• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a dryer fabric woven from machine direction yarns (2) and cross direction yarns (3). The machine direction yarns (2) have on a paper side (P) of the dryer fabric (1) free long floats above at least seven transverse yarns. Furthermore, the fabric has a double-cloth structure with machine direction yarns in two successive layers (2a, 2b).
    公开号:AT15788U1
    申请号:TGM50059/2017U
    申请日:2016-03-18
    公开日:2018-06-15
    发明作者:Enqvist Rauno；Liitola Aira
    申请人:Valmet Technologies Oy；
    IPC主号:
    专利说明:

    description
    DRYER FABRIC STATE OF THE ART
    The invention relates to a dryer fabric which is adapted to be used in a dryer section of a paper machine. The dryer fabric is a woven structure and includes machine direction yarns, i. H. Warp yarns, and cross direction yarns, d. H. Weft yarns.
    The field of the invention is more particularly defined in the preamble of the independent claim.
    In a dryer section of a paper machine dryer fabric and screens are used. The dryer fabric allows the paper web to be dried to be passed through the dryer section. However, it has been found that the known solutions have some disadvantages.
    BRIEF DESCRIPTION OF THE INVENTION
    It is an object of the invention to provide a new and better dryer fabric available.
    The object of the invention is achieved by a dryer fabric for a dryer section of a paper machine according to claim 1. Advantageous embodiments are set forth in the dependent claims.
    The dryer fabric of the invention is characterized by the characterizing features of independent claim 1.
    One idea of the disclosed solution is that as machine direction yarns, i. H. MD yarns or warp yarns, flat yarns are used. The fabric has a dual machine direction yarn structure, i. H. a double-warp system whereby the machine direction yarns are arranged in two successive layers. In addition, the MD yarns have extremely long floats on at least one paper side surface of the dryer fabric. The long float means that the MD yarns have at least seven cross-direction yarns; H. CMD yarns or weft yarns, run away.
    Furthermore, the dryer fabric has a double-cloth structure. The dryer fabric then has two independent fabric layers each comprising its own yarns. However, the structure is self-sewn, and therefore the layers of the fabric are bonded together so that the machine direction yarns engage the paper side layer and the roll side layer at appropriate intervals.
    An advantage of the disclosed solution is that the paper side of the dryer wire is very smooth and its contact area is large. The smooth surface prevents the pattern of the product. The substantial contact area also allows for proper heat transfer between the paper web and the dryer fabric, which gives the fabric a higher drying performance.
    The disclosed dryer fabric also provides good runnability in the dryer section of a paper machine. This is due to the fact that the amount of air that is carried by a smooth-surfaced dryer fabric is low. Thus, the fabric can have low air transport and good aerodynamic properties.
    In addition, the tendency or force to hold the web in place is good on a smooth dryer fabric, and therefore the fabric controls the course of the web even at high speeds. Another advantage of a smooth-surfaced dryer fabric is that the fabric remains clean and can be easily cleaned in the event of fouling.
    The disclosed double cloth structure or double yarn structure of the dryer fabric makes the fabric strong and stable. The machine direction elongation of the fabric may be small because the structure, due to the double-cloth structure, includes a large amount of machine direction material. In addition, due to the large amount of machine direction material, the wear resistance of the disclosed dryer fabric can be excellent.
    In one embodiment, the dryer fabric has an eight-ply double cloth structure.
    According to one embodiment, the machine direction yarns in the structure of the dryer fabric are stacked vertically one on top of the other. Alternatively, the machine direction yarns are vertically stacked but slightly misaligned with each other.
    According to one embodiment, the contact area of the paper side of the dryer fabric is 50% or more. The large contact area is formed by long floats of flat machine direction yarns. It has been found that the drying ability is excellent when the contact area is 50% or more.
    According to one embodiment, the air permeability of the dryer fabric after heat treatment is between 90 - 400 cfm (cubic feet per minute). The heat treatment, by and large, densifies the fabric as the MD yarns are moved towards each other due to shrinkage of the fabric.
