JP7029498B2 - How to determine the characteristics of the fabric - Google Patents

Description

The present invention relates to characterizing the surface of a papermaking fabric (woven fabric). In certain examples, the invention relates to devices, methods, and systems for determining the properties of the contact surface of a fabric used to form a three-dimensional structure of a web in a papermaking process.

In the process of forming paper products such as tissue paper and paper towels, 3 while the paper web is still highly deformable, i.e., when the paper web has a high moisture content. Dimensional molding is performed. Often, this three-dimensional molding of the web takes place on a structuring fabric, which is a woven fabric. The fabric provides a contact surface consisting of knuckles in the threads of the fabric (the intersections where the warps intersect the wefts and are woven into the tissue and are exposed to the surface), and the pockets are between the knuckles. It is formed in the fabric. When the paper web is applied to the fabric, one part of the web touches the knuckle and the other part of the web is pulled into the pocket. Before being removed from the fabric, the web is dried to the extent that its shape is fixed or locked. Thereby, a dome is formed in the dry web, where the web is pulled into the pockets in the fabric, and the dome is present in the finished paper product. Therefore, the paper product has a unique three-dimensional structure partially formed by the knuckle and pocket properties of the structuring fabric.

Since the contact surface of the structuring fabric is directly related to the shape of the finished product, the selection of the structuring fabric is often based on the desired product shape. However, it is difficult to characterize the contact surface of the structuring fabric based on a simple visual inspection of the fabric. Fabric knuckles are easy to see, but it is difficult to accurately determine the size of the knuckles, it is difficult to determine the area of the pockets between the knuckles, and the paper web is pulled in during the papermaking process. It is often difficult to determine the depth of a pocket. So, for example, there are prior techniques that attempt to quantify the properties of the contact surface of a fabric using formulas based on the fabric's yarn parameters. However, it is often found that such formulas are not accurate enough to characterize the contact surface of the fabric so as to allow accurate predictions of the paper product structure that will be formed by the fabric. It has been issued. In addition, the contact area characteristics will often change as the fabric is run over the papermaking machine. For example, wear on the surface of the fabric will generally increase the length of the knuckle, thereby changing the composition that the fabric will provide on the web. Therefore, the formula for determining the contact surface properties applied to the initial fabric configuration does not necessarily apply to the fabric worn over time.

Therefore, it would be useful to provide a technique for accurately characterizing the contact area characteristics of the structuring fabric used in the papermaking process. Moreover, it would be useful to provide a technique that allows the fabric to be mounted on a papermaking machine while the contact area characteristics as the fabric wears over time can be easily determined.

U.S. Pat. No. 7,494,563 U.S. Pat. No. 6,350,336

According to the first aspect, the present invention provides a method of determining the characteristics of a fabric. The method is a step of forming a representation of a portion of the surface of the fabric, the representation of which is a knuckle within the surface of the fabric (the intersection where the warp intersects the weft and is woven into the tissue and is exposed to the surface). A step that indicates the location and size of the pocket and a step that produces an image of a portion of the surface of the fabric based on the representation, and at least a portion of the image on the screen associated with the computer with the processor. Includes a step to display and a step to outline around at least one of the knuckles in the displayed image. The method is the step of drawing a guideline in the displayed image, where the guideline (i) passes through the center of the contoured knuckle, (ii) through other knuckles, and (iii) the pocket is the knuckle. It further includes steps that draw to form a shape that surrounds the area of the image that corresponds to the location formed between them. Contours and guidelines are drawn using an image analysis program stored in a non-temporary computer-readable medium.

According to the second aspect, the present invention provides a method of determining the characteristics of the fabric. The method is a step of forming a representation of a portion of the surface of the fabric, where the representation indicates the location and size of knuckles and pockets within the surface of the fabric, where the representation is a print of the surface of the fabric, and. Includes a step, which is one of the photographs of the surface of the fabric. The method is to generate an image of a portion of the surface of the fabric based on the representation, to display at least a portion of the image on a screen associated with a computer with a processor, and to display the knuckle in the representation. It further includes a step of determining the size and location and a step of determining the size and location of the pocket in the display of the representation. Also, the method is a step of drawing a unit cell with respect to a part of the surface of the fabric in the displayed image, the unit cell is defined by a guideline, and the guideline passes through the center of (i) the knuckle. , (Ii) include steps that form a shape that surrounds the area of the image corresponding to where the pockets are formed between the knuckles. Based on the properties of the unit cells formed by the guidelines, at least one property of the surface of the fabric is calculated, and the contours and guidelines are stored using an image analysis program stored in a non-temporary computer-readable medium. be painted.

It is a schematic diagram of a paper machine using a structuring fabric. Top view of a section of structuring fabric. It is a figure of the contact surface printing apparatus by this invention. It is a figure of the contact surface printing apparatus by this invention. 3A and 3B are detailed views of the press section of the print forming apparatus shown in FIGS. 3A and 3B. This is an example of a print of a structuring fabric produced by the present invention. This is an example of a print of a structuring fabric produced by the present invention. This is an example of a print of a structuring fabric produced by the present invention. This is an example of a print of a structuring fabric produced by the present invention. It is a figure which shows the step which establishes the coordinate system about a structuring fabric print. It is a figure which shows the step which establishes the coordinate system about a structuring fabric print. It is a figure which shows the step which establishes the coordinate system about a structuring fabric print. It is a figure which shows the step which establishes the coordinate system about a structuring fabric print. It is a figure which shows the step which establishes the coordinate system about a structuring fabric print. It is a figure which shows the application of the analysis technique of this specification applied to the photograph of the knuckle of a fabric. It is a figure which shows the application of the analysis technique of this specification applied to the photograph of the knuckle of a fabric. It is a figure which shows the application of the analysis technique of this specification applied to the photograph of the knuckle of a fabric. It is a figure showing an alternative analysis technique applied to a photograph and a print of a knuckle of a fabric. It is a diagram showing an alternative analysis technique applied to photographs and prints of fabric knuckles. It is a figure showing the application of the analysis technique for determining the pocket surrounded by the knuckle in the structuring fabric. It is a figure which shows the application of the analysis technique for determining the depth of a pocket shown in FIG. It is a figure which shows the application of the analysis technique applied to the image of a paper product and its structuring fabric. It is a figure which shows the application of the analysis technique applied to the image of a paper product and its structuring fabric.

The present invention relates to devices, methods, and systems for determining the contact surface properties of fabrics used in the papermaking process. As will be apparent from the discussion below, "fabric contact surface properties" represent the properties of the contact surface resulting from the knuckle and pocket configurations that make up the fabric contact surface. In certain embodiments, the present invention is adapted for use with the structuring fabric used to form the three-dimensional structure of the web in a papermaking process. Such structuring fabrics are often constructed with threads made from, for example, polyethylene terephthalate (PET), polyester, polyamide, and polypropylene. Further, as described below, certain contact surfaces of the structuring fabric will have a significant effect on the structure of the paper product, and the present invention utilizes techniques for characterizing aspects of the contact surface. do. However, it should be noted that the present invention is applicable to any type of fabric used in the papermaking process, including fabrics used for purposes other than web structure formation.

