KR20050110665A - Fabric support element for a papermaking machine - Google Patents

Abstract

A fabric support element (80) for a papermaking machine has improved fluid drainage means, comprising openings which can include flow-through vents. The element can comprise an impingement shoe for a forming section of a papermaking machine. The openings can be defined by a plurality of laminar segments (85), at least some of which define a paper side surface of the element, and which segments can be spaced apart by additional laminar segments (86) or other spacing means. Laminar segments for use in the element, a method of constructing the element, and a papermaking machine, or a forming section thereof, including the element are also provided.

Description

Fabric Support Element for Paper Machine {FABRIC SUPPORT ELEMENT FOR A PAPERMAKING MACHINE}

The present invention relates to a fabric support element for use in a paper machine, a segment for use in the element, a paper machine and a method of manufacturing the element or a forming section thereof.

In the initial portion of the forming section of the papermaking machine, an unsupported jet of highly water soluble stock is injected from the head box slice onto the surface of the moving forming fabric. Unsupported jets typically traverse a distance of about 6 cm to about 40 cm before impacting the surface of the forming fabric at the point of impact. The angle of impact, α, formed between the stock jet and the plane of the forming fabric at the point of impact, is typically about 4 ° to about 10 °. It is well known that improved paper formation can be obtained by minimizing both the length and angle α of the unsupported free jet. As the angle α increases, the magnitude of the pressure exerted by the jet on the surface of the forming fabric also increases.

Impingement angles above about 5 ° have generally been found to cause peak impact pressures that can cause sheet marking, low retention of paper particles and fillers, and clogging of the forming fabric. Thus, the angle α should be formed as small as possible, so that ideally unsupported stock jets impinge on the fabric in a substantially tangential manner.

As the unsupported length of the free stock jet increases, its outer surface begins to separate into ridges and furrows, which can result in sheet basis weight changes. Moreover, the finely dispersed fabric in the stock quickly begins to reaggregate in the unsupported jet before the impact point. Therefore, unsupported stock jets should be formed as short as possible to initiate this effect.

Due to the complete space requirements of both the adjacent upstream rolls and the headbox slice lips, such as breast rolls or forming rolls, it is difficult to shorten unsupported stock jet lengths without increasing the angle α. The air trapped in the small wedge shaped space between the surface of the forming fabric and the surface of the unsupported stock jet, even if the head box slice lip can be positioned so that the angle α is very small and the free jet is nearly in contact with the forming fabric. Is entrained into stock and forms bubbles which are lethal to sheet formation.

Some proposals have been made to address these issues. US Pat. No. 3,440,136 to Nelson et al. Discloses a method of preventing air entrainment by scavenging air from a forming zone and a method of flooding such a zone with water. However, it has been found that this proposal is difficult to implement in practice. Irwin et al. US Pat. No. 4,734,164 discloses a forming plate for a single weaving machine that somewhat curves the first blade to cause the breast roll to be somewhat lower. The problem with this proposal is that air is trapped in the shallow wedge space between the jet and the forming fabric as it passes over the unvented solid side of the curved first blade. This air is forced into the stock, such as foam, causing the formation defect. US Pat. No. 4,802,954 to Malashenko discloses a tip positioned in front of a curved blade element proposed by Irwin et al. Start the blade. However, a small wedge shaped air space remains. The pressure in this space is controlled by a vacuum pump to reduce jet disturbances. US Patent No. 5,084,138 to Ewald raises the issue of excessive free jet length by using curved bar rotation to replace large diameter breast rolls and solid curved blades, but traps air in the wedge between the jet and the fabric. Does not prevent.

Fujiwara, US Pat. No. 4,425,188, uses longitudinally spaced grooves in twin wire forming shoes that create cross-direction flow to realign the fabric in the initial web to reduce machine direction fabric alignment. US 6,372,091 to Wildfong et al. Presents improved removal of water by the use of grooves in terms of forming shoe.

However, although it is known that grooving forming shoes, also known as impingement shoes, can improve the properties of the final paper, it has been found that there are problems associated with the use of such grooves. First, the grooves lose their beneficial effect in practice because the grooves are quickly filled with stock and thus there is no good means to quickly remove the drained fluid from the fabric contact surface. Second, it has been found that the grooves can create a foiling effect between the machine side of the fabric and the inside of the grooves, creating a sufficient level of suction to result in degradation of the paper properties. Third, it is difficult, time consuming and expensive to create precisely sized grooves on the typical ceramic surface of such blades, and the integrity of the ceramic can be compromised by the machining process.

The following terms have the meanings indicated below. Other terms used herein have ordinary meanings related to terms in the paper industry.

The cross machine direction CD is actually in the plane of the paper sheet and in a direction substantially perpendicular to the machine direction MD.

Downstream is the direction of the paper machine where the final paper product actually faces towards the reels present in the machine.

