Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/0209—Wet presses with extended press nip
  • D21F3/0218—Shoe presses
  • D21F3/0227—Belts or sleeves therefor
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C37/00—Component parts, details, accessories or auxiliary operations, not covered by group B29C33/00 or B29C35/00
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C37/00—Component parts, details, accessories or auxiliary operations, not covered by group B29C33/00 or B29C35/00
  • B29C37/0053—Moulding articles characterised by the shape of the surface, e.g. ribs, high polish
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
  • B29C67/24—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 characterised by the choice of material
  • B29C67/246—Moulding high reactive monomers or prepolymers, e.g. by reaction injection moulding [RIM], liquid injection moulding [LIM]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D29/00—Producing belts or bands
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/36—Guiding mechanisms
  • D21F1/40—Rolls
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/0209—Wet presses with extended press nip
  • D21F3/0218—Shoe presses
  • D21F3/0227—Belts or sleeves therefor
  • D21F3/0236—Belts or sleeves therefor manufacturing methods
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/08—Pressure rolls
  • D21F3/086—Pressure rolls having a grooved surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2075/00—Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2029/00—Belts or bands
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/733—Fourdrinier belts
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S162/00—Paper making and fiber liberation
  • Y10S162/901—Impermeable belts for extended nip press

Definitions

• the present invention is directed to the field of papermaking, particularly to a method of making a grooved belt, or roll cover where applicable, used in papermaking machines and processes.
• the invention concerns using ribbon placement to create the grooves without machining the belt surface.
• a cellulosic fibrous web is formed by depositing a fibrous slurry, that is, an aqueous dispersion of cellulose fibers, onto a moving forming fabric in the forming section of a paper machine. A large amount of water is drained from the slurry through the forming fabric, leaving the cellulosic fibrous web on the surface of the forming fabric .
• a fibrous slurry that is, an aqueous dispersion of cellulose fibers
• the newly formed cellulosic fibrous web proceeds from the forming section to a press section, which includes a series of press nips.
• the cellulosic fibrous web passes through the press nips supported by a press fabric, or, as is often the case, between two such press fabrics.
• the press nips the cellulosic fibrous web is subjected to compressive forces which squeeze water therefrom, and which adhere the cellulosic fibers in the web to one another to turn the cellulosic fibrous web into a paper sheet .
• the water is accepted by the press fabric or fabrics and, ideally, does not return to the paper sheet .
• the paper sheet finally proceeds to a dryer section, which includes at least one series of rotatable dryer drums or cylinders, which are internally heated by steam.
• the newly formed paper sheet is directed in a serpentine path sequentially around each in the series of drums by a dryer fabric, which holds the paper sheet closely against the surfaces of the drums.
• the heated drums reduce the water content of the paper sheet to a desirable level through evaporation.
• the forming, press and dryer fabrics all take the form of endless loops on the paper machine and function in the manner of conveyors. It should further be appreciated that paper manufacture is a continuous process which proceeds at considerable speeds. That is to say, the fibrous slurry is continuously deposited onto the forming fabric in the forming section, while a newly manufactured paper sheet is continuously wound onto rolls after it exits from the dryer section.
• press sections have included a series of nips formed by pairs of adjacent cylindrical press rolls.
• the use of long press nips of the shoe type has been found to be more advantageous than the use of nips formed by pairs of adjacent press rolls. This is because the longer the time a web can be subjected to pressure in the nip, the more water can be removed there, and, consequently, the less water will remain behind in the web for removal through evaporation in the dryer section.
• the present invention relates, in part, to long nip presses of the shoe type. In this variety of long nip press, the nip is formed between a cylindrical press roll and an arcuate pressure shoe.
• the latter has a cylindrically concave surface having a radius of curvature close to that of the cylindrical press roll.
• a nip which can be five to ten times longer in the machine direction than one formed between two press rolls, is formed. Since the long nip may be five to ten times longer than that in a conventional two-roll press, the so-called dwell time, during which the fibrous web is under pressure in the long nip, may be correspondingly longer than it would be in a two-roll press. The result is a dramatic increase in the dewatering of the fibrous web in the long nip relative to that obtained using conventional nips on paper machines .
• a long nip press of the shoe type requires a special belt, such as that shown in U.S. Patent No. 5,238,537 to Dutt ' (Albany International Corp.), the teachings of which are incorporated herein by reference.
• the belt is designed to protect the press fabric, which supports, carries and dewaters the fibrous web, from the accelerated wear that would result from direct, sliding contact over the stationary pressure shoe.
• Such a belt must be provided with a smooth, impervious surface that rides, or slides, over the stationary shoe on a lubricating film of oil .