FIG. 1 shows an example of a draft drying (TAD) papermaking process. In the draft drying (TAD) papermaking process, the structuring fabric 48 is used to form the three-dimensional structure of the paper product. To initiate the process, the papermaking material (furnish) supplied through the headbox 20 is jet-directed into the nip formed between the forming fabric 24 and the transfer fabric 28. The forming fabric 24 and the transfer fabric pass between the forming roll 32 and the breast roll 36. The forming fabric 24 and the transfer fabric 28 are separated after passing between the forming roll 32 and the breast roll 36. The transfer fabric 28 then passes through the dehydration zone 40, where the suction box 44 removes moisture from the web and transfer fabric 28, thereby pre-transferring the web to the structuring fabric 48. In addition, the concentration of the web is increased, for example, from about 10% to about 25%. In some cases, among other things, the so-called rush transfer, in which the transfer fabric 28 moves faster than the structuring fabric 48, gives a significant amount of crepe fabric to the web in the transfer zone 56. At that time, it would be advantageous to apply some amount of vacuum in the transfer zone 56, as shown through the vacuum assist box 52.

Since the web still has a high moisture content when transferred to the structuring fabric 48, the web is deformable and a portion of the web is formed between the threads that make up the structuring fabric 48. It can be pulled into the pocket (the structure of the pocket in the fabric will be described in detail below). As the structuring fabric 48 passes around the draft dryers 60 and 64, the concentration of the web is increased, for example, from about 60% to about 90%. Thereby, the web is given a shape approximately permanently by the structuring fabric 48, which includes the dome. The dome is where the web is pulled into the pocket of the structuring fabric 48. Thus, the structuring fabric 48 provides (transfers) a three-dimensional shape to the web, which results in a paper product with a dome structure.

By contacting the web with an adhesive sprayed onto the Yankee cylinder 68 just prior to contacting the translating web to complete the paper forming process, the web is structuring without major degradation in its nature. Transferred from fabric 48 to Yankee cylinder 68. After the web reaches a concentration of at least about 96%, light creeping is used to remove the web from the Yankee cylinder 68.

FIG. 1 shows one type of process in which a structuring fabric is used to give a three-dimensional shape to a paper product, but many structuring fabrics can be used to give a three-dimensional structure to a paper product. There are other papermaking processes. For example, structuring fabrics can be used in papermaking processes that do not utilize draft drying (TAD). Examples of such non-TAD processes are disclosed in US Pat. No. 7,494,563, the disclosure of which is incorporated by reference in its entirety. As will be appreciated by those skilled in the art, the invention disclosed herein is not limited to use in any particular papermaking process, but rather to fabrics used in a wide variety of papermaking processes. Can be applied.

FIG. 2 is a view of a portion of the structuring fabric 200 facing the web. The fabric 200 includes warp 202 and warp 204, the warp 202 will run in the machine direction (MD) when the fabric 200 is used in the papermaking process, and the weft 204 will be used by the fabric 200 in the papermaking process. When it is done, it runs in the direction of the cross machine (CD). The warp and weft 202 and 204 are woven together to form the structure of the fabric 200. When looking down at FIG. 2, at the surface of the structuring fabric 200 that contacts the web, some of the threads 202 and 204 shown are planes that contact the web during the papermaking process, i.e., the contact of the fabric 200. Note that it is below (back) the surface. The uppermost points of the threads 202 and 204 that define the plane of the contact surface are the knuckles 206 and 208. That is, the knuckles 206 and 208 form the actual contact surface of the forming fabric 200. Pocket 210 (shown as the area outlined in FIG. 2) is defined in the area between the knuckles 206 and 208. During the papermaking operation, a portion of the web can be pulled into the pocket 210, and as also explained above, the dome in the finished paper product is pulled into the pocket 210. Is part of the web.

It should be noted that the structuring fabric may not initially be manufactured with knuckles such as the knuckles 206 and 208 of FIG. Instead, knuckles are often formed by sanding or polishing one of the surfaces of the structuring fabric. In addition, when the structuring fabric is used in a papermaking operation, wear on the surface of the structuring fabric can further increase the length of the knuckle. As described below, the invention provides to determine the properties of a knuckle, including the properties of the knuckle when the fabric is being worn.

It should also be noted that the structuring fabric can take many forms, for example, depending on the weave of the warp and weft, as well as the size of the yarn. The structuring fabric 200 shown in FIG. 2 includes a knuckle 206 formed on the warp 202 and a knuckle 208 formed on the weft 204. This can result from the fabric 200 being sanded or from the fabric 200 being worn to the point where the knuckles are formed on both the warp and weft 202 and 204. However, with less sanding, it is possible that the fabric 200 has only the knuckle 206 on the warp 202 and no knuckle 208 on the weft 204, and vice versa. Numerous configurations of wefts and warps within structuring fabrics are known in the art, and the numerous configurations allow differently shaped paper products to be formed by the fabric.

Devices and techniques for forming prints (transfers) of contact surfaces formed by fabric knuckles are shown in FIGS. 3A and 3B. 3A is a side view of the contact surface printing device 300, and FIG. 3B is a front view of the contact surface printing device 300. The device 300 includes a C-shaped frame structure 302 comprising first and second arms 303 and 305. The first plate 304 is movably supported by the first arm 303, and the stationary second plate 306 is supported by the second arm 305. A print of the fabric knuckle is formed between the first plate 304 and the second plate 306, as described in detail below.

The first plate 304 is operably connected to a hydraulic pump 308 for activating the movement of the first plate 304 towards the second plate 306. In some embodiments, the hydraulic pump 308 is manual and comprises a release valve to allow the first plate 304 to retract from the second plate 306. However, the pump 308 can take many other forms to achieve the movement of the first plate 304. The pump 308 may be connected to a transducer and a transducer indicator 310 for measuring the pressure applied to the first plate 304 by the pump 308 when the first plate 304 is pressed against the second plate 306. .. As a specific example, Milwaukee, Wisconsin's Actuant Corp. ENERAPAC® Hydralic Hand Pump Model CST-18381 can be used. Specific examples of pressure transducers include Temecula, California Transducer Technologies, Inc. A Transducer Techniques Load Cell Model DSM-5K with a corresponding indicator can be used. Of course, in other embodiments, the pump 308, as well as the transducer and transducer indicator 310, can be combined into a single unit.

The frame 302 of the contact surface printing device 300 includes a wheel 312 adjacent to the front end of the frame 302, as well as a mount 313 that can be used to hold the pump 308 and / or the transducer 310. One or more wheels provided on the frame 312 make it easier for the frame 302 to move. According to an embodiment of the present invention, an advantageous feature of the contact surface printing device 300 is its portability. For example, with configurations as shown in FIGS. 3A and 3B, the printing device 300 can be easily moved around a section of fabric mounted on top of a papermaking machine. As will be appreciated by those skilled in the art, the ability to form prints on the contact surface of the fabric while the fabric is mounted on the papermaking machine, and therefore characterize the fabric according to the techniques described below. The ability to do provides a number of benefits. As an example, the wear of the fabric on the papermaking machine is easily monitored by using the contact surface printing appliance 300, and after different periods of operation of the papermaking machine, the printing (transfer) of the knuckle of the fabric. Draw so that you can take things).

