MXPA95000627A - Computed system to simulate the formation of paper sheets and the appearance of the impression - Google Patents

Abstract

The present invention relates to a system for simulating the formation of a fibrous sheet comprising. a plurality of databases having means for storing parameters related to sheet formation, a configuration base having means to relate the input data in said plurality of databases, means for interactively obtaining said input data from a user, means to simulate, adapted to interact with said configuration base to produce at least one simulation of at least a portion of a sheet, means to display said at least one simulation

Description

"COMPUTED SYSTEM TO SIMULATE THE FORMATION OF PAPER SHEETS AND THE APPEARANCE OF PRINTING ON IT" INVENTORIES: ROGER DANBY ALAIN BOUCHARD NATIONALITY: CITIZENS CANADI ENSES RESIDENCE: 143 RUSELL STREET ARNPRIOR, ONTARIO CA AD 1000-206 BRIGHTHURST DRIVE RALEIGH, NC E U A OWNER: HUYCK LICENSCO, INC.

NATIONALITY: NORTH AMERICAN SOCIETY RESIDENCE: WILMINGTON, DEL. E U A FIELD OF THE INVENTION The present invention relates to a computerized system for simulating the formation of a fibrous sheet and printing on it.

DEFINITIONS A fiber is matter, natural or synthetic, of any size, shape or weight that can be used to produce a sheet of matter. The water paste includes any liquid-fiber mixture. A fibrous sheet or paper, includes any material which is formed with watery paste. A machine for making paper is any machine that accepts slurry and produces a fibrous sheet of any thickness, weight, gradation, density, porosity. A simulated representation includes any image which is virtual, one-dimensional, multidimensional, digital, numerical or graphic, and exhibits characteristics that the image would possess if physically modeled.

BACKGROUND OF THE INVENTION The goal of improving the quality of paper is shared by those in the pa-pei manufacturing industry. The experience allows many paper manufacturers to estimate what is needed to produce a desirable sheet of paper with improved quality. Either way, with many samples of slurry that now involve the use of recycled materials, other natural materials, and newly developed synthetic fibers, and with many new meshes and machines emerging continuously, the papermaking industry is considering methods unknown by means of which to make paper of improved quality. Instead of that opportunity, the risk of the increase in costs becomes apparent. Not all of these new methods produce an acceptable output, and some methods are not worth the expense of experimentation. For example, some slurry samples may have fibers of too short a length to be used with a certain mesh. Similarly, some machines produce lower quality sheets when used with a watery paste and / or incompatible meshes. Without incurring expensive test runs, the industry currently lacks a method to determine the quality that a final sheet possesses. if it were used with a new combination of water paste, mesh and machine. The need to determine the final quality of the paper is particularly great for those involved in supplying paper for printing applications. In such a sand, it is important that the quality of the final sheet is suitable for printing. The printer can control the degree of ink absorption that occurs on the sheet during the printing process, by controlling the mixture and viscosity of the ink itself. In any case, for any pass through the printing press, the quality of the final print will be directly related to the degree of absorption of the ink from one area of the sheet to the other. This degree of absorption and the degree to which the ink penetrates the sheet is controlled by the density of the area of the sheet on which the ink solution is deposited. The differences in density on paper, if they are large, often make the sheet lumpy or 'numb', as can be seen when looking through the sheet, which affects the appearance of the print to through a simple sheet. The design of the distribution head used in the machine and its performance have the greatest effect on the density of the blade. This, in combination with the turbulence created by the main stationary elements they dte the final formation of the sheet on a large scale. Additionally, the wire marks on the final sheet caused by the structure of the formation mesh on which the sheet was produced, explain the finer levels of density differences in the paper. In order to determine the differences in density, the paper manufacturer must analyze the final product after it is produced in the machine or after it stops through the printing phase. Such a method for determining density variations is often expensive and does not provide a clear indication of where the problem lies. The paper manufacturer must modify separately variables such as slurry, meshes and even the used machine, until the perfect formation is achieved for a uniform density. This also increases the cost incurred by the paper manufacturer, which is eventually transferred to the consumer.

