JP2013516553A - Method and system for producing fiber-containing products - Google Patents

Abstract

The present invention relates to a method and system for producing a textile material. In the method, the fiber suspension is fed onto the wire so that the web is formed, and the formed web is dried. Further, in the above method, after the web is formed, the web is at least partially in contact with the long wire, at least to the press part, in any case, until the dry matter content of the web exceeds a predetermined limit value. Continues continuously. A system for producing fiber material in a web forming machine includes fastening means for positioning the wire on the web forming machine so that the wire runs continuously from at least the web forming portion to substantially the press portion.

Description

  The present invention relates to a method for producing a fiber-containing product. The present invention also relates to a system for producing a fiber-containing product.

  It has been found that fiber-containing sheets with a relatively high nanofibrous cellulose (NFC) content have particularly interesting properties. Since the relative ratio of the surface of a piece to the volume of the piece increases as the piece becomes smaller, the properties of the nanoparticles differ greatly from the properties of the macroscopic piece. Properties that can be achieved by nanofibrinated cellulose and are of interest from the industry are, for example, particularly high tensile strength, very low porosity, and partial translucency. Among other things, these properties make nanofibrous cellulose a popular raw material, and products containing nanofibrous cellulose would have a wide range of industrial uses.

  At present, the application of nanofibrinated cellulose as a raw material for textile products such as paper or paperboard is actually limited by various challenges. Nanofibrinated cellulose is a gel-like material, even at low consistency, and removing water from fiber materials having high nanofibrotic cellulose content is often time consuming. Furthermore, since the nanofibrous cellulose small particles adhere particularly strongly to the scissors, the nanofibrous cellulose easily sticks to the wire used, which means that in the manufacturing process of textile products containing nanofibrous cellulose, The strong adhesion can cause the problem that peeling the web from the wire requires a relatively large force. The problem caused by adhesion to the wire because wet nanofibrinated cellulose has a relatively low internal strength is often significant, so the force required to peel the web from the wire has been wetted May be greater than the internal strength of the fiber suspension. Especially when the nanofibrinated cellulose content in the pulp suspension is relatively high, the internal wet strength of the web tends to be low in relation to the force between the web and the wire, and the intact web is peeled off the wire Is particularly problematic.

  In prior art papermaking processes, the web is usually peeled from the wire in the very early stages when the web still has a low dry matter content, so that the nano to pulp suspension in the web forming machine. The addition of fiberized cellulose can result in exceptionally low operating speeds of the web former, which in turn can substantially reduce the cost efficiency of the grade to be operated. In addition, this problem can be significant because dehydration of webs containing nanofibrinated cellulose can be slower than usual.

  In addition to the problems described above, a further problem with the use of nanofibrinated cellulose is that current wires commonly used in manufacturing are usually relatively coarse for small particles and such wires are used. This may be the fact that the degree of nanofibrous cellulose retention may remain at a very low level.

  Under laboratory conditions, the aforementioned problems of peeling the pulp from the wire, and the density problem of the wire, inter alia, use particularly small mesh wires, for example so-called fine wires whose density may be 200 mesh. Has been solved by doing. In this way, a sufficiently high degree of nanofibrous cellulose retention is usually achieved. In addition to first producing a fiber sheet with a high nanofibrinated cellulose content on fine wire, the fiber sheet is under laboratory conditions until the dry matter content of the sheet increases on fine wire. It is also dried. The dry strength of a sheet substantially containing nanofibrinated cellulose is much higher than the wet strength of the sheet, so that a sheet that has been dried to a sufficient degree is usually peeled off from a long wire without any problems. be able to.

  When the fiber web is dried, the fiber web has a tendency to shrink. Usually products such as webs are tightened in the longitudinal direction of the web, so the problem of dry shrinkage usually appears in the width direction of the web. These problems may occur both in the production of conventional textile products and in the production of textile products that substantially contain nanofibrinated cellulose. Since drying shrinkage occurs when the web is dried, it may be possible to overcome this problem by operating the web so that it is in contact with the gills where the web is formed longer than usual. There is.

  In large-scale cases, for example in paper mills, there was no practical solution to these problems mentioned above. Thus, there would have been a need for a solution that would allow textile products to be manufactured in a better manner in the manufacturing process on various web forming machines or similar machines.

