CA2325906A1 - High speed coating apparatus and method - Google Patents
High speed coating apparatus and method Download PDFInfo
- Publication number
- CA2325906A1 CA2325906A1 CA002325906A CA2325906A CA2325906A1 CA 2325906 A1 CA2325906 A1 CA 2325906A1 CA 002325906 A CA002325906 A CA 002325906A CA 2325906 A CA2325906 A CA 2325906A CA 2325906 A1 CA2325906 A1 CA 2325906A1
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- Canada
- Prior art keywords
- roll
- coating material
- web
- enclosed
- coater
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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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
- D21H23/52—Addition to the formed paper by contacting paper with a device carrying the material
- D21H23/56—Rolls
-
- 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
- D21H23/52—Addition to the formed paper by contacting paper with a device carrying the material
- D21H23/56—Rolls
- D21H23/58—Details thereof, e.g. surface characteristics, peripheral speed
Abstract
A coating apparatus for a paper web in which the web is advanced at a high speed on a backing roll. An enclosed coater applies coating material to a roll applicator which is rotating at a slow speed relative to the speed of the backing roll. The roll applicator rotates adjacent the web and backing roll at a spacing gap from the web to apply the coating material to the web at the gap. The thickness of the coating material applied to the web is controlled by the enclosed coater controlling the coating material applied to the roll applicator.
Description
WO 99/23308 . PCT/US98118107 PATENT APPLICATION
TITLE: HIGH SPEED COATING APPARATUS AND METHOD
FIELD OF THE INVENTION
This invention relates to high speed application of liquid coating material to a paper web. In particular, the invention relates to utilizing several application stages to apply a uniform coating layer.
BACKGROUND OF THE INVENTION
Applying of a coating material to a paper web involves various problems for which solutions have been sought over a number of years. In particular, as speeds of the paper webs being coated have increased, the difficulties in applying a uniform coating has correspondingly increased. Further, where high viscosity coating materials are applied at high speeds, the maintaining of the quality of the coating is particularly challenging.
One type of applicator apparatus that has been used for a considerable length of time is known as a flooded nip coater. This type of coater includes an applicator roll which rotates in a pan of coating material thereby picking up the coating onto the applicator roll and transferring the coating film to a web sheet as it travels on the surface of a backing roll. The applicator roll and the sheet move in the same direction and the coating is applied to the sheet at a small gap between the sheet and the applicator roll. At high applicator roll and web speeds, the high speed of applicator roll in the pan causes splashing of the coating material and pond instability and consequent lack of uniformity in applying the coating to the sheet. Also, if the sheet breaks, broke may collect in the applicator pan resulting in increased cleanup work and downtime.
An improvement in coaters that has been developed is known as a short dwell coating applicator. A short dwell applicator has an enclosed type of pond of coating material which eliminates the problem of broke collecting in an open pan or pond. It also eliminates the splashing and turbulence of an open pan.
However, unstable vortices in the pond immediately adjacent the web being coated form due to the high speed of the web as it passes the pond of coating material. With high viscosity coating materials and as speed increases, coating defects in the form of streaks and blotchy patterns appear on the paper web.
An effort to solve this problem has been to provide a low angle premetering blade to minimize the unstable vortices and help expel air that is brought in with the passing web. Although this improvement has improved the quality of coating, the basic problem still persists.
Another type of coater improvement that has been developed is a jet coating applicator which includes an enclosure and a coating applicator nozzle through which coating material is applied to a passing web. Due to the enclosed nature of the jet applicator, there is no turbulence of an open pan or broke falling into the pan. However, there is a high speed turbulence problem in that the high speed of a passing web causes turbulence in the coating material as it is applied to the web causing breakup and non-uniformity of the coating.
The present invention is directed to a further improvement in the coating process which wilt permit coating at high speeds using high viscosity coating materials without the turbulence resulting in coating quality defects.
SUMMARY OF THE INVENTION
It is a general object of this invention to utilize a coating applicator and roll applicator together to apply a uniform coating of material to a moving paper web. It is a further object of the invention to apply a coating material with an enclosed type of coater to a roll applicator that is moving at a relatively slow speed. A further object of the invention is to apply a coating material to a moving paper web at a gap between the paper web and a roll applicator which is moving relatively slowly in comparison to the speed of the paper web and to WO 99lZ3308 3 PCT/US98118107 which coating material has been applied by am enclosed type of coater.
