KR100800438B1 - Fabric support element for a papermaking machine - Google Patents

Abstract

The fabric support element 80 for the paper machine has an improved fluid discharge means comprising an opening that may include a flow through hole. This support element may comprise an impact shoe for shaping the paper machine. The opening may be defined by a plurality of sheet segments 85, at least some of which are defining the paper side of the support element, which sheets are spaced apart by an additional sheet segment 86 or other spacer means. Can be. Also provided is a thin sheet segment for use in this support element, a method of constructing the support element, and a paper machine or molded part comprising the support element.

Fabric support elements, sheet segments, forming parts, paper machines, impingement shoes

Description

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 support element, a method of making the support element, and a forming part used in the paper machine or the paper machine.

In the initial portion of the forming section of the paper machine, an unsupported jet of highly aqueous raw material is ejected from the head box slice onto the surface of the mobile 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 impingement angle α formed between the raw material jetting stream and the face of the forming fabric at the point of impact was typically about 4 ° to about 10 °. It is well known that improved paper molding can be obtained by minimizing both the length and angle α of the unsupported free jet stream. As the angle α increases, the magnitude of pressure exerted by the jetting flow on the surface of the molded fabric also increases.

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

As the unsupported length of the free raw jet stream increases, its outer surface begins to separate into ridges and furrows, which in turn causes the basis weight variation of the sheet. In addition, the finely dispersed fibers in the raw material begin to reaggregate quickly in the unsupported jet stream before the impact point, so the unsupported raw jet stream should be as short as possible to initiate these effects.

Due to the head-box slice lip structure and the conflicting space requirements of adjacent upstream rolls, such as breast rolls or forming rolls, the unsupported raw material jet stream length is increased without increasing the angle α. It is difficult to shorten. Even if the angle α is very small and the headbox slice lip can be placed so that the free jet is almost tangential to the molding fabric, it is trapped in a small wedge-shaped space between the surface of the molding fabric and the surface of the unsupported raw material jet. The contained air is contained in the raw material, forming bubbles which are lethal for sheet formation.

Several proposals have been made to overcome these shortcomings. Nelson et al., U. S. Patent No. 3,440, 136, discloses a method of avoiding air incorporation by evacuating air from the forming zone and supplying water to the zone. However, this proposal proved to be difficult to implement in practice. Irwin et al. US Pat. No. 4,734,164 discloses a forming board for a single weaving machine in which the first blade is slightly curved so that the breast roll is slightly lowered. A disadvantage with this proposal is that air is trapped in the shallow wedge space between the jetting flow and the forming fabric because the forming fabric passes over the solid surface without the hole of the curved first blade. This air is forced into the raw material as bubbles causing molding defects. Malasenko US Pat. No. 4,802,954 discloses an entry blade disposed in front of the curved blade element proposed by Irwin et al., Which blade is pumped by the forming fabric into the wedge shaped space between the jetting and the fabric. It is said to reduce the amount of fluid. However, a small wedge shaped air space remains. The pressure in this space is controlled by a vacuum pump to reduce jet flow disturbances. US Patent No. 5,084,138 to Ewald presents the problem of excess free jet length by using curved rotating bars to replace large diameter breast rolls and rigid curved blades, but air in the wedge between jet and fabric Do not evade capture.

Fujiwara US Pat. No. 4,425,188 uses longitudinally spaced grooves in a twin wire forming shoe to create a cross machine flow that realigns the fibers in the initial web to reduce machine direction fiber alignment. US Patent No. 6,372,091 to Wildfong et al. Proposes the use of grooves on the face of a molding shoe to improve water removal.

However, although it is known that forming grooves in molding shoes, also known as impingement shoes, can provide an improvement in the quality of the paper obtained, it has proven to be a problem associated with the use of such grooves. First, it was found that the grooves were quickly filled with raw material and substantially lost their beneficial effects, because there is no active means to quickly remove the drained fluid from the fabric contact surface. Second, it has been found that the grooves can produce a foiling effect between the machine side of the fabric and the inside of the grooves, creating a sufficient level of suction to cause a decrease in paper quality. Third, the formation of precisely dimensioned grooves on the typical ceramic surfaces of these blades is difficult, time consuming and expensive, and ceramic integrity can be compromised by machining.

The following terms used herein have the following meanings, and other terms used herein have the usual meanings related to them in the paper industry.

The cross-machine direction (CD) is essentially a direction in the plane of the paper sheet and substantially perpendicular to the machine direction (MD).

Downstream is the direction in the paper machine, towards the reel where the finished paper product exits the machine.

The fabric support element includes, but is not limited to, shoe, blade, foil and stirrer of the molded part and Uhle box (suction box) cover of the crimped part, at least among paper machine fabrics. One is any stationary element passing above in sliding contact.

The thin segment is a relatively thin component having a thickness ranging from about 1 mm (0.04 inch) or less to about 254 mm (1 inch) or more, which are laterally formed to form the desired width of the fabric support element. Can be assembled in a lateral relationship. The thin segment is typically formed of ceramic or other wear resistant material.

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

The machine side (MS) side is the side of the fabric or fabric support element opposite the paper side and not in contact with the paper sheet.

The paper side (PS) side is the side of the fabric or fabric support element that is in contact with or directed to the paper sheet made in the paper machine and conveyed through the paper machine.

