DE1043808B - Device for the mutual moistening of sheet material, especially for the development of light-sensitive copying material - Google Patents

Description

GERMAN

The invention relates to a device for moistening sheet-like material on both sides a thin layer of liquid, especially for the semi-wet development of photosensitive copying material, which device is provided with two rotatable liquid application rollers, which are longitudinal of the surface lines touch, have liquid-tight surfaces, the length of which is at least 30 times their diameter and their diameter is at least 15 mm. Devices of this type are known.

One-sided wetting of sheet-like material generally causes this material to become strong curls up, especially with the semi-wet development of diazo-type copies. That is why at this technique prefers moistening both sides at the same time. That way you will be flat, yourself Received non-curling copies. This is of course also achieved when making double-sided copies be developed at the same time. There is a device ao for developing copies known, which both zv / ei contacting application rolls as well as aids to one of the application rolls with To provide developer liquid and the other with water. In this device, the liquid application rollers, between which the copies are passed, arranged horizontally and one above the other. Preferably one of these roles is with covered in soft rubber. Devices have also become known in which a liquid application roller carried by more than one role. One embodiment relates to a device for Developing copies by the semi-wet process, in which a liquid applicator roller, which is provided on its surface with capillary grooves extending transversely to its axis, by means of a liquid transfer roller is supplied with liquid, while the transfer roller with cooperates with a doctor blade device to limit the amount of liquid transferred. the Corresponding devices are particularly suitable, those applied to the copies per unit area Amount of liquid despite the change in the speed at which copies are made through the device are passed through, to be kept almost constant. With a device for moistening on both sides of copies, two liquid application rollers arranged next to one another work with two liquid transfer rollers together, while these continue to work together with two squeegee rollers. All these Rollers can be either hard or soft. Rubber is mentioned as a suitable material. With others Embodiments will not make use of liquid applicator rollers, the surfaces of which with transverse to contraption

for moistening on both sides

of sheet material,

especially for development

of photosensitive copying material

Applicant:

Chemical Fabriek L. van der Grinten NV _r Venlo (The Netherlands)

Representative:

Dr. W. Schalk and Dipl.-Ing. P. Wirth, patent attorneys, Frankfurt / M., Große Eschenheimer Str. 39

Claimed priority:
Netherlands 30 November 1954

Peter Henricus Heldens, Venlo (Netherlands),
has been named as the inventor

are provided with grooves extending along their axes, made. But about the necessary liquid passage in the contact zones between the liquid transfer rollers and to enable the liquid discharge rollers are the liquid transfer rollers or all rollers are provided with annular flanges at their ends so that the Support the rollers at the ends only. For the practice of copying, only roles with one are of interest Diameter practically always more than 15 mm, and with a length at least 30 times theirs Diameter is.

With such dimensions of the known rollers, the problem is addressed in the conventional devices dry spots appear on the material passed between the applicator rollers can. The latter is due to the fact that the roles are not even, reciprocal Have contact along their entire length, d. H.

809 678/585

3 4

that gaps are formed between them, due to In Figs. 1, 2 and 3, 1 and 2 are the liquid

the contact of the material passed through application rollers, which in the application zone 27 a

with z. B. one of the roles is lost locally, so that thin layer of a liquid 35, z. B. a diazo

no liquid is applied locally. Columns in type developer, on both sides of the to be moistened

of the order of 0.1 mm are already resilient materials40, e.g. diazo-type paper of 80g / m ² ,

enough to bring that about. hand over. The roles of the devices according to

If sheet-like material is between two liquid Fig. 1, 2 and 3 rotate in the indicated by arrows.

job roles, between which a column has given directions.