    In one embodiment, the cross-direction yarns are highly shrinking yarns, whereby a heat treatment of the dryer fabric is designed to cause a transverse directional shrinkage of the dryer fabric so that adjacent machine direction yarns are moved towards each other. Further, the shrinkage of the cross-direction yarn is more than 10%, and the dryer fabric after heat-treatment weaving has shrunk at least 10% in the transverse direction. The shrinkage of the dryer fabric in the transverse direction also increases the contact area of the paper side.
    According to one embodiment, the thickness or thickness of the dryer fabric between 1.4 - 1.8 mm. If the thickness is in this range, the dryer fabric has the necessary stability and is still not too thick.
    According to one embodiment, the dryer fabric has a single-ply structure. Then the dryer fabric has cross-direction yarns in only a single layer.
    According to one embodiment, the cross-section of the cross-direction yarn is round or substantially round.
    According to one embodiment, the diameter of the cross-direction yarn is between 0.4 and 0.8 mm.
    According to one embodiment, the cross section of the machine direction yarns is rectangular or substantially rectangular. The cross-sectional shape of the rectangle may have rounded corners. Further, the width of the machine direction yarn is 0.6 mm or more and the height is 0.4 mm or less.
    In one embodiment, the machine direction yarns and the cross-direction yarns are polyethylene terephthalate (PET) yarns. PET yarns are less expensive compared to, for example, polyphenylene sulfide (PPS) yarns. The PET yarns may contain an additive to improve the heat resistance and stability. Thanks to the disclosed fabric structure, less expensive material can be used without compromising the wear properties, stability and durability of the dryer fabric.
    According to one embodiment, the dryer fabric is a flat fabric. Then, the dryer fabric has two opposite longitudinal edges in the machine direction and two opposite ends in the transverse direction. The connection ends can be connected together during the installation of the dryer fabric in a dryer section.
    According to one embodiment, the dryer fabric is provided in the transverse direction of the fabric with a first seam end and a second seam end. The seam ends are provided with connecting elements for connecting the seam ends in order to form a seam and to be able to form an endless dryer fabric through the seam. The dryer fabric may be flat woven and may be provided with any type of integrated or separate sewing aids or fasteners to bond the distal ends together when the dryer fabric is installed in an application position.
    In one embodiment, at least a portion of the machine direction yarns are arranged to form seam loops at the seam ends. The machine direction yarns may then provide the dryer fabric with a strong and non-scribing warp loop seam. The seam loops may be relatively long due to the long floats of the machine direction yarns forming the seam loops. Thanks to the relatively long seam loops, the installation of the dryer fabric is easy and fast. However, the long seam loops lead to no patterning of the web.
    According to one embodiment, all machine direction yarns form seam loops at both seam ends. Sewing such a dryer fabric is easy and fast.
    In one embodiment, at least a portion of the machine direction yarns are arranged to form seam loops at the seam ends. The loops are grouped at the seam end so that two adjacent MD yarns are arranged to form a pair of long loops and the following two adjacent MD yarns are arranged to form short loops and the next two adjacent MD yarns in turn form two long seam loops and so on. Thus, the seam ends may comprise so-called double seam loops.
    According to one embodiment, the seam ends are provided with suture spirals, which serve as connecting elements.
    In one embodiment, the dryer fabric is produced using an endless weaving technology whereby the dryer fabric does not include seam ends. Instead, the dryer fabric is in the form of an endless loop.
    According to one embodiment, the machine direction yarns pass on the roll side of the dryer fabric under at least seven transverse yarns, thereby forming long floats on the roll side. Long floats of the machine direction yarns on the roll side surface improve the wear resistance of the dryer fabric.
    In one embodiment, the machine direction yarns have free long floats that traverse at least eleven cross direction yarns. It is possible for the machine direction yarns to pass over fifteen, nineteen or even several CMD yarns on the paper side surface and / or on the roll side surface.
    According to one embodiment, the dryer fabric has an asymmetric structure with respect to the free long run of the machine direction yarns on the paper surface side and the roll surface side. This means that the size of the floats on the paper side surface and the roll side surface may be different.
    In one embodiment, adjacent machine direction yarns have a phase offset of two cross direction yarns.
    In one embodiment, the machine direction yarns are monofilament yarns.
    In one embodiment, the cross-direction yarns are monofilament yarns.