The upstream is essentially the direction in the paper machine, towards the headbox.

By "outlet hole" is meant that there is an open passageway from the paper side to the machine side of the support element, ie from the fabric contact side to the opposite side, which passage is referred to herein as a flow through outlet hole. do.

Some of the above disadvantages have been found to be completely or nearly eliminated by the use of discharge holes that penetrate the crash shoe completely, allowing efficient removal of sufficient fluid to prevent filling of the grooves. These flow through holes are open from the paper side of the impingement shoe to the machine side and draw a greater amount of fluid than was previously possible on the grooved surface as defined in US Pat. No. 6,372,091 to Wildpong et al. It is possible to remove from the initial impact zone on the impact shoe with the air trapped between the forming fabric and the raw spray.

In addition, these flow through holes have been found to take into account significant fluctuations in both the impact angle of the raw jetting stream and the production position of the impact point without any noticeable adverse effect on the resulting paper quality. This result is surprising, because so far, changing the impingement angle of the raw material jet stream by an angle of less than 1/2 degree from the optimum value would produce significant adverse effects on sheet quality with regard to sheet marking, retention and molding. Because it can. Accordingly, the present invention enables a wider range of raw material jet stream impact angles than has ever been feasible.

In addition, these flow through holes allow impingement shoes from a number of relatively thin sheet metal segments mounted together in appropriate retaining means of the paper machine to be essentially parallel to each other and in contact with each other and oriented at a substantially constant angle with respect to the machine direction MD. It turns out that by constructing it can be most advantageously provided. These thin plate segments are machine side faced to be mounted on a holding means, a paper side face toward the forming fabric in use, an upstream face (or front edge), and a downstream face (or trailing edge). Section), and in use it is preferably formed of a suitable material, such as a ceramic, to have substantially parallel sides facing in the cross machine direction (CD). The PS side (paper side) of at least the first set of segments together defines the fabric contact surface of the crash shoe intended to support the forming fabric. This surface may have any desired profile suitable for general papermaking requirements. The second set of segments having a PS face profile that may differ from that of the first set of segments may be disposed at appropriate intervals in the machine transverse direction between the first pair of segments. Preferably, the second set of segments may be shaped to allow opening of the outlet contact openings from the PS side to the MS side and forming an opening in the fabric contact surface of the support element. Alternatively, the spacer means may be integrally constructed on one or both of the sides of the first set of segments only in the machine transverse direction, in which case the impact shoe generally consists only of such first segments. It has been found that the spacer means integrally constructed with the first set of segments or consisting of the second segment can have a suitable shape that optimizes the removal of fluid and entrapped air from the raw material injection stream.

Also, any part of the paper machine using a plurality of at least first and second thin plate segments mounted on suitable holding means and configured to be disposed as required in any of the forming, pressing or drying parts of the paper machine. It has been determined that it is possible to assemble a segmented fabric support element intended for use in. These first and second thin sheet segments are mounted on known holding means in essentially parallel and contact with each other and are oriented essentially in a machine direction or at an angle to this machine direction. The structure and shape of these segments are substantially the same as described above with regard to the impact shoe, and define at least the fabric contact surface intended to support the papermaking fabric, with the PS sides of the first segments together. At least the PS face of the first and second segments is shaped to provide to the PS face of the support element in any desired profile of the assembled stand suitable for general papermaking conditions. The second set of segments includes selected pairs of first segments to allow for the definition of an opening that may (but not necessarily) include a vent hole that opens from the PS side of the support element to the MS side (machine side). It can be arranged as spacer means or profile imparting means at appropriate intervals in the machine transverse direction therebetween. The PS faces of the first and second segments can be shaped to provide either or both of the desired machine direction profile and the machine direction profile to the assembled support element. The third or fourth segment and the like can also be used in combination with the first and second segments as well.

The present invention seeks to provide a crash shoe with discharge holes for use in a paper machine having a plurality of flow through holes extending from an upper surface to a lower surface with a profile of the impact shoe.

The present invention seeks to provide, as segmented fabric support elements for use in the impact zone of the forming part of a high speed paper machine, a fabric support element composed of a plurality of thin segments. The PS side of these segments is shaped to contribute to the desired contact profile of the fabric side or the fabric contact surface of the support element, and if required, the exit hole through the support element is defined by the opening between the selected sheet segments.

Thus, a collision shoe constructed in accordance with the present invention performs four main functions. Firstly, it acts to support the forming fabric as it enters the impact zone, and secondly, to release at least a majority of the air trapped in the wedge shaped space between the surface of the forming fabric and the surface of the raw jetting stream. do. Third, it allows the drained water to be removed effectively and quickly, and fourth, provides a previously unattainable tolerance of the impact angle and the location of the impact point.

The present invention also seeks to provide a stationary fabric support element for a paper machine, consisting of a plurality of at least first and second relatively thin sheet segments.

The invention also seeks to provide a segment for use in a collision shoe or other stationary fabric support element, such that the PS face of at least some of the segments contributes to the fabric contact surface with the profile of the support element, The exit hole through the support element may be defined by an opening between at least some of the segments. This segment is shaped such that the fabric support element can be releasably fixed and mounted by a suitable holding means.