SUMMARY OF THE INVENTION It is therefore an object of the invention to simulate the formation of a sheet of paper so that a user is allowed to see the quality of the paper prior to the manufacture thereof.

It is also an object of the invention to implement the production of paper and the printing on it, by allowing the user to see a simulation of a final sheet of printed paper and modify according to the quality of the data, the parameters configured for get the sheet. It is yet another object of the invention to determine the percentage of fibers of a dispensing head paste which has been retained on a sheet of paper. It is still another object of the invention to determine the distribution of fibers on a sheet of paper. It is also another object of the invention to determine density variations within a sheet of paper. It is yet another object of the invention to determine the characteristics of the surface of a paper sheet. It is yet another object of the invention to determine the structure of a sheet of paper. It is also another object of the invention to determine the uniformity of brightness provided by the ink on a sheet of paper. It is a further object of the invention to determine the degree of penetration of the ink into a sheet of paper. It is a final object of the invention to determine the degree of penetration of the ink through a sheet of paper . These and other objects of the invention are carried out by a computerized system to simulate the production of a sheet of paper. The interactive system is adapted to receive input parameters related to a type of desired distribution head paste, the mesh on which the paper will be formed, together with the papermaking machine and the desired printing process, so that a simulation of the formation of a sheet of paper is provided together with the print quality provided by it. The data related to the actual production of paper are configured with the other fixed parameters so as to simulate a series of fibers that are deposited on the surface of the mesh, so that a determination is made as to whether there is sufficient support for it. that each fiber be retained. After it has been simulated that a sufficient amount of fiber has been deposited on the mesh creating a fibrous mesh of the same weight and the same density differences as the desired final product, a final sheet of paper is considered finished and a Report about the characteristics of the sheet is generated. The user is then provided with data concerning the retention of fiber, a representation of the simulated sheet together with its density, surface characteristics and structure. The system ma, adapted to accept data related to the type of printing process, configures said data with those previously entered, so that a simulation of ink is provided by printing on the simulated sheet. The user therefore has a visual output representative of the quality that a final sheet of physical paper would possess after manufacturing and printing.

