Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
  • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
  • D21H23/22—Addition to the formed paper
  • D21H23/32—Addition to the formed paper by contacting paper with an excess of material, e.g. from a reservoir or in a manner necessitating removal of applied excess material from the paper
  • D21H23/34—Knife or blade type coaters

Definitions

• This invention relates to paper coaters and, more particularly, to a mounting assembly for placing multiple paper coaters about a single backing roll coating station.
• the overflow pan in order to insure the bladed off coating did not spill over a gravity flow, coating overflow pan, it was necessary for the overflow pan to be relatively deep, say eighteen inches (20 cm) or more in depth. The requirement for such a deep pan, itself, can make it difficult, if not impossible, to put two or more coater or blade units around a single backing roll but yet permit the coaters or blade units to be properly adjusted.
• SUBSTITUTE-SHEET (RULE 26) unit it carries and the beam's own weight.
• One approach used to limit the deflection is by pre-stressing the cross beam, itself, to counter the anticipated deflection due to gravity and operational loading.
• Such a deflection control system is shown in U.S. patent No. 4,907,528 or 5,005,515.
• the mounting assembly of the present invention permits two or more coater or doctor blade units or three coater units to be assembled or mounted at a single backing roll coating station, but yet permits the coater and doctor or blade units to be easily adjusted, operated and maintained.
• the mounting assembly of the present invention for use on a paper machine comprises a single backing roll rotatably mounted to the paper machine, at least first and second coater or blade (also doctor) units, first mounting means for locating one of the coater or blade units at a lower portion of the backing roll, and at least second mounting means for locating the other of the coater or blade (or doctor) units at an upper portion of the backing roll, each of said first and second mounting means being pivotable about at least one locus.
• each of said first and second mounting means pivots its associated coater or blade unit into an operating position and a servicing position which does not interfere with the operating and/or servicing position of the other coater blade units or any other coater unit (a third coater) located at the backing roll.
• each of said first and second mounting means is pivotable about two loci, one locus adjacent the paper machine frame to which said mounting means is secured and the other loci being spaced some distance away and adjacent the associated coater or blade unit carried by that mounting means.
• the double loci construction permits the coater and particularly the doctor or blade units to be pivoted to desired blade angles with respect to the backing roll.
• the compactness of the first and second mounting means permits, if desired, three coating applicators or coater units to be located around a single backing roll, such as two SDTA coater units, each having an applicator unit with an integral doctor or blade and a separate doctor or blade unit, and in addition a dip roll coater unit which also may or may not have its own doctor or blade.
• the drainage can be assisted by the provision of suction or scavaging pump means to help pull the bladed off coating from the shallow overflow pan means.
• auger means extending along the length of the shallow overflow pan means in the cross machine direction, can be used to physically push and pull the coating from one or more of the shallow overflow pan means.
• the mounting assembly of the present invention includes a cross beam and means for controlling the deflection of the cross beam and coater or doctor or blade unit thereon which is similar to that shown in U.S. patent 4,907,528 or 5,005,515.
• the cross beam and cross beam deflection control means comprise an inner beam portion and an outer beam portion extending in a cross machine direction, said inner and outer beam portions being supported at the ends or sides adjacent the web.
• Pressure means is provided spaced between the inner and outer cross beam portions which may be selectively pressurized with fluid to control or eliminate the beam's deflection.
• Another object of the mounting assembly of the present invention is to mount three coaters about a single backing roll.
• Still another object of the mounting assembly of the present invention is to mount two or more coater or blade units on a single backing roll and permit each of the coater or blade units to pivot independently into an operating position and a maintenance or service position.
• Yet another object of the mounting assembly of the present invention is to provide shallow overflow pans means workable with two or more wide coater or blade units on a single backing roll.
• Still a further object of the mounting assembly of the present invention is to control overflow from wide cross machine direction coater or blade units.
• a further object of the mounting assembly of the present invention is to provide means for withdrawing coating from shallow depth, long length (cross machine direction) overflow pans without the coating spilling over the pans.
• a still further object of the mounting assembly of the present invention is to limit and control the deflection of two or more coater or blade units placed around a single backing roll.
• Figure 1 is an elevational view of a first embodiment of mounting assembly of the present invention for mounting a dip roll coater unit and a short dwell time applicator (SDTA) coater unit which has its own doctor blade and a separate doctor blade unit around a single backing roll to form a coating station, the latter two units being shown in operation positions in full lines and in maintenance or service positions in dashed lines.
• SDTA short dwell time applicator
• Figure 2 shows the coater unit and separate doctor blade unit in Figure 1 in one of their pivoted blade angle operating positions.