    In one embodiment, the dryer fabric has an at least eightfold weave structure. Thus, the fabric may have an 8, 10, 12 or 16-fan structure with respect to its weave pattern. Thanks to this structure, the fabric can have very long free floats of MD yarns.
    The embodiments disclosed above may be combined to form suitable solutions provided with the necessary features.
    BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, some embodiments will be described in more detail. 1 shows a schematic perspective view of a dryer fabric which is provided with a seam and thereby has the shape of an endless loop, FIG. 2 is a schematic view of a dryer fabric as seen from a paper-side surface, [0043] FIG schematically and from the transverse direction of a Endab section of a conceivable single-layer dryer fabric, which is provided with Verbindungsnahtschlaufen to allow the formation of a seam, Figures 4 and 5 are schematic views of a dryer fabric on a paper-side surface and on a Figure 6 shows schematically a difference between a conventional solution with short floats of MD yarns and the disclosed solution with long floats of MD yarns. Figure 7 shows a roll or machine side surface with long floats of machine direction yarns Surface of a paper-side surface of a dry 8 shows a surface topography of a paper-side surface of a dryer fabric, wherein a potential surface contact area is indicated in the figure by different colors, and FIG. 9 shows an example of features and properties of a dryer web according to the disclosed solution.
    For clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals designate like elements.
    DETAILED DESCRIPTION OF SOME EMBODIMENTS
    Figures 1 and 2 show some basic features of a conceivable dryer fabric 1. The dryer fabric 1 may have a weave structure with machine direction yarns 2 and cross direction yarns 3 crossing each other. The dryer fabric may be flat woven and its seam ends SE1 and SE2 may be joined together to form a seam S when installed in a dryer section of a paper machine. The dryer fabric 1 is designed to run in the machine direction MD. The dryer fabric 1 comprises a paper-side surface P, opposite to which a paper web to be dried is arranged in the dryer section. The opposite side is a roller-side surface facing rollers and other machine elements of the paper machine.
    3 shows an end portion of a conceivable single-layer dryer fabric 1, which is provided with Verbindungsnahtschlaufen 4. When opposing seam ends SE1 and SE2 are opposed to each other so that the seam loops 4 are interlocked at their ends and a seam channel is formed, a seam S is formed. Within the suture channel, a connecting yarn or suture 5 is inserted to connect the suture ends SE1 and SE2.
    In Figure 3, the basic structure of the dryer fabric 1 is a single-ply fabric with the cross-direction yarns 3a and 3b in a single ply. The structure may include cross-directional fill yarns 3a and cross-directional ground yarns 3b. The yarns 3 are connected to the machine direction yarns 2. The machine direction yarns 2 are arranged in two layers 2a, 2b which are superimposed so that the yarns 2a on the paper side surface P and the yarns 2b on the roll side surface R pass. Thus, the fabric has a double weave structure comprising a double warp yarn system. The machine direction yarns form seam loops at the seam ends SE1 and SE2. The machine direction yarns 2 have free long floats LFP over seven cross direction yarns 3 on the paper side surface P. The roll side surface R may also be provided with the long floats LFR. The number of transverse yarns 3 traversed by the machine direction yarns 2 with the long floats may be the same or different, which means that the structure may be symmetrical or asymmetrical. As can be seen in Figure 3, the dryer fabric has an eight-ply weave structure with the machine direction yarn 2 passing over seven CMD yarns 3, passing under a CMD yarn 3, and continuing to repeat the same pattern. It should be noted that other weave patterns can be used which allow extremely long floats.
    Figures 4 and 5 show a dryer fabric 1 having a double-cloth structure with CMD yarns 3 in two layers. In FIGS. 4 and 5, CMD yarns of a bottom layer are identified by the reference character 3d. Further, the dryer fabric 1 is provided on a paper side surface P and also on a roll or machine side surface R with long floats LFP of machine direction yarns 2. Figure 4 also illustrates that all machine direction yarns 2 have the same weave pattern, but an adjacent MD yarn pattern includes a phase shift of one or two CMD yarns in the same direction.
    FIG. 6 schematically illustrates the difference between a conventional solution with short floats SF of MD yarns 2 and the disclosed solution with long floats LF of MD yarns 2.
