US3854446A

US3854446A - Apparatus for wet treatment of sheet or strip material

Info

Publication number: US3854446A
Application number: US00363079A
Authority: US
Inventors: E Stievenart; H Deconinck; J Muller
Original assignee: Agfa Gevaert AG
Current assignee: Agfa Gevaert AG
Priority date: 1972-05-26
Filing date: 1973-05-23
Publication date: 1974-12-17
Anticipated expiration: 1991-12-17
Also published as: DE2225637A1; BE799707A; DE2225637C3; FR2189777B1; FR2189777A1; DE2225637B2; IT987693B

Abstract

Apparatus for wet treatment of sheet- or strip-shaped material which is provided at its underside with a photosensitive layer has a liquid-containing vessel with rolls which advance the material along a substantially horizontal path above one or more liquid applying devices whose hollow tubular housings rotate about horizontal axes and dip into the supply of liquid in the vessel to apply liquid to the underside of the material. Each housing contains a feed screw which rotates therewith and conveys a stream of liquid from openings at one end to openings at the other end of the respective housing. A pump draws liquid from the vessel and discharges the thus withdrawn liquid into the vessel at right angles to the direction of transport of material so that the chemical activity of liquid which is being fed by the pump decreases in a direction from one marginal portion toward the other marginal portion of the material. Each housing discharges liquid at the other marginal portion of the material whereby such liquid flows transversely of the path and its chemical activity decreases in a direction counter to that of the chemical activity of liquid which is being fed by the pump. This insures a more uniform treatment of each portion of the photosensitive layer.

Description

United States Patent [191 Stievenart et al.

[4 1 Dec. 17,1974

1 1 APPARATUS FOR WET TREATMENT OF SHEET OR STRIP MATERIAL [75] Inventors: Emile Frans Stievenart, Antwerp;

Hugo Frans Deconinck, Deurne Zuid, both of Belgium; Jiirgen Miiller, Munich, Germany [73] Assignee: AGFA-Gevaert Aktiengesellschaft,

Leverhausen, Germany [22] Filed: May 23, 1973 [21] App]. No.: 363,079

[30] Foreign Application Priority Data May 26. 1972 Germany 2225637 [52] US. Cl. 118/223, 178/248 [51] Int. Cl. B05c H08 [58] Field of Search... 1 18/223, 246, 224, 258259; 354/89, 318, 324

[56] References Cited UNITED STATES PATENTS 1.570.857 l/l926 Perkins 118/258 2.333.369 11/1943 Glickman.... 118/258 X 2.611.336 9/1952 Sachs 118/246 X 2.622.313 12/1952 MacDonald 118/258 X 3.081.737 3/1963 Frantz et al.... 118/223 X 3.722.453 3/1973 Dahlquist 118/246 IIl-| l4 Primary ExaminerRonald Feldbaum Attorney, Agent, 0r-Firm-Michael S. Striker 57 ABSTRACT Apparatus for wet treatment of sheetor strip-shaped material which is provided at its underside with a photosensitive layer has a liquid-containing vessel with rolls which advance the material along a substantially horizontal path above one or more liquid applying devices whose hollow tubular housings rotate about hori' zontal axes and dip into the supply of liquid in the vessel to apply liquid to the underside of the material. Each housing contains a feed screw which rotates therewith and conveys a stream of liquid from openings at one end to openings at the other end of the respective housing. A pump draws liquid from the vessel and discharges the thus withdrawn liquid into the vessel at right angles to the direction of transport of material so that the chemical activity of liquid which is being fed by the pump decreases in a direction from one marginal portion toward the other marginal portion of the material. Each housing discharges liquid at the other marginal portion of the material whereby such liquid flows transversely of the path and its chemical activity decreases in a direction counter to that of the chemical activity of liquid which is being fed by the pump. This insures a more uniform treatment of each portion of the photosensitive layer.