is handled, is passed through and the mentioned in Fig. 1, the liquid application roller 1 is rotating material narrower than the width of the column and thinner io bar in the liquid trough 33, which is partially filled with liquid whose width is, so sometimes difficulty 35 arises, stored. The pins of roller 1 opportunities, such as slipping, especially when the device is in a part of the frame 30 forming pin not stored with special means of passage. The liquid application roller 2 is is provided, which is mostly the case. a flexible tube filled with fluid, so The mentioned phenomena are of course with 15 z. B. a rubber hose, which at its ends with a soft roller cover less troublesome if pin 7 is provided. It lies on reel 1 and will it is thick enough; such soft coatings have held in this position because the pegs 7 in slots but other disadvantages. Such rollers run with difficulty, 32 are movably arranged in the frame plates 30, and thin sheets of relatively large dimensions. Both rolls have a length of 120 cm. The role 1 gene tend when passing through the device ao has a diameter of 30 mm, the roller 2 a to wrinkling. In fact, the contact between them is 27 mm. Role 1 is an "ordinary" one. see the roles and the role between them, e.g. a massive metal role, which despite its guided material along the circumference due to the stiffness due to their own weight and the balance Contact pressure between the rolls different. In addition, as a result of the differences, around 0.2 mm. Since the tubular roller 2 Differences in the soft cover by at least 0.8 mm per meter of roll length effective radius of the roller, which can be bent under, this role of the bend of the roller 1 differ in their tangential velocity. follow completely. The surface of the roller 1 can The invention overcomes these difficulties. be smooth or profiled. The role 2 has one with According to the invention, the surface provided with at least one 30 capillary grooves, which is a second fluid Role-supported application roller erecting its lengthwise amount from trough 33 over roller 1 so flexible that, when it is taken into position, when the device is in operation, without zontal position is held only at their ends, in any materials between the two rolls follow the dead weight after a steady or guided through. This amount of liquid will broken curve deflects, the deflection 35 during the passage of sheet-like material lowest surface line given off at least 0.1% of the length rial. Devices according to Fig. 1 are suitable the role is. A deflection of 0.8 mm is necessary to moisten leaves on both sides. The upper a great value with regards to the average role may be their capillaries between wetting Paper thickness, which is approximately 0.1 mm. fill two sheets.

In the device according to the invention, therefore, 40. In the device according to Fig. 2, two liquid one of the liquid application rollers have a flexibility, keitströmge 33 and 34 at a small distance from which allows them to be arranged completely or at least differently. Both are partially filled with liquid considerably from the other roller or rollers 15, 35. In the trough 33, the liquid application with or with whom it works is to be rolled 1 and in the trough 34 the liquid transfer fit. As a result, the occurrence of dry 45 roll 3 is rotatably supported. Both rollers are provided with pins 6 points during the two-sided moistening of the or 8, which avoid sheet-like material in fixed pin bearings. The columns will be held. The liquid application roller 2 is closer or completely canceled, as a result of which it is on the rollers 1 and 3. It can transport the sheet-like material considerably, guided by means of pins, but it can also lie freely. That leaves better, even if it is narrow and thin. The 50-like material 40 is passed between the troughs 33 and contact pressure between the liquid applicators 34 and the rollers 1 and 2. In the roll it becomes more uniform, so that even if the flexible application zone 27 is made on both sides with the same roll of soft material, the thin layer of liquid is provided. With this pre-contact between the rollers and the intermediate direction, the rollers 1 and 2 are continuously supplied with material passed through them in the direction of the 55 liquid, so that the sheet-like material circumference over the entire length of the liquid 40 can be a long paper web. Deposition zone is practically the same and no sub I _n the apparatus of Fig. 3, the troughs 33 are differences in the tangential velocity upstream and arrived from each other at a greater distance 34, arranged as in the apparatus of Fig. 2. In both the invention will be described in more detail with reference to 60 trays, liquid transfer rollers 3 and 4 are described on the drawing. rotatably mounted. You are with pin 8 and 9 ver-Fig. 1 to 3 are schematic cross-sections which are held in fixed journal bearings of various embodiments perpendicular to the. The liquid application rollers 1 and 2 lie axes of the co-operating application rollers in Fig. 4 on the liquid transfer rollers 3 and 4 and devices according to the invention; 65 lay against each other. One of the liquid-order fig. 4 shows schematically the distribution of the forces rolling can be flexible and the other can be one in the embodiment according to FIG. 2; cozy «stiff role. Both FIGS. 5 to 10 can also show schematically in cross section rollers 1 and 2 be flexible rollers, in the sense that different embodiments according to the invention are flexible in that at least one of them is provided with journal bearings for the same liquid application rollers. 70 bearing is provided at its ends and is the same

early enough is still stiff enough to work in conjunction with the liquid transfer rollers 3 and 4 to hold itself and the other fluid applicator roll in place. In this way, z. B. the pins 6 of the roller 1 are held in fixed pin bearings. The role 2 can lie freely, it can however, it can also be provided with pins 7 which are in bearings be kept displaceable. The liquid application rollers 1 and 2 are driven by the liquid transfer rollers 3 and 4 continuously provided with liquid. The surfaces of the liquid applicator rollers 1 and 2 of the devices of FIGS. 2 and 3 can be smooth or profiled, i. H. with grooves or the like be. The surfaces of the liquid transfer rollers 3 and 4 can also be smooth or profiled be. For the device to work satisfactorily, however, it is necessary that a sufficient amount of liquid in the contact zones between the liquid transfer and the liquid application rollers is let through. It may be useful to have ample opportunities for fluid flow in the contact zones between the liquid transfer rollers and the liquid application rollers but to limit the amount of liquid that can pass through. That can in a known manner by means of a doctor blade device for wiping off the excess liquid from the Surface of the transfer rollers. Such a doctor device is z. B. dashed in Fig. 3 indicated »squeegee roller« 5. By means of such squeegee devices an almost constant supply of liquid can be achieved with variable passage speeds of the sheet-like material.