• Figure 3 shows the coater unit and separate doctor blade unit in Figure 1 in another of their pivoted blade angle operating positions.
• FIG. 4 shows a second embodiment of mounting assembly of the present invention showing two SDTA coater units each having its own doctor blade and a separate doctor blade unit, all mounted around a single backing roll.
• Figure 5 shows a third embodiment of mounting assembly of the present invention showing a dip roll coater unit and two SDTA coater units mounted around a single backing roll.
• Figure 6 is a partial view of a mounting assembly of the present invention having a blade unit with a shallow, quarter-point gravity flow overflow pan means to assist drainage of coating bladed off from the web running on the single backing roll.
• Figure 7 is an enlarged cross-sectional view of the overflow pan shown in Figure 6, taken along the lines 7-7.
• Figure 8 is a partial view of a mounting assembly of the present invention having a shallow, auger assisted overflow pan to assist drainage of coating bladed off from the web on the single backing roll.
• Figure 9 is an enlarged cross-sectional view of the auger overflow pan shown in Figure 8, taken along the lines 9-9.
• Figure 10 is a cross-sectional view of a cross beam deflection control means for use with any of the embodiments of the present invention shown in the other figures.
• Figure 11 is a schematic diagram of one form of coating flow system for use with the present invention.
• a first embodiment 10 of the mounting assembly of the present invention is shown.
• the embodiment 10 as shown is a multiple of coaters located at a coating station located on a single backing roll 12.
• the backing roll 12 is considerably larger in diameter than the usual 30 to 40 inches (86 to 92 cm) , being 59 inches (about 150 cm) in diameter.
• any roll with a diameter of at least 48 inches (122 cm) may be suitable.
• the center of the backing roll 12 is indicated at 13 and is mounted in the paper machine frame to rotate about its center as is conventional.
• a moving paper web 14 is shown on the backing roll.
• Spaced about the backing roll 12 is a dip roll coater unit 16, having a dip roll 18 rotating in a dip roll pan 20, as is conventional.
• the dip roll coater in normal operation is not movable to any significant degree, the exception being the "nip" between the backing roll 12 and the dip roll 18 can be varied.
• the dip roll 18, itself is removable.
• dip roll coater 16 Operation characteristics of the dip roll coater 16 require it to be placed generally at the bottom of the backing roll so that only the top of the dip roll 18 touches the web on the backing roll, and that excess coating does not spill out of the dip roll pan 20.
• the dip roll coater when used in a multiple coater arrangement is usually the first coater, that usually relegates any subsequent coater or doctor blade units to be positioned further down the web and along the periphery of the backing roll, and in the instance of Figure 1, in what would mathematically be referred to as the third quadrant.
• a second coater unit 22 like that described in U.S. Patent application Serial No. 375,241, comprising a short dwell time applicator (SDTA) unit 24 (as disclosed in U.S. Patent No. 4,250,211), with its integral doctor blade 23 and overflow pan 27 and its separate blade unit 26 with its doctor blade 25 and another overflow pan 29.
• SDTA short dwell time applicator
• the second coater unit 22 has two blades, the first doctor blade 23 being on the applicator unit 24 and the second doctor blade 25, being on the separate doctor or blade unit 26.
• the second coater (in Figure 1, reference numerals 24 and 26) must be placed on the web on the backing roll in a manner that the two doctors or blades 23 and 25 drain by gravity away from the web.
• Such gravity drainage can be accomplished in the Figure 1 embodiment when the unit 22 is in or near the above referred to mathematical third quadrant.
• the general placements of the dip roll coater unit 16, the SDTA unit 24 and the separate blade unit 26 are determined by their individual requirements.
• the dip roll coater 16 does not move significantly, for servicing is usually provided simply by giving access to its two cross machine sides. As shown in Figure 1, service for the upstream web (right) side is relatively easy as that side is unincumbered by adjacent machinery. On the other hand, the downstream (left) side is essentially closed off from access by the SDTA coater 24 when in its operating position. Likewise, the upstream side of the SDTA coater 24 is closed off from access by the dip roll coater 16. In order to provide access to both the dip roll coater 16 and the SDTA coater 24, the SDTA coater is movably mounted so that it can be swung away and down into its service position shown in dashed lines in Figure 1.
• the mounting means for the SDTA coater 24 is carried on a base 30 secured to the paper machine floor or frame 32. Pivoted to this base are large side arms 34 which carry the SDTA coater. The lower pivot point or locus for the side arms 34 is indicated a point 36. A cross shaft 36A connects the side arms 34. The side arms 34 and the cross shaft 36A for the coater 24 are connected to one or more hydraulic cylinders 37 which also are connected to the base 30.