Another object of the invention is to control the thickness of the coating on the paper web by controlling or metering the amount of coating material applied by an enclosed coater to the roll applicator.
The invention is carried out in a coating apparatus in which a paper web is advanced at a relatively high speed with a backing roll which provides a backup surface for the web as it advances. An enclosed coater applies coating material to a roll applicator which is rotating at a slow linear speed relative to the speed of the web. The coating material applied to the roll applicator by the water is, in turn, applied to the web by the roll applicator moving at the slower speed relative to the web speed. The coating material is applied to the web at a spacing gap between the roll applicator and the web on the backing roil with which the web is advancing.
The use of the enclosed coater eliminates an open pan which may produce turbulence and splashing and also the possibility of broke falling into the pan. The application of the coating material by the enclosed coater to a roll applicator moving at a slow speed eliminates the breakup in the coating material due to turbulence at the web or roll surface or the vortice type turbulence, both associated with applying coating material with an enclosed coater to a web or roll moving at high speed. Further, the application of the coating material by the roll applicator to the web wherein the roll applicator is moving at a slower speed relative to that of the web also eliminates turbulence in such application and permits a uniform coating of material to be applied to the web.
The thickness of the coating material applied to the web is controlled by controlling or metering the amount of coating material applied from the enclosed coater to the roll applicator. Utilizing an enclosed coater for controlling the amount of coating material applied to the web permits greater precision in controlling the thickness of the coating on the web than can be obtained with the common method using a doctor. Also, the enclosed coater can be used to vary the thickness of the coating applied to the web across the width of the web.
The above and further objects, features and advantages of the invention will become apparent upon consideration of the following detailed description taken in conjunction with the accompanying drawings as follows:
Fig. 1 is an end elevation schematic view of the coating apparatus according to the invention;
Fig. 2 is a side elevation schematic view of the invention shown in Fig. 2;
Fig. 3 is an end elevation schematic view, partially in cross-section, of one embodiment of an enclosed coater utilized in the invention; and Fig. 4 is an end elevation schematic view, partially in cross-section, of an alternate embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring generally to the drawings, wherein like numbers refer to similar parts, a web coating apparatus 2 is shown in Figs. 1 and 2. The web coating apparatus 2 includes a roll 4 having a circumferential surtace 14 and which rotates in the direction of arrow 8 about an axis 6. The roll 4, as it rotates, advances a paper web 10 having surfaces 16, 18 and a width w and acts as a support and backing for the paper web 10.
The embodiment of the invention shown in Figs. 1 and 2, and also in Fig. 3, includes an enclosed coating applicator 20 which is of an enclosed pond type of applicator. Enclosed coating applicators of the enclosed pond type are well-known in the papermaking industry for coating of continuously moving paper webs. Such enclosed pond coating applicators include blades, smooth rods and grooved rods for metering and controlling the coating material applied WO 99/23308 ~ PCTNS98118107 to the web. In the embodiment of the invention described herein, an enclosed pond coating applicator utilizing a blade metering device is utilized, but it should be understood that other types of enclosed pond applicators including those mentioned above are also suitable.
The enclosed applicator 20 applies coating material 22 to a roll applicator 30. The roll applicator 30 has a circumferential surface 32 onto which the coating material 22 is applied by the enclosed applicator 20 and rotates about an axis 34 in the direction of arrow 36. The direction of rotation of the roll applicator 30 immediately opposite the roll 4 and web 10 is thus in the same direction as the advancing movement of the web 10 and the rotation of the roll 4. Also, as can be seen in Fig. 1, the roll applicator 30 forms a gap 38 with the web 10 and roll 30 in the area at which the web 10 and roll 30 are most adjacent to each other.
