US3893410A - Cascade coater - Google Patents

Cascade coater Download PDF

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Publication number
US3893410A
US3893410A US384080A US38408073A US3893410A US 3893410 A US3893410 A US 3893410A US 384080 A US384080 A US 384080A US 38408073 A US38408073 A US 38408073A US 3893410 A US3893410 A US 3893410A
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United States
Prior art keywords
pressure
coater
coating
pipe
bores
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Expired - Lifetime
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US384080A
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English (en)
Inventor
Peter Herzhoff
Hans Gref
Fritz Maus
Wolfgang Schweicher
Hans Frenken
Kurt Browatzki
Karl Voss
Willi Wasser
Heinrich Bubmann
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Agfa Gevaert AG
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Agfa Gevaert AG
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/74—Applying photosensitive compositions to the base; Drying processes therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
    • B05C5/007—Slide-hopper coaters, i.e. apparatus in which the liquid or other fluent material flows freely on an inclined surface before contacting the work
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C9/00—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important
    • B05C9/06—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important for applying two different liquids or other fluent materials, or the same liquid or other fluent material twice, to the same side of the work

Definitions

  • CASCADE COATER This invention relates to a cascade coater for the multiple coating of sheet material.
  • a coater of this kind consists of a coating block extending over the entire width of the sheet-form material with an inclined flow plane interrupted by the gaps through which the coating liquids are introduced.
  • the coating roller, over which the sheet to be coated is guided, is arranged at a short distance from the coating block.
  • Cascade coaters are known in which the coating liquid initially flows through a distributing chamber situated inside the coating block and then through a narrow slot onto a downwardly inclined flow plane.
  • the coating liquid flows downwards on this flow plane in a thin layer and successively encounters other layers formed in the same way.
  • the various layers are superimposed without mixing to form a multilayer liquid band which flows to the lower end of the flow plane where a so-called coating meniscus is formed.
  • This coating meniscus wets the sheet-form material over its entire width so that the sheet is uniformly coated with the multiple liquid band. Coaters of this kind are described for example in US. Pat. Nos. 2,761,417 and 2,76] ,419.
  • the uniformity of the coating transversely of the sheet is governed to a very large extent by the uniformity of the narrow slots which open into the flow plane. In order to obtain favorable results, these slots have to be precision made. For a slot width of 0.3 mm (cf. the above mentioned patent specifications), fluctuations in layer thickness of 3 percent occur even with a tolerance limit of only 0.003 mm. The overall irregularity produced by the machining tolerance and, additionally, by surface tension and the effect of temperature is generally much greater. In practice, therefore, it is not possible to satisfy such stringent accuracy requirements on the uniformity of the slot width over the entire width of the sheet-form material. Another disadvantage is that caked-on coating residues are extremely difficult to remove from the narrow slots. Accordingly, the coating block is generally designed in such a way that it can be opened up to make the slots accessible. However, this makes the tolerance limits even more difficult to maintain. In addition, the cleaning operation and subsequent readjustment of the coating block takes considerable time.
  • DOS No. 2,042,195 describes a cascade coater which has relatively wide chutes instead of narrow slots.
  • This coater is designed for coating relatively narrow sheetform materials.
  • the chutes are provided with supply pipes. Accordingly, the coating liquid flows from the relatively narrow supply pipe into the relatively wide chute. It is impossible to prevent sedimentation in the wide chutes, in addition to which a velocity profile deviating from a completely uniform flow is inevitably developed in the chute. This velocity profile continues substantially up to the upper edge of the chute and leads to irregularities in layer thickness. It will readily be appreciated that the layer thickness is at its greatest where the rate of flow is at its maximum.
  • the object of the invention is to develop a cascade coater which, even with relatively wide manufacturing tolerances, still guarantees extremely high stability of the layer thickness across the sheet-form material.