13 Claims, 6 Drawing Figures APPARATUS FOR WET TREATMENT OF SHEET OR STRIP MATERIAL BACKGROUND OF THE INVENTION The present invention relates to apparatus for wet treatment of sheet or strip material, such as photographic films or web-like carriers for photosensitive layers. More particularly, the invention relates to improvements in apparatus for wet treatment of running sheet or strip stock which is transported through a developing or like station wherein its photosensitive layer is treated with a liquid substance. Still more particularly, the invention relates to improvements in apparatus wherein at least one side of running sheet or strip stock is provided with a layer of liquid which is being withdrawn from a suitable supply by one or more rotary members whose peripheral surfaces are in contact with the material.

Apparatus of the just outlined character are often used in photographic processing laboratories, for example, as developing machines wherein a running sheet or strip is first contacted with an activating agent or accelerator and thereupon with a suitable stabilizing agent which is applied with a predetermined delay to terminate the development of photosensitive material. In such apparatus, the uniformity of treatment is of great importance, i.e., the chemical activity as well as the temperature of the liquid agent or agents should be uniform in all portions of the running sheet or strip. Even minor deviations of liquid temperature or chemical activity from a desired optimum value greatly affect the quality of the developing treatment.

Attempts to enhance the uniformity of treatment of photosensitive layers with one or more liquid agents include the provision of a device for circulating the agent which device cooperates with means for supplying a regenerated liquid. The circulating device is normally adjacent to one side of the path for sheet or strip material and serves to circulate the liquid substantially at right angles to the direction of travel of the material. A drawback of such circulating devices is that, when the width of a sheet or strip is considerable, the activity of circulated agent decreases appreciably from the one toward the other side of the path with the result that the development is non-uniform, often to such an extent that the final product is practically useless.

SUMMARY OF THE INVENTION An object of the invention is to provide an apparatus for wet treatment of running sheet or strip materials wherein the characteristics of the liquid agent or agents can be maintained within an optimum range to thus insure a highly satisfactory uniformity in the quality of treated material.

Another object of the invention is to provide an apparatus for wet treatment of sheet or strip material with novel and improved liquid applying means which complements the action of conventional liquid circulating devices to thus insure a greater uniformity in the chemical activity and temperature of one or more liquid agents.

A further object of the invention is to provide in an apparatus for wet treatment of running sheet or strip stock novel and improved means for circulating a liquid treating medium to thus insure that each portion of the stock is contacted by a liquid whose activity and/or temperature does not deviate appreciably from a desired value.

An additional object of the invention is to provide the apparatus with novel and improved means for applying liquid media to running sheet or strip stock and for simultaneously effecting a desirable circulation of liquid media in the body or bodies of liquid.

A further object of the invention is to provide the above outlined apparatus with novel and improved means which complements the liquid circulating action of conventional circulating devices and is capable of performing additional important functions.

The apparatus of the present invention is utilized for wet treatment of running sheet or strip material, particularly a material whose underside is provided with a photosensitive layer. The apparatus comprises a vessel containing a supply of a treating liquid (e.g., a developing solution) and having an inlet for introduction and an outlet for evacuation of sheet or strip material which travels in the vessel lengthwise along a path located above the supply of liquid, and at least one liquid applying device which is mounted in the vessel at a level below the path and includes an elongated tubular housing having at least one liquid-admitting opening in the region of one end and at least one liquid-discharging opening in the region of the other end. The housing is rotatable in the vessel about a substantially horizontal axis extending transversely of the path, and at least a portion of the housing dips into the supply of liquid so that its peripheral surface transfers a film of liquid from the supply to the underside of the sheet or strip material in the path. The liquid applying device further comprises liquid conveying means (preferably a feed screw) which is mounted in the housing to establish a flow of liquid from the liquidadmitting opening to and through the liquid-discharging opening when the housing rotates whereby the housing delivers liquid to that marginal portion of the running sheet or strip material which is remote from the region of admission of regenerated liquid into the vessel.