With reference in particular to Figs. 2 and 3, the enclosed applicator 20 includes a tube 24 through which coating material 22 is delivered by a pump (not shown). The coating material 22 moves through the tube 24 into a chamber 26 of the applicator 20 which contains a pond 44 of coating material 22. The chamber 26 has walls formed by member 28, a premetering element 29, a metering blade 42 of a metering mechanism 40 and a portion of the circumferentiai surface 32 of the roll applicator as it moves past the enclosed applicator 20. The applicator 20 has a width parallel to the axis 34 of the roll 30 at least the width w of the web 10 and a plurality of metering mechanisms 40 mounted along this width In the operation of the coating apparatus 2 utilizing the enclosed coating applicator 20, the roll 4 and paper web 10 travel at a relatively high linear speed which may be, for example, in the range of 200 to 3000 meters per minute. On the other hand, the roll applicator 30, traveling in the same direction as the web 10, is moving at a relatively slower linear speed in the WO 99n3308 6 PCT/US98/18107 range of 5 to 30 per cent of the roll 4 and web 10 speed. Consequently, as the coating material 22 is applied to the circumferential surface 32 of the roll 30 by the enclosed coating applicator 20, the linear speed of the roll 30 will be insufficient to cause vortice or other turbulence typical in the pond of an enclosed coating applicator as would be the case if the coating material application were to a web or roll surface traveling at high speed. As the coating material 22 being carried on the surface 32 of the roll 30 passes through the gap 38 and is applied to surface 16 of the web 10, turbulence which may disturb the uniformity of the application of the coating material to the web 10 is minimized due to the relatively slow linear speed of the roll 30.
Note also that the gap space between the web 10 and the surface 32 of the roll 30 is such that only the coating material 22 engages the web 10.
The enclosed coating applicator 20 also controls the thickness and thus the weight of the coating material 22 applied to the surface 16 of the web 10 by a metering action in applying coating material to the surface 32 of the roll 30.
This metered amount may be controlled or adjusted by adjusting the position and thereby the pressure applied by the metering blade 42 of the metering mechanism 40. Increasing the pressure of the metering blade 42 reduces the weight and thickness of the coating material 22 and, conversely, reducing the metering blade pressure increases the coating material weight and thickness.
Since the enclosed coating applicator 20 extends in the axial direction of the applicator roll 30 across the lateral surface width w of the web, the coating material thickness may be controlled on this entire surtace. Inasmuch as the metering ability of the coating applicator 20, by use of the plurality of metering mechanisms 40, can very precisely control the amount of coating material 22 being applied to the roll surface 30 along its axial length, the weight and thickness of the coating applied downstream to the web 10 can consequently be also precisely controlled.
With reference to Fig. 4, an alternative embodiment is illustrated in which the coating apparatus 2 utilizes an enclosed coating applicator 50 of the jet type. The enclosed coating applicator 50 may be used rather than the applicator 20 as shown in Fig. 1. The components of the invention, other than the applicator 20, would remain the same as in Fig. 1 The enclosed jet coating applicator 50 is well-known in the prior art and includes a casing or enclosure 52 and a coating applicator nozzle 54 extending from the enclosure to a position adjacent the roll applicator 30. The applicator nozzle 54 has a nozzle gap 48, an adjustable lip 56, lip adjusting screws 58, and a metering mechanism 60. The metering mechanism includes a metering lip 62 which also forms part of the nozzle 54 and a lip control fi4. The adjustable lip 56 extends across the entire width of the applicator 50 and controls the basic coating thickness applied to the applicator roll by setting the opening size of the nozzle gap 48 across the applicator by manipulation of the screws 58. There are a series of lip controls 64 spaced apart across the width of the applicator 50 and each lip control 64 sets the position of a metering lip fit to control the thickness and weight of coating material applied to the roll applicator adjacent the particular lip control 64. This permits profiling of the coating material applied to the roll applicator and thus also to the web 10. A pump 46 supplies coating material 22 through pipe 6fi and passageway 68 to the nozzle 54 at a pressure above atmospheric pressure.
Referring further to Fig. 4, as in the embodiment of Fig. 1, the roil 4 and paper web 10 travel at a relatively high linear speed of, for example, in the range of 200 to 3000 meters per minute. However, the roll applicator 30 moves at a relatively slower linear speed in the range of 5 to 30 per cent of the roll 4 and web 10 speed. Thus, as the coating material 22 is applied onto the circumferential surface 32 of the roll 30 by the enclosed coating applicator 50, the low linear speed of the roll 30 will not create turbulence affecting the coating material which is sufficient to cause breakup of the coating material.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof that come within the scope of the following claims.
TITLE: HIGH SPEED COATING APPARATUS AND METHOD
FIELD OF THE INVENTION
This invention relates to high speed application of liquid coating material to a paper web. In particular, the invention relates to utilizing several application stages to apply a uniform coating layer.