  The object of the present invention is to find a solution to the above-mentioned problems caused by the low dry matter content in such a way that the textile product is in contact with the plow net where the web is formed for a sufficiently long time. In accordance with an advantageous embodiment, the object of the present invention is to address the problem of peeling a fibrous web containing nanofibrinated cellulose from a wire in the manufacture of a textile product such as a web prior to the web being peeled from the wire. It is to relax by drying the web to a sufficient extent. In another advantageous embodiment, the object of the invention is to reduce and / or control the drying shrinkage of the web in the width direction.

  In the solution according to the invention, peeling of the web from the wire can take place when the dry matter content of the web has reached a predetermined limit value. In an advantageous embodiment, this is achieved when the internal strength of the web is greater than the effective force between the web and the wire. In this way, the web can be intact when peeled from the wire. According to an advantageous embodiment, a substantial amount of nanofibrinated cellulose can be included in the product in such a way that the web can still be peeled from the wire without breaking the web. In accordance with another advantageous embodiment, the web can be peeled from the web forming wire when the dry matter content of the web is an amount that reduces the drying shrinkage in the width direction of the web to the desired degree.

  According to an embodiment of the invention, the web is supported on at least one wire from the formation of the web to at least the press part, for example at least beyond the first press nip of the press, preferably to the drying part of the web forming machine. Is done. In this case, the web is supported substantially and continuously by the same at least one wire from web formation to at least the location described above. In one embodiment, the web to be manufactured is supported by at least one identical wire substantially at least until the middle of the press. According to one embodiment, the web is supported by the same wire from formation of the web to a position beyond the first drying group in the drying section, preferably substantially in the middle of the drying section. In one embodiment, the web is supported by the same wire to a position beyond the entire drying section, for example, to a position where the web is close to the first calendar, coating unit, or machine roll of the web forming machine.

  In one embodiment, the web is supported by only one long wire, i.e., supported on only one side of the web. In an advantageous embodiment in which a long wire is used, the mesh size of the long wire is advantageously selected so that it is possible to improve the holding power of the fiber material containing nanofibrinated cellulose. In one embodiment of the invention, the web is supported by wires that are denser than the wires commonly used in papermaking, so-called fine wires. In an example embodiment, these fine wires are provided on both sides of the web.

  In one embodiment of the invention, the long wire in contact with the web is supported by a separate wire that may be coarser than the long wire. In this case, the long wire is preferably arranged between the pulp and the normal wire. Some of these so-called normal wires can be arranged along the entire path along which the long wire travels, or can be arranged, for example, only in the drying section. In an advantageous embodiment, the web is supported on both sides by a long wire all the way to at least the dry part and the normal wire is not applied at all or is applied only in the dry part.

  The method for producing a textile product according to the invention is mainly characterized by what is presented in claim 1. The system for producing a textile product according to the invention is mainly characterized by what is presented in claim 6.

1 is a side view illustrating an embodiment of a web former having a wire solution according to an example. FIG. Fig. 2 shows advantageous details of a wire solution according to the embodiment shown in Fig. 1;

  Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

  In the present application, a machine for producing a web containing fiber material is called a web forming machine. Such a machine may be, for example, a paper machine, a paperboard machine, or another similar machine.

  A web is a planar product that flows in the form of a continuous web, whose basic structure is a network formed at least partially from fibers, or is part of a fiber. At least some of the fibers include cellulose. The web may also contain various amounts of other materials such as fillers, surfactants, and additives. Furthermore, water is usually used in the manufacturing process. The final product of the manufacturing process may be, for example, paper, paperboard, thin wood plastic composite, or similar product.

  As used herein, fine wire refers to a dense wire having a mesh number of at least 130, 140, or 150. Fine wire may be denser, for example, wires having a mesh number of at least 180, at least 200, or at least 220. In this application, normal wire refers to a prior art wet wire or dry wire commonly used in web forming machines. The number of meshes indicates the number of filaments per inch in a filter such as a wire.

  In this application, a long wire refers to a wire that extends substantially from a web forming part (wire part) to at least a press part, preferably to a first press nip in the press part.

  The normal wire 9 refers to a conventional wire, and includes both a wet wire and a dry wire. The normal wire 9 is also referred to as a second wire 9 in the present application.