The novelfeatures which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a longitudinal vertical sectional view of an apparatus which embodies the invention;

FIG. 2 is an axial sectional view of a liquid applying device substantially as seen in the direction of arrows from the line II-II of FIG. 1;

FIG. 3a is a diagrammatic fragmentary horizontal sectional view of a conventional apparatus, showing the changes in chemical activity of treating liquid in a direction at right angles to the direction of travel of sheet or strip material;

FIG. 3b is a similar diagrammatic sectional view of an apparatus which constitutes a slight modification of the apparatus shown in FIG. 1;

FIG. 30 is a similar diagrammatic sectional view of the apparatus shown in FIG. 1; and

FIG. 4 is an enlarged sectional view as seen in the direction of arrows from the line IV--IV of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, there is shown an apparatus for wet treatment of sheet or strip material 30, e.g., webs of photographic film or webs of flexible carrier material the underside of which is coated with a photosensitive layer. The apparatus is assumed to constitute a developer for photographic films or the like and is installed in a laboratory at a developing station 10. A vessel 11 contains a supply 18 of developing or treating liquid and is provided with an inlet 13 for introduction and an outlet 12 for evacuation of sheet or strip material 30. The material which is transported in the vessel 11 from the inlet 13 toward the outlet 12 advances along an elongated path 60 (indicated by a phantom line) which is located at a level above the supply 18 of liquid in the vessel 11. The means for transporting the material 30 from the inlet 13 toward and through the outlet 12 comprises a first pair of advancing

rolls

14, 15 which are mounted in the vessel 11 adjacent to the inlet 13 and a second pair of advancing

rolls

16, 17 which are mounted in the vessel 11 adjacent to the outlet 12. The

rolls

16, 17 further serve to remove the surplus of treating liquid from the underside of the material 30 whereby such surplus flows along the lower roll 16 and back into the main body of liquid in the vessel 11.

The shaft 15a of the roll 15 and/or the shaft 14a of the roll 14 is driven in the direction indicated by the arrow. Analogously, the shaft 160 for the roll 16 and/or the shaft 17a for the roll 17 is driven to rotate in the direction indicated by the arrow.

The apparatus further comprises means for circulating the treating liquid in the vessel 11. Such circulating means comprises a pump 19 which is driven by a motor 22 (e.g., an electric motor) and draws liquid from the vessel 11 by way of a first pipe 20 having an intake end communicating with the interior of the vessel 11 in a region located below the advancing roll 16. A second pipe 21 receives liquid from the pump 19 and discharges such liquid into the vessel 11 between the advancing

rolls

15, 16 at one side of the path 60. The apparatus also comprises means for admitting into the vessel or into the pipe 21 regenerated liquid at a rate which is necessary to maintain the supply 18 at a constant level 70. The regenerated liquid is admitted to compensate for evaporation of liquid from the vessel 11, to compensate for removal of some liquid by the material which leaves the vessel 11 by way of the outlet 12, and also to insure that the chemical activity of liquid in the vessel 11 remains at least substantially constant. The vessel 11 preferably further contains and/or is connected with suitable means for insuring that the temperature of the supply of liquid does not exceed or does not drop below a predetermined range of acceptable temperatures. Such means may include one or more thermometers and one or more heaters for liquid.

In accordance with a feature of the invention, the apparatus further comprises one or more novel liquid applying devices one of which is shown at 50. This device is mounted in the vessel 11 at a level below the path 60 and includes a hollow tubular housing 23 in the form of a cylinder having a shell 23A ((see FIG. 2) and two

end walls

23B, 23C. The axis of the housing 23 is preferably horizontal and extends transversely of the path 60. The liquid applying device further comprises liquid conveying means 25 here shown as a feed screw which is received in the interior of the housing 23 and has a shaft 24 forming part of drive means for rotating the device 50 in the vessel 11. The threads 2511 of the feed screw 25 sealingly engage the cylindrical internal surface 2312 (FIG. 4) of the housing 23. The housing 23 is mounted in the vessel 11 in such a way that about one-third thereof dips into the supply 18 of liquid whereby the peripheral surface 23a of the housing transfers a film of liquid to the underside of the material 30 in the path when the shaft 24 is driven to rotate the

parts

23 and 25 as a unit, preferably in a counterclockwise direction, as viewed in FIG. 1. Thus, the peripheral surface 23a rotates counter to the direction (arrow 61) of transport of material 30 along the path 60.