  • the new cascade coater is also intended to be suitable for coating extremely wide sheet-form materials, the uniformity of the layer thickness again having to meet extremely stringent requirements.
  • wide sheets are sheets with a width of from I to 4 meters.
  • a cascade coater for coating sheet material comprising a coating block extending over the entire sheet width with an inclined flow plane interrupted by a delivery gap for the or each coating liquid, and a coating roller arranged at a short distance from the coating block over which the sheet to be coated is guided, wherein the delivery gaps open into a second pressure-distributing chamber which is connected to a first pressure-distributing chamber through a narrow connecting gap or through a number of openings of small overall cross section, the cross section of the connecting gap or the overall cross section of the openings being small in relation to the cross section of the delivery gap.
  • the cross section of the connecting gap or the overall cross section of the openings is preferably at least 5 to ID times smaller than the cross section of a delivery gap.
  • the gap width s of the connecting gap is preferably amounts to between 0.3 and 0.5 mm and its length h to between 10 and 20 mm, whilst the width S of the delivery gap is between 1.5 and 5 mm and its length H between l0 and 20 mm.
  • the first pressure-distributing chamber consists of a pipe running parallel to the coating roller which, at one end, is provided with an inlet for the coating liquid and communicates with the second pressure-distributing chamher through a number of bores.
  • the bores are preferably arranged at intervals of l to 8 mm apart from one another and have a diameter of from 0.3 to l mm.
  • the pipe is arranged within the second pressure-distributing chamber and is provided along its lowest generatrix with bores directed vertically downwards.
  • the bores are arranged at equal intervals apart from one another, but their diameter increases from the point at which the coating liquid enters towards the end of the pipe, corresponding to the pressure drop, in such a way that the same quantity of coating liquid flows through each bore per unit of time.
  • the bores can all have the same diameter, but are arranged at intervals apart from one another which decrease towards the end of the pipe, corresponding to the pressure drop, in such a way that the same quantity of coating liquid flows into the second pressure-distributing chamber per unit width.
  • the interval between and the diameters of the bores are constant. However, their diameters are sufficiently small that the flow-induced pressure drop between the point at which the coating liquid enters and the end of the pipe amounts to at most 5 percent of the total pressure prevailing in the pipe.
  • the two pressure-distributing chambers are separated by a narrow flow cross section. This measure leads on the one hand to an extremely uniform velocity profile, even in cases where the delivery gaps have a relatively wide cross section.
  • the wide delivery gaps are easy to clean.
  • Another advantage is that the wide delivery gaps can be formed with lower relative deviations. Even with wide sheet-form materials, it is possible with the new coater to produce layer profiles with a deviation in layer thickness of less than I percent across the width of the sheet.
  • FIG. 1 shows a cascade coater with two pressuredistributing chambers communicating through a narrow gap.
  • FIG. 2 shows a modified arrangement of the pressure-distributing chambers in the cascade coater shown in FIG. 1.
  • FIG. 3 shows a cascade coater in which the first pressure-distributing chamber is in the form of a perforated pipe.
  • FIG. 4 is a cross section through the first pressuredistributing chamber shown in FIG. 3.
  • the sheet I to be coated is guided over the coating roller 3 at a short distance from the coating block 2. Coating takes place at the lower end of the flow plane 4 where the coating meniscus 5 is formed.
  • the coating liquids flow onto the flow plane 4 through the relatively wide delivery gaps 6.
  • the pressure-distributing chambers 8, 9 and the gaps 6 and 7 extend over the entire width of the sheet.
  • the supply pipes for the coating liquids are connected to the pressure-distributing chambers 9. Accordingly, the pressure-distributing chamber 9 is referred to by definition as the first pressure-distributing chamber.
  • the coating liquids are delivered in quantities dosed as a function of time. Since the connecting gap 7 is extremely narrow and has a high flow resistance, a high pressure is built up in the first pressure-distributing chamber 9. It is at its greatest at the inlet point and drops by only about 5 percent towards the edges of the pressure-distributing chamber.
  • the narrow connecting gap 7 has a width s of from 0.3 to 0.5 mm and a height h offrom 10 to mm.