The contact surface printing device 300 shown in FIGS. 3A and 3B includes a frame structure 302 connecting the first plate 304 and the second plate 306, but in other embodiments, the contact surface printing device is It is not necessary to include such a single frame structure 302. Instead, the first and second plates 304 and 306 may be unconnected structures, which are individually aligned to form a print of the fabric. In yet another embodiment, the plates 304 and 306 can take very different forms than those shown in FIGS. 3A and 3B. For example, one of the plates 304 and 306 can be formed as an enlarged surface, while the other plate is formed as a circular structure that is rolled across the enlarged surface. The term "plate", as used herein, is a broad term that includes any structure sufficient to contact and / or support components for making fabric prints. Further, as is clear from the above description, the relative motion of the first and second plates 304 and 306 of any embodiment can be reversed, while the first plate 304 remains stationary. The second plate 306 is drawn so as to be movable. FIG. 4 is a detailed view of section A of the contact surface printing device 300 shown in FIG. 3A, where device 300 is set up to make a print of the section of fabric 312. The fabric 312 is positioned between the plate 304 and the plate 306, with a strip of pressure measuring film 314 positioned facing the structuring fabric 312. There is one or more sheets of paper 316 between the pressure measuring film 314 and the first plate 304. There is a strip of rubber 318 between the fabric 312 and the second plate 306.

Pressure measurement film is a material structured so that applying force to the film causes the microcapsules in the film to burst, giving a momentary and permanent high resolution image of the contacted area of the film. Create inside. An example of such a pressure measuring film is sold as Prescale film by Fuji Film Holdings Co., Ltd. in Tokyo, Japan. Another example of a pressure measurement film is from Madison, New Jersey, Sensor Products, Inc. PRESSUREX-MICRO®. Those skilled in the art will appreciate that other types of pressure measurement films can be used in the printing techniques described herein. In this regard, with respect to the analytical techniques described below, the pressure gauge film need not provide an indication of the actual pressure applied to the film by the fabric, but rather the pressure gauge film is by the knuckle of the fabric. Note that it is only necessary to provide a printed image showing the contact surface formed.

The pressure applied to the plate 304 is to simulate the pressure that would be applied to the web facing the fabric 312 in the actual papermaking process when forming the print of the fabric 310 on the pressure measurement film 314. Can be selected for. That is, the pump 308 can be used to generate pressure on the plate 304 (as measured by the transducer 310), which will be applied to the web facing the fabric 312 in the papermaking process. To simulate. In the papermaking process described above in connection with FIG. 1, the simulated pressure will be the pressure applied from the fabric 48 to the web facing the Yankee cylinder 68. In some papermaking processes, such as the method described in US Pat. No. 7,494,563 above, the pressure applied to the web facing the fabric is generally in the range of 600 psi. Therefore, in order to simulate this papermaking process, a pressure of 600 psi will be applied to the plate 304 by the hydraulic pump 308 when forming the image of the knuckle of the fabric 312 in the pressure measurement film 314. .. With respect to such operation, it has been found that the Prescale film for medium pressure 10-50 MPa by Fujifilm is capable of providing a good image of the knuckle of the structuring fabric.

Referring again to FIG. 4, the paper 316 serves as a cushion to improve the print of the fabric 312 formed on the pressure measurement film 314. That is, the paper 316 provides a compressible and smooth surface, so that the knuckle of the fabric 312 can "sink" into the pressure measurement film 314, which is the knuckle in the film 314. Form a high resolution image. To provide these properties, construction and craft are examples of paper types that can be used with respect to paper 316.

The strip of rubber 318 creates a horizontal contact surface to support the fabric 314. In embodiments of the invention, the plates 304 and 306 are made of a metallic material such as steel. The steel sheet is most likely to have imperfections that reduce the print quality of the fabric knuckles formed in the pressure gauge paper 316. However, the paper 316 and rubber 318 used between the plates 304 and the plates 306, as well as the pressure measurement films 314 and the fabric 312, provide a more horizontal contact surface than the surfaces of the metal plates 304 and 306, which they provide. A better image is formed in the pressure measurement film 314. As an alternative to paper 316 and rubber 318, those skilled in the art will appreciate that other materials can be used as structures that provide a horizontal surface between the plates 304 and 306 of the device 300. ..

In another embodiment, the print is made from a fabric knuckle in a material other than the pressure gauge film. Another example of a material that can be used to form a print on a film is waxed paper. A print of the contact surface of the fabric can be made in the wax surface by pressing the contact surface of the fabric against the waxed paper. The prints in waxed paper can be made using the plates 304 and 306 in the print forming apparatus 300 described above, or can be made by other configurations of the plates. Waxed paper prints can then be analyzed in the same manner as pressure measurement film prints, as described below.

5A-5D show an example of printing a knuckle formed in a pressure measuring film using the contact surface printing device 300. In these prints it is possible to see the unique shape and pattern of the fabric knuckles. As discussed above, the knuckle forms a contact surface for the fabric. Therefore, high resolution printing of knuckles in pressure measurement films, such as those shown in FIGS. 5A-5D, provides a good representation of the contact surface of the fabric.

Next, a system for analyzing knuckle prints, such as those shown in FIGS. 5A-5D, will be described. Within the system, graphical analysis will be performed on a traditional computer system. Such computer systems are such as at least one computer processor (eg, central processing unit or multiple processing units) connected to a communication infrastructure (eg, communication bus, crossover bar device, or network). Will include well-known components. A further component of a computer system is a display interface (or other output interface) that transfers video graphics, text, etc. for display on the display screen. Computer systems can further include common components such as keyboards, mouse devices, main memory, hard disk drives, removable storage drives, network interfaces, and so on.

As a first step in the analysis, the print of the contact area of the knuckle of the fabric is transformed into a computer readable image using a photoscanner. Any type of photo scanner can be used to generate computer-readable images. However, in certain embodiments, it has been found that a photoscanner with at least 2400 dpi provides a good image for analysis. Depending on the resolution of the scan of the image, an imaging analysis program (as described below) can apply an accurate scale to the image. Accurate scaling will be used in the calculation of the surface properties of the structuring fabric, as described below.

The scanned image may be stored on a non-temporary computer-readable medium to facilitate the analysis described below. As used herein, non-temporary computer-readable media includes all computer-readable media except temporary propagating signals. Examples of non-temporary computer-readable media include, for example, hard disk drives and / or removable storage drives representing disk drives, magnetic tape drives, optical disk drives, and the like.

The characteristics of the image to be scanned, as well as the contact surface scanned image determined according to the techniques described below, may be associated with the database. As used herein, "database" means the collection of data organized in such a way that a computer program quickly selects the desired piece of data, for example an electronic filing system. ing. In some implementations, the term "database" can be used as an abbreviation for "database management system."

An image analysis program is used with the scanned image of the fabric knuckle to perform a quantitative analysis of the scanned print image. Such image analysis programs are developed, for example, by computational software that works with graphical images. One example of such computational development software is Wolfram Research, LLC, Champaign, Illinois, MATHMATICA®. As described below, the image analysis program will be used to specifically identify the knuckles within the fabric print image of the structuring fabric, and by known scaling of the fabric print image, the image. The analysis program can calculate the size of the knuckle and estimate the size of the pocket.