• Operation of the hydraulic cylinder 37 can pivot the side arms 34 and cross shaft 36A about the point 36 (in Figure 1 located a distance below and a small distance to the left of the center 13 of the backing roll) to raise or lower the coater unit 24 between one of its operating (solid lines) and service (dashed lines) positions.
• the mounting means could utilize mechanical devices or pneumatic devices or cylinders, instead of hydraulic cylinders 37.
• the SDTA unit 24 comprises a large cross- section cross beam 38 which, in fact, carries the actual coating application or applying portion and blade across the width of the web 14.
• This cross beam 38 is generally similar to that shown in Figure 10, but somewhat larger in cross section, in this instance 22 X 26 inches
• the cross beam 38 itself is pivotally mounted to the upper portion of the side arms 34 about a locus or point indicated at 40 which coincides with the line established by the tip of the blade 23 touching the circumference of the backing roll.
• the operating envelope required by the SDTA unit 24 also must include sufficient space to permit angular movement of that coater to adjust blade angle, making it even more difficult to locate two or more or three coaters in what is essentially one (the third) quadrant of the backing roll.
• the coater 24 can, when in its operating position, also be pivoted about the upper pivot point 40 to vary the operating angle the doctor blade 23 of the SDTA 24 makes with the web on the backong roll.
• an electrically operated screw jack 42 is provided in order to pivot the SDTA coater 24 to a desired blade angle.
• the screw jack 42 has its upper end pivotally mounted to the coater 24, schematically indicated at 44, and its lower end pivotally mounted to the cross shaft 36A, schematically indicated at 46.
• the screw jack 42 is, preferably, operable from the paper machine's control or operator's console and can be lengthened or shortened to increase or decrease blade angle.
• Two of the various doctor blade angles for the SDTA 24 can be seen in Figures 2 and 3, and in this instance the angle of the blade to the web can be varied about 30°, anywhere between 25° to 55°. To achieve such doctor blade angle range may require the unit on which the blade is mounted to have angular movement of up to 70°. This is because in order to achieve a desired blade angle, the unit may have to be moved a greater amount to compensate for blade deflection. This construction, of course, requires a greater envelope of space for each unit. Thus, not only can the position of the coater unit 24 be varied to permit service of the coater unit 24 or of the dip roll coater unit 16, the coater unit 24 can also be varied for operation at different blade angles.
• the separate doctor blade unit 26 ( Figure 1) , it is similar in construction to the coater unit 24 in that it is carried on the large cross beam 60 (more fully shown in Figure 10) .
• the blade unit 26 is somewhat smaller in size and lighter in weight, its cross beam is smaller, being approximately 20 X 20 inches (approximately 51 cm X 51 cm) in cross-section.
• the blade unit 26 too is similarly mounted to permit placement of that unit in an operating position (solid lines) and service position (dashed lines) .
• two large upper side arms 70 are mounted to and suspended from the paper machine frame 71 to pivot about a locus or point indicated at 72 (in Figure 1, located above and to the left of the center 13 of the backing roll) .
• the location of the pivot point 36 for the first or coater unit 24 and the pivot point 72 of the second or blade unit 26 is such that a straight line 73 drawn between these two points lies outside the backing roll circumference or perimeter 75.
• the blade unit 26 is movable between its operating position (solid lines) and maintenance or service position (dashed lines) by an upper hydraulic cylinder 74 which has one or upper end 76 pivotally connected to the paper machine frame 77 and the other or lower end 78 pivotally connected to the upper side arms 70.
• a mechanical means such as screw jacks or a fluid or pneumatic devices or cylinders could be utilized instead of hydraulic cylinders 74.
• the cylinder 74 (hydraulic or pneumatic or other fluid) or mechanical equivalent could have two strokes, a long stroke to move the unit 26 to a service position and a shorter stroke for use in the operating position.
• the doctor blade unit 26, at each side is pivotably mounted about an axis 64 on the side arms 70.
• the side arms 70 locate the axis or line 64 (seen as a point in Figure 1, but in reality a line) and the tip of the blade 25 generally on the circumference of the backing roll.
• the blade unit 26 too can pivot about the axis 64 to adjust the angle of the blade 25.
• the unit 26 can be moved to vary the blade angle, say anywhere between 5° to 55°; or the blade could also be of the bent blade type.
• a large electrically operated screw jack 82 similar to screw jack 42 previously described, is provided.
• an upper cross shaft 86 of a smaller cross section than the beam 60 is provided.