Fabric support elements include, but are not limited to, shoes, blades, foils and agitators in the forming section and Uhle box covers in the press section, to secure any of the papermaking machines through which the at least one papermaking machine cloth slides through. Element.

Laminator segments are relatively thin components having a thickness ranging from about 1 mm (0.04 inch) or less to about 254 mm (1 inch) or more that can be assembled in a side to side relationship to form a fabric support element of the desired width. Laminator segments may typically be formed of ceramic or other abrasive wear materials.

The machine direction MD is the direction in the paper machine which is substantially parallel to the overall direction of the conveyance of the paper sheet.

The machine side (MS) surface is the side of the fabric or fabric support element that is opposite to the paper side surface without contacting the paper sheet.

The paper side (PS) surface is the side of the fabric or fabric support element which is formed on the paper machine and which contacts or opposes the paper sheet being conveyed through the paper machine.

Upstream is the direction of the paper machine which is essentially opposite towards the headbox.

Aeration describes the presence of an open passage that penetrates through the paper side surface to the machine side surface of the support element, ie through the fabric contact side and through to the opposite side, the passage being referred to herein as a flow through vent. To mention.

It has been found that some of the above mentioned drawbacks can be completely or virtually eliminated by the use of vents, which can penetrate completely through the impact shoe to allow efficient removal of sufficient fluid to prevent filling of the grooves. This fluid penetrating vent opens from the paper-side surface penetration to the machine-side surface of the impact shoe, such that an initial impact on the impact shoe is more likely than previously possible with a grooved surface, as defined by Wildpong et al. US Pat. No. 6,372,091. It is possible to remove larger amounts of fluid with air trapped between the stock jet and the forming fabric from the zone.

Moreover, it has been found that such flow through vents allow significant changes in both the final position of the impact point and the impact angle of the stock jets without any significant adverse effect on the final paper properties. This result is of significant importance because a change in the impact angle of a stock jet, which is conventionally as small as 1/2 of a degree from the best value, can produce a significant toxic effect on sheet properties with regard to sheet making, holding and forming. Thus, the present invention allows a wider range in the impact angle of the stock jets than was previously viable.

In addition, such flow through vents are most advantageous by constructing a collision shoe from a plurality of relatively thin laminator segments mounted together in a suitable holding means in the papermaking machine to be substantially parallel and in contact with each other and oriented substantially at an angle in the machine direction (MD). It was discovered that it could be an enemy. These laminator segments are in fact machine side configured to be mounted on the retaining means, paper side facing the forming fabric in use, upstream (or leading edge) and downstream (or trailing edge) and cross machine directions (CD) facing. It is preferably formed of a suitable material, such as ceramic, to have parallel side mating surfaces. The PS face of at least the first set of segments together defines the fabric contact surface of the impact shoe intended to support the forming fabric. This surface can have any desired profile suitable for good paper making requirements. The second set of segments, where the PS side profile may differ from the first set, may be located at appropriate intervals in the CD between the first pair of segments. Preferably, the second set of segments may be defined to define an opening in the fabric contacting surface of the element and open through the MS surface from the PS surface. Alternatively, the spacing means can be constructed integrally with only one or both of the lateral CD surfaces of the first set of segments, in which case the impact shoe generally consists only of this first segment. It has been found that the spacing means constructed integrally with the first set of segments or having the second segment can have a suitable shape to optimize the removal of trapped air and fluid from the stock jet.

Furthermore, in any section of the paper machine using a plurality of at least first and second laminator segments that are positioned as required for any of the forming section, the press of the paper machine or the drying section and are mounted to be mounted on appropriate holding means. It has been determined that it is possible to assemble a segmented fabric support element intended for use. These first and second laminator segments are mounted on known holding means to be substantially parallel and in contact with each other and positioned substantially at the MD or at an angle. The configuration and shape of this segment is as described above with respect to the impact shoe, and at least the PS side of the first segment together defines a fabric contact surface intended to support the papermaking fabric. The PS face of at least the first and second segments is formed to provide the PS face of the element in any desired profile upon assembly suitable for good paper making conditions. The second set of segments is not absolute but means for spacing or profiling at appropriate intervals in the CD between selected pairs of the first pair of segments that may be formed of an opening that may include a vent opening from the PS side through the MS side of the element. Can be located. The PS faces of the first and second segments can be formed to provide elements assembled to one or both of the desired MD and CD profiles. The third or fourth segment or the like can also be used in a similar manner in combination with the first and second segments.

The present invention provides a vented crash shoe for use in a papermaking machine having a plurality of flow through vents extending from the profiled top surface and through the bottom surface of the crash shoe.

The present invention provides a segmented fabric support element for use in the impact zone of the forming section of a high speed papermaking machine, the element consisting of a plurality of laminate segments. The PS face of this segment is formed to contribute to the overall desired profile of the PS or fabric contact surface of the element, and if desired, the vent through the element is defined by the opening between the selected laminator segments.