When analyzing a scanned image, any size area containing multiple knuckles and pockets may be used for the analysis described below. In certain embodiments, an area of 1.25 inches x 1.25 inches (3.175 x 3.175 cm) of the image of the fabric is pocket-sized using the techniques described herein. It has been found to enable good estimation of properties such as. Among other things, when the image is formed with 2400 dpi resolution (discussed above) and 1.25 inches x 1.25 inches (3.175 x 3.175 cm) of the image for analysis. It has been found that good characterization of the contact surface can be made when using the area (meters). Of course, other resolutions and / or regions can also provide good results.

6A-6E show steps to identify a knuckle in an enlarged portion of a scanned image of a print using an image analysis program. First, as shown in FIG. 6A, an enlarged portion of the image 600 can be seen on the display screen of the computer system running the analysis program. The image 602 can be formed using the printing technique described above, and the image 602 shows the knuckle 602. While using the image 600 by the analysis program, the scaling of the image 600 can be input into the analysis program. Such scaling can be input as, for example, 2400 dpi, from which the analysis program can apply the scale SC to image 600. The analysis program will then use the scale to calculate the size and position of the knuckle, as described below.

6B and 6C show steps for identifying a particular knuckle 602A using an analysis program. The knuckle 602A is initially selected based on its location in the central region of the magnified image 600. In this step, the rough contour of the knuckle 602A is applied. The rectangular box 604 can be the shape stored in the analysis program, and the rectangular box 604 is first applied around the knuckle 602A to initiate the knuckle identification process. The first rectangular box 604 shape can then be more elaborately refined to match the shape of the knuckle 602A, as shown in FIG. 6C. In this case, the ends 606 and 608 are reshaped to be more rounded and, therefore, to more accurately correspond to the ends of the knuckle 602A. Although not shown, further refinement may be made to the contours of the knuckle 602A until sufficient matching has been achieved. Such refinement can be done by further magnifying the image 600.

As shown in FIG. 6D, guidelines 610 and 612 are drawn after the knuckle 602A is identified by contour. Guidelines 610 and 612 are drawn to pass through the center of the knuckle 602A and extend in a straight line through the center of the other knuckles, respectively. Also, in particular, guidelines 610 and 612 are drawn so that the pockets do not intersect the area formed in the fabric, which area is known to correspond to the area between the groups of knuckles. There is. By drawing the guidelines 610 and 612 straight between the centers of the knuckles, the guidelines 610 and 612 do not cross the area of the pocket formed between the knuckles.

After the guidelines 610 and 612 are drawn, additional guidelines are drawn as shown in FIG. 6E. These guidelines are similar to the guidelines 610 and 612, i.e., drawn through the center of the knuckle and do not pass through the area where the pocket is formed. Lower magnifications may be used to assist in the process of drawing guidelines. The guidelines effectively establish a coordinate system with respect to the position of the knuckle. Therefore, the analysis program can now identify the size and shape of the knuckle based on the contour 602A and can identify the location of the knuckle as determined by the point at which the guidelines intersect. Is. The analysis program further has a scale SC of image 600 inputs. Therefore, it will be possible for the analysis program to apply the scale to the contour knuckle 602A and knuckle positioning to calculate the actual size and spacing of the knuckle. Similarly, it should be noted that the analysis program can calculate the frequency of the guideline, such as the number of times the guideline 612 intersects the guideline 610 per unit length. The frequency of each set of guidelines 610 and 612 will be used in the calculation of the properties of the fabric and in other aspects of the invention will be used as described below.

As shown in FIGS. 6D and 6E, the knuckles are all the same size and all have the same shape, and the knuckles are regularly spaced along the guidelines. Please note that. This is not surprising. The reason is that most fabrics for paper machines are manufactured with a highly consistent thread pattern, which results in consistent knuckle size and position. Knuckle size, shape, and installation consistency of all knuckles on the contact surface of the fabric, based on a single selected knuckle or based on a limited number of identified knuckles. Accurate estimation of size and shape is possible, and precise estimation of knuckle size and location can be achieved without identifying each knuckle. Of course, to achieve further accuracy, two or more knuckles can be identified and contours and guidelines can be drawn in different parts of the image.

As shown in FIG. 6E, guidelines 610 and 612 define a plurality of unit cells. Specific unit cells 613 are shown between the guideline segments 610A, 610B, 612A, and 612B. Unit cell 613 effectively indicates the minimum repeat pattern in the fabric and the maximum acceptable pocket size. The fabrics shown in FIGS. 6A-6E have about one warp direction knuckle per unit cell, whereas the other fabrics have two or more warp direction knuckles and / or 2 per unit cell. Note that it is also possible to have more than one weft direction knuckle. In other words, the unit cells defined by the knuckle pattern will vary with different fabric patterns.

As will be readily apparent to those of skill in the art, any or all of the steps shown in FIGS. 6A-6E may be performed by the user on the display screen or, as an alternative, run an analysis program. It can be either that can be automated as done by. That is, the analysis program is configured to automatically identify the knuckle as a darkened area of the image, outline the knuckle, and then draw guidelines based on the identified knuckle, as described above. Can be done.

After the selected knuckle has been identified and after the guidelines have been established through the knuckle, multiple properties of the fabric can be calculated using the knuckle size and position determined by the analysis program. To perform such calculations, knuckle size and positioning data can be exported from the analysis program to a traditional spreadsheet program to calculate the properties of the fabric. Table 1 shows examples of the decisions made by the analysis program and the calculations that follow from such decisions.

The fabric obtained from Image 600 contained only the knuckle 602 on the warp threads. However, other fabrics can include knuckles on the warp and weft, such as the fabrics that formed the prints of FIGS. 5B and 5D. By such a fabric, the knuckle on the warp and weft can be identified using the contouring technique described above, and the guidelines are the weft direction knuckle using the technique described above. Can be drawn through.

The contact surface of the fabric can be characterized, for example, by using a print (transfer) of the knuckle of the fabric formed by the contact surface printing device 300, but in other embodiments, the image of the contact surface of the fabric is , Can be obtained differently. An alternative to forming a print of a fabric knuckle is to take a photo of the fabric knuckle and then use the procedures and techniques described above to analyze the image formed from the photo. .. In this regard, it has been found that photographs with 2400 dpi provide high enough and low resolution to be analyzed by the techniques described herein.

An example of Photo 700 of a portion of a papermaking fabric with a knuckle 702a is shown in FIG. 7A, and the analysis techniques described above can be applied to images generated from Photo 700B and FIG. Shown in 7C. Photo 700 of FIG. 7A shows fabric 701 next to ruler R. When the photo is transformed into an image for use with the analysis program, the scale for the image 700A may be entered based on the ruler R on which the photo was taken. That is, the ruler R in the image 700A provides an input from which the analysis can apply the scale to the image. The displayed image 700A, along with the scale SC, is shown in FIG. 7B.