    FIG. 7 shows a surface of a paper-side surface P of a dryer fabric 1. FIG. 8 shows a surface topography of a paper-side surface P of a dryer fabric 1. The potential surface contact area is shown in FIG. 8 by means of yellow color. The yellow or lighter color indicates the potential contact areas, while the red or darker color indicates contactless areas. As can easily be seen from FIG. 8, the contact surfaces represent more than 50% of the total area of the dryer fabric 1.
    Figure 9 shows an example of features and properties of a dryer fabric having an air permeability of 110 cfm according to the disclosed solution. The characteristics and properties of the dryer fabric determined in laboratory measurements are as follows:
    - Design 8-fold DT
    - weft profile, mm 0.3 x 0.8 [0059] - number of shots, 1/10 cm 240 [0060] - thickness, mm 1.6 [0061] - basis weight, g / m2 1300 [0062] - MD Strength kN / m 270 - MD Elongation @ 5 kN / m,% 0.9 - CMD Stiffness, mN 250 [0065] - Contact Area,% 52 The MD yarns and CMD Yarns can be both monofilaments and made of plastic material. As MD yarns flat threads are used, whose cross section preferably resembles a rectangle with rounded corners. Such a thread is compared with, for example, flat oval threads, which can be used in principle, provided with a larger contact surface. Again, the cross-section of the CMD yarns may be substantially round, whereby the MD yarns run as smoothly as possible between the CMD yarns as they pass between the paper side P and the roll side R of the fabric. As CMD yarns extremely high shrinkage filaments can be used, which means that the longitudinal shrinkage of a single filament is at least 10%. In addition, the shrinkage in the width direction of the entire dryer fabric is at least 10%.
    This application relates to a dryer fabric used in a dryer section of a paper machine. However, it has been recognized that the disclosed fabric structure could also be used in filtering devices such as horizontal band filters. The disclosed structure may also be conveniently used as a conveyor belt in a paper machine or any other machine processing a fibrous web.
    The drawings and the description associated therewith are merely intended to illustrate the idea of the invention. The details of the invention may vary within the scope of the claims.
    权利要求:
    Claims (7)
    [1]
    claims
    A dryer fabric for a dryer section of a paper machine, the dryer fabric (1) being a woven structure comprising: a paper side surface (P) facing a fibrous web to be dried during use of the dryer fabric (1); a roll side surface (R) facing the paper machine during use in the dryer section; several machine direction (MD) yarns (2) having flat cross sections; and a plurality of cross-directional (CMD) yarns (3), characterized in that the dryer fabric (1) has a dual machine direction yarn structure comprising machine direction yarns (2) in two successive layers (2a, 2b); the machine direction yarns (2) on at least the paper side (P) of the dryer fabric (1) over at least seven transverse yarns (3), whereby on the paper side (P) long floats (LF, LFP) are formed and the dryer fabric (1) on the Paper side (P) is given a smooth surface; and the dryer fabric also has a double-cloth structure such that the fabric has two independent fabric layers over each other and the fabric layers are self-sewn to bond the fabric layers together.
    [2]
    2. dryer fabric according to claim 1, characterized in that the contact surface of the paper side (P) of the dryer fabric (1) is 50% or more.
    [3]
    3. dryer fabric according to claim 1 or 2, characterized in that the transverse yarns (3) are highly shrinking yarns; and the shrinkage of the cross-direction yarn (3) is more than 10%, and that the dryer fabric (1) has shrunk after being subjected to heat treatment by at least 10% in the transverse direction.
    [4]
    4. dryer fabric according to one of claims 1-3, characterized in that the cross section of the machine direction yarns (2) is rectangular or substantially rectangular; and the width of the machine direction yarn (2) is 0.6 mm or more and the height is 0.4 mm or less.
    [5]
    5. dryer fabric according to any one of claims 1-4, characterized in that the machine direction yarns (2) on the roll side (R) of the dryer fabric (1) under at least seven transverse yarns (3) pass through.