BACKGROUND OF THE INVENTION
Applying of a coating material to a paper web involves various problems for which solutions have been sought over a number of years. In particular, as speeds of the paper webs being coated have increased, the difficulties in applying a uniform coating has correspondingly increased. Further, where high viscosity coating materials are applied at high speeds, the maintaining of the quality of the coating is particularly challenging.
One type of applicator apparatus that has been used for a considerable length of time is known as a flooded nip coater. This type of coater includes an applicator roll which rotates in a pan of coating material thereby picking up the coating onto the applicator roll and transferring the coating film to a web sheet as it travels on the surface of a backing roll. The applicator roll and the sheet move in the same direction and the coating is applied to the sheet at a small gap between the sheet and the applicator roll. At high applicator roll and web speeds, the high speed of applicator roll in the pan causes splashing of the coating material and pond instability and consequent lack of uniformity in applying the coating to the sheet. Also, if the sheet breaks, broke may collect in the applicator pan resulting in increased cleanup work and downtime.
An improvement in coaters that has been developed is known as a short dwell coating applicator. A short dwell applicator has an enclosed type of pond of coating material which eliminates the problem of broke collecting in an open pan or pond. It also eliminates the splashing and turbulence of an open pan.
However, unstable vortices in the pond immediately adjacent the web being coated form due to the high speed of the web as it passes the pond of coating material. With high viscosity coating materials and as speed increases, coating defects in the form of streaks and blotchy patterns appear on the paper web.
An effort to solve this problem has been to provide a low angle premetering blade to minimize the unstable vortices and help expel air that is brought in with the passing web. Although this improvement has improved the quality of coating, the basic problem still persists.
Another type of coater improvement that has been developed is a jet coating applicator which includes an enclosure and a coating applicator nozzle through which coating material is applied to a passing web. Due to the enclosed nature of the jet applicator, there is no turbulence of an open pan or broke falling into the pan. However, there is a high speed turbulence problem in that the high speed of a passing web causes turbulence in the coating material as it is applied to the web causing breakup and non-uniformity of the coating.
The present invention is directed to a further improvement in the coating process which wilt permit coating at high speeds using high viscosity coating materials without the turbulence resulting in coating quality defects.
SUMMARY OF THE INVENTION
It is a general object of this invention to utilize a coating applicator and roll applicator together to apply a uniform coating of material to a moving paper web. It is a further object of the invention to apply a coating material with an enclosed type of coater to a roll applicator that is moving at a relatively slow speed. A further object of the invention is to apply a coating material to a moving paper web at a gap between the paper web and a roll applicator which is moving relatively slowly in comparison to the speed of the paper web and to WO 99lZ3308 3 PCT/US98118107 which coating material has been applied by am enclosed type of coater.
Another object of the invention is to control the thickness of the coating on the paper web by controlling or metering the amount of coating material applied by an enclosed coater to the roll applicator.
The invention is carried out in a coating apparatus in which a paper web is advanced at a relatively high speed with a backing roll which provides a backup surface for the web as it advances. An enclosed coater applies coating material to a roll applicator which is rotating at a slow linear speed relative to the speed of the web. The coating material applied to the roll applicator by the water is, in turn, applied to the web by the roll applicator moving at the slower speed relative to the web speed. The coating material is applied to the web at a spacing gap between the roll applicator and the web on the backing roil with which the web is advancing.
The use of the enclosed coater eliminates an open pan which may produce turbulence and splashing and also the possibility of broke falling into the pan. The application of the coating material by the enclosed coater to a roll applicator moving at a slow speed eliminates the breakup in the coating material due to turbulence at the web or roll surface or the vortice type turbulence, both associated with applying coating material with an enclosed coater to a web or roll moving at high speed. Further, the application of the coating material by the roll applicator to the web wherein the roll applicator is moving at a slower speed relative to that of the web also eliminates turbulence in such application and permits a uniform coating of material to be applied to the web.
The thickness of the coating material applied to the web is controlled by controlling or metering the amount of coating material applied from the enclosed coater to the roll applicator. Utilizing an enclosed coater for controlling the amount of coating material applied to the web permits greater precision in controlling the thickness of the coating on the web than can be obtained with the common method using a doctor. Also, the enclosed coater can be used to vary the thickness of the coating applied to the web across the width of the web.