Figure 1 shows a block diagram of the hardware (physical elements) of the system. Figure 2A shows a flow chart that describes the steps that the software executes (programs) while acquiring and processing information. Figure 2B shows a flow diagram that also describes the steps that the software performs during the simulation. Figure 3A shows the simulated three-dimensional workspace created by the system memory. Figure 3B shows a top view of the place where the fiber is deposited with respect to a drainage function. Figure 3C shows a plan view of the place where a fiber is deposited with respect to a func- drainage and support points. Figure 4 shows an example of a representation generated after a simulation application. Figure 5 shows an example of a report generated after a simulation application, particularly after the simulated paper has been printed.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 illustrates a block diagram of the hardware (physical elements) used in the system of the present invention. The program preferably operates on an IBM 2-compatible PC computer with a data entry keypad, with an 80486 processor at 25 Mhz or higher, which has an extended memory of 4 Mb. The simulation program runs under MS-WINDOWS 3.1 ™, an extended graphic program produced by Microsoft Corporation, with the code preferably written with Object-Oriented Programming in Turbo Pascal for WINDOWS ™. The program accepts input from several units. A Kajaani FS-200 Fiber Length Analyzer ™, produced by Kajaani Automation, a member of the Valmet Automation Group, to be described in more detail later, provides data concerning slurry paste 1 or sample. of paper 8 used in the simulation application. 1 o Additionally, the system may comprise a scanner / digitizer 6 for entering the topography of the mesh surface to be used in the analysis, when accepting a photograph 8 or sheet of paper 10 presenting it. Additionally, a work station 12 is provided where the user enters the necessary parameters for the simulation application one of these are the characteristics of the mesh 14 on which the paper will be formed, so that solid molding can be carried out if required. The display monitor 16 to provide the simulated sheet must be VGA compatible, and an ouse (mouse) or some other type of pointer is also useful. Peripheral devices such as a printer 17 for making prints or transparencies, and a modem 18 for transmitting the results to another database or to personnel located in the field, can be used. Although such hardware (physical configuration) and programming language are preferable, those skilled in the art may employ other products which perform the same functions without departing from the scope of the present invention. The program requires the user to enter the necessary parameters for the simulation, from the IBM PC 2 computer and in some cases from the workstation 12. Once such parameters have been entered and the program is running, the computer 2 will generate a report, allowing the display monitor to provide the user with an image of the formation of sheets of paper, along with many of the characteristics of the final sheet, including the appearance of the print on it. Additionally, the user can obtain a paper print of the report of the printer 17. Figure 2a describes the programming sequence that operates on the system hardware. As shown in block 20 the system is first initialized and the main windows are built. Next, in block 22, the user is required to enter the type of paste sample for the distribution head to be used, and the specifications of the machine. With respect to the type of distribution head paste, the program accepts any sample of watery paste, whether pulp, fabric, corrugation media, thick paper, thinner paper or newspaper. Additionally, the user can introduce more than one type of slurry if the paper to be produced is formed by a machine with multiple or styled distribution heads. The fiber roughness parameter is also entered, and is set to be constant for all fibers in a sample of a distribution head. Therefore, the system assumes that each fiber in the sample has the same roughness. Once such data with respect to the distribution head paste is introduced, the total fiber length distribution is taken from that previously introduced for such watery paste by means of the Kajaani FS-200 ™ Fiber Length Analyzer (hereinafter 'Kajaani1), as described in block 4 of Figure 1. The Kajaani machine of the prior art 4, is an optical instrument that digitizes the lengths of the fibers in a particular waxy paste. Using a laser light source, this instrument is capable of carrying out rapid and reproducible measurements with an average resolution of 50 micrometers. An extremely sensitive detector measures the length of the fibers at a rate of up to 100 fibers per second. Furthermore, the instrument automatically determines the lengths of the fiber in the range of 0 to 7.2 mm, regardless of which is fixed. The slurry samples are obtained from the distribution head of a machine to be simulated and then tested with this instrument. The outputs with respect to the upper and lower limits of the length of the fibers, the arithmetic average, the total fibers in a sample of pulp for distribution head 1, length of fibers, and the percentage comprising such lengths in the all of the pasta for distribution head 1 are given. This data is transferred to the IBM-PC 2 computer in such a way that when the user enters the sample of dough for head of di- The desired distribution, the distribution of the fibers, which is the number of fibers of several increments in their length which form the whole of this paste for distribution head 1, is available for use in the formation of the sheet of paper. Other parameters regarding the shape of the fiber and its width are fixed in the system. Therefore, the fibers are configured as slat-like structures, which are 30 to 40 micrometers wide. Additionally, in block 22, the user is instructed to enter the mesh sample on which the paper will be formed. This can be done by sending a paper 8 or photograph 10 having the design of the mesh on it, through the scanner / digitizer 6. On the other hand, the workstation 12 can create, by solid molding, a plot according to the user's specifications. The frame designs that can be introduced are: single layer, double layer, double layer in 'X', triple layer or any hypothetical design in which the user can think. Single-layer meshes produce the roughest paper sheets that have the highest probability of non-uniform density due to less fiber retention and because of the protuberances and holes in the mesh. Triple-coated meshes are the most desirable as long as they provide a density sheet and eleven smoothness uniform. Whichever mode and mesh are chosen, the input is thus sent to the computer for use in the simulation application. Similarly, the user is encouraged to enter the specifications of the sheets such as the basis weight of the sheets, the graduation and anisotropy, which refers to the property of the direction of the fibers in the final sheet. The user is also indicated to enter the type of paper machine in which the paper is being manufactured. This may include a pulp machine, an endless wire mesh machine, twin cable formers, a weaving machine, and a hypothetical papermaking machine. The user can also introduce the printing process such as rotogravure, lithogravure, rotogravure or a hypothetical process. After all the above parameters have been entered, the system calculates the total length of the fiber from the Kajaani data, shown in block 23 of Figure 2b, and runs the simulation program, as shown in the blo-que 24. As shown in Figure 3A, when the program is run, a three-dimensional workspace 1 is created in memory. This workspace contains data with respect to the screen of the mesh 9, and the placement of fibers of watery paste with respect to it.