The same technique described above can be used with the image from the fabric print to identify the size and location of the knuckle in the image obtained from the fabric photo. For example, a contoured knuckle 702A, as well as guidelines 710 and 712, are shown above image 700A in FIG. 7C. With knuckle sizing and location data from the analysis program, it is possible to perform all of the calculations described above and characterize the contact surface of the photographed fabric 700.

Table 2 below shows the results of calculation of surface properties for the fabric, one set of calculations is derived from the print of the fabric and the second set of calculations is derived from the photographs of the fabric. There is.

The results shown in Table 2 show that the contact surface characterization calculations performed using photographic techniques closely correspond to the calculations performed using fabric printing.

The techniques described above provide a good estimate of the properties of the fabric, especially when the shape of the unit cells formed by the guideline segments is substantially rectangular. However, if the shape of the unit cell formed by the guidelines is a non-rectangular parallelogram, alternative techniques may be used to provide a more accurate estimate of the properties of the fabric. An example of this alternative technique is shown in FIG. 8A, which is an image generated from a photograph of the surface of the fabric using the image analysis program described above. In this figure, the unit cell 813 is defined by the guideline segments 810A, 810B, 812A, and 812B. The unit cell 813 formed by the guideline segments 810A, 810B, 812A, and 812B is a substantially non-rectangular parallelogram shape. In this parallelogram, the angle θ is defined at the corner A where the guideline segments 810A and 812B intersect, and the angle θ is defined at the corner B where the guideline segments 810B and 812A intersect. This angle θ can be easily determined using an image analysis program based on the difference in orientation angles of the guidelines. In addition, the image analysis program is generally based on the scale of the image as described above, the distance between the guideline segments 810A and 810B (“DIST1”) and between the guideline segments 812A and 812B. It is possible to determine the distance (“DIST2”). Once the intersection angles θ, DIST1, and DIST2 have been determined, the area of the unit cell (UCA) can be calculated using either formula (1) or formula (2).
UC A = (DIST1 / sinθ) × DIST2 (1)
UC A = (DIST2 / sinθ) × DIST1 (2)
Formulas (1) and (2) are derived from the standard formula for calculating the area of a parallelogram, ie area = base length x height, where DIST1 or DIST2 is a parallelogram. Used as the height of, then the base length is calculated from the sine of angle θ and the other of DIST1 or DIST2.

Table 3 shows examples of the decisions made by the analysis program and the calculations that follow from such decisions when using an alternative technique based on area calculations for non-rectangular parallelogram unit cells.

Some of the properties in Table 3 have been determined or calculated in the same manner as described above in Table 1, but with knuckle density, total warp or weft knuckle contact area, contact area ratio. Note that the percent area contribution, pocket area estimation, and pocket density characteristics are calculated in Table 3, unlike those in Table 1. By considering the non-rectangular parallelogram of the unit cells, these different calculations provide a more accurate estimate of the properties of the fabric with the unit cells of the non-rectangular parallelogram.

FIG. 8B is a print of fabric made using the techniques described above. In this case, the fabric has an overly non-rectangular unit cell, and one of the angles θ at the corners of the parallelogram defining the unit cell is about 140 degrees. To demonstrate the difference between the first technique described (it is not specifically adapted for parallelogram unit cells) and the technique for non-rectangular parallelogram unit cells. Two sets of calculations have been performed on the fabric and the results are shown in Table 4.

Note that some of the properties shown in Table 4 are the same for the two calculations, but the total in-plane contact area and pocket density are different. The calculation method adapted to the non-rectangular parallelogram unit cell is non-rectangular parallel, considering that it utilizes measurements that are more closely matched to the actual intrinsic shape and structure of the fabric shown in FIG. 8B. The total in-plane contact area (ie, the percentage of fabric corresponding to the knuckle) and pocket density, as determined by computational techniques specifically adapted to the quadrilateral unit cell, will be more accurate. As those skilled in the art will appreciate, the total in-plane contact area and pocket density of the fabric will have a significant effect on the papermaking properties of the fabric. Therefore, the non-rectangular parallelogram calculation provides a more accurate estimate of the important properties of a given fabric.

Another important property of the papermaking fabric is the depth at which the web can be drawn into the pockets inside the fabric during the papermaking process. As discussed above, a dome is formed in the final paper product, which corresponds to a portion of the web that is pulled into a pocket in the fabric. Therefore, the pocket depth of the papermaking fabric directly affects the paper products formed using the fabric. Techniques for determining the pocket depth of the fabric will be described here.

FIG. 9 shows an enlarged photograph of the structuring fabric. The four knuckles K1 through K4 are identified using photographs and using the image analysis program described above. The parallelogram is drawn to connect the knuckles K1 to K4, and the parallelogram line is drawn so as not to pass through the pocket area formed between the knuckles K1 to K4. With the parallelogram drawn, a profile direction line PL can be drawn from the knuckle K1 through the center of the pocket to the knuckle K3. The profile direction line PL will be used to determine the pocket depth using a depth measuring instrument as described below. Note that the profile direction line PL from knuckle K1 and knuckle K3 passes through the center of the pocket. As described below, the pocket depth of the structuring fabric is determined as the depth within the pocket that the cellulosic fibers can reach during the papermaking process. For the fabric shown in FIG. 9, the maximum fiber migration depth is at the center of the pocket. Thus, a profile orientation line may be alternative drawn from knuckle K2 to knuckle K4 through the center of the pocket, and an alternative profile orientation line may be used for pocket depth determination as described below. It will be. Also, different structuring fabrics will have different configurations of knuckles and pockets, but the profile orientation lines will have different structures, just as the profile orientation lines are determined as shown in FIG. Those skilled in the art will appreciate that the ring fabric can be easily determined.

FIG. 10 is a screenshot of the program used to determine the profile of the pockets of the structuring fabric shown in FIG. Screenshots were formed using a VHX-1000 digital microscope manufactured by KEYENCE CORPORATION in Osaka, Japan. The microscope was equipped with VHX-H3M application software, also provided by KEYENCE CORPORATION. A microscopic image of the pocket is shown in the upper part of FIG. In this image, the knuckles K'1 and K'3, as well as the pockets between the knuckles, can be easily seen. The depth determination line DL is drawn from point D to point C, and the depth determination line DL passes through the knuckles K'1 and K'3, as well as the center of the pocket. The depth determination line DL is drawn so as to closely approximate the profile determination line PL shown in FIG. That is, based on the inspection of the depth determination line DL derived using the knuckle and pocket images shown in FIG. 9, the user can see the depth determination line DL in the microscope image shown in FIG. The depth determination line DL passes through the knuckles K'3 and K'1 as well as the area corresponding to the central portion of the pocket.