Thus, the collision shoe constructed in accordance with the present invention performs four main functions. It first acts to support the forming fabric when entering the impact zone and secondly to vent at least substantially some of any air trapped in the wedge shaped space between the surface of the forming fabric and the surface of the stock jet. Third, it allows the drained water to be removed effectively and quickly, and fourth, provides tolerances that cannot be previously achieved at the location of the impact angle and the point of impact.

Moreover, the present invention provides a fixed fabric support element for a paper machine, which element is composed of a plurality of at least first and second relatively thin laminator segments.

Moreover, the present invention provides a segment for use in a crash shoe or other fixed fabric support element, such that at least some segments of the PS side contribute to the profiled fabric contact surface of the element, and the vent through the element is provided between at least some segments. It can be defined by the opening. This segment is formed such that the fabric support element can be mounted to a fixing means that is releasable with appropriate holding means.

The invention also provides a forming section for a papermaking machine, the forming section comprising a segmented fabric support element comprising a flow through vent as impingement shoe.

The present invention also provides a method of manufacturing an element assembled from a plurality of segments.

1 shows a part of an open surface paper machine comprising an impact shoe.

2 and 3 show parts of two different twin fabric paper machines.

4, 5, and 6 show segments of three different embodiments of the present invention, respectively.

7 shows an alternative arrangement for the use of an optional profile for the laminate segment of the present invention.

8 is an isometric view of a vented fixed support element in an embodiment of the invention.

9 is a plan view of a device for a segment in an embodiment of the invention.

Thus, in a first broad embodiment, the present invention is to provide a vented segmented fabric support element for use as a crash shoe in the initial impact zone of the forming section of a papermaking machine.

The impingement shoe consists of a plurality of laminate segments arranged and configured on the joint support means to be releasably secured substantially parallel in contact with each other so that the forming fabric is slidably contacted against the joint PS fabric in contact with the surface of the segment. do.

In one alternative configuration of the impact shoe, the laminator segments may comprise spacer means which are not absolute but may be constructed integrally therewith and are identical in shape.

In a second alternative configuration, the impact shoe consists of at least first and linear second segments, where the first segment contributes to the PS fabric contact surface and the second segment does not, but instead any two segments or two or more segments. It is located between groups. The second segment is formed to form a vent between two adjacent segments and, if desired, an additional opening on the PS side of the element, which vent opens through the PS side to the MS side of the impact shoe and allows the passage of fluid and forms the fabric. Accompany air from the stock jet through. Optionally, this venting can be augmented by vacuum means connected to the underside of the impact shoe. Advantageously, the second segment can be hydrodynamically shaped to assist in the removal of large amounts of fluid movement at a relatively high speed. The second segment generally separates a portion of the first segment to form an opening on the fabric contact surface of the impact shoe. Such openings can be directed at any desired angle to the MD by appropriately forming a laminator segment. Preferably, this opening is directed at an angle of about 2 to about 20 degrees to the MD and is slot shaped. Both the vent and the opening are directed at the same angle to the MD due to the structure of the impact shoe.

In a third alternative structure, a third segment is provided and positioned as needed between the selected first and second segments, the PS face of the third segment having an appropriate profile for the intended application.

Releasable fixed mounting of the segment can be performed by a variety of known means such as T slots or dovetail mounts. Alternatively or additionally, the segment may have an opening through which a rod or cable can be screwed, for example, as described in US Pat. No. 3,871,953 to Lee et al. For a plurality of identical segments. Thus, the rod or cable can be secured by known means to a suitable end block located on the side of the forming section.

Accordingly, the present invention provides an aeration impingement shoe for use in a papermaking machine as located adjacent to the point of impact of a stock jet emitted from a headbox slice on a moving forming fabric, the impingement shoe being

(i) the leading edge located upstream of the collision point;

(ii) the trailing edge,

(iii) a machine side configured to be releasably secured to the paper machine by fastening means,

(iv) a paper side having a predetermined cross machine direction and a machine direction profile configured to support the forming fabric at the slide contact,

The paper side includes a plurality of vents that extend from the paper side through the machine side of the impingement shoe, starting from the adjoining edge of the leading edge and ending with the adjoining of the trailing edge.

Preferably, the profiled PS surface of the impact shoe between the leading and trailing edges is generally convex but may be of any suitable shape for the particular environment. This may include a circularly convex curved surface with a constant radius or a surface with a radius of curvature that increases toward the trailing edge, such that the shaped trailing edge may be flat. When intended to be used in other areas of the papermaking machine, i.e., other than the impact shoe, the PS surface may be flat, grooved or otherwise profiled. This choice depends on the restraint conditions in the intended area of use.