  Nanofibrinated cellulose (NFC) refers to a fibrous material in which single microfibrils are separated from one another. Nanofibrinated cellulose particles usually have a length of 1 μm or less, and their diameter is usually less than 1 μm and about 2 nm to 200 nm. The size of the nanofibrous cellulose particles depends on the method for producing the nanofibrous cellulose. Unlike the conventional pulverization of cellulose, in the production of nanofibrous cellulose, the purpose is to crush the cellulose fibers. In its appearance, nanofibrous cellulose is usually a transparent gel-like substance.

  FIG. 1 shows an advantageous embodiment of the invention. FIG. 2 shows advantageous details of the wire solution according to the embodiment of FIG. 1 and 2 show a web forming machine 1, a head box 2, a web forming unit (wire unit) 3, a press unit 4, a drying unit 5, a calendar 6, a reel up 7, a long wire 8, a normal wire 9, and a web. 10 is shown.

  In the solution according to the invention, one or more normal wires 9 may be provided, but the solution according to the invention can also be provided with no normal wires 9 at all. The normal wire 9 can be removed in particular from the part where at least one long wire of the machine is present. In an advantageous example of the invention, the long wire 8 is preferably a fine wire. According to an advantageous embodiment of the invention, the normal wire 9 is connected to the long wire 8 in a web forming machine such that the normal wire is at least partly disposed between the long wire 8 and the roll of the web forming machine. It can be used at substantially the same location. In this way, the normal wire 9 may prevent the wear of one or more long wires 8. This is advantageous because the long wire 8 may be a relatively expensive wire and replacing the normal wire 9 is often less expensive than the long wire 8.

  Usually, the web 10 is supplied from the head box 2 to the web forming unit 3. In the machine according to the present invention, there is at least one long wire 8, and the number of suitable long wires usually depends on the type of web 10 forming machine 1. Usually, the number of long wires 8 is exactly 1 or exactly 2 depending on the type of web forming machine 1. The long wire 8 can be supported by the normal wire 9 (a) in the web forming unit 3. In this case, the normal wire 9 (a) can slow down the wear of the long wire 8.

  From the web forming section 3, the web 10 is supported by at least one long wire 8 and is usually conveyed to the press 4 section in the drying process, where the long wire 8 is fed by the normal wires 9b and 9c of the press section. In this case, the normal wires 9 b and 9 c can delay the wear of the long wire 8. In the press section, one or both of the normal wires 9b, 9c can also be excluded from the solution according to the invention if they are replaced by the long wire 8. In an advantageous embodiment, the long wire 8 is arranged to support the web 10 from the web forming part 3 to a position beyond the first press nip of the press part 4, after which the long wire 8 is again formed into the web forming part. Led to the department. According to another advantageous embodiment, the long wire 8 is arranged to support the web to a position beyond the second press nip and / or the third press nip in the press section 4, after which the web is Then, the long wire 8 is guided to the web forming unit 3.

  From the press section 4, the web 10 is further advantageously guided to the drying section 5. In an advantageous embodiment, the web 10 is guided by the web forming part 3 to the drying part 5 supported on at least one identical long wire 8. In an advantageous embodiment, the long wire is such that the web 10 is in the first drying group, the second drying group, the third drying group, the fourth drying group, or the first in the web forming unit 3 to the drying unit 5. It is arranged to contact the same long wire 8 all the way to the desired drying group, such as 5 drying groups. The web 10 is then peeled from the long wire 8 and then the process can proceed so that the web can come into contact with, for example, the normal wire 9 as in conventional papermaking. The drying unit 5 may include one or more normal wires 9 d to 9 g in addition to the long wire 8. At least some of the normal wires 9 may be provided at substantially the same position as the long wires 8 in the drying unit 5 of the web forming machine 1, and one or more of the long wires 8 and the web forming machine 1 may be provided. It may be arranged between the rolls, and the normal wire 9 may delay the wear of the long wire 8.