The present invention also seeks to provide a molded part for a paper machine comprising a segmented fabric support element comprising a flow through hole as a collision shoe.

The present invention also seeks to provide a method of manufacturing an element assembled from a plurality of segments.

Accordingly, in the first broad embodiment, the present invention seeks to provide a fabric support element segmented with discharge holes for use as a collision shoe in the initial impact zone of the forming part of the paper machine.

The impingement shoe consists of a plurality of thin sheet segments configured to be releasably secured in a substantially parallel and in contact relationship with each other and, as a result, the molded fabric having a common fabric contact PS face of the segments. Go from sliding contact from above.

In one alternative configuration of the impact shoe, the thin segments are identical in shape and may comprise spacer means, which spacer means may, but are not necessarily, integral with the segment.

In a second alternative configuration, the impact shoe consists of at least first and second thin sheet segments, wherein the first segment contributes to the PS fabric contact surface, and the second segment is between any two segments or two or more segments. Placed between groups of. The second segment is shaped to form a discharge hole between two adjacent segments and, if necessary, to form an additional opening on the PS face of the support element, which discharge hole extends from the PS face to the MS face of the impact shoe. It is open and allows passage of fluid and contained air from the raw material jet stream through the forming fabric. Optionally, this discharge can be augmented by vacuum means connected to the underside of the crash shoe. Advantageously, the second segment can be hydrodynamically shaped to assist in the removal of a large amount of fluid moving at a relatively high speed. The second segment generally separates a portion of the first segment to form an opening in the fabric contacting surface of the impact shoe. These openings can be oriented at any desired angle with respect to the MD by making the thin plate segments appropriate. Preferably, these openings are slot shaped and oriented at an angle of about 2 degrees to about 20 degrees relative to the MD. Both the exit hole and the opening are oriented at the same angle with respect to the MD due to the structure of the impact shoe.

In a third alternative structure, a third segment is provided, disposed as needed between the selected first and second segments, and the PS face of the third segment has a profile appropriate for the intended use.

Releasable fixed mounting of the segment can be performed by various known means such as T-slot or dovetail mounting. Alternatively or additionally, the segments may have an opening into which a rod or cable may be fitted, for example in the case of a plurality of identical segments, as disclosed, for example, in US Pat. No. 3,871,953. Thus, the rod or cable can be secured by known means to a suitable end block located on the side of the forming part.

Accordingly, the present invention relates to a collision shoe having a discharge hole for a paper machine, which is disposed adjacent to a collision point of a raw material jet stream discharged onto a forming fabric moving from a head box slice.
(i) a leading edge located upstream of the impact point,
(ii) trailing edges,
(iii) the machine side being adapted to be releasably fixed to the paper machine by the fixing means, and
(iv) having a paper-side face having a predetermined machine cross-direction profile and machine direction profile adapted to support the molded fabric in sliding contact,
The paper side surface includes a plurality of discharge holes starting at a portion substantially adjacent to the leading edge and ending at a portion substantially adjacent to the trailing edge and extending from the paper side to the machine side. To provide a collision shoe.

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Preferably, the PS face with the profile between the leading and trailing edges of the impact shoe is essentially convex but can be of any suitable shape for the particular environment. This may include an essentially circular convex curved surface with a constant radius, or a surface with a radius of curvature so that it increases toward the trailing edge and the trailing edge portion is essentially flat. If intended for use in other areas of the paper machine, ie in addition to the impact shoe, the PS face may be flat, grooved or have a different profile. This choice depends on the restraint conditions in the intended area of use.

In a second broad embodiment, the present invention relates to a paper machine forming part having a machine direction and a machine cross direction,
At least one forming fabric moving in the machine direction;
A head box comprising a head box slice for providing a paper stock jet stream impinging a predetermined impact angle on the first forming fabric at the point of impact;
A roll passing around the first forming fabric and located upstream of the head box slice; And
A stationary support element located downstream of the impact point and defining a fabric passageway through which each forming fabric passes;
The at least one molding fabric has an impingement shoe with a vent hole, located adjacent each point where the paper stock is in contact with each molding fabric,
The collision shoe,
(i) the leading edge,
(ii) trailing edge,
(iii) the machine side being adapted to be releasably fixed to the paper machine by the fixing means, and
(iv) having a paper side surface with a predetermined machine cross direction profile and a machine direction profile comprising a fabric contact surface adapted to support the molded fabric in sliding contact,
The paper side includes a plurality of discharge holes starting at an area substantially adjacent to the leading edge and ending at an area substantially adjacent to the trailing edge and extending from the paper side to the machine side of the crash shoe. And a molding part for a paper machine.

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In paper machines with two forming fabrics, it is generally preferred that the two impact shoes are the same, and the fabric support surface with the profile of those impact shoes has the same shape. However, in certain situations, the two impact shoes and the fabric support surfaces with their profiles may be of different shapes.

In addition to using as a crash shoe, the segmented fabric support element may be suitable for use in various places in a paper machine, including dewatering blades or Uhle box covers.