In a second broad embodiment, the present invention provides a forming section for a papermaking machine having a machine direction and a cross machine direction, at least one forming fabric moving in the machine direction, and an impact angle on the first forming fabric at the point of impact. A head box having a head box slice that provides a jet of paper stock impinging on the roll, a roll through which the first forming fabric passes and located upstream of the head box slice, and located downstream of the point of impact, An aeration impingement shoe comprising a forming section having a fixed support element defining a fabric path through which the forming fabric passes, wherein at least one forming fabric is positioned adjacent each point where each forming fabric and stock contact. And

Each crash shoe

(i) the leading edge,

(ii) the trailing edge,

(iii) a machine side configured to be releasably secured to the paper machine by fastening means,

(iv) a paper side having a predetermined cross machine direction and a machine direction profile having a fabric contact surface configured to support the formed fabric in sliding contact,

The paper side includes a plurality of vents that extend from the paper side through the machine side of the impingement shoe, starting from the adjoining edge of the leading edge and ending with the adjoining edge of the trailing edge.

In papermaking machines with two forming fabrics, it is generally preferred that the two impingement shoes are identical, and the profiled fabric support surface has the same shape. However, in certain situations, the two impact shoes and their profiled fabric support surfaces may achieve different shapes.

In addition to being used as impingement shoes, segmented fabric support elements may be suitable for use at various locations in papermaking machines including dewatering blades or woolly box covers.

In a third broad embodiment, the present invention is directed to a fabric support element for use in a papermaking machine,

(i) the leading edge,

(ii) the trailing edge,

(iii) a machine side configured to be releasably secured to the paper machine by fastening means,

(iv) a fabric support element having a paper side having a predetermined cross machine direction profile and a machine direction comprising a fabric contact surface configured to slide contact the papermaking fabric,

(a) the element comprises a plurality of at least first and second laminate segments,

(b) the fabric in contact with the paper side profile of the first laminate segment is different from the paper side profile of the second laminate segment,

(c) at least some of the first and second laminate segments contribute to a desired profile of the fabric in contact with the paper side of the element.

In a fourth broad embodiment, the present invention provides a paper machine having a machine direction and a cross machine direction, the paper machine moving in the machine direction,

(i) the leading edge,

(ii) the trailing edge,

(iii) a machine side configured to be releasably secured to the paper machine by fastening means,

(iv) a fabric support element having a paper side having a predetermined cross machine direction profile and a machine direction comprising a fabric contact surface configured to slidely support the papermaking fabric,

(a) the element comprises a plurality of at least first and second laminate segments,

(b) the paper side profile of the first laminate segment is different from the paper side of the second laminate segment,

(c) At least some of the first laminator segments contribute to a predetermined profile of the fabric in contact with the paper side of the element.

In a fifth broad embodiment, the present invention includes a plurality of segments that can be releaseably fixed to include a fixed fabric support element for supporting the fabric of a mobile papermaking machine, such that the PS face of at least some segments is a profile of the element. The flow through vents contributing in the MD to the PS surface, and through the elements, can be defined by the space between at least some segments and further defined by the spacing means to contribute to the CD and MD profiles of the elements.

When the fabric support element is used as a collision shoe, it has been found to be advantageous for the leading edge of a flow through vent having a substantially convexly curved shape and the trailing edge of the vent having a corresponding substantially concavely curved shape. This shape has been found to assist in handling large volumes of fluid draining through the fabric in the impact zone.

Moreover, the structure of the impact shoe or other stationary fabric support element from a plurality of segments is rigid, such as ceramic for complex shapes, without the problems associated with grinding large castings or complex shapes involved in creating shapes for larger parts. It is possible to enable the use of internal abrasive materials.

In a sixth broad embodiment, the present invention provides a method of manufacturing a fixed fabric support element for supporting a papermaking fabric moving in a papermaking machine,

(i) assembling a plurality of laminator segments in a spaced and substantially parallel configuration, forming an opening between at least some adjacent pair of segments, wherein the paper side of at least some segments is movable An assembly step of forming a side of the composite paper to be brought into contact with,

(ii) a fixing step of releasingly fixing the segment such that the fixing means is oriented substantially parallel to the holding means on the paper machine or at a small angle.

The invention is now described with reference to the accompanying drawings.

In Figures 1-3, only a portion of the papermaking machine necessary to aid in the understanding of the present invention is shown.

1 shows an initial impact zone of a papermaking machine including a crash shoe vented in accordance with the teachings of the present invention. The slice lips 1A, 1B of the head box 10 carry a jet of stock 2 over the PS face 13 of the forming fabric 3 at the point of impact I. The forming fabric 3 passes around the roll 6, wraps around the vented impingement shoe 5, and then passes over the first fixed support element 4 in the forming section. The impingement shoe 5 has a fluid through vent 20 defining a slotted opening 22 at its PS surface. This crash shoe 5 is releasably fixed to an appropriate mounting means (not shown) in a drain box (not shown) and can be assembled from a plurality of relatively thin laminator segments. Alternatively, the impact shoe 5 may comprise a monolithic configuration comprising a fluid through vent 20.