  • the delivery gaps 6 have a width S of about 1.5 mm and a height H of about l5 mm. With the usual machining tolerances for the delivery gaps 6, it is possible to obtain a layer thickness uniform to i 1 percent with the dimensions specified. This represents a considerable improvement over the prior art.
  • FIG. 2 The arrangement shown in FIG. 2 is similar in structure to the coater shown in FIG. I. The only difference is that the connecting gap 7 has a different location. Substantially the same results were obtained.
  • FIGS. 3 and 4 show a different structure.
  • the first pressure-distributing chamber 11 is in the form of a long tube 12 extending over the entire coating width.
  • This pipe 12 is situated completely within the second pressure-distributing chamber 13.
  • bores I4 are arranged along the lowest generatrix of the pipe (see FIG. 4). A considerable pressure gradient builds up in these bores. Only a comparatively small pressure drop prevails in the following annular gap 15 between the pipe 12 and the inner wall of the second pressuredistributing chamber 13.
  • the coating liquid is delivered in the middle of the first pressure-distributing chamber 9, a lateral feed 16 is provided in the arrangement shown in FIGS. 3 and 4. Accordingly, the first pressure-distributing chamber 11 is filled with the coating liquid from the side.
  • the inevitable drop in pressure from the point 16 at which the coating liquid enters the first pressure-distributing chamber 11 to the end of the pipe 12 can be eliminated by the following alternative measures:
  • the interval A of the bores from one another is constant over the entire length of the pipe.
  • the diameter of the bores increases steadily from the pipe inlet to the end of the pipe.
  • the diameter of the bores is graduated in such a way that the same quantity of coating liquid flows through each bore per unit time.
  • the diameter of the bores is constant over the entire length of the pipe.
  • their interval A decreases towards the end of the pipe. Accordingly, the intervals are selected in such a way that the same quantity of coating liquid flows into the second pressure-distributing chamber 13 per unit width.
  • the intervals between and the diameters of the bores are constant. However, the diameter of the bores is selected in such a way that the flowinduced pressure drop between the point 16 at which the coating liquid enters and the end of the pipe amounts to at most 5 percent of the overall pressure prevailing in the pipe.
  • the delivery gaps 6 in the arrangement shown in FIGS. 3 and 4 have a width S of from 1.5 to 2 mm and a height H of from 15 to 20 mm.
  • the pipe I2 has a diameter of about 30 mm.
  • the bores 14 have a diameter of from 0.3 to 1 mm, depending upon the arrangement (cf. measures 1 to 3). Accordingly, the interval A between the bores 14 is between I and 8 mm. As with the coater shown in FIGS. 1 and 2, it was possible in this case to obtain a layer thickness uniform to i l percent.
  • This coater is the special configuration of the pressure-distributing chambers H and 13, by virtue of which deposits of solids present in the coating liquid and, hence, undesirable reductions in cross section and cleaning difficulties are avoided.
  • the examples quoted relate to two-layer coating.
  • the coaters can of course also be used for one-layer coating.
  • the following Example relates to one-layer coating with the coater shown in FIGS. 3 and 4.
  • the dimensions of the coater and the flow data for coating a sheet of film with a photographic emulsion are quoted.
  • EXAMPLE 1 Dimensions of the coater Width of the delivery gap (coating width) 1 H mm Inclination of the flow plane 4 23 Width S of the delivery gap 6 1.5 mm Height H of the delivery gap 6 l7.() mm Radius of the circular part of the second pressure-distributing chamber l3 16.0 mm Outer radius of the pipe l2 12.5 mm Inner radius of the pipe 12 10.0 mm Interval between the bores 14 (constant interval A) 2.0 mm Diameter of the bores l4 (constant diameter) 0.4 mm
  • a cascade coater for coating sheet material comprising a coating block extending over the entire sheet width with an inclined flow plane interrupted by a delivery gap for the delivery or each coating liquid, and a coating roller arranged at a short distance from the coating block over which the sheet to be coated is guided, wherein the delivery gaps open into a second pressure-distributing chamber which is connected to a first pressure-distributing chamber through a narrow connecting gap means, the cross section of the connecting gap means being small in relation to the cross section of the delivery gap.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Coating Apparatus (AREA)
  • Paper (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
US384080A 1972-08-03 1973-07-30 Cascade coater Expired - Lifetime US3893410A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19722238133 DE2238133B2 (de) 1972-08-03 1972-08-03 Kaskadengiesser