Referring now to Figure 2B, in a flow chart further describing the steps that the software performs during the actual simulation, it should be noted in block 40, a fiber is first randomly taken from the slurry sample defined by the Kajaani data. Next in block 42, the program selects the orientation of the fiber. Both orientation directions of the machine fiber and normal to the machine are selected either randomly or from a definable bell curve shape. The program then calculates where the next fiber will fall when it is deposited in block 44. The probability of where the fiber will be deposited is based on a function of draining the slurry through the forming mesh. This is a statistical function with changes every time a fiber lies through a hole in the formation mesh. Therefore, this function changes at the same time that a number of fibers create a fiber mesh, because when a fiber is retained over a hole in a forming mesh the dimensions of the hole are modified, so a single hole is transformed in two holes and so on. While each fiber is deposited, it creates holes of different sizes which must be registered for when subsequent fibers are deposited, since such holes change the support points.

The fiber is then deposited, as shown in block 46, where the location in which it is deposited is the most likely flow path around the mesh. Certain fibers when they are deposited will be supported by their center, others will be held by two points of contact on each side of their center of mass. This process is recorded during the simulation and can be reproduced later, or presented in the reports. In Figures 3B and 3C, the location of the fiber 3 is shown with reference to the drainage function of the slurry sample 5, and the support points 7. The support points 7, as mentioned above can be formed due to the weft of the mesh or the layer on the mesh created by fibers previously deposited. The user can also modify the degree of support to evaluate different conditions. Based on this hold or not. The determination of the retention of fiber takes into account the flexible nature of the fibers, since the length of the fiber is modified with a function that calculates the proportion of the fiber that must be supported so that it is retained. For example, a fiber may appear to be adequately supported for retention, but, the drainage function of the slurry with respect to the mesh, in combination with the fiber's flexibility, may cause the fiber to pass through a liquid. jero in the mesh. Therefore, the degree of support necessary for retention is determined. If the fiber is not retained, the block 48 determines that it has passed through the holes in the mesh with the remainder of the white water 49, and the program returns to block 40 where another fiber is chosen. If this is retained as shown in block 48, it is deposited in the mesh of the mesh to eventually form a mesh with the other fibers as shown in block 50. Returning to the program, in block 52, after a fiber has been deposited, the program determines if the sheet of paper is finished by corroborating whether the simulated sheet is equal to the specifications entered by the user for the sheet, such as the basis weight and the gradation. If the program determines that a sheet of paper has not been completed, the program returns to block 40 and a new fiber is chosen randomly from the supply of slurry. The previous sequence of the steps will be repeated until enough fiber has been deposited creating a fibrous mesh of the same base weight and graduation as the desired final product initially introduced by the user. At this point, the question of block 52 will be affirmative, that the sheet of paper has been formed. The final simulated sheet will have the same density differences, these being heavy areas of fiber over the holes and light areas on the protuberances of the mesh, as can be expected from a sheet formed on a real papermaking machine. Once the program determines that the sheet of paper is complete, the program calculates the retention of the first pass, as shown in block 54. This is determined by an average of the mass of fibers that are present in the sheet and of those retained, divided among those that were initially present in the paste for distribution equipment, as given by the data from the Kajaani. The higher the percentage retained, the better the quality of the paper sheet, as well as the probability that small holes or areas of low density is significantly low when a large number of fibers form the sheet. With respect to this determination, the user will be provided with the percentage of fibers that have been retained. Based on this information, the user will be able to modify in a subsequent simulation application: the sample of slurry, the mesh, the machine, and the specifications of the sheet, particularly if a large number of fibers are lost with white water . The results of a first iteration are saved in block 58 and the program returns to block 24 to run the program again. As shown in the block 24 in Figure 2A, other iterations such as a one-step iteration which provides the user with a table of the sheet, or repeated / multiple iterations which provide the user with cumulative blocks or multiple blocks that form the sheet, can be carried out. Similarly, an iteration to create a layered sheet formed by print heads stowed with multiple samples of slurry can be carried out. It should be noted that for the iteration of a layered sheet, the user is required to introduce more than one sample of slurry into block 22. Additionally, a twin wire iteration can be carried out, where two different types of meshes are used while the drainage is carried out on both sides of the sheet that is formed. For the twin wire iteration, the user, the user is required to enter two types of meshes in block 22. Once the desired iterations have been carried out, the run of the program ends and the results are used to prepare the output, as shown in block 60 of Figure 2B. At this point a report can be generated, when each location of the fiber that forms the simulated sheet contains matrix data associated with it, which provide the user with the ability to dissect the characteristics of the simulated sheet in many senses. tures, particularly