When the moving forming fabric 3 and the stock jet 2 converge and meet at an impingement angle α, the lower surface 9 of the stock jet 2 and the lower surface 11 of the head box lip 1B Air 8 in the wedge-shaped space between the PS faces 16 of the forming fabric 3 is captured and enters the forming fabric 3. At this point the air, together with some liquid of the forming fabric, passes through the MS face 23 of the forming fabric 3 into the fluid through vent 20, through the PS face 16 of the impact shoe 5, The fluid comprising trapped air 8 is drained through the MS face 18 of the vented impact shoe 5. Various shapes and functions of the fluid through vent 20 are described in detail below with reference to FIGS. 4, 5, and 6. The vent 20 is an opening 22, which may be slotted, as shown in FIG. 1, on the PS surface 16 of the impact shoe 5 starting at the adjacent leading edge 12 and ending with the adjacent trailing edge 14. ).

In the device, the impingement angle α can be set since the roll 6 can be located far from the diameter of the forming fabric 3 and the vented impingement shoe 5 occupies much less space than the roll 6. It is possible to keep close to zero and to significantly reduce the unsupported length of the stock jet 2. Moreover, all or the actual part of any trapped air 8 passes rapidly along the liquid drained through the MS face 18 of the impact shoe 5 vented by the fluid penetrating vent 20 and thus the forming section. Interference is prevented in the forming process in the stock of.

As will be described in detail below with reference to FIG. 6, the depth of the opening 22 is also PS profiled toward the trailing edge 14 of the vented impact shoe 5 to allow removal of added liquid and trapped air. May be increased at face 16.

2 and 3 show an initial impact zone of a papermaking machine with two forming fabrics, which incorporate two vented impact shoes 51, 52 in accordance with the teachings of the present invention. In describing these two figures, the terms "top" and "bottom" actually refer to only the direction shown, although the forming section is often oriented vertically or at some angle thereto in a twin fabric machine. Vented impingement shoes 51, 52 include a fluid through vent 120 forming a slotted opening 122 at the PS side.

2 shows the point of contact between the initial forming web where the point of impact I of the stock jet 2 on the bottom forming fabric 31 is carried on the PS side of the top forming fabric 32. J shows the impact zone of the twin weaving machine. The impact point I is located at a position where the lower surface 123 of the undercarriage fabric 31 is supported by the vented impact shoe 51. Similarly, the contact point J is located at a position where the PS face 124 of the top forming fabric 32 is supported by the vented impact shoe 2. Since the moving forming fabric 31 and the stock jet 2 converge, the lower face 91 of the stock jet 2, the lower face 101 of the head box lip 1B and the PS of the forming fabric 31 Air 81 in the wedge shaped space between the faces 113 is captured and enters the forming fabric 31. At this point the air 81 together with some liquid carried by the forming fabric 31 passes through the MS face 123 of the forming fabric 31 into the lower vented impingement shoe 51 and the MS face 118. Comes out). Thus, the configuration in consideration of the bottom forming fabric 31 is substantially the same as in FIG. Downstream of the impact point I, the upper forming fabric 32 converges at the contact point J with the upper side 92 of the stock jet 2 and is now supported by the lower forming fabric 31. Air is also trapped in the space 82 between the PS face 112 of the top forming fabric 32 and the surface 92 of the stock 2. This additional air and some fluid in the forming fabric 32 pass through the MS face 124 of the forming fabric 32 into the flow through vent 120 and impingement shoe 52 at the MS face 119. Is vented from.

3 shows a different arrangement from FIG. 2. The arrangement of the bottom forming fabric 31 is the same. The top forming fabric 32 converges to the stock jet 2 at the same point as the bottom forming fabric 31, in effect at the point of impact I. With respect to the top forming fabric 32, air 82 is directed to the top face 92 of the stock jet, the PS face 112 of the top forming fabric 32, and the top face 102 of the head box lip 1A. Captured in space bounded by Virtually all trapping air 82 flows through the MS face 118 of the lower aeration impact shoe 51 and through the MS face 119 of the aeration impact shoe 52 with some fluid in the two forming fabrics. Ventilated through 120.

In both of these twin weaving machines, the two aeration impingement shoes are often identical and have the same convex curve shape. However, in some circumstances it may be desirable to use two different aeration impingement shoes that may have different convex curve shapes. Alternatively, in other circumstances, the twin weaving machine may have a single impact shoe.

The aeration impingement shoe shown in each of FIGS. 1, 2 and 3 may comprise a single integral structure or may comprise a plurality of laminator segments mounted in a substantially parallel relationship as described in more detail below. have.