• the belt moves through the nip at roughly the same speed as the press fabric, thereby subjecting the press fabric to minimal amounts of rubbing against the surface of the belt .
• Belts of the variety shown in U.S. Patent No. 5,238,537 are made by impregnating a woven base fabric, which takes the form of an endless loop, with a synthetic polymeric resin.
• the resin forms a coating of some predetermined thickness on at least the inner surface of the belt, so that the yarns from which the base fabric is woven may be protected from direct contact with the arcuate pressure shoe component of the long nip press. It is specifically this coating which must have a smooth, impervious surface to slide readily over the lubricated shoe and to prevent any of the lubricating oil from penetrating the structure of the belt to contaminate the press fabric, or fabrics, and fibrous web.
• the base fabric of the belt shown in U.S. Patent No. 5,238,537 may be woven from monofilament yarns in a single or multi-layer weave, and is woven so as to be sufficiently open to allow the impregnating material to totally impregnate the weave. This eliminates the possibility of any voids forming in the final belt. Such voids may allow the lubrication used between the belt and shoe to pass through the belt and contaminate the press fabric or fabrics and fibrous web.
• the base fabric may be flat-woven, and subsequently seamed into endless form, or woven endless in tubular form.
• the impregnating material When the impregnating material is cured to a solid condition, it is primarily bound to the base fabric by a mechanical interlock, wherein the cured impregnating material surrounds the yarns of the base fabric. In addition, there may be some chemical bonding or adhesion between the cured impregnating material and the material of the yarns of the base fabric. Long nip press belts, such as that shown in U.S. Patent No.
• 5,238,537 depending on the size requirements of the long nip presses on which they are installed, have lengths from roughly 10 to 35 feet (approximately 3 to 11 meters) , measured longitudinally around their endless-loop forms, and widths from roughly 6 to 35 feet (approximately 2 to 11 meters) , measured transversely across those forms.
• the manufacture of such belts is complicated by the requirement that the base fabric be endless prior to its impregnation with a synthetic polymeric resin.
• the belt It is often desirable to provide the belt with a resin coating of some predetermined thickness on its outer surface as well as on its inner surface.
• its woven base fabric By coating both sides of the belt, its woven base fabric will be closer to, if not coincident with, the neutral axis of bending of the belt. In such a circumstance, internal stresses which arise when the belt is flexed on passing around a roll or the like on the paper machine will be less likely to cause the coating to delaminate from either side of the belt.
• the outer surface of the belt has a resin coating of some predetermined thickness, it permits grooves, blind-drilled holes or other cavities to be formed on that surface without exposing any part of the woven base fabric.
• the present invention relates particularly to a grooved press belt which could be used in a long nip press or also in a conventional press.
• the present invention relates to a grooved roll cover.
• a machining ! process is typically used to create the surface grooves.
• the grooves define channels and are separated from one another by what may be referred to as land areas.
• the width and depth of the grooves and the number of grooves per inch dictate the void volume of the grooved belt surface.
• the need for the belt to flex dictates certain material characteristics. For instance, the material must be sufficiently flexible to conform to the belt path and still be rigid enough so as not to collapse under press loads. In this regard, it is noted that elastomers such as urethane have been successfully used heretofore.
• Roll covers are manufactured in a variety of ways, using varied materials such as rubber, rubber- like materials, polymers or metal alloys.
• Current methods of manufacturing roll covers include "laying up" sections of uncured mats of polymeric compounds onto a roll body, sometimes with textile reinforcement . This forms a roll cover of several sections, which is finished by heat curing to form a continuous cover. This cover is ground and may undergo other surface finishing steps. Finally, grooves are cut in a circumferential pattern in the surface to assist sheet dewatering in the press nip.
• Another method used to form roll covers is to spiral wind a semi-solid resin onto a body, followed by curing and surface finishing. Again, grooves are cut in the surface to assist dewatering in the nip.
• Yet another method is to cast or mold a resin-fiber system onto a mandrel or roll body, forming a composite system.
• Other covers may be formed of mixtures of resins (i.e., "alloys" of resins), metals and resins, ceramics, and the like.
• the surface grooves are typically created by machining the roll cover surface. Again, the width and depth of the grooves and the number of grooves per inch dictate the void volume of the grooved surface. It is also noted that there are many different materials used to create grooved roll surfaces . During the machining of grooves especially in belts, the interior walls (the sides of the lands separating the grooves) of synthetic surface material are left with microscopic surface cuts created by the action of the machine tool . These microscopic cuts can constitute crack initiation sites which may lead to larger cracks and eventual failure or delaminating of the land area on either side of the groove. In this connection, U.S. Patent No.
• 5,171,389 is directed toward a method of making a grooved void-volume belt for use on a long nip press. After applying an adhesive, a strip of material having a groove already formed therein is wound about a partially completed belt and suitably attached. This, among other things, avoids having to cut grooves in the belt surface.