By drawing the depth determination line DL, the digital microscope is then instructed to calculate the pocket depth profile along the depth determination line DL, as shown in the bottom portion of FIG. Can be done. The profile of the pocket is highest in the area corresponding to the knuckles K'3 and K'1, and the profile drops to its lowest point in the center of the pocket. Pocket depth is determined from this profile as starting from the height of knuckles K'3 and K'1, and the height of knuckles K'3 and K'1 is determined by line A above the depth profile. It is marked. Like any two knuckles of the structuring fabric measured with this degree of accuracy, the knuckles K'3 and K'1 do not have exactly the same height. Therefore, the height A is determined as the average between the two heights of the knuckles K'3 and K'1. Pocket depth is determined to end at a point just above the lowest point in the depth profile, which is marked by line B above the depth profile. As those skilled in the art will understand, the depth of the pocket from line A to line B roughly corresponds to the depth in the pocket where the cellulosic fibers in the web can migrate during the papermaking process. Note that the VHX-H3M software (discussed above) forms a complete depth profile from multiple slices in the thickness direction of the fabric. It should also be noted that in forming the depth profile, the VHX-H3M software uses a filtering function to smooth the depth profile formed from the thickness slices. Note that the measured pocket depth will vary slightly from pocket to pocket in the fabric. However, we have found that the average of the five measured pocket depths for the structuring fabric provides a good characterization of the pocket depth.

A digital microscope is used in the embodiments described above to determine the pocket depth, but other instruments, as an alternative, use the techniques described herein to determine the pocket depth. Can be used to determine. For example, in other embodiments, a laser profiler (or "laser profiler") is used, and it is possible to determine the pocket depth, similar to the digital microscope described above. The laser profiler can determine the depth profile of the pocket, and the depth profile of the pocket is the pocket depth, which is the depth profile generated using a digital microscope as described above. Can be used to determine pocket depth, just as it is used to determine. Examples of such laser profilers are Leicester, United kingdom's Taylor Hobson, Ltd. TALYSURF® CLI high resolution 3D surface profiling system manufactured by. In yet another embodiment, an in-line laser profile measuring device (“laser line scanner”) is used and the techniques described herein can determine the pocket depth of the fabric. An example of such a laser line scanner is the LJ-V7000 series high speed inline profile inspection device manufactured by KEYENCE CORPORATION.

When using a laser profiler or laser line scanner, the same steps described above in relation to a digital microscope can be used to determine the pocket depth. That is, as shown in FIG. 9, the knuckles and pockets are determined based on the representation of the surface of the structuring fabric. The laser profiler or laser line scanner is then configured to determine the depth profile across the pocket from one knuckle to another, i.e. the laser profiler or laser line scanner is as in the line PL of FIG. Scan across the oriented line. From this measured profile, the pocket depth can be determined in the same manner as the method described above in connection with FIG. Various analysis software programs can be used to analyze the depth profile measured by a laser profiler or laser scanner. One example is the surface weighing software provided by TrueGage of North Huntingdon, Pennsylvania.

Each of the alternative depth measuring instruments, namely a digital microscope, a laser profiler, or a laser line scanner, can provide a particular advantage. For example, a digital microscope can provide a highly accurate measurement of pocket depth. On the other hand, a laser profiler is generally an easy instrument to work with, thereby being able to provide a rapid measurement of pocket depth. As another example, laser line scanners have the ability to quickly collect large volumes of data and therefore measure many depth profiles in a short period of time. In this regard, embodiments of the present invention include the use of a laser line scanner to determine the pocket depth profile of a structuring fabric running over a papermaking machine. In this embodiment, the laser line scanner is positioned adjacent to the structuring fabric on the machine, and the laser line scanner measures the pocket depth profile as the fabric travels through the scanner. As will be appreciated by those skilled in the art, the structuring fabric in a papermaking machine can travel at speeds faster than 3,000 feet per minute (914.4 m / min). However, laser line scanners such as the LJ-V7000 series inspection system described above by KEYENCE CORPORATION have the ability to measure thousands of depth profiles per second. Therefore, the laser line scanner has the ability to measure the pocket depth in a rapidly moving structuring fabric, thereby allowing the structuring fabric to be in actual use on a papermaking machine. Provides highly useful pocket depth data.

It should be noted that regardless of the measuring instrument and technique used to determine the pocket depth, the measured pocket depth will vary slightly from pocket to pocket in the fabric. Generally speaking, it has been found that the average of the five measured pocket depths for the structuring fabric provides a good characterization of the pocket depth. Of course, more or less measurements may be made to determine the average pocket depth, for example, depending on the level of accuracy desired in the measurement.

In the pocket depth determination technique described above, the structuring fabric itself is used to determine the pocket depth. In some cases, it may be easier to form a representation of the fabric and then determine the pocket depth from that representation. For example, the representation of the fabric's knuckle and pocket structure can be formed by pressing the contact surface of the fabric against waxed paper, as also described above. The wax representation of the fabric can then be scanned using one of the techniques described above. For example, a laser line scanner may be used to determine the depth in the wax print between the knuckles in the wax print.

The effective volume of a pocket in a structuring fabric is an important property of the structuring fabric, which can be easily determined once the pocket size is calculated according to one of the techniques described above. Those skilled in the art will understand. The effective volume of the pocket is the cross-sectional area of the pocket on the surface of the structuring fabric (ie, between the knuckle surfaces) multiplied by the depth of the pocket where the cellulosic fibers in the web can migrate during the papermaking process. It is a product. The cross-sectional area of the pocket is the same as the estimation of pocket area (PA) as described in Table 1 or Table 2 above. Therefore, the effective pocket volume can be easily calculated as the product of the pocket area estimate and the measured pocket depth.

Another important property of the structuring fabric can be defined as a planar volumetric index for the fabric. Generally speaking, the flexibility, absorbency, and caliper of a paper product made using a fabric depends on the contact area of the fabric, that is, the knuckle surface of the fabric with which the web contacts during the papermaking process. It can be affected by the area formed. In addition, the flexibility, absorbency, and thickness of paper products can be affected by the size of the pockets in the fabric. The planar volume index is the contact area ratio (CAR) multiplied by the effective pocket volume (EPV) (as described in Table 1 or 2 above) multiplied by 100, i.e., CAR. Calculated as × EPV × 100, the planar volume index provides indications for contact area and pocket size. The contact area ratio and effective pocket volume can be calculated using the techniques described above, after which a planar volume index for the fabric can be readily calculated.

Knowing the characteristics of the fabric's knuckles and pockets, such as the size and density of the knuckles and pockets, provides a deep understanding of the fabric, as will be reliably understood by those skilled in the art. One example of the use of properties involves developing the correlation between specific contact surface properties and the resulting paper products. Correlation allows additional fabric configurations to be developed and those configurations to be characterized without testing the full scale fabric on a papermaking machine. Therefore, the techniques described above for determining the contact surface properties of fabrics can save time and resources for both fabric manufacturers and / or papermakers trying different fabrics. ..

The techniques described above can also be used in methods of analyzing wear on papermaking fabrics. In one such method, the first representation of the knuckle within a portion of the fabric is formed within the medium. This first representation can be a print on a pressure measuring film, or the representation can be a photograph of a portion of the fabric and can be stored in the camera. The first image of the fabric knuckle is generated based on the first representation, for example, by scanning a pressure measurement film or by downloading a photo from a camera. From the generated image, at least one property with respect to the contact area of the fabric can be determined as described above. The fabric can then be subject to wear. If the fabric is mounted on top of the papermaking machine, wear can easily occur by operating the papermaking machine. Alternatively, wear simulation can be done on the fabric by sanding or polishing.