4, 5 and 6, three different structures of the laminate segments 55, 65, 75 are shown, respectively. These may be suitable for use in the venting impingement shoe 5 as described above or for other fixed fabric support elements 80 (shown in FIGS. 8 and 9). In FIG. 4, the laminate segment 55 has a leading edge 212, a trailing edge 214, a cross sectional PS surface 216, and an MS surface 218. An opening 220 is provided in the laminator segment 55 at an appropriate location and is provided with a rod or cable (not shown) to facilitate release of the plurality of laminator segments 55 to form the impact shoe 5. Fastening means such as this can pass through it. As with the recess 221, additional mounting means for the laminate segment 55 may be provided on the bottom surface 218.

As shown in FIG. 1, the PS side 216 of the laminate segment 55 supports the fabric and together provides the fabric supporting the PS side of the aeration impingement shoe 5. Likewise, the MS face 218 of the laminate segment 55 may be provided together to the MS face 18 of the aeration impact shoe 5.

Between the adjacent segment laminator segments 55, second segments 56, 57, 58 are provided. Two purposes of this provision are to provide spacing by first forcing the adjacent laminator segment 55 apart, and secondly from the PS face 16 to the MS face 18 of the venting impact shoe 5. To limit the structure of the vent (20). The second segment 56, 57, 58 may comprise a separate segment or alternatively all or part may be integrally formed with the laminator segment 55. As shown in FIG. 4, the vent leading edge 258 is defined by each of the second segments 56 and 57, and the vent trailing edge 259 is defined by each of the second segments 57 and 58. do. The vent leading edge 258 may be of any suitable configuration, but is preferably inclined regularly or irregularly in a direction toward the MS surface 218 to form an obtuse angle (β or δ) with the downstream portion of the MS surface 218. Do.

In FIG. 5, the laminate segment 65 may have substantially the same configuration as the laminate segment 55 shown in FIG. 4. However, the second segments 265, 266, 267 together form a substantially curved vent 20, and the trailing edge 269 of the first vent 20 is substantially concave in the curved second segment 266. And the leading edge 268 and the trailing edge 269 of the second vent 20 are each curved substantially convexly and concavely.

The PS surface 260 of the second segment 255, 256, 257 or 265, 266, 267 may have any suitable configuration. They may provide a fabric that supports the PS face 16 of the aeration impingement shoe 5, as shown in connection with the second segment 255, 257, 265, 267, for example. have. In contrast, as shown in FIG. 6, the PS face 260 of the second segment 276, 277 does not extend into a fabric supporting the PS face 16 of the aeration impact shoe 5, but the aeration impact shoe Together with the opening 22 provided for the additional discharge of the liquid 8 and the liquid trapped at the trailing edge 214 of each laminator segment 75 forming the trailing edge 14 of (5). do.

Also, as can be appreciated with reference to FIGS. 7A-7D, a third laminator segment can be provided, these paper sides partially providing the paper side 16 of the fixed fabric support element, and forming fabric It may have a suitable configuration such as shallow "V" to impart a stirring effect to the stock 2 supported on (3).

Referring to FIG. 7A, the fixed fabric support element 180 includes first and second laminate segment 85A, 85B. The first laminator segments 85A are mounted substantially parallel to each other at small angles θ, each preselected for MD, and substantially parallel to the second laminator segment 85B at the theoretical intersection line 181 in the CD. Adjacently inclined in a manner. Between the first and second laminate segments 85A, 85B, the third and fourth laminate segments 86A, 86B, each having a different PS surface profile than the first and second laminate segments 85A, 85B. ) Is mounted in a similar manner, and is releasably fixed to the subassembly of element 180 by mounting means (not shown).

7B shows three examples of another configuration for the laminate segment of this embodiment showing the difference in the PS plane. Thus, the PS surface profile of the first laminate segment 185A includes a shallow “V”, the PS surface of the second laminate segment 285A includes a deep “V”, and the third laminate segment 385A. ) PS side is virtually flat.

FIG. 7C shows a top view of a group of laminate segments for the element 180 shown in FIG. 7B. In this variant, the laminator segments 385A alternately space with the laminator segments 185A and 285A. However, the third laminate segment having any PS surface profile, such as laminate segments 185A, 285A, 385A, etc., may be constructed in accordance with the general configuration shown in FIGS. 4, 5 or 6, depending on the intended use of element 180. It can be used in combination with any of the laminator segments.

FIG. 7D shows a fixed fabric support element 280 having a different configuration, with the tip laminator segments 85A and 86A mounted at an angle θ1 relative to the CD, at an imaginary cross line 281 at the CD. Rear laminator segments 85B and 86B adjacent to the leading segment are mounted at an angle 2θ1 with respect to the CD. Each block 282, 283 is provided at the lateral edges 242, 243, respectively. Although FIG. 7D illustrates the use of two sets of laminator segments, the laminator segments 86A, 86B may be a combination of different configurations depending on the intended use of the element 280 in the manner shown schematically in FIG. 7C by way of example. It will be appreciated that it may be replaced with a segment having.