• the present invention provides an approach towards forming grooves or other patterns on both belt and roll surfaces without machining using ribbon placement to create the grooves.
• the present invention is directed towards a method of making a grooved belt or surface roll.
• a chemically reactive material is first placed on the surface of the partially processed belt or roll.
• a second material is then deposited as a ribbon on the chemically reactive surface to create a pattern of grooves .
• the placement of the ribbon is used to create the grooves therebetween and no machining is required. This eliminates the potential problem of cracking and delamination of the belt or roll surface.
• the resulting ribbon is smooth and uniform.
• Figure 1 illustrates the method by which the belt of the present invention may be manufactured
• Figure 2 illustrates using the placement of the ribbons to create the grooves
• Figure 3A illustrates the strip profile of the prior art
• Figure 3B illustrates exemplary profiles of the ribbons of the present invention.
• the belt may include a base structure or substrate which may be any conventional belt base substrate known in the art, including woven, nonwoven, spiral-link, MD or CD yarn arrays, knitted fabric, extruded mesh, and spiral wound strips of woven and nonwoven materials .
• These substrates may comprise yarns of any of the varieties used in the production of paper machine clothing, such as monofilament, plied monofilament, multifilament and plied multifilament yarns. These yarns may be obtained by extrusion from any of the polymeric resin materials used for this purpose by those of ordinary skill in the art .
• the present invention can be, produced by using a device similar to that shown in Figure 1.
• the device has (A) a mandrel 11 for supporting a belt substrate 10 (or roll cover base where applicable) during production of the belt,- (B) means for applying (not shown) a chemically reactive material 12 on the belt substrate 10; (C) means for depositing 14 a second material 16 onto the belt substrate 10 to form a pattern.
• material 16 may be elastomer ribbons placed so as to form grooves therebetween;
• (C) means for mounting (not shown) the depositing means 14 for movement in at least one direction relative to the surface of the belt substrate 10; and (D) means to control (not shown) the movements and to control the depositing of the second material 16 from the depositing means 14.
• a belt forming mandrel 11 is provided.
• the belt substrate 10 can and usually does have at least a partial impregnation of resin already.
• the inside surface that is, the surface against the mandrel 11 also has a smooth layer of resin applied by any means known in the art.
• a thin film of chemically reactive elastomeric material 12 is placed on the belt substrate 10 to create a chemical bond between the substrate 10 and the second material 16 to be deposited.
• the thin layer 12 must be chemically reactive for the time which is required to apply the second material 16.
• this second material is a liquid elastomeric ribbon stream 16.
• a chemical mixing head 14 containing the elastomeric material is so angled and controlled to traverse the width of the belt substrate 10. In this way, each revolution of the mandrel leaves a ribbon deposition of raised land areas with grooves on either side. That is, the placement of the ribbons 16 is used to create the grooves .
• Figure 2 shows the distribution of the small liquid elastomer ribbons which nestle next to each other to form the lands 20 and the shaped grooves 22.
• the elastomer is engineered so that it turns from a liquid to a solid in a sufficiently short time (i.e., seconds), thus allowing the ribbon of material to retain its shape.
• the resulting ribbon laid surface 24 is uniform and smooth without cuts or cracks .
• the mixing head 14 shown in Figure 1 may have either one port or multiple ports. However, a mixing head 14 having multiple ports is preferred.
• the number of ports and dimensions thereof, and the amount of material being applied determine the size and shape of the ribbons 16.
• controlling precisely the traverse speed of the mixing head 14 is very important, since the ribbon lay must match each previous pass .
• the weld lines i.e., where the respective ribbons start and end
• a superior grooved belt or surface roll can be produced using the aforedescribed method.
• the direct deposition of the ribbons to produce the grooves eliminates the problems caused by the machining of grooves as practiced in the prior art.
• the present invention uses the ribbons' placement to create the grooves.
• the resulting ribbon laid surface is uniform and smooth without cuts and cracks that lead to delamination of the belt or roll surface.
• a relatively greater amount of material may be applied to the desired region of the belt or roll surface in a controlled manner in a controlled geometry in three planes (x, y and z) .
• this permits the formation of, for example, a crown formed as part of a roll cover, or the formation of other variations in the diameter of the surface along the cross machine direction.
• the present invention differs from the aforementioned Patent No. 5,171,389 in that the present invention specifies first placing a chemically reactive layer 34 (see Figure 3B) onto the belt surface prior to depositing the elastomeric ribbon stream, whereas the ⁇ 389 patent instead mentions merely preapplying an adhesive.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Paper (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)
• Electrostatic Charge, Transfer And Separation In Electrography (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Coating Apparatus (AREA)
• Materials For Medical Uses (AREA)
• Delivering By Means Of Belts And Rollers (AREA)