In a third broad embodiment, the present invention provides a fabric support element for use in a paper machine, the fabric support element comprising:
(i) the leading edge,
(ii) trailing edge,
(iii) the machine side being adapted to be releasably fixed to the paper machine by the fixing means, and
(iv) having a paper side face with a predetermined machine cross direction profile and a machine direction profile including a fabric contact face adapted to support the papermaking fabric in sliding contact,
(a) the support element comprises a plurality of at least first and second thin sheet segments,
(b) the fabric contact paper side face profile of the first thin sheet segment is different from the paper side face profile of the second thin sheet segment,
and (c) at least some of said first and second thin sheet segments contribute to a predetermined profile of the fabric contacting paper side face of said support element.

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In a fourth broad embodiment, the present invention provides a paper machine having a machine direction and a machine direction,
Papermaking fabric moving in the machine direction;
(i) the leading edge,
(ii) trailing edge,
(iii) the machine side being adapted to be releasably fixed to the paper machine by the fixing means, and
(iv) a fabric support element having a paper side face with a predetermined machine cross direction profile and a machine direction profile including a fabric contact face adapted to support the papermaking fabric in sliding contact,
(a) the fabric support element comprises a plurality of at least first and second thin sheet segments,
(b) the paper side face profile of the first thin plate segment is different from the paper side face profile of the second thin plate segment,
(c) At least some of the first thin sheet segments provide a paper machine that contributes to a predetermined profile of the fabric contacting paper side face of the fabric support element.

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In a fifth broad embodiment, the present invention relates to a segment in which a plurality of releasable fastenings are made to form a stationary fabric support element for supporting a moving papermaking fabric, wherein the PS face of at least some of the segments Spacers so as to contribute to the PS face with the profile of the support element in the machine direction, a flow through hole penetrating the support element being defined by the space between at least some of the segments and contributing to the CD and MD profiles of the support element. Providing a segment that can be further defined by means.

When the fabric support element is used as a collision shoe, it has proven advantageous for the leading edge of the flow through hole to have a substantially convexly curved shape, and the trailing edge of the flow through hole to have a corresponding substantially concavely curved shape. These shapes have been found to support the management of large amounts of fluid discharged through the fabric in the impact zone.

In addition, the structure of the impact shoe or other stationary fabric support element from multiple segments is rigid, such as ceramic, over complex shapes, without the problems associated with grinding complex shapes or the large-scale casting associated with forming complex shapes in large parts. It has been found that it is possible to use a wear resistant material.

In a sixth broad aspect, the present invention provides a method of manufacturing a stationary fabric support element for supporting a papermaking fabric moving in a paper machine.
(i) forming outlet holes between adjacent pairs of at least some of the plurality of sheet segments, wherein the paper side side of at least some of the sheet segments form a plurality of composite paper side sides where the moving fabric may be in sliding contact. Assembling the sheet segments of the substrate in spaced and parallel relationship,
(ii) releasably securing the sheet segments to the retaining means on the paper machine by means of fastening means such that the sheet segments are substantially parallel to the machine direction or oriented at a small angle with respect to the machine direction. Provide a method.

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

1 is a view showing a part of an open surface paper machine including an impact shoe with discharge holes.

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

4, 5 and 6 are diagrams illustrating segments of each of three different embodiments of the present invention.

7 shows an alternative configuration for the use of any optional profile for the thin segment of the present invention.

Fig. 8 is a perspective view of a stationary support element having a discharge hole in one embodiment of the present invention.

9 is a plan view of a configuration of a segment in one embodiment of the present invention.

1 to 3, only parts of the paper machine necessary for understanding the present invention are shown.

1 shows an initial impact zone of a paper machine comprising an impact shoe with discharge holes, according to the teachings of the present invention. Slice lips 1A and 1B of the head box 10 blow the raw material jet stream 2 onto the PS side (paper side surface) 13 of the forming fabric 3 at the impact point I. do. The forming fabric 3 passes around the roll 6, wraps around the impact shoe 5 with the discharge hole, and then passes over the first stationary support element 4 of the forming part. The impingement shoe 5 has flow through holes 20 which form a slotted opening 22 in the PS side. This impingement shoe 5 is assembled from a plurality of relatively thin sheet segments and can be releasably secured to a suitable mounting means (not shown) on a drain box (not shown). Alternatively, the impact shoe 5 may be of a monolithic configuration comprising the flow through holes 20.

When the moving molding fabric 3 and the raw material jet stream 2 converge and meet at the collision angle α, the lower surface 9 of the raw material jet stream 2 and the lower surface 11 of the slice lip 1B of the head box 11 ) And air 8 in the wedge shaped space between the PS face 13 of the forming fabric 3 are captured and enters into the forming fabric 3. This air, together with some liquid in the forming fabric at this point, flows through the MS side (machine side) 23 of the forming fabric 3 and the PS side 16 of the impingement shoe 5. The fluid passing into 20 and containing the trapped air 8 exits through the MS face 18 of the impact shoe 5. Various configurations and functions of the flow through holes 20 will be described in more detail below with reference to FIGS. 4, 5, and 6. This flow passage hole 20 is located on the PS surface 16 of the collision shoe 5 starting from the front edge 12 and ending in the vicinity of the trailing edge 14. An opening 22 may be formed which may be slot shaped as shown in FIG. 1.