Referring to FIG. 8, the aeration fastening fabric support element 80 for use in any of a variety of locations in the papermaking machine is shown isometric. Element 80 may be a plurality of laminate segments 85, which may be any one or any other suitable configuration of laminate segments 55, 65, 75 shown in FIGS. 4, 5, and 6, respectively. ). The selected laminator segment 85 may comprise or be configured of a second segment (56, 57, 58; FIG. 4) or (265, 266, 267; FIG. 5) or (275, 276, 277; FIG. 6)). It is pressed in a spaced apart relationship by second, third and fourth laminator segments that are optionally identical to the laminator segments, which may include separate segments of other suitable configurations. Alternatively, as shown, the second segment 86 may be of any suitable configuration and may be integrally formed with the laminate segment 85. Laminator segments 85 and 86 are releasably secured to subassembly 87 by appropriate mounting means such as fixed rod 88 and T-slot 89 at predetermined locations on the paper machine. The rod 88 passes through an opening 220 in the laminator segment 85 to release releasely adjacent the lateral edges 24, 25 of the element 80.

Appropriately shaped end blocks, such as end blocks 182 and 183 shown in FIG. 7A or end blocks 282 and 283 shown in FIG. 7D, facilitate the placement of the laminate segments 85 in the configuration of the element 80. Can be positioned at each lateral edge 24, 25 of the element 80.

As best shown in FIG. 9, the laminator segments 85 are releasably fixed in a substantially parallel relationship with each other in the MD but can be fixed at an angle θ. This angle θ is preferably in the range of about 2 degrees to about 20 degrees.

In operation, a preselected number of laminate segments of good construction, such as laminate segment 85, may be aligned to form segmented fabric support element 80, and on the paper machine to support the papermaking fabric at that location. 8 may be mounted as shown in FIGS. 8 and 9 in a subassembly 87 which is mounted in a preferred position by suitable means (not shown). The first laminator segment 85 is second, third and fourth laminations as in 56, 57 and 58 (FIG. 4) or 265, 266 and 267 (FIG. 5) or 275, 276 and 277 (FIG. 6). It may be separated as required by groups of nugget segments or other appropriately shaped laminate segments. The number, shape and arrangement of the second or additional laminator segments can be varied by good papermaking conditions.

Thus, the PS side profile of element 80 may be shaped to produce a good and beneficial effect on the stock or initial web supported on the fabric. By way of example, the PS surface may be slotted in the manner described above or may have an MD profile such as shallow “V” or may be substantially flat. The PS shape of this surface may be used to assemble the fabric support element 80. Depending on the appropriate choice of laminator segment used, flow through vent 120 may be provided but not required.

The laminate segments 55, 65, 75, 85 of the present invention are preferably made of a wear resistant material such as ceramic or high density polyethylene. If the second, third and fourth laminator segments 56, 57, 58 and equivalents thereof, which are not in contact with the end-fabric fabric, are not formed integrally with the laminator segments, they are easily made of different materials from the laminator segments. Can be prepared.

Claims (22)