After the fabric has worn, the process of obtaining an image of a portion of the fabric and determining the contact surface properties is repeated. That is, a second representation of the knuckle within a portion of the fabric is formed in the medium, which is used to generate a second image, which is used to determine the surface properties of the film. Is analyzed. In this regard, the second representation may or may not be taken from the same piece of fabric as the first representation. Knuckles in the fabric will be expected to increase in size as a result of wear. In addition, new knuckles can be formed within the fabric. As part of the contact surface characterization, the increase in knuckle size can be quantified by comparing the analysis of the second image after wear with the analysis of the first image before wear. The process of wearing the fabric and then determining the contact surface properties can be repeated any number of times and with any given amount of wear during each analysis.

Further part of analyzing the wear on the fabric involves correlating the paper products made with the fabric to the changes in the contact surface due to the wear. For example, a paper product is formed using the fabric before the first representation of the fabric is taken. The properties of the paper product, such as the size of the dome in the product, or the thickness of the product, correlate with the contact surface properties that are then determined through analysis of the first image formed by the first representation. Be made to. A second paper product is then formed using the fabric after the fabric has been worn and before the second representation of the fabric is taken. The properties of the second formed paper product are then correlated with the contact surface properties determined through analysis of the second image. Therefore, an understanding of how the paper products formed change as a particular fabric configuration wears can be realized.

In a further aspect of the invention, the techniques and methods described above can be used, among other things, to compare different parts of the fabric after the fabric has run over a papermaking machine for a long period of time. It is known that different parts of the fabric will exhibit different wear due to inconsistencies in the tracks that the fabric follows in the papermaking machine. According to different embodiments, surface characterization techniques can be applied, for example, to different parts of the fabric before and after the fabric is run over the papermaking machine. Alternatively, surface characterization techniques can be applied to different parts of the fabric while the fabric is still mounted on the papermaking machine. Therefore, an understanding of how different parts of the fabric wear in a papermaking machine can be realized.

According to yet another aspect of the invention, contact surface characterization can be used to obtain fabrics for making paper products with a particular three-dimensional structure. 11A and 11B show such a process. FIG. 11A shows an example of an image 800 of a paper product analyzed using the techniques described above. In particular, paper products have a three-dimensional structure, which includes a plurality of dome separated by a land region. As described above, such paper products can be made using structuring fabrics. However, if the particular structuring fabric configuration used to make such a product is not known, the method according to the invention can be used to identify the structuring fabric configuration. .. As shown in FIG. 11A, contour 802A can be drawn on top of the image of the paper product by using an analysis program in the land area of the paper product, which is used to make the paper product. Corresponds to the position of the knuckle of the structuring fabric. In addition, a coordinate system containing guidelines 812 and 814 can be drawn through contour 802A and through positions corresponding to other knuckles. Note that the dome in the paper product corresponds to the pocket in the structuring fabric, so the coordinate system is drawn without passing through the dome.

After the contour 802A is formed and the coordinate system with guidelines 812 and 814 is drawn, the contour 802A and the coordinate system determine the configuration that creates the three-dimensional structure of the paper product, as shown in FIG. 11A. In addition, it can be matched to the image of the fabric. An example of such matching is shown in FIG. 11B, in which the contour 802A and the coordinate system with guidelines 812 and 814 are superimposed on the image 800A of the fabric. Note that the contour 802A matches the size and shape of the knuckle in the fabric and the guideline passes through the knuckle but not in the area corresponding to the pocket in the fabric. This matching indicates that the fabric shown in image 800A can be used to produce a paper product similar to that shown in image 800.

Matching contours and coordinate systems from paper products to a particular fabric can be facilitated by generating a searchable database of known fabrics. Such a database will include previously determined contact surface properties of the fabric, such as knuckle size, location, pocket size, etc. After determining the size and position of the fabric for knuckles and pockets from contours and coordinate systems formed from paper products, the database may be searched for fabrics with similar knuckle and pocket sizes and positions.

Additional parameters developed during the analysis of the paper product may be used to facilitate the process of matching the analyzed image of the paper product with the fabric. One such additional parameter is the frequency with which the guidelines in one set intersect with the guidelines from the guidelines in the other set. Note that the "set" of guidelines represents parallel guidelines, for example, Guideline 812, and all guidelines parallel to it form a set. In FIG. 11A, the frequency of a set of guidelines, including guideline 812, will be calculated, eg, the distance between two of the guidelines that intersect guideline 810 when measured along one guideline 810. Let the analysis program decide. For example, if the guideline intersecting the guideline 810 is spaced 0.130 cm apart when measured along the guideline 810, the intersecting guideline is 7.7 cm ^-1 (1 / 0. It will have a frequency of 130 cm). By measuring the spacing between the guidelines in this set along one of the guidelines 812, similar frequency calculations can be made for the other set of guidelines that intersect the guideline 812. Once determined, the frequency of guideline spacing for paper products could be matched to the previously determined frequency of guideline spacing for fabrics, which has been stored in a searchable database.

Another parameter that can be calculated to facilitate the process of matching contoured knuckles and guidelines to a particular fabric from paper products is the angle of the set from the reference line to the guidelines. For example, the scale line SC in FIG. 11A can be used as a reference and the angle α can be determined between the scale line SC and one set of guidelines. Also, the angle from the scale line SC to the other set of guidelines can be determined. Once determined, the angle from the criteria for paper products to the set of guidelines can be matched to the previously determined angle from the criteria for fabrics to the set of guidelines, and the previously determined angles are searchable. It has been stored in a database.

The method described above is described from the perspective of matching the paper product to a known fabric, but other embodiments are on top of a desired but not yet produced three-dimensional paper structure. It will be readily understood to include selecting known fabrics made. That is, one or more contour knuckles can be generated in the blank image, and knuckles and pocket patterns can be generated by drawing guidelines in the blank image. The generated image can then be matched to a known fabric as described above.

In yet another embodiment, the fabric may be designed and manufactured based on the analysis of the paper product image or on the generated image representing the knuckle and pocket composition. In this method, warps and wefts are selected to accommodate the desired knuckle and pocket configuration as determined by analysis of the paper product image or generated within the blank image. Techniques for producing fabrics with specific textures of warp and weft are well known in the art. Therefore, the fabric can be produced by the warp and weft composition chosen.

In another embodiment of the invention, the fabric characterization techniques described herein are used to modify the configuration of the first papermaking fabric to create a new second papermaking fabric with different properties. It is possible. In these embodiments, at least one knuckle or pocket property of the first papermaking fabric is determined by the technique described above. The property can be, for example, one or more of the properties described in Table 1 or Table 2 above. In addition, the property can be pocket depth or effective pocket volume, which is determined according to the technique described above. Based on the determined characteristics, a modified fabric design is generated and the characteristics are changed. For example, the pocket depth can be increased from the pocket depth measured in the first papermaking fabric. Those skilled in the art will understand the factors that determine the characteristics of the papermaking fabric, and therefore how the design of the first papermaking fabric can be modified to create new papermaking fabrics with different characteristics. You will understand what you will get. Fabric aspects such as, for example, yarn diameter, yarn density, yarn shape, texture, and one or more of the thermal settings used to bond the yarns together, have modified properties. Can be modified to create a second papermaking fabric with. One of many examples of paper fabric manufacturing techniques that utilize some of these factors can be found in US Pat. No. 6,350,336, the disclosure of which is in its entirety. Incorporated by reference.