shown in block 28 of Figure 2A. As shown in block 28 of Figure 2A, the user is provided with the ability to analyze and display; the portions of fiber that have been retained and those that have been lost, the distribution of the fiber portions, the density of the leaves, porosity, surface characteristics, structure of the sheets, penetration of the ink, holes, simulation of halftones and bilatera-lidad. With respect to the distribution of the fiber portions, the user will be provided with a display of a simulated sheet showing where the longest and the shortest fiber were deposited along with digital data representative of them. Additionally, the user is provided with density information to determine if the final sheet is of uniform or non-uniform density. Furthermore, a "through" view is provided, which has the same effect on the sheet as if it were held against the light. This view gives the user the ability to see variations in the den- sity and structure of the paper. Also with respect to the structure of the sheet, the user is also provided with the ability to reconstruct the sheet in strips. Similarly, uniformity, porosity and holes can be calculated and viewed. The holes, as well as variations in density are indicators of a lack of retention in certain areas, commonly due to a very short fiber length, or due to an error in the choice of mesh. The above features, determined in a test simulation application are shown in Figure 4. As shown in this illustration, the monitor 10 screen can be divided into as many windows as desired. In this illustration, the user selected four quadrants 100, 102, 104 and 106, with one of the quadrants 106 further divided into four quadrants 108, 110, 112 and 114. As shown in quadrant 100, the surface of the selected mesh is displayed so that the user can see how the mesh affects the final quality of the sheet surface as shown in quadrant 102. The density of the sheet is also shown, and it is important, since the user may wish to determine if Such a sheet can lend itself well for printing. Finally, in quadrant 106, the stages in which the fibers are deposited are shown. For example, in quadrant 108, we can see the final sheet of paper. In quadrant 110, the user sees the retention at the moment when the first 25% of the fibers have been deposited on the mesh. Next, in quadrant 112, the structure of the sheet when the percentage of the fibers that complete 75% of the sheet is displayed. Finally, in quadrant 114, the last 25% of the deposited fibers is displayed. Each quadrant provides an indication about fiber length, distribution, retention, orientation and density to name a few. Additionally, if the user would like to see how the ink would appear on the sheet of paper, the quality of the printing of said sheet is better evaluated. The user will be provided with presentations regarding the uniformity of the brightness in the simulated sheet along with the degree of penetration of the ink and if a penetration occurs through it. Provided additionally is the ability to see a printed sheet with simulation of halftones. A number of different screens are available for use in a printing process. Each screen has a grid with lines every inch, representing drops of ink per inch, which is programmed into the system. The most common is 100 lines per square inch, with the lines being lines of round holes, the diameter of which can be varied to control the total area covered by the hole against the settlement area. A hole that forms a screen controls the amount of ink that reaches the paper. The final result in the halftone area is that a drop of ink is transferred onto the surface of the paper sheet. So that the printer reproduces an equal quality, not only from one impression to the next, but also from a small area of the impression to the next, it is important for each half-tone point to penetrate to an equal degree with respect to all others. This therefore assumes that the user will be able to determine the correlation between the holes and the protuberances on the screen, so that the ink penetrates the areas of the sheet which will produce the most desirable print quality. For example, the density over each 'hole' in the sheet can be determined, then the degree of penetration of the ink can be simulated for that hole compared to any other. A simulation of droplet scattering can also be carried out. The combination of the two would then provide the user with the opportunity to predict the quality of the impression on each hole from the point of view of the penetration through the sheet, brightness and dispersion of the drops. The holes and large porosities will be indicative of penetration of the ink and penetration characteristics through it. Also the variation between holes can be simulated and the total effect of this variation can be determined with respect to the overall print quality. The above features, determined in a test simulation application, are shown in Figure 5. In this illustration, the user is provided with an ink penetration display with respect to the penetration through the sheet. As in Figure 4, the screen is divided into quadrants. In quadrant 200, the mesh used is shown for comparison with the sheet formed on it, which sheet is shown in the table 202. Since this is a print simulation, the print screen is also shown, as in quadrant 204. The user selected a grid of 50 lines per inch, which means that a row of 50 uniformly spaced ink droplets will equal one inch if measured along a 45 ° angle. Below in quadrant 206, it is evident that the simulated sheet exhibits some penetration through the sheet when it is subjected to a printing process. The user, once he analyzed the simulated sheet in any way he wishes, can return to block 22 and introduce different parameters with respect to a sample of slurry, a sample of the mesh, specifications of the sheet and specifications of the machine to improve the quality of the leaf, particularly the distribution of leaf density. If the user has finished, such results may be saved or eliminated, as shown in block 30. Although the invention has been particularly shown and described with reference to the modalities mentioned below, it must be understood by those skilled in the art.