An impingement impingement shoe for use in a papermaking machine, positioned adjacent to an impact point of a stock jet emitted from a headbox slice on a moving forming fabric, the impingement shoe, (i) the leading edge located upstream of the collision point; (ii) the trailing edge, (iii) a machine side configured to be releasably secured to the paper machine by fastening means, (iv) a paper side having a predetermined cross machine direction and a machine direction profile configured to support the forming fabric at the slide contact, And the paper side substantially includes a plurality of vents, starting at an adjacent portion of the leading edge and ending at an adjacent portion of the trailing edge and extending from the paper side through the machine side of the impact shoe. A plurality of vents are provided between the plurality of laminate segments having a fabric in contact with the paper side which together contribute to the paper side of the impingement shoe, the plurality of vents being configured to be releasably fixed by means of fastening means and spaced apart. Aeration impingement shoes pressurized in a spaced apart relationship by means. The aeration impingement shoe of claim 2, wherein at least some of the spacer means is integrally formed with at least some of the laminate segments. 2. The plurality of vents of claim 1 wherein the plurality of vents do not include at least a portion of the fabric contact surface and at least some of the first laminate segments having the fabric in contact with the paper side provided on the paper side of the impact shoe on which the forming fabric is moved. Is provided between a plurality of second laminator segments configured to be positioned between the selected first laminator segments, wherein the first and second laminator segments are releasably fixed by means of fastening and spaced by spacing means Aeration impingement shoes configured to be pressurized in relationship. 5. The aeration impingement shoe of claim 4, wherein each first laminator segment has a first paper side profile and each second laminator segment has a second paper side profile different from the first paper side profile. The aeration impingement shoe of claim 4, wherein at least some of the second laminator segments contribute substantially to the configuration of the plurality of vents. The aeration impingement shoe as recited in claim 4, wherein said spacing means comprises at least some second laminate segment. Forming section for a paper machine having a machine direction and a cross machine direction, At least one forming fabric moving in the machine direction, A head box comprising a head box slice providing a jet of paper stock impinging at an impact angle on the first forming fabric at the point of impact; A roll through which the first forming fabric passes about and located upstream of the head box slice, A forming section located downstream of the impact point, the forming section having a fixed support element for forming a fabric path through which each forming fabric passes; The at least one forming fabric has a venting impingement shoe positioned adjacent to each point where each forming fabric and stock contact, Each crash shoe (i) the leading edge, (ii) the trailing edge, (iii) a machine side configured to be releasably secured to the paper machine by fastening means, (iv) a paper side having a predetermined cross machine direction and a machine direction profile having a fabric contact surface configured to support the formed fabric in sliding contact, Wherein the paper side comprises a plurality of vents, starting at the adjoining edge of the leading edge and ending at the adjoining edge of the trailing edge, and extending from the paper side through the machine side of the impact shoe. 9. The method of claim 8, wherein for each impingement shoe, at least a plurality of first laminate segments having a fabric contact surface contributing to the paper side of the impingement shoe on which a plurality of vents are formed, the fabric contact surface being at least partially fabric contact surface Is provided between a plurality of second segments configured to be positioned between the selected first laminator segments, the first and second laminator segments being releasably fixed by means of fastening and Forming section for a paper machine configured to pressurize in a spaced relationship. 10. The forming section of claim 9, wherein each first laminator segment has a first paper side profile and each second laminator segment has a second paper side profile different from the first paper side profile. . 11. The forming section of claim 10, wherein the separation means comprises at least a portion of the second laminator segment. Fabric support element for use in paper machines, (i) the leading edge, (ii) the trailing edge, (iii) a machine side configured to be releasably secured to the paper machine by fastening means, (iv) a fabric support element having a paper side having a predetermined cross machine direction profile and a machine direction comprising a fabric contact surface configured to slide contact the papermaking fabric, (a) said element comprises a plurality of at least first and second laminate segments in an adjacent relationship in the cross machine direction and in a longitudinal relationship substantially parallel in the machine direction, (b) the fabric in contact with the paper side profile of the first laminate segment is different from the paper side profile of the second laminate segment, (c) at least some of the first and second laminate segments contribute to a predetermined profile of the fabric contact paper side of the element, (d) at least some of the first and second laminate segments form a plurality of vent openings from the paper side through the machine side. 13. The vent opening of claim 12 wherein the vent openings do not contribute to the paper side of the impact shoe and at least a plurality of first laminate segments each having a fabric contact paper side that contributes to the paper side of the impact shoe through which the forming fabric moves. Provided between a plurality of second laminator segments configured to be positioned between the selected first laminator segments, wherein the first and second laminator segments are releasably fixed by the fastening means and spaced apart by the spacing means. Fabric support element configured to be pressurized. The fabric of claim 13, wherein each first laminate segment has a first paper side profile having a fabric contact surface, and each second laminate segment has a second paper side profile different from the first paper side profile. Supporting elements. 15. The fabric support element of claim 13 wherein said spacer means comprises at least a portion of a second laminate segment. The fabric support element of claim 13 wherein the at least some plurality of vents further comprise V-notches. A paper machine having a machine direction and a cross machine direction, Papermaking fabric moving in the machine direction, (i) the leading edge, (ii) the trailing edge, (iii) a machine side configured to be releasably secured to the paper machine by fastening means, (iv) a fabric support element having a paper side having a predetermined cross machine direction profile and a machine direction comprising a fabric contact surface configured to slidely support the papermaking fabric, (a) the element comprises a plurality of at least first and second laminate segments, (b) the paper side profile of the first laminate segment is different from the paper side of the second laminate segment, (c) at least some of the first laminator segments contribute to a predetermined profile of the side of the fabric contact paper, (d) at least some of the first and second laminate segments form a vent opening from the paper side through the machine side. 18. The papermaking machine according to claim 17, wherein the first and second laminator segments are pressed in a spaced relationship by the spaced means. 18. The papermaking machine of claim 17, wherein each first laminator segment has a first paper side profile and each second laminator segment has a second paper side profile different from the first paper side profile. 18. The papermaking machine according to claim 17, wherein the spacing means comprises at least some second laminate segment. A laminate segment configured to be plurally releasably secured to the fabric support element in a longitudinal relationship substantially parallel to the machine direction of the paper machine, The laminate segment having a profiled fabric in contact with the paper side, a leading edge and a trailing edge, wherein the profiled paper side can be configured to contribute to the profiled paper side of the element. A method of manufacturing a fixed fabric support element for supporting a papermaking fabric moving in a papermaking machine, (i) assembling a plurality of laminator segments in a spaced and substantially parallel configuration, forming a vent opening between at least some adjacent pair of segments, wherein the paper side of the at least some segment has a moving fabric bow An assembling step of forming a composite paper side which is in stock contact; (ii) releasably securing the segment to be oriented by the securing means on the papermaking machine substantially parallel to the holding means or at a small angle.