In addition to, or in conjunction with, the embodiments for modifying the composition of the papermaking fabric design, the characteristics of the paper product made using the structuring fabric can be used in the development of the papermaking fabric with specific characteristics. .. For example, the properties of the first papermaking fabric can be determined using the techniques described above. Also, the first papermaking fabric can be used, for example, to make a papermaking product using the papermaking method described above. The properties of the paper product can then be determined and then correlated with the determined properties of the first papermaking fabric. For example, the density and height of a dome formed in a paper product can be measured by examining the dome under a microscope. As discussed above, the dome is formed in the pockets of the papermaking fabric. Therefore, the pocket density and pocket depth determined within the papermaking fabric can be correlated with the dome density and dome height found in the paper products made using the papermaking fabric. Such correlations can then be used to determine what paper products can be expected to be made by another papermaking fabric with comparable properties. In addition, as described above, new paper fabric designs with adjusted properties may be developed to produce paper products with modified properties as needed.

Although the present invention has been described in certain exemplary embodiments, many additional modifications and variations will be apparent to those skilled in the art in light of the present disclosure. Therefore, it should be understood that the present invention may be practiced in addition to those specifically described. Accordingly, it should be taken into account that the exemplary embodiments of the invention are exemplary and not restrictive in all respects, the scope of the invention is said to be by the aforementioned description. Rather, it should be determined by any claims and their equivalents that can be supported by this application.

Claims (15)

A method of determining the depth of pockets in a woven fabric containing warps and wefts.
A step of forming a representation of a portion of the surface of the woven fabric to provide the fabric representation, wherein the fabric representation is (i) the contour, location and of a plurality of knuckles that are part of the surface of the fabric. A step, which is an expression representing the size , and (ii) the location and size of the pocket formed in the area between the knuckles.
A step of identifying a plurality of specific knuckles surrounding a specific pocket of one of the pockets in the fabric representation among the plurality of the knuckles in the fabric representation.
In the fabric representation, the second of the plurality of specific knuckles identified from the center of the first knuckle of the identified plurality of specific knuckles through the center of the one particular pocket. Steps to determine the route to the center of the knuckle,
A step of scanning the woven fabric with a measuring device along the line corresponding to the determined path to provide a scan of the woven fabric.
A method comprising the step of determining the depth of the particular pocket to which the cellulosic fibers can reach in the papermaking process based on the scan along the line corresponding to the determined path. The method of claim 1, wherein the measuring device is one of a digital microscope, a laser profiler, and a laser line scanner. The method of claim 1, wherein the step of forming the representation produces an image of the portion of the woven fabric based on the fabric representation and the image on a screen associated with a computer having a processor. Methods, including displaying at least a portion of. The method of claim 1, wherein the step of forming the expression comprises forming a print of the fabric on waxed paper. The method of claim 1, wherein the step of determining the depth of the particular pocket is (i) determining the depth profile of the pocket and (ii) the plurality of said depth profiles. Each point corresponding to the knuckle is determined, (iii) the point corresponding to the lowest point of the pocket is determined, and (iv) the points corresponding to the plurality of knuckles and the lowest point of the pocket are corresponded to. A method comprising calculating the depth of the pocket based on said point. A method of determining the depth of pockets in a woven fabric containing warps and wefts.
A step of forming a representation of a portion of the surface of the woven fabric to provide the fabric representation, wherein the fabric representation is (i) the contours, locations and sizes of the plurality of knuckles that are part of the surface , as well as. (Ii) A step, which is an expression representing the location and size of a pocket formed in the area between the knuckles.
A step of identifying a plurality of specific knuckles surrounding a specific pocket of one of the pockets in the fabric representation among the plurality of the knuckles in the fabric representation.
In the fabric representation, the second of the plurality of specific knuckles identified from the center of the first knuckle of the identified plurality of specific knuckles through the center of the one particular pocket. Steps to determine the route to the center of the knuckle,
A step of scanning the woven fabric with a measuring device along the line corresponding to the determined path to provide a scan of the woven fabric.
A step of determining the depth profile and depth of the particular pocket based on the scan along the line corresponding to the determined path, wherein the depth profile and the depth are during the papermaking process. A method comprising a step, which is a depth corresponding to the amount of cellulosic fibers that can enter the particular pocket. The method of claim 6, wherein the measuring device is one of a digital microscope, a laser profiler, and a laser line scanner. The screen according to claim 6, wherein the step of forming the representation produces an image of said portion of the surface of the woven fabric based on the fabric representation and is associated with a computer having a processor. A method comprising displaying at least a portion of the image. 6. The method of claim 6, wherein the step of forming the expression comprises forming a print of the fabric on waxed paper. 6. The method of claim 6, wherein the step of determining the depth of the particular pocket is (i) determining the depth profile of the pocket and (ii) the plurality of said depth profiles. Each point corresponding to the knuckle is determined, (iii) the point corresponding to the lowest point of the pocket is determined, and (iv) the points corresponding to the plurality of knuckles and the lowest point of the pocket are corresponded to. A method comprising calculating the depth of the pocket based on said point. A method of determining the depth of pockets in a woven fabric containing warps and wefts.
A step of forming a representation of a portion of the surface of the woven fabric to provide the fabric representation, wherein the fabric representation is (i) the contours, locations and sizes of the plurality of knuckles that are part of the surface , as well as. (Ii) A step, which is an expression representing the location and size of a pocket formed in the area between the knuckles.
A step of determining a unit cell of the woven fabric by identifying a plurality of specific knuckles surrounding one particular pocket of the pockets in the fabric representation among the plurality of knuckles in the fabric representation. When,
In the fabric representation, from the center of the first knuckle of the particular knuckles through the center of the one particular pocket to the center of the second knuckle of the particular knuckles. Steps to determine the route and
A step of scanning the woven fabric with a measuring device along a line corresponding to the determined path to provide a scan of the woven fabric.
A method comprising the step of determining the depth of the particular pocket to which the cellulosic fibers can reach during the papermaking process, based on the scan along the line corresponding to the determined path. 11. The method of claim 11, wherein the measuring device is one of a digital microscope, a laser profiler, and a laser line scanner. 11. The method of claim 11, wherein the step of forming the representation produces an image of the portion of the woven fabric based on the fabric representation, and the image is displayed on a screen associated with a computer having a processor. Methods, including displaying at least a portion of. 11. The method of claim 11, wherein the step of forming the expression comprises forming a print of the fabric on waxed paper. 11. The method of claim 11, wherein the step of determining the depth of the particular pocket is (i) determining the depth profile of the pocket and (ii) the plurality of said depth profiles. Each point corresponding to the knuckle is determined, (iii) the point corresponding to the lowest point of the pocket is determined, and (iv) the points corresponding to the plurality of knuckles and the lowest point of the pocket are corresponded to. A method comprising calculating the depth of the pocket based on said point.

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