The drive means for the liquid applying device 50 further comprises a gear 24a which is fixed to the shaft 24 and receives torque from a suitable motor (not shown) by way of a gear train. The housing 23 has one or more liquid-admitting first openings 26 which are provided in the end wall 238 and an annulus of liquiddischarging second openings 27 which are provided in the shell 23A adjacent to the end wall 23C. As shown in FIG. 4, the partitions between the second openings 27 are arranged to cause streams of liquid to flow from the housing 23 substantially tangentially of the peripheral surface 23a. The means for urging the underside of the material 30 in the path 60 against the peripheral surface 23a of the housing 23 comprises a stationary or movable biasing member 31 having an undulate bottom surface 31a and being mounted in the vessel 11 above the path 60. The film of liquid which is transferred to the underside of the material 30 in the path 60 by the peripheral surface 23a adheres to the material 30 and advances therewith toward an additional or auxiliary liquid applying device 29 here shown as a roll or drum driven by a shaft 29a and a gear 29b so as to rotate clockwise, as viewed in FIG. 1. The peripheral surface 29c of the drum 29 dips into the supply 18 of liquid in the vessel 11 and applies a film of liquid to the underside of the material 30. At the same time, the peripheral surface 29c removes spent treating liquid from the underside of the material 30. The gear 291; is driven by the aforementioned motor for the gear 24a, preferably at an RPM which is less than the RPM of the shaft 24, i.e., the RPM of the additional liquid applying device 29 is less than that of the device 50. Also, whereas the peripheral surface 23a rotates counter to the direction indicated by the arrow 61,. the peripheral surface 29c rotates in such direction. The RPM of the advancing rolls l5 and 16 is preferably less than the rotational speed of the liquid applying device 50. Thus, the RPM of the device 50 preferably exceeds the RPM of each other device (15, 29, 16) which dips into the supply of liquid in the vessel 11.

The shaft 24 of the feed screw 25 is sealingly surrounded by the

end walls

23B, 23C of the housing 23 so that the latter can receive liquid only by way of the openings 26. About one-third of the diameter of the feed screw 25 extends into the supply 18 of liquid in the vessel 11. When the gear 24a drives the shaft 24 in a clockwise direction, as viewed in FIG. 4, the housing 23 rotates with the feed screw 25. The liquid which has entered the housing 23 tends to remain in the lower part of the interior of the housing, even when the latter rotates with the feed screw 25, whereby the openings 26 draw or suck liquid from the surrounding supply 18. The liquid which enters the housing 23 in the direction indicated in FIG. 2 by arrows 26a flows toward the openings 27 and is expelled from the housing by flowing tangentially or substantially tangentially of the peripheral surface 23a. The shell 23A with its openings 27 acts not unlike the impeller of a radical pump and cooperates with the feed screw 25 to induce the flow of a continuous stream of liquid through the housing 23 from one side to the other side of the path 60, i.e., in the direction in which the pipe 21 discharges liquid into the vessel 11 in the space between the advancing rolls 15 and 16.

The inflow of liquid into the housing 23 can be enhanced by changing the configuration and/or the position of openings 26. For example, the openings 26 can be designed to provide helical paths for admission of liquid into the housing 23. Also, the openings 26 can be provided in the peripheral surface 23a adjacent to the end wall 23B and may be arranged to induce a tangential flow of liquid into the housing. The just described openings 26 can resemble the openings 27 shown in FIG. 4 except that their orientation is opposite to that of the openings 27. The extent to which the housing 23 dips into the supply 18 of liquid influences the rate of liquid flow from the openings 26 towards the openings 27. It was found that the flow of liquid in the housing 23 is very satisfactory if about one-third of the diameter of the feed screw dips into the liquid in the vessel 11.