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US3893410A true US3893410A (en) 1975-07-08

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US384080A Expired - Lifetime US3893410A (en) 1972-08-03 1973-07-30 Cascade coater

Country Status (8)

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US (1) US3893410A (de)
JP (1) JPS5535990B2 (de)
BE (1) BE802172A (de)
CH (1) CH552415A (de)
DE (1) DE2238133B2 (de)
FR (1) FR2195171A5 (de)
GB (1) GB1388245A (de)
IT (1) IT990463B (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4143190A (en) * 1977-01-27 1979-03-06 Polaroid Corporation Method and apparatus for coating webs
US4411614A (en) * 1982-02-18 1983-10-25 E. I. Du Pont De Nemours & Co. Removable contoured insert for an extrusion die
US4489671A (en) * 1978-07-03 1984-12-25 Polaroid Corporation Coating apparatus
US4572849A (en) * 1982-10-21 1986-02-25 Agfa-Gevaert Aktiengesellschaft Process for the multiple coating of moving webs
US5234330A (en) * 1991-06-14 1993-08-10 Eastman Kodak Company Dies
US5332440A (en) * 1992-01-21 1994-07-26 E. I. Du Pont De Nemours And Company Coating lip geometry for slide bead coating
WO2002002244A2 (en) 2000-06-30 2002-01-10 3M Innovative Properties Company Coating apparatus and methods of applying a polymer coating
US20030124254A1 (en) * 2001-12-27 2003-07-03 Rexam Image Products, Inc. Wet on wet process for producing films
US20030197076A1 (en) * 2001-12-20 2003-10-23 Yasui Seiki Co., Ltd. Coating material supply nozzle
CN105921360A (zh) * 2016-07-01 2016-09-07 深圳市华星光电技术有限公司 狭缝喷嘴和涂布装置
CN115427157A (zh) * 2020-05-28 2022-12-02 株式会社Lg新能源 狭缝模具涂布装置

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2721184C2 (de) * 1977-05-11 1983-09-01 Agfa-Gevaert Ag, 5090 Leverkusen Formbeständiger Gießerblock
SE426657B (sv) * 1977-12-30 1983-02-07 Svenska Traeforskningsinst Forfarande och anordning for applicering av vetska pa en rorlig yta
JPS54127940A (en) * 1978-03-29 1979-10-04 Fujitsu Ltd Coating blade
DE102005042289A1 (de) * 2005-09-06 2007-03-15 Fleissner Gmbh Vorrichtung zum Aufbringen einer über eine große Arbeitsbreite gleichmäßig dicken Flüssigkeitsschicht auf eine Warenbahn

Citations (7)

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US2681294A (en) * 1951-08-23 1954-06-15 Eastman Kodak Co Method of coating strip material
US2761419A (en) * 1955-02-23 1956-09-04 Eastman Kodak Co Multiple coating apparatus
US3413143A (en) * 1963-12-10 1968-11-26 Ilford Ltd High speed coating apparatus
US3442304A (en) * 1966-04-28 1969-05-06 Dole Eng Co James Filling apparatus
US3469563A (en) * 1966-10-12 1969-09-30 Dennison Mfg Co Apparatus for developing electrostatic images
US3479989A (en) * 1967-11-28 1969-11-25 Eastman Kodak Co Extrusion coating apparatus
US3712264A (en) * 1970-09-16 1973-01-23 Lehara W Inc Rotating paste depositer