In this configuration, since the roll 6 can be positioned away from the passage of the forming fabric 3 and the impact shoe 5 with the discharge hole occupies much less space than the roll 6, the impact angle α ) Can be kept close to zero, and the unsupported length of the raw material injection stream 2 can be greatly reduced. In addition, all or most of the entrapped air 8 passes rapidly by the flow through hole 20 together with the liquid discharged through the MS face 18 of the impact shoe 5 with the discharge hole, thus, It is prevented from interfering with the molding of the raw material in the molding portion.

As will be explained in more detail below with reference to FIG. 6, the depth of the opening 22 can also be increased at the PS face 16 toward the trailing edge 14 of the impact shoe 5 with the discharge hole. It allows for the removal of additional liquid and entrapped air.

2 and 3 show an initial impact zone of a paper machine with two forming fabrics, which are provided with two impact shoes 51, 52 according to the teachings of the present invention. In describing these two figures, the terms " top " and " bottom " refer only to the directions shown in the figures, and in practice, in the twin fabric paper machine, the forming part is arranged at an angle with respect to the vertical direction or the vertical direction. In some cases. Impingement shoes 51, 52 with discharge holes have flow through holes 120 forming slot-shaped openings 122 at the PS side.

2 shows an initial web in which the impact point I of the raw material jet stream 2 on the lower forming fabric 31 is carried on the upper forming fabric 32 and on the PS side of the lower forming fabric 31. The impact zone of the twin woven paper machine ahead of the contact point J between them. The impact point I is located at a position where the lower surface 123 of the lower molding fabric 31 is supported by the impact shoe 51 having the discharge hole. Similarly, the contact point J is located at a position where the PS face 124 of the upper forming fabric 32 is supported by the impact shoe 52 with the discharge hole. When the moving forming fabric 31 and the raw material injection stream 2 converge, the lower surface 91 of the raw material injection stream 2 and the lower surface 101 of the slice lip 1B of the head box and the molding fabric 31 Air 81 in the wedge shaped space between the PS face 113 is captured and enters the forming fabric 31. This air 81, together with some liquid that the molding fabric 31 has at this point, is through the MS face 123 of the molding fabric 31 into the flow through hole 120 of the lower impact shoe 51. Pass through and exit through MS face 118. Thus, the configuration for the lower forming fabric 31 is essentially the same as in FIG. 1. On the downstream side of the impact point I, the upper forming fabric 32 is brought into contact with the upper surface 92 of the raw material injection stream 2 which is still supported by the lower forming fabric 31 at the contact point J. Converge. Further air is also trapped in the space 82 between the PS face 112 of the upper forming fabric 32 and the upper face 92 of the raw material jet stream 2. This additional air and some liquid in the forming fabric 32 pass through the MS face 124 of the forming fabric 32 into the flow through hole 120 and exit from the impact shoe 52 at the MS face 119. .

3 shows an alternative to the configuration of FIG. 2. The arrangement of the lower forming fabric 31 is the same. The upper forming fabric 32 converges into the raw material jet stream 2 at the same point as the lower forming fabric 31, substantially at the point of impact I. As for the upper molding fabric 32, the space formed by the upper surface 92 of the raw material injection stream, the PS surface 112 of the upper molding fabric 32, and the upper surface 102 of the slice lip 1A of the head box. Air 82 is captured within. Virtually all of the trapped air 82, together with some liquid in the two forming fabrics, through the flow through hole 120 the MS face 118 of the lower impact shoe 51 and the upper impact shoe 52 It is discharged through the MS surface 119 of the.

In both of these twin-weaving paper machines, the two impingement shoes may be identical or may have the same convex curved shape. However, in some circumstances it may be desirable to use two different impact shoes, which may have different convex curved shapes. Alternatively, in other circumstances, the twin fabric paper machine may have a single impact shoe.

1, 2 and 3, the impact shoe with discharge holes may consist of a monolithic configuration or may consist of a plurality of thin plate segments arranged substantially parallel, as described in more detail below.

4, 5 and 6, three different configurations of sheet segments 55, 65 and 75 are shown, respectively. They are suitable for use in the impact shoe 5 with discharge holes as described above or for other stationary fabric support elements 80 (shown in FIGS. 8 and 9). First, referring to FIG. 4, the thin plate segment 55 has a leading edge 212, a trailing edge 214, a PS face 216 with a profile, and an MS face 218. Openings 220 are provided at appropriate locations of the thin plate segment 55 through which fastening means, such as rods or cables (not shown), pass, forming a number of impingement shoes 5. Releasable fixing of the thin plate segment 55 can be facilitated. Additional mounting means for the thin plate segment 55, such as recess 221, may be provided on the MS face 218.

The PS faces 216 of the sheet segments 55 together support the fabric and provide the fabric support PS side of the impact shoe 5 with the exit hole, as shown in FIG. 1. Likewise, the MS faces 218 of the thin plate segments 55 together constitute the MS faces 18 of the impact shoe 5 with the discharge holes.

Between the thin plate segments 55 of adjacent pairs, minor segments 56, 57, 58 are provided. They serve two purposes. First, a flow through hole 20 which serves to provide spacer means to space adjacent thin sheet segments 55, and secondly, from the PS face 16 to the MS face 18 of the impact shoe 5 with discharge holes. Acts to define the shape of These sub-segments 56, 57, 58 may be made of separate segments, or all or part of them may be integrally formed with the thin plate segment 55. As shown in FIG. 4, the leading edge 258 of the flow through hole is defined by each of the sub segments 56 and 57, and the trailing edge 259 of the flow through hole is connected to each of the sub segments 57 and 58. It is limited by. The leading edge 258 of the flow through hole may be of any suitable configuration, but is regularly or irregularly inclined toward the MS face 218 to form an obtuse angle (β or δ) with the downstream portion of the MS face 218. It is desirable to have.