FIG. 3a illustrates the effect of circulation of treating liquid in a conventional apparatus. The direction of material transport is indicated by the arrow 61 and the direction of flow of liquid which issues from the pipe 21 is indicated by the arrow 62. Thus, the regenerated liquid flows at right angles to the direction of transport of the material whereby its activity or effectiveness decreases in the direction of arrow 62 so that the treatment of photosensitive material along the remote marginal portion of the strip or sheet is much less intensive than along the marginal portion which is nearer to the outlet of the pipe 21. The trapezoid 118 indicates the decrease in chemical activity of treating liquid in the direction in which the liquid flows from the pipe 21 toward the remote side of the vessel. Therefore, the development of material which is being treated by the liquid is unsatisfactory because it is much more intensive along the marginal portion which is closer to the pipe 21. This is particularly felt when the material to be treated is rather wide and the quantity of treating liquid in the vessel is small.

FIG. 3b illustrates the effect of treatment of material 30 in an apparatus which embodies the present invention. The activity of liquid which issues from the pipe 21 decreases in the same way as described in connection with FIG. 3a (see the trapezoid 1 18). However, the activity of liquid which has passed through the housing 23 and has entered the vessel 11 by way of the openings 27 is just as high or nearly as high as that of the liquid issuing from the pipe 21. The liquid which issues from the openings 27 flows across the path 60 (arrow 63) and its activity decreases in a direction toward the outlet of the pipe 21. The decrease of activity of liquid issuing from the openings 27 is indicated by the triangle 218 which is superimposed upon the trapezoid 118 so that the overall effect of liquid on the photosensitive material at the underside of the running sheet or strip material 30 is substantially constant or uniform from one side to the other side of the path 60. The flow of liquid as indicated by the triangle 218 (arrow 63) is induced by the pipe 20 which draws liquid from the vessel 11 and feeds such liquid to the pump 19. It is assumed in FIG. 3b that the axis of the pipe 21 is located in a vertical plane which includes the axis of the shaft 24.

FIG. 3c illustrates the effect of treatment of material 30 in an apparatus which is identical or nearly identical with that shown in FIG.. 1, i.e., wherein the pipe 21 is offset relative to the housing 23, as considered in the direction of the arrow 61. The triangle 218 represents the drop of chemical activity of liquid issuing from the openings 27 and flowing transversely of the direction of travel (arrow 61) of the material 30. The overall intensity of treatment is very similar to that described in connection with FIG. 3b, i.e., the chemical activity of liquid is substantially uniform all the way from the one to the other marginal portion of the material 30 in the vessel 11. The only difference is that the triangle 218 is slightly shifted to the trapezoid 118, as considered in the direction of material travel in the vessel 11. This does not affect the quality of treatment due to timely integration during transport of material from the inlet 13 toward the outlet 12.

The housing 23 of the liquid applying device 50 preferably consists of a metallic material which is provided with a coating of rubber or the like. The conveying means 25 preferably consists of a synthetic plastic material which can stand the corrosive action of liquid in the vessel 11. The other rotary parts of the apparatus, especially those (15, 29 and 16) which dip into the supply 18 of liquid in the vessel 11, preferably consist of a metallic material having a coat of rubber or another relatively soft substance which can produce sufficient friction for satisfactory transport of material 30 through the vessel.

The improved apparatus can be used with particular advantage for wet treatment of photosensitive material in a developing unit which operates with a relatively small quantity of a liquid medium. If the supply of liquid is relatively small, even minor fluctuations in chemical activity and/or temperature of the liquid medium might greatly affect the quality or intensity of treatment, regardless of whether the fluctuations are of localized nature or take place at timely spaced intervals. The improved apparatus insures a highly satisfactory mixing of the supply of liquid as well as a thorough dispersion of admitted regenerated liquid to thus reduce the likelihood of fluctuations in chemical activity and- /or temperature.

The drive means for the liquid applying device 50 may be of the reversible type. This is desirable in connection with the treatment of certain types of materials. If the direction of rotation of the device 50 shown in FIGS. 1, 2 and 4 is reversed, the liquid will flow through the housing 23 in a direction from the openings 27 toward the openings 26. In such apparatus, the openings 27 are preferably replaced by openings similar to the openings 26 and are provided in the end wall 23C of the housing 23.

The apparatus may comprise two or more liquid applying devices 50. For example, the drum 29 can be replaced with a liquid applying device having a hollow housing and liquid conveying means in the hollow housing.