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2679231A (en) * 1951-09-07 1954-05-25 John Waldron Corp Web coating apparatus
US2940418A (en) * 1959-03-27 1960-06-14 Black Clawson Co Paper machinery
JPS5139264B2 (de) * 1971-09-09 1976-10-27

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2681294A (en) * 1951-08-23 1954-06-15 Eastman Kodak Co Method of coating strip material
US2761419A (en) * 1955-02-23 1956-09-04 Eastman Kodak Co Multiple coating apparatus
US3413143A (en) * 1963-12-10 1968-11-26 Ilford Ltd High speed coating apparatus
US3442304A (en) * 1966-04-28 1969-05-06 Dole Eng Co James Filling apparatus
US3469563A (en) * 1966-10-12 1969-09-30 Dennison Mfg Co Apparatus for developing electrostatic images
US3479989A (en) * 1967-11-28 1969-11-25 Eastman Kodak Co Extrusion coating apparatus
US3712264A (en) * 1970-09-16 1973-01-23 Lehara W Inc Rotating paste depositer

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4143190A (en) * 1977-01-27 1979-03-06 Polaroid Corporation Method and apparatus for coating webs
US4489671A (en) * 1978-07-03 1984-12-25 Polaroid Corporation Coating apparatus
US4411614A (en) * 1982-02-18 1983-10-25 E. I. Du Pont De Nemours & Co. Removable contoured insert for an extrusion die
US4572849A (en) * 1982-10-21 1986-02-25 Agfa-Gevaert Aktiengesellschaft Process for the multiple coating of moving webs
US5234330A (en) * 1991-06-14 1993-08-10 Eastman Kodak Company Dies
US5332440A (en) * 1992-01-21 1994-07-26 E. I. Du Pont De Nemours And Company Coating lip geometry for slide bead coating
US20040138397A1 (en) * 2000-06-30 2004-07-15 3M Innovative Properties Company Coating apparatus and methods of applying a polymer coating
WO2002002244A2 (en) 2000-06-30 2002-01-10 3M Innovative Properties Company Coating apparatus and methods of applying a polymer coating
US6991745B2 (en) 2000-06-30 2006-01-31 3M Innovative Properties Company Coating apparatus and methods of applying a polymer coating
US6676754B1 (en) 2000-06-30 2004-01-13 3M Innovative Properties Company Coating apparatus and methods of applying a polymer coating
US20030197076A1 (en) * 2001-12-20 2003-10-23 Yasui Seiki Co., Ltd. Coating material supply nozzle
EP1321194A3 (de) * 2001-12-20 2004-10-20 Yasui Seiki Co., Ltd. Düse für Beschichtungsmaterial
US6824818B2 (en) 2001-12-27 2004-11-30 Soliant Llc Wet on wet process for producing films
US20030124254A1 (en) * 2001-12-27 2003-07-03 Rexam Image Products, Inc. Wet on wet process for producing films
CN105921360A (zh) * 2016-07-01 2016-09-07 深圳市华星光电技术有限公司 狭缝喷嘴和涂布装置
CN105921360B (zh) * 2016-07-01 2019-02-12 深圳市华星光电技术有限公司 狭缝喷嘴和涂布装置
CN115427157A (zh) * 2020-05-28 2022-12-02 株式会社Lg新能源 狭缝模具涂布装置
US11964298B2 (en) 2020-05-28 2024-04-23 Lg Energy Solution, Ltd. Slot die coating device for electrode production

Also Published As

Publication number Publication date
CH552415A (de) 1974-08-15
GB1388245A (en) 1975-03-26
DE2238133A1 (de) 1974-02-14
BE802172A (nl) 1974-01-11
FR2195171A5 (de) 1974-03-01
JPS5535990B2 (de) 1980-09-18
JPS4959838A (de) 1974-06-11
IT990463B (it) 1975-06-20
DE2238133B2 (de) 1976-11-11

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