Referring to FIG. 5, the thin plate segment 65 has substantially the same configuration as the thin plate segment 55 shown in FIG. 4, but the sub-segments 265, 266, and 267 together, have substantially curved flow through holes. (20), the trailing edge 269 of the first flow through hole 20 is defined by a substantially concave curved subsegment 266, and the leading edge of the second flow through hole 20 ( 268 and trailing edge 269 are each curved substantially convexly and concavely.

The PS faces 260 of the sub segments 55, 56, 57 or the sub segments 265, 266, 267 may have any suitable shape. These PS faces 260 provide the fabric support PS faces 16 of the impact shoe 5 with vent holes, as shown, for example, with respect to the subsegments 55, 57, 265, 267. can do. Alternatively, as shown in FIG. 6, the PS faces 260 of the subsegments 276, 277 do not extend to the fabric support PS faces 16 of the impact shoe 5 with discharge holes, which together The opening 22 is defined. This opening 22 further discharges the liquid and trapped air 8 at the trailing edge 214 of each of the sheet segments 277 forming the trailing edge 14 of the impact shoe 5 with the discharge hole. To provide.

Also, as is better understood with reference to FIGS. 7A-7D, a third thin sheet segment may be provided, the paper side of which is the paper side of the stationary fabric support element. Part 16 is configured and has an appropriate shape, such as a shallow "V", to impart a stirring effect to the raw material 2 supported on the forming fabric 3.

Referring to FIG. 7A, the stationary fabric support element 180 includes first and second thin sheet segments 85A, 85B. Each of the first thin plate segments 85A is mounted substantially parallel to each other at a preselected small angle θ relative to the MD (machine direction), and at the conceptual intersection line 181 in the CD (cross machine direction) as well Each of the parallel second thin plate segments 85B abuts in an angled manner. Between the first and second thin plate segments 85A, 85B, the third and fourth thin plate segments 86A, 86B have different PS face profiles than the first and second thin plate segments 85A, 85B, respectively. And is releasably fixed to the subassembly of the support element 180 by mounting means (not shown). End blocks 182 and 183 are provided at the side edges 241 and 251 of the support element 180, respectively.

Referring to Fig. 7B, three examples of other configurations for the thin segment of the present embodiment are shown to show the difference in the PS plane. Thus, the PS surface profile of the first thin plate segment 185A forms a shallow V ″ character, the PS surface of the second thin plate segment 285A forms a deep “V” character, and the PS surface of the third thin plate segment 385A substantially It is flat.

FIG. 7C shows a plan view of a group of sheet segments for the support element 180 shown in FIG. 7B. In this modification, the thin plate segments 385A are alternately sandwiched with the thin plate segments 185A, 285A. However, according to the intended use of the support element 180, the third thin sheet segment having any of the PS face profiles, such as thin plate segments 185A, 285A, 385A, etc. It can be used in combination with the thin segment of any of the configurations.

FIG. 7D shows a stationary fabric support element 280 having an alternative configuration, in which the leading sheet metal segments 85A, 86A are mounted at an angle θ ₁ with respect to the CD, and conceptual intersection at the CD. Subsequent thin plate segments 85B, 86B abutting the leading thin plate segment at line 281 are mounted at an angle 2θ ₁ with respect to the CD. End blocks 282, 283 are provided at the side edges 242, 252, respectively. FIG. 7D shows the use of two sets of thin segments, but the thin segments 86A, 86B are intended to support the support element 280 in the manner shown, for example, in the schematic diagram of FIG. 7C. It will be appreciated that it may be replaced by segments having a combination of different configurations depending on the application.

Referring to FIG. 8, there is shown a perspective view of a stationary fabric support element 80 with discharge holes for use in any of the various positions of the paper machine. This support element 80 comprises a plurality of sheet segments 85, which sheet any one or any of the configurations of the sheet segments 55, 65, 75 shown in FIGS. 4, 5 and 6. Can be of any suitable configuration. The selected thin segments 85 are spaced apart by second, third and fourth minor thin segments which are collectively specified as thin segment 86, and the thin segments 86 are divided into sub segments 56, 57, 58 (FIG. 4) or sub-segments 265, 266, 267 (FIG. 5) or sub-segments 275, 276, 277 (FIG. 6) or any other suitable configuration. . Alternatively, as shown, sub-segment 86 may be of any suitable configuration and may be integrally formed with thin plate segment 85. The thin segment 85 and subsegment 86 are releasably fixed to the subassembly 87 (not shown in detail) by suitable mounting means, such as the lobe 88 and the T-slot 89. Is fixed at a preselected location on the paper machine. The rod 88 passes through the aperture of the thin plate segment 85 and is releasably secured adjacent the side edges 24, 25 of the support element 80.

A thinly shaped end block in the configuration of the support element 80 is provided with an end block of suitable shape, such as the end blocks 182, 183 shown in FIG. 7A or the end blocks 282, 283 shown in FIG. 7D. It may be disposed at each of the side edges 24, 25 of the support element 80 to facilitate firm placement of the 85.