In the art, various changes in form and detail can be made in it without departing from the spirit and extension of the invention. Therefore, any modification in the form, configuration and composition of the elements comprising the invention is within the scope of the present invention.

Claims (30)

2 NOVELTY OF THE INVENTION Having described the invention, it is considered as a novelty, and therefore it is claimed as established in the following: CLAUSES

1. A system for simulating the formation of a fibrous sheet comprising; a plurality of databases having means for storing parameters related to the formation of leaves, a configuration base that has means to relate the input data in said plurality of databases, means for interactively obtaining said input data from a user, means for simulating, adapted to interact with said configuration base to produce at least one simulation of at least a portion of a sheet, means to show said at least one simulation.

2. The system for simulating the formation of a leaf as described in Clause 1, said input data comprising the information with respect to at least one sample of watery paste.

3. The system for simulating the formation of a sheet as described in Clause 1, said input data comprises information related to at least one mesh on which said simulation of at least a portion of a sheet is formed.

4. The system for simulating the formation of a sheet as described in Clause 1, said input data comprises information related to at least one machine for the manufacture of paper.

5. The system for simulating the formation of a sheet as described in Clause 1, said input data comprises information related to at least one printing process.

6. The system for simulating the formation of a leaf as described in Clause 1, said means for simulating Furthermore, they have means for producing a simulation of at least a portion of a mesh sample.

7. The system for simulating the formation of a sheet as described in Clause 1, said means for simulation also have means to produce a simulation of at least a portion of a sheet having an impression on it.

8. The system for simulating the formation of a sheet as described in Clause 1, said simulation means also have means to produce a simulation of the density of said sheet.

9. The system for simulating the formation of a sheet as described in Clause 1, said means for simulation also have means to produce a simulation of the surface of said sheet.

10. The system for simulating the formation of a sheet as described in Clause 1, said means for simulation also have means to produce a simulation of a grid used to print said sheet.

11. The system to simulate the formation of a As described in Clause 1, said means for simulation also have means to produce a simulation of the penetration of the ink into said sheet.

12. A system to simulate the formation of a sheet of paper comprising: at least one database that contains rules that relate characteristics of papermaking to a sheet of paper, a computer, comprising means for interacting with said database, means for receiving an entry by a user, and means for processing said entry with said rules in such a way that simulation signals are generated, means for receiving said simulation signals and displaying a simulated representation of the formation of a sheet of paper.

13. The system for simulating the formation of a sheet of paper, as described in Clause 12, said at least one database additionally comprises data related to a plurality of different samples of paste for ca- distribution beads.