The above and further objects, features and advantages of the invention will become apparent upon consideration of the following detailed description taken in conjunction with the accompanying drawings as follows:
Fig. 1 is an end elevation schematic view of the coating apparatus according to the invention;
Fig. 2 is a side elevation schematic view of the invention shown in Fig. 2;
Fig. 3 is an end elevation schematic view, partially in cross-section, of one embodiment of an enclosed coater utilized in the invention; and Fig. 4 is an end elevation schematic view, partially in cross-section, of an alternate embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring generally to the drawings, wherein like numbers refer to similar parts, a web coating apparatus 2 is shown in Figs. 1 and 2. The web coating apparatus 2 includes a roll 4 having a circumferential surtace 14 and which rotates in the direction of arrow 8 about an axis 6. The roll 4, as it rotates, advances a paper web 10 having surfaces 16, 18 and a width w and acts as a support and backing for the paper web 10.
The embodiment of the invention shown in Figs. 1 and 2, and also in Fig. 3, includes an enclosed coating applicator 20 which is of an enclosed pond type of applicator. Enclosed coating applicators of the enclosed pond type are well-known in the papermaking industry for coating of continuously moving paper webs. Such enclosed pond coating applicators include blades, smooth rods and grooved rods for metering and controlling the coating material applied WO 99/23308 ~ PCTNS98118107 to the web. In the embodiment of the invention described herein, an enclosed pond coating applicator utilizing a blade metering device is utilized, but it should be understood that other types of enclosed pond applicators including those mentioned above are also suitable.
The enclosed applicator 20 applies coating material 22 to a roll applicator 30. The roll applicator 30 has a circumferential surface 32 onto which the coating material 22 is applied by the enclosed applicator 20 and rotates about an axis 34 in the direction of arrow 36. The direction of rotation of the roll applicator 30 immediately opposite the roll 4 and web 10 is thus in the same direction as the advancing movement of the web 10 and the rotation of the roll 4. Also, as can be seen in Fig. 1, the roll applicator 30 forms a gap 38 with the web 10 and roll 30 in the area at which the web 10 and roll 30 are most adjacent to each other.
With reference in particular to Figs. 2 and 3, the enclosed applicator 20 includes a tube 24 through which coating material 22 is delivered by a pump (not shown). The coating material 22 moves through the tube 24 into a chamber 26 of the applicator 20 which contains a pond 44 of coating material 22. The chamber 26 has walls formed by member 28, a premetering element 29, a metering blade 42 of a metering mechanism 40 and a portion of the circumferentiai surface 32 of the roll applicator as it moves past the enclosed applicator 20. The applicator 20 has a width parallel to the axis 34 of the roll 30 at least the width w of the web 10 and a plurality of metering mechanisms 40 mounted along this width In the operation of the coating apparatus 2 utilizing the enclosed coating applicator 20, the roll 4 and paper web 10 travel at a relatively high linear speed which may be, for example, in the range of 200 to 3000 meters per minute. On the other hand, the roll applicator 30, traveling in the same direction as the web 10, is moving at a relatively slower linear speed in the WO 99n3308 6 PCT/US98/18107 range of 5 to 30 per cent of the roll 4 and web 10 speed. Consequently, as the coating material 22 is applied to the circumferential surface 32 of the roll 30 by the enclosed coating applicator 20, the linear speed of the roll 30 will be insufficient to cause vortice or other turbulence typical in the pond of an enclosed coating applicator as would be the case if the coating material application were to a web or roll surface traveling at high speed. As the coating material 22 being carried on the surface 32 of the roll 30 passes through the gap 38 and is applied to surface 16 of the web 10, turbulence which may disturb the uniformity of the application of the coating material to the web 10 is minimized due to the relatively slow linear speed of the roll 30.
Note also that the gap space between the web 10 and the surface 32 of the roll 30 is such that only the coating material 22 engages the web 10.
The enclosed coating applicator 20 also controls the thickness and thus the weight of the coating material 22 applied to the surface 16 of the web 10 by a metering action in applying coating material to the surface 32 of the roll 30.
This metered amount may be controlled or adjusted by adjusting the position and thereby the pressure applied by the metering blade 42 of the metering mechanism 40. Increasing the pressure of the metering blade 42 reduces the weight and thickness of the coating material 22 and, conversely, reducing the metering blade pressure increases the coating material weight and thickness.