• the screw jack 82 has the upper end bracket 83 pivoted at . 88 to bracket 89 on the cross beam 60 of the unit 26. Again, varying the length of the screw jack 82 alters the blade angle.
• a movable workmen's platform 90 is provided, shown in the solid lines positioned to service the lower coater unit 24 and in the dashed lines positioned to service the upper blade unit 26.
• the platform 90 can be moved by any conventional means, such as but not limited to hydraulic or pneumatic cylinders or donuts or scissor jacks.
• each of the units 24 and 26 can be moved into a service position or operating position; when in the service positions the units are at least ten feet apart to permit service; when in the operating position the blade angles of the doctor blade 23 or 25 to the web can be, likewise, varied between 0° and 55° and/or a bent blade used as desired, all while permitting use and/or service of the dip roll coater unit 16 which is located on the same single backing roll 12, forming a very versatile coating station.
• the operation of the various coater units 16 and/or 24 and/or the doctor blade unit 26 is well known in the prior art, such as from U.S. Patent Nos. 4,250,211, 4,310,573 or 4,512,279 or U.S. Patent Application No. 375,241.
• FIG 4 an embodiment 98 generally similar to that in Figure 1 is shown, the difference being the dip roll coater unit 16 of Figure 1 is replaced by another (earlier on the web) SDTA coater unit 100.
• the trailing or second SDTA unit 102 and the trailing blade unit 104 are similar to those units 24 and 26 shown in Figure 2, they will not be further described.
• the coater unit 100 has a doctor or blade 108 or any other means for metering (smooth or profiled rod) and an overflow pan 110 and is also generally similar to the coater unit 24, previously described.
• the coater unit 100 has a cross beam ill which carries the coating applicator or applying portion, and itself is pivotal about an axis, locus or point 112 (which is the line of contact of the tip of the doctor blade 108 with the circumference of the backing roll 113) on side arms 114.
• the side arms 114 in turn, pivoted at their lower ends with respect to the paper machine about a locus or axis 118.
• coater 100 can be pivoted to adjust blade angle about the locus or axis 112 or about the locus or axis 118 to move the coater 100 into or out of a service position.
• a screw jack 120 is provided, the lower or right end of the screw jack being pivot mounted to a cross shaft (similar to 36A or 86 of Figure 1) and the upper or left end being pivot mounted to the cross beam 111 at the locus or axis 124.
• a hydraulic or pneumatic cylinder 130 is provided, the cylinder at its upper end being pivotally mounted to the side arms, as indicated at the locus 132, and being pivotally mounted at its lower end to the paper machine, as indicated at the locus 134.
• the entire of the coater unit 100 is slidably mounted on the base 121 so that the entire coater 100 can be first moved to the right (as indicated by the arrow 121A) about 2.5 feet (.75 meters) for servicing of either the first or second coater units on the web.
• Such slidable construction is well known in the papermachinery field and need not be further described.
• the coater 100 can be swung or pivoted clockwise (as shown in dotted lines) about the axis 118 to a service position so that the upstream side of the coater 102 and/or the coater 100 can be maintained.
• an embodiment 140 is shown and is generally similar to that shown in Figure 1, except a second short dwell coater unit 142 is located and used on the backing roll, instead of the doctor blade unit 26.
• the coater unit 142 has a doctor or blade 144 and a coater overflow pan 146 which are generally similar to those of the separate blade unit 26 of Figure 1.
• the installation is similar to that of Figure 1 and need not be further described to a person skilled in the art, it being known to such person to use the second SDTA coater unit 142 in a manner similar to that described in U.S. Patent Application 375,241.
• FIG. 5 shows a dip roll coater unit and two separate SDTA coater units all on one backing roll, should it be desired, it would be possible to apply three individual coatings to the same side of the web, or any of the various combinations could be used such as, but not limited to: (1) the dip roll and one SDTA, (2) the dip roll, one SDTA and the separate doctor or blade (of the second SDTA) , or (3) the dip roll, the doctor or blade of the first SDTA and the second SDTA, giving a wide variety of coating operations and techniques that could be performed at this three coater - one backing roll coating station.
• a shallow, or limited depth, 12 to 15 inches (30 to 38 cm) overflow pan 200 can be provided for use with the blade unit 26 or coater units 104 or 142.
• the pan 200 can be mounted to its associated unit by the side brackets 202 (only one being shown) .
• the overflow pan would be of conventional double wall construction to permit the circulation of chilled water to prevent premature coagulation of coating in the pan.
• This pan 200 has two take off points 206 j(only one being shown) for removal of the bladed off coating from the pan, one at each side of the pan.