14. The system for simulating the formation of a sheet of paper, as described in Clause 12, said at least one database also comprises data related to a plurality of different meshes for training.

15. The system for simulating the formation of a sheet of paper as described in Clause 12, said at least one database also comprises data related to a plurality of different papermaking machines.

16. The system for simulating the formation of a sheet of paper as described in Clause 12, said at least one database further comprises data related to a plurality of different printing processes.

17. The system for simulating the formation of a sheet of paper as described in Clause 12 also comprises means for providing a paper printout of said simulated representation.

18. The system to simulate the formation of a sheet of paper as described in Clause 12 that also T1 comprises means for providing a transmission means for said simulation signals to a remote location.

19. The system to simulate the formation of a sheet of paper as described in Clause 12, said entry comprises at least one of the following parameters, samples of slurry, samples of meshes, machine for the manufacture of paper and printing process.

20. The system to simulate the formation of a sheet of paper as described in Clause 19, said simulation signals contain data related to the characteristics of the fibers that make up the sheet.

21. The system for simulating the formation of a sheet of paper as described in Clause 20, said simulation signals also contain data related to the distribution of the fibers in said sample of watery pulp which constitute the sheet.

22. The system for simulating the formation of a sheet of paper as described in Clause 20, said simulation signals also contain data related to the percentage of the fibers retained on said mesh sample.

23. The system for simulating the formation of a sheet of paper as described in Clause 20, said means for receiving said simulation signals and presenting them, also has means to present at least one of the following characteristics of the sheet: density, porosity, characteristics of the surface and structure.

24. A method to simulate the formation of a sheet of paper comprising: create at least one database that contains rules that relate characteristics for making paper to a sheet of paper, provide a computer to interact with said database, and to receive input from a user, processing said user input with said rules so that simulation signals are generated, provide simulation signals, display a simulated representation of the form- of a sheet of paper based on said simulation signals.

25. The method to simulate the formation of a sheet of paper as described in Clause 24, said entry also includes data related to the elements required to produce a sheet of paper.

26. The method to simulate the formation of a sheet of paper as described in Clause 24, said elements are between at least one of the following: a sample of slurry, a sample of mesh, a machine for the manufacture of paper, and a printing process.

27. The method to simulate the formation of a sheet of paper as described in Clause 26, which also includes: displaying an image of fibers in said slurry sample while said fibers create a sheet, and unfold an image of the final sheet.

28. The method to simulate the formation of a sheet of paper as described in Clause 26 that also compares it captures and provides a digital representation of a 4. distribution of fibers retained in said mesh sample.

29. The method for simulating the formation of a sheet of paper as described in Clause 26 which also comprises and provides a digital representation of the percentage of fibers retained on said mesh example.

30. The method for simulating the formation of a sheet of paper as described in Clause 24 which also comprises and provides a representation of at least one of the following characteristics of the sheet: density, porosity, surface characteristics, and structure. IN WITNESS WHEREOVER, I have signed the above description and claims of novelty as a proxy of HUYCK LICENSCO, INC., In Mexico City, Mexico on January 24, 1995. SUMMARY OF THE INVENTION To provide a simulation of the formation of a sheet of paper and the appearance of printing on it, a computerized system is adapted to receive input parameters related to a type of desired distribution head paste, the mesh over which the paper will be formed, the paper machine to be used, and the desired printing process. The data related to the actual production of paper are configured to simulate a series of fibers that are deposited on the surface of the mesh to create a layer on the mesh. After it has been simulated that a sufficient amount of fiber has been deposited on the mesh, creating a fibrous mesh, the system will indicate that a final sheet has been completed when it has the desired basis weight as initially entered by the user. . After a final sheet of paper is finished a report concerning the characteristics of the sheet is generated. The report provides the user with data related to fiber retention, a display of the simulated sheet along with its variations in density, surface characteristics, and structure. The system, adapted to accept data related to the type of printing process, configures said data with those previously introduced, and by this means see a simulation of printing with ink on the simulated sheet. The user therefore has a visual output representative of the final quality that a physical sheet of paper would possess after the manufacturing and printing on it.