4 shows schematically how the roller 2 in a device according to FIG. 2 exerts a pressure on both the roller 1 and the roller 3. The vectors 22, 23 and 24 show the forces acting on the rollers 2, 1 and 3 as a result of the weight of each of these rollers. The weight of the roller 2 can be broken down into the vectors 22 α and 22 b , which represent the forces with which the lower rollers are loaded as a result of the weight of the roller 2. The resulting forces acting on rollers 1 and 3 are ultimately determined by vectors 25 and 26 in terms of magnitude and direction. Under the influence of these forces, the lower rollers will bend somewhat in the direction of the vectors 25 and 26. Since the rollers 1 and 3 are supported at their ends, the bend will be greatest in the middle of the rollers and decrease towards the ends. In general, this curvature will be different for different roles, but at least different for roles 1 and 3 on the one hand and role 2 on the other. Therefore, gaps appear in the liquid application zone 27 and in the contact zone 28.

In a device according to FIG. 2, the liquid application roller 2 be so flexible that their roll cross-section is not completely circular when they is on rolls 1 and 3. Preferably the flexible roller is in the device according to the invention elastically deformable, yet stiff enough to practically maintain the circular roll cross-section.

Fig. 5 is an illustration of a longitudinal section of a tube 11 having a circular cross-section Role. The tube can e.g. B. made of relatively soft rubber (e.g. 50 to 70 ° Shore hardness) be made and have a wall thickness of a few millimeters. Such a tube is in length • very flexible, while its cross-section is quite stiff. In a device according to FIG. 2, the Very satisfactory roller 2 if it is produced according to FIG. Also made from softer materials Tubes or rubber hoses with a very thin wall can be used. So it is z. B. possible flexible, elastically deformable, tubular rollers with a rigidity which is sufficient to the circular roll cross-section practically to maintain by means of a sleeve made of flexible Construct material, e.g. B. made of waterproof fabric, with an insert of a continuous row of rings, the outer diameter of which is equal to the inner diameter of the envelope. If a rubber hose with a wall thickness of 1 mm or less is used, it is possible to use one to maintain of the circular roller cross-section to obtain sufficient rigidity by attaching the hose to its Ends closed and air is pumped into it.

Fig. 6 shows a schematic longitudinal section of a tubular roller, the elastically deformable The tube wall consists of a coating 11 and a helical spring 12. Close small plates 13 the tube at the ends. Instead of the helical spring 12, individual rings can also be used, to support the sheath 11 inside.

In devices for the two-sided moistening of the sheet-like material, the liquid application rollers have also often to provide for the transport of the material against a certain resistance. Frequently wide and long sheet-like material must be passed through the device, e.g. Legs somewhat stretched paper web. In order to get a sufficient pull for this, either the liquid application rollers be pressed against each other with the necessary force, or, if they rest on or against each other with their own weight, difficult to be enough. In the device according to the invention, there can be sufficient pressure between the liquid application rollers easily obtained by a tubular, flexible liquid applicator roller with a filling made of a liquid substance or of solid bodies, which in relation to each other at least are movable in a direction transverse to the tube. The liquid substance can be a liquid, e.g. B. Water, aqueous solutions, mercury and the like, or a powder or granulated material such as sand, grist and the like.

In Fig. 7 is a schematic longitudinal section through a tubular roller with an elastically deformable shell 11 is shown, which is filled with pieces of solid material 15 α and 15 b , which are mutually movable. The material is e.g. B. iron. Instead of using very large pieces such as 15a and 15b , the tube can also be used with smaller pieces, e.g. B. the discs 16 be filled.

The pieces 15 a and 15 b are connected like a ball joint so that they form a joint with one another, but cannot move transversely.

Since the rollers according to FIGS. 5, 6 and 7 are not provided with pins, they are only for use in devices suitable in which they are carried by at least two other roles, such as. B. in devices according to Fig. 2 or 3. In devices according to Fig. 1 it is necessary to provide the flexible roller with some kind of bearing to prevent it from rolling off the lower liquid applicator roll. The flexibility the role must not be unlimited in this device either. In the devices according to FIGS. 2 and 3 however, it is also desirable to use the flexible roll

len to give any bearings to prevent them from being moved, e.g. B. as a result of an impact. Flexible rollers suitable for holding in bearings consist of a tube with a continuous, rigid core is provided, which has sufficient longitudinal freedom of movement, both with respect to the tube wall as well as for tube filling, to maintain the desired degree of deformability the tube wall. These flexible rollers are easier to work with than those without a core, ίο They can easily be taken out of the device and with the ends of the core lying on holders be kept.

