conduits 40. Preferably, the regions of the cellulosic fibrous structure coincident the protuberances 20 will be densified by the transfer of the cellulosic fibrous structure to a rigid backing surface, such as a Yankee drying drum. The geometry of the protuberances 20 may be considered in a single direction, or may be considered in two dimensions, and may be considered as either lying within or normal to the plane of the secondary belt 10 according to the present invention. Particularly, the Z-direction extent of the protuberances 20 in a single direction normal to the plane of the belt 10 determines the height of the protuberances 20 above the paper contacting surface of the reinforcing structure 30. 'If the height of the protuberances 20 is too great, pinholing and apparent transparencies or light transmission through the cellulosic fibrous structure will occur. Conversely, if the Z-direction dimension of the protuberances 20 is smaller, the resulting cellulosic fibrous structure will have less caliper. As noted above, both pinholing and low caliper are undesirable because they present an apparently lower quality cellulosic fibrous structure to the consumer. For the embodiments described herein, the protuberances 20 preferably have a height between 0.05 and 0.64 millimeters (0.002 and 0.025 inches), preferably between 0.13 and 0.38 millimeters (0.005 and 0.015 Inches), and more preferably between 0.20 and 0.26 millimeters (0.008 and 0.010 inches). Referring back to Figure 1 and continuing the single direction analysis, the spacing between inwardly facing edges of adjacent protuberances 20 must be considered. If, within limits, the spacing is too great for a given Z-direction extent, pinholing is more likely to occur. Also, if the spacing between the inwardly facing edges of adjacent protuberances 20 is too great, another undesired resultant phenomenon may be that fibers will not span the distal ends 46 of adjacent protuberances 20, resulting in a cellulosic fibrous structure having lesser strength than can be obtained if individual fibers span adjacent protuberances 20. Conversely, if the spacing between the inwardly facing edges of adjacent protuberances 20 is too small, the cellulosic fibers will bridge adjacent protuberances 20, and in an extreme case little caliper generation will result. Therefore, the spacing between the inwardly facing surfaces of adjacent protuberances 20 must be optimized to allow sufficient caliper generation to occur and minimize pinholing. For the embodiments described herein, the inwardly facing surfaces of adjacent protuberances 20 may be spaced about 0.64 to about 1.40 millimeters apart (0.025 to 0.055 inches) in a direction generally orthogonal to such surfaces. This spacing will result in a cellulosic fibrous structure which generates maximum caliper when made of conventional cellulosic fibers, such as Northern softwood kraft or eucalyptus. A further single dimension analysis relates to the width across the distal edge of the protuberance 20. The width is measured generally normal to the principal dimension of the protuberance 20 within the plane of the belt 10 at a given location. If the protuberance 20 is not wide enough, the protuberance 20 will not withstand the pressures and temperature differentials encountered during and incidental to the papermaking process. Accordingly, such a papermaking belt 10 will have a relatively short life and have to be frequently replaced. If the protuberances 20 are too wide, a more one-sided texture will again result and the cell size, discussed below, must be increased to compensate. Of course, it is to be recognized' that the protuberances 20 are typically tapered and may occupy a greater projected surface area at the proximal edge of the protuberance 20. For the embodiments described herein, typically the proximal area of the protuberances 20 is about 25 to 75 percent of the belt 10 surface area and the distal area of the protuberances 20 is about 15 to 65 percent of the belt 10 surface area. Generally, for the embodiment described herein, protuberances 20 having a width at the proximal ends of about 0.3 to 1.3 millimeters (0.011 to 0.050 inches) are suitable. The protuberances 20 may have a width at the distal ends 46 of about 0.13 to 0.64 millimeters (0.005 to 0.025 Inches), and preferably may have a width at the distal ends 46 of about 0.20 to 0.46 millimeters (0.008 to 0.018 inches). All of the protuberances 20 are generally nonintersecting. The protuberances 20, illustrated in Figure 1, are generally parallel (although not necessarily straight) protuberances 20. These protuberances 20 have generally equal spacings in the deflection conduits 40 therebetween. In an alternative embodiment of the invention, the belt 10 having a semicontinuous pattern of protuberances 20 and semicontinuous pattern of deflection conduits 40 may be used as a forming wire in the wet end of the papermaking machine. When such a belt 10 is used as a forming wire in the papermaking machine, a cellulosic fibrous structure having regions of at least two mutually different basis weights will result. The at least two mutually different basis weights in the cellulosic fibrous structure are aligned diagonally to the machine direction and the cross machine direction. It is recognized that many variations and combinations of patterns, protuberance 20 sizes, and spacings may be made within the scope of the present invention. All such variations are within the scope of the following claims.

Claims: A macroscopically monoplanar apparatus used in manufacturing a cellulosic fibrous structure and having two mutually orthogonal principal directions, namely a machine direction (MD) and a cross machine direction (CD), said apparatus comprising a reinforcing structure (30) and a semicontinuous patterned framework of protuberances (20) joined to the reinforcing structure (30) and extending outwardly therefrom to define deflection conduits (40) between said protuberances (20), characterised in that semicontinuous patterned framework of protuberances (20) forms a parallel pattern running diagonally relative to the machine and cross machine directions. An apparatus according to claim 1 characterised in that the framework of protuberances (20) comprises photosensitive resin. An apparatus according to either of claims 1 or 2 characterised in that the protuberances (20) span the entire cross machine direction of the apparatus (10).

Inventors: AYERS PETER GRAVES, HENSLER THOMAS ANTHONY, TROKHAN PAUL DENNIS, AYERS, PETER, GRAVES, HENSLER, THOMAS, ANTHONY, TROKHAN, PAUL, DENNIS
Applicants: PROCTER & GAMBLE, THE PROCTER & GAMBLE COMPANY
Application year: 1993
Main classification: D21F11
IPC codes: D21F11