Priority Applications (11)

Applications Claiming Priority (2)

Publications (2)

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ID=33450654

Family Applications (1)

Country Status (17)

Cited By (1)

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Citations (1)

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• 2003
  • 2003-05-23 US US10/444,416 patent/US7374640B2/en not_active Expired - Lifetime
• 2004
  • 2004-05-19 KR KR1020057022388A patent/KR101108522B1/ko not_active Expired - Fee Related
  • 2004-05-19 PL PL04752611T patent/PL1633926T3/pl unknown
  • 2004-05-19 MX MXPA05012629A patent/MXPA05012629A/es active IP Right Grant
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  • 2004-05-19 JP JP2006533203A patent/JP4869934B2/ja not_active Expired - Fee Related
  • 2004-05-19 CN CN200480014241A patent/CN100575601C/zh not_active Expired - Fee Related
  • 2004-05-19 ES ES04752611T patent/ES2395905T3/es not_active Expired - Lifetime
  • 2004-05-19 RU RU2005136422/12A patent/RU2363795C2/ru not_active IP Right Cessation
  • 2004-05-19 PL PL11187893T patent/PL2431518T3/pl unknown
  • 2004-05-19 EP EP11187893.0A patent/EP2431518B1/en not_active Expired - Lifetime
  • 2004-05-19 NZ NZ544225A patent/NZ544225A/en unknown
  • 2004-05-19 ZA ZA200509439A patent/ZA200509439B/en unknown
  • 2004-05-19 WO PCT/US2004/015620 patent/WO2004110729A2/en not_active Ceased
  • 2004-05-19 EP EP04752611A patent/EP1633926B1/en not_active Expired - Lifetime
  • 2004-05-19 ES ES11187893.0T patent/ES2452555T3/es not_active Expired - Lifetime
  • 2004-05-19 BR BRPI0410605-9A patent/BRPI0410605B1/pt not_active IP Right Cessation
  • 2004-05-19 AU AU2004247629A patent/AU2004247629B2/en not_active Ceased
  • 2004-05-21 TW TW093114454A patent/TWI327182B/zh not_active IP Right Cessation
• 2005
  • 2005-12-22 NO NO20056124A patent/NO20056124L/no not_active Application Discontinuation
• 2010
  • 2010-03-18 JP JP2010062296A patent/JP4990993B2/ja not_active Expired - Fee Related

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