  One long wire 8 may be provided, in which case the long wire 8 may be disposed on one side of the web 10 or, for example, the first long wire is disposed on one side of the web 10. The two long wires 8 may be provided so that the other long wire is disposed on the other side of the web 10. When two long wires are provided, the normal wire 9 may be provided in association with one long wire, for example, or may be provided in association with both long wires 8 as required. . In some cases, it may be preferable to place the normal wire 9 in association with both long wires 8, for example, to prevent wear of the long wires 8. If there are two long wires 8 in the machine, i.e. preferably there is one long wire 8 on each side of the web, peeling of the web from the long wire 8 will occur at substantially the same time or substantially It may be performed at different times, i.e., the webs 10 may be performed one by one so that they are first peeled from the long wire 8 and then peeled from the other long wire 8. In many cases, it is more preferable to use only one long wire 8 to minimize costs, if possible considering the functionality of the process. However, in some cases it may be necessary to use two long wires 8 for at least part of the dry length of the web. This type of situation may occur, for example, in connection with a so-called gap former.

  The long wire 8 is arranged so that the web 10 is continuously in contact with the long wire 8 at least from the web 10 forming unit 3 to the press unit 4 of the web 10, for example, to the middle of the press unit or to the drying unit 5. The forming machine 1 is advantageously arranged. When the web forming machine 1 includes a normal wire 9 that is in contact with the long wire 8, the long wire 8 is preferably configured such that the long wire 8 is a web 10 between at least one normal wire 9 and the web 10. Arranged to be on at least one side. The long wire 8 and the web 10 are preferably brought into contact with each other until the web 10 is sufficiently dry to be peeled from the long wire 8. The desired dry matter content of the web can be determined, for example, so that the web is intact when peeled from the wire and / or can prevent drying shrinkage in the width direction of the web. . Thereafter, the web 10 can be supported by the normal wire 9 as required.

  The number and location of possible normal wires may vary further from some of the advantageous embodiments described above. The essential aspect is that the long wire is in a continuous manner, at least from the web forming part 3 to the pressing part 4, more preferably to the drying part, or even to the first calendar or machine roll possible, for example. That is, the long wire 8 is arranged on the web forming machine 1 so as to support the web 10. Normally, inserting the long wire 8 through the calendar 6 is not necessary for the desired final result, and it is preferable not to transport the long wire through the calendar 6 in consideration of the desired final result. May be.

  Preferably, the long wire 8 includes a cleaning member for cleaning the long wire 8 or a part thereof between each circumference of the long wire. In practice, this can be implemented by mounting a suitable cleaning member in the prior art, such as a jet, for cleaning the long wire 8, for example. Preferably, in the cleaning of each position of the long wire 8, after the web 10 is peeled from the long wire 8, the position of the web 10 is supplied again to the web forming unit (wire unit) of the web forming machine. Always before the position is reached.

  In order to ensure efficient drying of the web 10, it is often advantageous to provide the web forming section 3 and / or the press section 4 with several separate means or devices for promoting drying. These may be prior art means or devices, for example suction boxes and / or suction rolls. In particular, when two wires are superimposed, there is a need to provide more such devices than usual and / or to be more efficient than usual.

  The web 10 can be peeled from the long wire 8 when the dry matter content of the web 10 is sufficient. The dry matter content may be sufficient when it is at least 8%, 9%, 10%, 11%, 12%, 13%, or 14% by weight, for example, Depending on the structure of the wire, it may advantageously be at least 15%, 18%, 20%, 25%, 30%, 40% or at least 60% by weight. The appropriate dry matter content is influenced, inter alia, by the equipment for drying the web and in particular the nature of the wire in contact with the web.

  In one example, the result of the present invention is that the nanofibrinated cellulose content in the pulp suspension can be set high, for example to achieve the desired properties in the final product. Thus, by applying the long wire solution according to the present invention, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60% by weight of the dry matter of the web 10 It is also possible to include a relatively large amount of nanofibrotic cellulose in the pulp, such that at least 70% by weight consists of nanofibrous cellulose. If necessary, for example, as required by the nature of the final product, further so that at least 80%, or even at least 90% by weight of the dry product of the web 10 is composed of nanofibrous cellulose. Many nanofibrinated celluloses can be included. In some cases, if the nanofibrinated cellulose content in the web is increased, the solution of the present invention becomes more useful because peeling of the web from the wire becomes more difficult than before the increase. With the solution according to the invention, it may be possible, in part or in whole, to prevent situations where the mechanical properties of the machine hinder the increase in the amount of nanofibrinated cellulose.