Since the enclosed coating applicator 20 extends in the axial direction of the applicator roll 30 across the lateral surface width w of the web, the coating material thickness may be controlled on this entire surtace. Inasmuch as the metering ability of the coating applicator 20, by use of the plurality of metering mechanisms 40, can very precisely control the amount of coating material 22 being applied to the roll surface 30 along its axial length, the weight and thickness of the coating applied downstream to the web 10 can consequently be also precisely controlled.
With reference to Fig. 4, an alternative embodiment is illustrated in which the coating apparatus 2 utilizes an enclosed coating applicator 50 of the jet type. The enclosed coating applicator 50 may be used rather than the applicator 20 as shown in Fig. 1. The components of the invention, other than the applicator 20, would remain the same as in Fig. 1 The enclosed jet coating applicator 50 is well-known in the prior art and includes a casing or enclosure 52 and a coating applicator nozzle 54 extending from the enclosure to a position adjacent the roll applicator 30. The applicator nozzle 54 has a nozzle gap 48, an adjustable lip 56, lip adjusting screws 58, and a metering mechanism 60. The metering mechanism includes a metering lip 62 which also forms part of the nozzle 54 and a lip control fi4. The adjustable lip 56 extends across the entire width of the applicator 50 and controls the basic coating thickness applied to the applicator roll by setting the opening size of the nozzle gap 48 across the applicator by manipulation of the screws 58. There are a series of lip controls 64 spaced apart across the width of the applicator 50 and each lip control 64 sets the position of a metering lip fit to control the thickness and weight of coating material applied to the roll applicator adjacent the particular lip control 64. This permits profiling of the coating material applied to the roll applicator and thus also to the web 10. A pump 46 supplies coating material 22 through pipe 6fi and passageway 68 to the nozzle 54 at a pressure above atmospheric pressure.
Referring further to Fig. 4, as in the embodiment of Fig. 1, the roil 4 and paper web 10 travel at a relatively high linear speed of, for example, in the range of 200 to 3000 meters per minute. However, the roll applicator 30 moves at a relatively slower linear speed in the range of 5 to 30 per cent of the roll 4 and web 10 speed. Thus, as the coating material 22 is applied onto the circumferential surface 32 of the roll 30 by the enclosed coating applicator 50, the low linear speed of the roll 30 will not create turbulence affecting the coating material which is sufficient to cause breakup of the coating material.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof that come within the scope of the following claims.
Claims (26)
1. An apparatus for applying coating material to a surface of a paper web moving in a direction transverse to its width comprising:
roll means rotating at a relatively high speed for advancing the web and providing a back-up surface supporting the web as it advances;
roll applicator means for applying coating material to the web, the roll applicator means rotating at a relatively low speed less than that of the roll means; and enclosed coater means for applying coating material to the roll applicator means as the latter rotates at said low speed such that turbulence affecting the coating material is minimized as it is applied to the roll applicator means and the roll applicator means receives a smooth, even layer of coating material.
roll means rotating at a relatively high speed for advancing the web and providing a back-up surface supporting the web as it advances;
roll applicator means for applying coating material to the web, the roll applicator means rotating at a relatively low speed less than that of the roll means; and enclosed coater means for applying coating material to the roll applicator means as the latter rotates at said low speed such that turbulence affecting the coating material is minimized as it is applied to the roll applicator means and the roll applicator means receives a smooth, even layer of coating material.
2. The apparatus according to claim 1 wherein the roll applicator means includes a rotating roll positioned to form a gap with the roll means through which coating material on the roll passes.
3. The apparatus according to claim 1 wherein:
the web has a broken condition resulting from web defects or web advancing interruptions;
the roll applicator means has a circumferential surface; and the enclosed coater means includes a chamber containing coating material, the chamber being positioned adjacent the circumferential surface of the roll applicator means such that the circumferential surface forms a wall of the chamber and the chamber thereby has an enclosed character for preventing broken web from entering the chamber.
the web has a broken condition resulting from web defects or web advancing interruptions;
the roll applicator means has a circumferential surface; and the enclosed coater means includes a chamber containing coating material, the chamber being positioned adjacent the circumferential surface of the roll applicator means such that the circumferential surface forms a wall of the chamber and the chamber thereby has an enclosed character for preventing broken web from entering the chamber.
4. The apparatus according to claim 1 wherein:
the roll applicator means has an axial length; and the enclosed coater means controls the coating material thickness across the width of the web.
the roll applicator means has an axial length; and the enclosed coater means controls the coating material thickness across the width of the web.