    [6]
    A dryer fabric according to any one of claims 1-5, characterized in that the machine direction yarns (2) have long free floats (LF, LFP, LFR) running over at least one surface of the dryer fabric (1) over at least eleven cross direction yarns (3) ,
    [7]
    7. dryer fabric according to any one of claims 1-6, characterized in that the dryer fabric has an at least achtfächrige weave structure. 4 sheets of drawings
    类似技术:
    公开号 | 公开日 | 专利标题
    DE60104770T2|2005-08-11|Forming fabric for papermaking
    EP0114656B1|1987-03-04|Compound fabric as a machine clothing for the sheet forming part of a paper machine
    DE60014912T2|2005-10-20|TISSUE
    DE69727944T2|2005-02-03|PAPERMAKER TISSUE WITH BOTH-SIDED ALTERNATIVE TAPES
    DE60026589T2|2006-08-10|PAPER MACHINE COVERING
    DE2540490A1|1976-04-22|TWO LAYER MOLDING SCREEN
    DE60300102T2|2005-12-01|METHOD OF CLEARING SPIRALLY PAPER MACHINE TENSIONS
    DE60104980T2|2005-09-08|papermaker
    DE69909628T2|2004-06-09|DOUBLE-PAGED FORMING FABRIC FOR PAPER MACHINES
    DE60131406T2|2008-09-11|MULTI-LAYER PRESS FABRIC WITH CONNECTIONS
    DE60203833T2|2006-01-12|Seam construction of a papermaker's fabric
    DE202016008247U1|2017-07-05|drying fabric
    DE69627234T2|2004-02-05|press fabric
    EP1054097B1|2002-06-05|Papermaking fabric, in particular a dryer cloth
    DE60119340T2|2007-03-29|dryer
    DE2263476B2|1980-03-13|Fabrics for paper machine screens
    DD295886A5|1991-11-14|Dewatering fabric for a press section
    DE102013106327B4|2015-01-08|papermaker
    DE60220132T2|2008-01-17|Improved seam for papermaker fabric with seam
    DE2455185A1|1975-05-22|FABRIC FOR THE MAKING OF PAPER
    EP2922995B1|2016-04-13|Paper machine wire having floats of different length on the machine side
    DE102014223972A1|2016-05-25|Double loop seam in stringing
    DE4304758C2|2002-06-27|Drier screen of a paper machine
    EP0190589A1|1986-08-13|Spiral fabric having protected margins
    EP2129829B1|2010-08-11|Belt for paper machine
    同族专利:
    公开号 | 公开日
    DE202016008247U1|2017-07-05|
    US20170275823A1|2017-09-28|
    FI20155205A|2016-09-25|
    WO2016151189A1|2016-09-29|
    CN206970995U|2018-02-06|
    CA2961867A1|2016-09-29|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US5713397A|1996-08-09|1998-02-03|Wangner Systems Corporation|Multi-layered through air drying fabric|
    WO2000009801A1|1998-08-11|2000-02-24|Asten, Inc.|Woven soft-faced press fabric|
    WO2001088260A1|2000-05-18|2001-11-22|Tamfelt Oyj Abp|Dryer screen|
    US5429686A|1994-04-12|1995-07-04|Lindsay Wire, Inc.|Apparatus for making soft tissue products|
    FI118694B|2006-04-27|2008-02-15|Tamfelt Oyj Abp|dryer screen|
    FI7901U1|2007-03-20|2008-06-25|Tamfelt Pmc Oy|Drying wire and drying wire seam area|
    FI20115222A|2011-03-04|2012-09-05|Metso Fabrics Oy|papermaker|
    FI20135500A|2013-05-13|2014-11-14|Metso Fabrics Oy|Filter element, method for its production and use|FI127677B|2016-02-26|2018-11-30|Valmet Technologies Oy|Industrial textile and use of the same|
    FI128025B|2017-03-24|2019-08-15|Valmet Technologies Oy|An industrial textile|
    US20180347114A1|2017-05-30|2018-12-06|Astenjohnson, Inc.|High stability stacked warp yarn dryer fabric with long warp floats|
    法律状态:
    2021-11-15| MM01| Lapse because of not paying annual fees|Effective date: 20210331 |
    优先权:
    申请号 | 申请日 | 专利标题
    FI20155205A|FI20155205A|2015-03-24|2015-03-24|The drying wire|
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