  According to one example of a solution, supporting the web to the wire with a considerable force is sufficient in the width direction if the support lasts for a sufficiently long time, or even substantially along the entire drying path of the web. The web may be prevented from drying and shrinking. In particular, in this case, the present invention may also be useful in the production of so-called normal fiber webs, and may be particularly useful for controlling drying shrinkage in the width direction. In the production of webs containing nanofibrinated cellulose, it has been found that the addition of nanofibrous cellulose often has an effect of increasing the dry shrinkage of the web, especially in the width direction. Further advantages are achieved. If the prior art solution is used, the aforementioned type of drying shrinkage in the width direction can thus even exceed 10%. Most of the drying shrinkage often occurs at the end of drying, in which case maintaining the web on the long wire 8, especially when maintaining from the web forming part to substantially the end of the drying part. In particular, drying shrinkage may be prevented.

  Although the present invention is particularly important for pulps containing nanofibrinated cellulose, the present invention can also be applied in connection with fiber pulps that do not contain nanofibrous cellulose. In this way, for example, it may be possible to substantially reduce web breakage in the press section. Furthermore, control of web shrinkage in the width direction may be facilitated. The present invention is suitable for application on various web forming machines, and the examples presented above do not limit the present invention. Accordingly, the invention is not limited to the examples presented in FIGS. 1 and 2 and the foregoing description, and the invention is characterized by what is presented in the following claims.

Claims (11)

A method for producing paper, paperboard, or similar fiber material comprising:
A pulp suspension is fed onto the first wire (8) so that a web (10) is formed,
In the method in which the formed web (10) is dried,
Further, after the web (10) is formed, the web (10) is continuously in contact with the same wire (8) from the web forming part (3) to the first press nip in the press part. A method for producing paper, paperboard or similar fiber material.   Nanofibrinated cellulose is included in the web, and the nanofibrinated cellulose content in the web is at least 10 wt%, at least 20 wt%, at least 30 wt%, or at least 40 wt%, calculated on dry matter content The method of claim 1, wherein:   The nanofibrinated cellulose content in the web is at least 50 wt%, at least 60 wt%, at least 70 wt%, or at least 80 wt%, calculated on dry matter content. The method described.   The first wire (8) according to any one of claims 1 to 3, characterized in that at least part of the first wire (8) is supported by the second wire (9) at least on one side. The method described.   In the method, the total length of the second wire (9) used is larger than the mesh size of the first wire (8) and / or shorter than the first wire (8). The method of claim 4, comprising:   The web is continuous until the dry matter content of the web is at least 10%, 12%, 15%, 20%, 25%, 30%, 40%, or at least 50% by weight. 6. A method according to any one of the preceding claims, wherein the contact with the first wire is continued. A system for producing paper, paperboard or similar fiber material, said system comprising a web forming machine (1), said web forming machine comprising at least a first wire (8);
A web forming part (3) comprising means for supplying a pulp suspension onto the first wire (8) for the formation of the web (10);
A system comprising a press part (4) comprising means for reducing the moisture content of the web,
The first wire (8) is disposed in the web forming machine (1) so as to continuously run at least from the web forming unit (3) to the press unit (4), and the wire (8) A system for producing paper, paperboard or similar fiber material, characterized in that the web to be formed is continuously supported from the web forming part (3) to at least the first press nip of the press part.   The system comprises at least a drying section (5), the drying section comprising means for reducing the moisture content of the web substantially by the effect of temperature, the first wire (8) comprising a first wire 8. The web forming machine (1) according to claim 6 or 7, characterized in that the wire (8) is arranged in the web forming machine (1) so that it runs continuously from at least the web forming part (3) to the drying part (5). system.   The drying section (5) includes a first drying group, a second drying group, and a third drying group, and the first wire (8) has the first wire from the web forming section (3). 9. System according to claim 8, characterized in that it is arranged to run continuously to at least the second drying group or the third drying group of the drying section (5).   The system includes not only the first wire (8) but also the second wire (9), the second wire (9) being a long wire (8) in several stages. 10. A system according to any one of claims 6 to 9, characterized in that it is arranged on the web forming machine (1) to support the first wire (8) so as to contact it.   The system further includes a third wire, the third wire is placed in the web forming machine (1), and the third wire is also continuous from at least the web forming part (3) to the pressing part (4). And the web forming machine (1) is arranged to continuously support the web to be formed from the web forming section (3) to at least the first press nip in the press section. The system according to any one of claims 6 to 10.

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