As can be seen well in FIG. 9, the thin plate segments 85 are releasably fixed in a substantially parallel relationship with one another in the MD but at an angle ε with respect to the MD. This angle ε is preferably in the range of about 2 degrees to about 20 degrees.

In operation, a preselected number of sheet segments of the desired configuration, such as sheet segment 85, are aligned to form segmented fabric support element 80 and the subassembly 87 in FIGS. 8 and 9. It may be mounted as shown, and the subassembly is then mounted by appropriate means (not shown) at that location to support the papermaker's fabric at the desired location of the paper machine. The first thin plate segment 85 is connected to the second, third and fourth thin plate segments such as 56, 57, 58 (FIG. 4) or 265, 266, 267 (FIG. 5) or 275, 276, 277 (FIG. 6). By means of a group of thinly shaped sheet segments or by other suitable shapes. The number, shape and arrangement of the second or additional sheet segments is determined by general papermaking conditions.

Thus, the PS side profile of the support element 80 may be shaped to produce the desired beneficial effect on the raw web or initial web supported on the fabric. For example, the PS face may have a slot in the manner described above or may have an MD profile such as a shallow “V” or may be substantially flat. The PS shape of this surface may be a fabric support element 80. It is determined by the appropriate choice of sheet segments used to assemble the flow-through hole 120 need not be provided.

The thin plate segments 55, 65, 75, 85 of the present invention are preferably made of a wear resistant material such as ceramic or high density polyethylene. The second, third, and fourth thin sheet segments 56, 57, 58, etc., which are not in contact with the papermaking fabric, can be easily made of a different material than the thin sheet segments when they are not integrally formed with the thin sheet segments.

Claims (37)