In the flexible roller of Fig. 8, the elastically deformable tube 11 is at its ends by plates 14 closed. The core 10 with the pin 7 is passed through these plates and attached to them. The space between the core 10 and the inner wall of the tube 11 is partially with rings 17 completed. These rings have a larger diameter than that of the core 10 in the clear width The outer diameter of the rings is smaller than the inner diameter of the tube 11. In this way, the Roller according to FIG. 8 good transverse deformability over its entire length.

It has already been proposed to improve the paper transport in devices for one-sided Processing of photographic papers on top of the liquid applicator roll rotating in a liquid trough to arrange a roller, which consists of a rigid axle over which an uninterrupted row is pushed by discs, which are covered on their periphery with rubber, and the clear width of the Discs have a larger diameter than the axis. The discs press the paper evenly against the liquid application roller. The device is not designed to moisten both sides at the same time suitable of sheet-like material. Such a disc roller would, if used as a liquid application roller have significant disadvantages. At the joints between the panes would be more or less Liquid applied to the paper than on the circumferential surface of the discs. The liquid would penetrate between the discs and between them and the axle and impurities, corrosion etc. cause on the rollers.

Fig. 9 shows a roll of similar construction to that of Fig. 8. The filling here consists of granulated Bodies 18 and 19. The grains 18 have a smaller size than the grains 19 with the same specific Weight or higher specific weight for the same size. This flexible role is therefore in the In the middle, exert more pressure on the other roller or rollers than at their ends.

In the flexible roll of Fig. 10, the gap is between the core 10 and the inner one Tube wall 11 partially filled with liquid 20. If the tube 11 is very flexible, it can be more circular Roll cross-section can be maintained by means of small discs 21, which are at regular intervals are attached to the core 10. These small disks can be provided with recesses, like this that the compartments into which they divide the tube are connected to one another.

In the flexible rollers of FIGS. 9 and 10, the spaces between the core 10 and the The inner wall of the tube 11 can be completely filled with a liquid substance 18, 19 or 20.

To evenly distribute a thin layer of liquid on both sides of the sheet-like To obtain material, the surfaces of the liquid application rollers were or are preferably provided with capillary depressions. Suitable wells are, for. B. notches, while atxch across the Axes of the rollers along their circumference extending grooves are very suitable. Grooves with a depth from Z. B. 1 mm and a width of 0.15 mm at intervals of 0.45 mm are very suitable.

If in the device according to the invention the flexibility of the flexible rollers and accordingly the uniformity of the application pressure in the liquid application zone between the liquid application rollers is increased, it is possible to increase the application pressure per unit length of the rollers and still enough train for the transport wider and long sheet-like materials and also sufficient uniformity of the liquid application to maintain. A low contact pressure is advantageous when working with sensitive materials will, e.g. B. with materials whose surface is covered with a soft film layer.

The invention is not limited to the illustrative embodiments, it can be used within the Within the scope of the claims.

Claims (9)

Patent app. Γ che 1. Device for moistening sheet-like material on both sides with a thin one Liquid layer, in particular for the development of photosensitive copying material, by means of of a pair of co-rotating applicator rollers with liquid-tight surfaces, of which the supported at least one of the other applicator roll held in bearings over its entire length and the length of the applicator rolls is at least 30fadhe of their diameter and ihir diameter is at least 15 mm, characterized in that the supported application roller is so flexible that it is supported by its own weight in its ends when it is supported Longitudinal deflection according to a steady or broken curve, the deflection the lowest surface line is at least 0.1% of the length of the roll. 2. Apparatus according to claim 1, characterized in that the flexible roller has a sufficient Has transverse stiffness to maintain the circular roll cross-section. 3. Apparatus according to claim 2, characterized in that the flexible roller is a Tube is. 4. Apparatus according to claim 3, characterized in that the tube is made of rubber. 5. Device according to claims 3 and 4, characterized in that the tube with a Filling made of a liquid substance or of solid bodies is provided, at least in the direction are relatively movable transversely to the tube axis. 6. Device according to claims 3 to 5, characterized in that the tube with a continuous rigid axle is provided, which has sufficient freedom of movement in the longitudinal and transverse direction to the tube wall or to the tube filling. 7. Device according to claims 3 and 4, characterized in that the tube wall a rigid core along its entire length is held, which is interrupted or flexible in at least one point. 8, - device according to claim 7, characterized in that that the core consists of rings or a helically wound wire. 9. Device according to claims 1 to 8, characterized in that the outer wall 10 the flexible roller, as known per se, is provided with grooves or notches. Documents considered: German Patent No. 589 875; Swiss Patent No. 268 872; British Patent No. 698,080. 1 sheet of drawings ® SW 678/585 11. 5 &