A feed screw 25 may alternatively or additionally be included in an advancing roll which is mounted in the vessel 11 in such a way that about one-third thereof dips into the liquid. The wet treatment apparatus may then be of a type wherein the photographic film is dipped into the liquid, too and which has no liquid applying devices.

Further there exists the possibility to rotate the hollow tubular housing 23 and the feed screw 25 at differ ent velocities by separate drive means for the shaft 24 and the tubular housing. The direction of rotation of the feed screw is determined in accordance with the conveying direction of the threads 25a.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by letters Patent is set forth in the appended claims:

1. In an apparatus for wet treatment of running sheet or strip material, combination comprising a vessel for a supply of treating liquid, said vessel having an inlet for introduction and an outlet for evacuation of material whereby the material which travels lengthwise between said inlet and said outlet advances along a predetermined path; at least one elongated roll mounted in said vessel and including an elongated hollow cylindrical housing having a peripheral surface contacting the material in said path, an internal surface, at least one liquid-admitting first opening in the region of one end and at least one liquid-discharging second opening in the region of the other end thereof, said housing being rotatable about a substantially horizontal axis extending transversely of said path and at least a portion thereof dipping into said supply of liquid; and liquid conveying means including a feed screw provided in said housing and arranged to establish a flow of liquid from said first to said second opening, said feed screw having threads in at least partial sealing engagement with said internal surface of said housing.

2. A combination as defined in claim 1, wherein said peripheral surface transfers liquid from said supply to the underside of material in said and the underside of material in said path is provided with a photosensitive layer.

3. A combination as defined in claim 1, further comprising means for rotating said feed screw relative to said vessel.

4. A combination as defined in claim 1, further comprising at least one liquid applying device mounted in said vessel at level below said path, said device being rotatable in said vessel about a second axis extending transversely of said path and having a peripheral surface dipping into said supply of liquid and contacting the material in said path, and drive means for rotating said housing and said additional device about the respective axes.

5. A combination as defined in claim 4, wherein said drive means includes means for rotating said housing at a first RPM and means for rotating said device at a lower second RPM.

6. A combination as defined in claim 5, wherein said feed screw which rotates with said housing at said first RPM.

7. A combination as defined in claim 1, further comprising drive means for rotating said housing so that said peripheral surface rotates counter to the direction of transport of material along said path.

8. A combination as defined in claim 7, wherein approximately one-third of said housing dips into said supply of liquid.

9. A combination as defined in claim 1, wherein said first and second openings are respectively located at a first and a second side of said path, and further comprising means for circulating the liquid of said supply in a direction from said first toward said second side of said path.

10. A combination as defined in claim 1, wherein said second opening is provided in said peripheral surface of said housing.

11. A combination as defined in claim 10, wherein said second opening is arranged to discharge liquid substantially tangentially of said housing.

12. A combination as defined in claim 1, wherein said housing has a cylindrical shell and two end walls, said first opening being provided in one of said end walls.

13. A combination as defined in claim 1, further comprising means for advancing sheet or strip material along said path, said means for advancing comprising a first pair of rolls in the region of said inlet and a second pair of rolls in the region of said outlet, said housing being located between said first and second pairs of rolls.

Claims

1. In an apparatus for wet treatment of running sheet or strip material, combination comprising a vessel for a supply of treating liquid, said vessel having an inlet for introduction and an outlet for evacuation of material whereby the material which travels lengthwise between said inlet and said outlet advances along a predetermined path; at least one elongated roll mounted in said vessel and including an elongated hollow cylindrical housing having a peripheral surface contacting the material in said path, an internal surface, at least one liquid-admitting first opening in the region of one end and at least one liquiddischarging second opening in the region of the other end thereof, said housing being rotatable about a substantially horizontal axis extending transversely of said path and at least a portion thereof dipping into said supply of liquid; and liquid conveying means including a feed screw provided in said housing and arranged to establish a flow of liquid from said first to said second opening, said feed screw having threads in at least partial sealing engagement with said internal surface of said housing.