5. The apparatus according to claim 4 wherein:
the roll applicator means has an axial length juxtaposed with the width of the web; and the enclosed coater means controls the coating material thickness applied to the roll applicator means along the axial length of the roll applicator means such that the thickness of the coating material applied to the web by the roll applicator means is thereby controlled by the enclosed coater means.
the roll applicator means has an axial length juxtaposed with the width of the web; and the enclosed coater means controls the coating material thickness applied to the roll applicator means along the axial length of the roll applicator means such that the thickness of the coating material applied to the web by the roll applicator means is thereby controlled by the enclosed coater means.
6. The apparatus according to claim 4 wherein:
the enclosed coater means comprises enclosed pond coater means;
and the enclosed pond coater means has a metering element positioned to limit the amount of coating material applied by the enclosed pond coater means to the roll applicator means.
the enclosed coater means comprises enclosed pond coater means;
and the enclosed pond coater means has a metering element positioned to limit the amount of coating material applied by the enclosed pond coater means to the roll applicator means.
7. The apparatus according to claim 2 wherein:
the enclosed water means comprises enclosed jet coater means; and wherein the jet coater means includes:
nozzle means for applying coating material under pressure to the roll applicator means; and pump means for supplying pressurized coating material to the nozzle means.
the enclosed water means comprises enclosed jet coater means; and wherein the jet coater means includes:
nozzle means for applying coating material under pressure to the roll applicator means; and pump means for supplying pressurized coating material to the nozzle means.
8. The apparatus according to claim 7 wherein the nozzle means has an adjustable gap opening for controlling the weight of the coating material applied to the roll applicator means.
9. The apparatus according to claim 1 wherein:
the roll applicator means has a circumferential surface;
the enclosed coater means has a chamber;
the coating material forms a pond within the chamber in engagement with the circumferential surface of the roll applicator means; and the enclosed coater means applies coating material to the roll applicator means such that turbulence in the coating material within the pond is eliminated.
the roll applicator means has a circumferential surface;
the enclosed coater means has a chamber;
the coating material forms a pond within the chamber in engagement with the circumferential surface of the roll applicator means; and the enclosed coater means applies coating material to the roll applicator means such that turbulence in the coating material within the pond is eliminated.
10. The apparatus according to claim 6 wherein:
the roll applicator means has an axial length juxtaposed with the width of the web; and the enclosed coater means applies coating material along the axial length of the roll applicator means to thereby control the coating material thickness across the width of the web.
the roll applicator means has an axial length juxtaposed with the width of the web; and the enclosed coater means applies coating material along the axial length of the roll applicator means to thereby control the coating material thickness across the width of the web.
11. An apparatus for applying coating material to a surface of a web moving in a direction transverse to its width comprising:
roll means for advancing the web and providing a back-up surface for supporting the web as it advances;
roll applicator means for applying coating material to the web and having an axial length; and coater means for applying coating material to the roll applicator means and controlling the coating thickness across the width of the web by metering the amount of coating material applied to the roll applicator means.
roll means for advancing the web and providing a back-up surface for supporting the web as it advances;
roll applicator means for applying coating material to the web and having an axial length; and coater means for applying coating material to the roll applicator means and controlling the coating thickness across the width of the web by metering the amount of coating material applied to the roll applicator means.
12. The apparatus according to claim 11 wherein the coater means includes enclosed pond coater means for metering coating material uniformly to the roll applicator means along the axial length of the latter.
13. The apparatus according to claim 11 wherein the roll applicator means includes a roll positioned to form a gap with the roll means through which coating material on the roll passes.
14. The apparatus according to claim 11 wherein:
the roll means rotates at a relatively high speed in advancing the web;
and the roll applicator means rotates at a speed less than that of the roll means such that turbulence affecting the coating material is eliminated as it is applied to the roll applicator means by the coater means.
the roll means rotates at a relatively high speed in advancing the web;
and the roll applicator means rotates at a speed less than that of the roll means such that turbulence affecting the coating material is eliminated as it is applied to the roll applicator means by the coater means.
15. The apparatus according to claim 14 wherein the roll applicator means includes a roll positioned to form a gap with the roll means through which coating on the roll passes.