• the inlets 210 elongated slots (shown) or multiple holes) to the take off points 206 are located at about the quarter-points of the length of the pan.
• each take off point would drain about one half the length of the pan (12.5 feet) and would be located about one quarter the length (6.25 feet) from each side.
• the pan floor 220 on either side of the inlet for about one quarter of the length would be sloped or tapered (Say a 1: 12 to 1: 8 taper) to the quarter-point inlet.
• the other side of the pan (not shown in Figure 7) would be a mirror image of what is shown.
• the coating can be suctioned from the take off points 206 by suction pump means, which will greatly increase the capacity of the pan to handle doctored or bladed off coating as compared to merely relying upon gravity flow from the overflow pan into the coating system.
• auger overflow pan means 240 is shown. This pan too is shallow in depth (12 or 15 inches or less) and preferably of a double wall construction.
• the pan has end walls 242, closed by a curved bottom wall 244 and two side walls 246.
• the bottom 244 has an outlet 248 for draining off the excess coating doctored or bladed off at each side.
• Inside the pan an inner bearing stand 250 is provided near the center of the pan.
• An auger 254 extending in the cross machine direction has a shaft 255 that is rotatably mounted in the bearing stand 250 and in a bearing mounted on the end wall 242.
• the shaft 255 of the auger 254 is driven by a motor means or gear motor depicted at 256. Rotation of the motor 256 turns the shaft 255 and auger 254 to pull bladed off coating from the center of the pan toward the end outlets 248, and then pushes the doctored or bladed off coating into the outlets 248.
• the auger would extend say 27 ft (about 110 % of the cross machine length of the pan) .
• the other end of the pan would have a similar auger installation or structure.
• the auger could be continuous from side to side or two shorter augers extending from each end toward the center could be used. In the latter case two motors would be needed, while in the former case one or two motors would be used. While this pan is shown with the doctor or blade unit 26, it could also be used with any of the coater units 104 or 142.
• the unit 26 has a doctor or blade 282 which rides on the web 14 on the roll 12. Beneath the blade is an overflow pan 283.
• the blade is mounted to the outside of a generally square tube or beam 284 which extends across the width of the web between the side arms.
• an outer circular tube 288 Inside the rectangular beam 284 is an outer circular tube 288, the outside of which is generally tangent ot the inside of the square tube 284. Inside this tube 288, is a smaller diameter but thicker inner tube 290.
• pressure means in the form of a plurality of hoses or bladders 292 are provided and may be selectively supplied with fluid, such as hydraulic oil, or preferably compressed air under pressure from a source (not shown) .
• the tubes 288 or 290 are contoured as indicated at 294 to provide a cavity to receive the bladders.
• the four bladders at 90° spacing on the circumference between the tubes 288 and 290 may be selectively pressurized to limit or eliminate beam deflection and consequently coater head and doctor or blade deflection due to weight or operational loading.
• this deflecting limiting means see U.S. Patent No. 4,907,528 or 5,005,515.
• the coating supply system for the multiple coater unit arrangement of Figure 1 is shown.
• the coating can be supplied from the coating supply tank 300, through a filter 302 to a pipe 304 and from there to the dip roll coater unit 16 and an SDTA coater unit 24.
• the coating can be doctored or bladed off by either doctor or blade 23 or 25 or both doctors or blades 23 and 25. This doctored or bladed off coating is caught in coater pan 20 or overflow pans 27 or 29. From there the coating can be collected in pipes 306, 308 or 310 and reprocessed and returned to the supply tank 300 to be reused as is conventional.
• the pipe 310 draining the doctor or blade unit 26 overflow pan 29 may be preferably connected to a positive displacement pump 312 to help withdraw or suck the coating from the shallow overflow pan 29.
• a similar pump arrangement can also be provided for overflow pans 200 ( Figure 6) or 240 ( Figure 8) .
• blade angles of between 0° to 55° are preferable, other angles could be used and/or a bent blade used.
• doctor is understood to include all types of coating doctoring or smoothing devices including such blades, rods and bars.

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• 1993
  • 1993-12-11 WO PCT/EP1993/003511 patent/WO1995016073A1/en not_active Application Discontinuation
  • 1993-12-11 JP JP51590993A patent/JPH08511993A/ja active Pending
  • 1993-12-11 EP EP94903757A patent/EP0683834A1/de not_active Ceased
  • 1993-12-11 BR BR9307832A patent/BR9307832A/pt not_active IP Right Cessation
• 1995
  • 1995-08-10 FI FI953802A patent/FI953802A/fi unknown

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