A vented impingement shoe with a discharge hole for a paper machine, disposed adjacent to an impact point of a raw material jet stream discharged from a head box slice onto a forming fabric, the impact sugar, (i) a leading edge located upstream of the impact point, (ii) the trailing edge, (iii) a machine side surface adapted to be releasably fixed to the paper machine by fixing means, and (iv) having a paper side surface with a predetermined machine cross direction profile and a machine direction profile adapted to support the molded fabric in sliding contact, The paper side face includes a plurality of discharge holes starting at a position adjacent to the leading edge and ending at a position adjacent to the trailing edge and extending from the paper side to the machine side. . The method of claim 1, wherein the plurality of ejection holes are provided between a plurality of sheet segments having a fabric contact paper side surface contributing to the paper side of the impingement shoe, wherein the plurality of sheet segments are provided by fastening means. A crash shoe with a discharge hole, configured to be releasably secured and spaced apart by a plurality of spacer means. 3. The impact shoe of claim 2 wherein at least some of the spacer means are integrally configured with at least some of the thin plate segments. 2. The apparatus of claim 1, wherein the plurality of outlet holes comprises at least a plurality of first thin sheet segments, each having at least a portion of a fabric contact paper side face that contributes to the paper side face of the impingement shoe from which a forming fabric moves from above. Without a contact surface, provided between a plurality of second sheet segments configured to be disposed between selected first sheet segments, the first and second sheet segments being configured to be releasably fixed by fastening means, the spacer Impingement shoes with discharge holes, spaced by means. 5. The method of claim 4, wherein each of the first thin sheet segments has a first paper side face profile, and each of the second thin sheet segments has a second paper side face profile different from the first paper side face profile. Collision shoe with exhaust hole. 5. The impact shoe of claim 4, wherein at least some of the second thin sheet segments contribute to the configuration of the plurality of outlet holes. 5. The impact shoe as claimed in claim 4, wherein the spacer means consists of at least part of the second thin sheet segment. A forming part for a paper machine having a machine direction and a machine cross direction, At least one forming fabric moving in the machine direction; A head box comprising a head box slice for providing a paper stock jet stream impinging a predetermined impact angle on the first forming fabric at the point of impact; A roll passing around the first forming fabric and located upstream of the head box slice; And A stationary support element located downstream of the impact point and defining a fabric passageway through which each forming fabric passes; The at least one molding fabric has an impingement shoe with a vent hole, located adjacent each point where the paper stock is in contact with each molding fabric, The collision shoe, (i) the leading edge, (ii) the trailing edge, (iii) the machine side being adapted to be releasably fixed to the paper machine by the fixing means, and (iv) having a paper side surface with a predetermined machine cross direction profile and a machine direction profile comprising a fabric contact surface adapted to support the molded fabric in sliding contact, The paper side surface includes a plurality of discharge holes starting at a position adjacent to the leading edge and ending at a position adjacent to the trailing edge and extending from the paper side of the crash shoe to the machine side. Molding part. 9. The apparatus of claim 8, wherein for each impingement shoe, the plurality of discharge holes comprises at least a plurality of first thin sheet segments each having a fabric contact surface contributing to a paper side surface of the impingement shoe from which a forming fabric is moved; At least a portion having no fabric contacting surface, provided between the plurality of second sheet segments configured to be disposed between the selected first sheet segments, wherein the first and second sheet segments are releasably fixed by means of fastening means. The molded part for paper machines comprised and spaced apart by the spacer means. 10. The method of claim 9, wherein each of the first thin sheet segments has a first paper side face profile, and each of the second thin sheet segments has a second paper side face profile that is different from the first paper side face profile. Forming part for paper machine. The paper machine molded part according to claim 10, wherein the spacer means consists of at least part of the second thin plate segments. As a fabric support element for use in paper machines, this fabric support element (i) the leading edge, (ii) the trailing edge, (iii) the machine side being adapted to be releasably fixed to the paper machine by the fixing means, and (iv) having a paper side face with a predetermined machine cross direction profile and a machine direction profile including a fabric contact face adapted to support the papermaking fabric in sliding contact, (a) the support element comprises a plurality of at least first and second thin plate segments, (b) the fabric contact paper side face profile of the first thin sheet segment is different from the paper side face profile of the second thin sheet segment, (c) at least some of the first and second thin sheet segments contribute to a predetermined profile of the textile contact paper side of the support element, (d) at least some of said first and second thin sheet segments together form a plurality of discharge holes extending from the paper side to the machine side. 13. The paper sheet of claim 12, wherein the ejection apertures comprise at least a plurality of first thin sheet segments each having a fabric contact paper side surface that contributes to the paper side surface of the crash shoe that the forming fabric moves from above. Without contributing, provided between a plurality of second thin plate segments arranged to be arranged between the selected first thin plate segments, the first and second thin plate segments being configured to be releasably fixed by fastening means, the spacer means Papermaking textile support element spaced by. 14. The second paper side of claim 13, wherein each of the first thin sheet segments has a first paper side face profile comprising a fabric contact surface, and wherein each of the second thin sheet segments is different from the first paper side face profile. A papermaker's fabric support element having a cotton profile. 14. The papermaker's fabric support element according to claim 13, wherein the spacer means consists of at least a portion of the second thin sheet segment. 15. The papermaker's fabric support element according to claim 13, wherein at least some of the plurality of outlet holes further comprise V-notches. As a paper machine having a machine direction and a machine cross direction, Papermaking fabric moving in the machine direction; (i) the leading edge, (ii) the trailing edge, (iii) the machine side being adapted to be releasably fixed to the paper machine by the fixing means, and (iv) a fabric support element having a paper side surface with a predetermined machine cross direction profile and a machine direction profile including a fabric contact surface adapted to support the papermaking fabric in sliding contact, (a) the fabric support element comprises a plurality of at least first and second thin sheet segments, (b) the paper side face profile of the first thin plate segment is different from the paper side face profile of the second thin plate segment, (c) at least a portion of the first thin sheet segment contributes to a predetermined profile of the fabric contacting paper side face of the fabric support element, (d) Paper machine at least some of said first and second thin sheet segments together form discharge holes extending from the paper side to the machine side. 18. The paper machine of claim 17, wherein the first and second thin plate segments are spaced apart by spacer means. 18. The paper machine of claim 17, wherein each of the first thin sheet segments has a first paper side face profile and each of the second thin sheet segments has a second paper side face profile different from the first paper side face profile. . 18. The papermaking machine according to claim 17, wherein the spacer means consists of at least part of the second thin sheet segment. A thin sheet segment configured to be releasably secured in a plurality in a machine-wise relationship in a machine direction to form a discharge hole through a fabric support element, The thin segment has a fabric contact paper side face having a profile, a leading edge, and a trailing edge, and the fabric contact paper side face having the profile can be configured to contribute to a paper side face having a profile of the fabric support element. Lamination segment. A method of making a stationary fabric support element for supporting a papermaking fabric moving in a paper machine, (i) forming outlet holes between adjacent pairs of at least some of the plurality of sheet segments, wherein the paper side side of at least some of the sheet segments form a plurality of composite paper side sides where the moving fabric may be in sliding contact. Assembling the sheet segments of the substrate in spaced and parallel relationship, (ii) releasably securing the sheet segments to the retaining means on the paper machine by means of fastening means such that the sheet segments are parallel to the machine direction or oriented at a small angle with respect to the machine direction. 22. The thin segment of claim 21 wherein the thin segment is configured to be releasably secured in plural in spaced apart relation by spacer means. The thin plate segment according to claim 23, wherein said spacer means is integrally formed with said thin plate segment. 3. The impact shoe of claim 2 wherein the sheet segments are releasably secured in a parallel relationship to each other such that they are oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. 26. The impact of claim 25 wherein the sheet segments are spaced apart by a plurality of spacer means, and wherein at least some of the spacer means are integrally configured with at least some of the plurality of sheet segments. Shu. 5. The collision as claimed in claim 4, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. Shu. 6. The impact as claimed in claim 5, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. Shu. 7. The impact of claim 6 wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. Shu. 8. The impact of claim 7 wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° relative to the machine direction. Shu. 10. The paper machine molded part according to claim 9, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. The paper machine molded part according to claim 10, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. 18. The paper machine according to claim 17, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. 19. The paper machine according to claim 18, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. 20. The paper machine according to claim 19, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. 21. The paper machine according to claim 20, wherein the first and second thin plate segments are releasably fixed in a parallel relationship to be oriented at an angle ε in the range of 2 ° to 20 ° with respect to the machine direction. The method of claim 22 wherein the small angle is in the range of 2 ° to 20 °.

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