16. The apparatus according to claim 15 wherein the water means includes enclosed pond coater means for metering coating material to the roll applicator means, the enclosed pond coater means having a width parallel to the axial length of the roll applicator means and a plurality of metering means spaced apart along said width, each metering means being adjustable to control the thickness of the coating material applied to the roll applicator means adjacent said each metering means.
13~
13~
17. An apparatus for applying coating material to a surface of a moving web comprising:
roll means for advancing the web and providing a back-up surface for receiving and supporting the web as it advances;
applicator means for applying coating material to the web including a rotating roll having a spacing gap from the roll means and carrying coating material into contact with the web; and enclosed coater means for applying coating material to the rotating roll.
roll means for advancing the web and providing a back-up surface for receiving and supporting the web as it advances;
applicator means for applying coating material to the web including a rotating roll having a spacing gap from the roll means and carrying coating material into contact with the web; and enclosed coater means for applying coating material to the rotating roll.
18. The method of applying coating material to a continuous web comprising:
advancing the web on a first roll surface at relatively high speed;
transferring coating material from an enclosed coating applicator onto a second roll surface; and rotating the second roll surface immediately adjacent the web at a slower linear speed than the speed of the web to transfer the coating material from the second roll surface to the web.
advancing the web on a first roll surface at relatively high speed;
transferring coating material from an enclosed coating applicator onto a second roll surface; and rotating the second roll surface immediately adjacent the web at a slower linear speed than the speed of the web to transfer the coating material from the second roll surface to the web.
19. The method according to claim 18 wherein the step of transferring the coating material onto the second roll surface is carried out while the second roll surface is rotating at said slower speed.
20. The method according to claim 19 further comprising the step of metering the coating material transferred to the second roll surface along the axial length of the latter to control the thickness of the coating material across the width of the web transferred from the second roll surface.
21. The method according to claim 20 wherein the step of rotating the second roll surface is carried out at a gap space from the web such that only the coating material engages the web.
22. The method according to claim 21 wherein the step of metering the coating material transferred to the second roll surface along its axial length includes varying the amount of coating material transferred along said axial length to thereby vary the thickness of the coating material across the width of the web.
23. The method according to claim 18 wherein the step of rotating the second roll surface is carried out at a gap space from the web such that only the coating material engages the web.
24. The method according to claim 18 further comprising the step of metering the coating material transferred to the second roll surface along the axial length of the latter to control the thickness of the coating material across the width of the web transferred from the second roll surface.
25. The method according to claim 18 wherein the step of transferring the coating material onto the second roll surface is accomplished by pumping coating material at a pressure above atmospheric pressure through a nozzle onto the second roll surface.
26. The method according to claim 25 wherein the step of transferring the coating material onto the second roll surface includes adjusting the opening size of the nozzle to control the weight of the coating material transferred to the second roll surface.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96215697A | 1997-10-31 | 1997-10-31 | |
| US08/962,156 | 1997-10-31 | ||
| PCT/US1998/018107 WO1999023308A1 (en) | 1997-10-31 | 1998-09-01 | High speed coating apparatus and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2325906A1 true CA2325906A1 (en) | 1999-05-14 |
Family
ID=25505490
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002325906A Abandoned CA2325906A1 (en) | 1997-10-31 | 1998-09-01 | High speed coating apparatus and method |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU9213498A (en) |
| CA (1) | CA2325906A1 (en) |
| WO (1) | WO1999023308A1 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB191421892A (en) * | 1913-10-31 | Comet Pierre | Improvements in or relating to the Tinting or Colouring of Paper and other Materials. | |
| US2329034A (en) * | 1941-01-15 | 1943-09-07 | Imp Paper & Color Corp | Apparatus for coating paper |
| US2428113A (en) * | 1942-11-09 | 1947-09-30 | John R Ditmars | Machine for coating paper |
| SE465709B (en) * | 1990-04-03 | 1991-10-21 | Btg Kaelle Inventing Ab | PROCEDURE APPLIES DUPLEXIC COATING OF A CURRENT COURT BY TWO OPPOSED TRANSFER ROLLS |
-
1998
- 1998-09-01 CA CA002325906A patent/CA2325906A1/en not_active Abandoned
- 1998-09-01 WO PCT/US1998/018107 patent/WO1999023308A1/en active Application Filing
- 1998-09-01 AU AU92134/98A patent/AU9213498A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| AU9213498A (en) | 1999-05-24 |
| WO1999023308A1 (en) | 1999-05-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |