EP1080885B1 - Method and apparatus for making a cylinder stencyl - Google Patents

Abstract

The rotatable cylinder fabric (4) during its patterning process is stretched between end rings (2, 3) and is supported from inside by means of a roll (21) - which extends virtually over the entire length of the cylinder screen against the external patterning head (23). An Independent claim is also included for an apparatus for implementation of the proposed method. It comprises means for rotating and fixing in required angular positions the cylinder fabric, and supporting it from inside during the patterning process.

Description

A method and an apparatus for producing a screen printing cylinder are already known from FR-A-1 552 436 and DE-AS 1 671 499. It is about the production of a two-layer screen printing or rotary screen printing cylinder for textile printing. The screen printing cylinder, too can be equipped with end rings, can have a structure as it for example, is known from British Patent 1,050,649. There is a relatively coarse-mesh cylinder from a relatively fine-mesh cylinder surround. In the prior art mentioned at the beginning, the screen printing cylinder held on the front on bundles, which are rotatably attached to a cross member are. Presses against the outer surface of the screen printing cylinder from the inside a backup roller which extends in the longitudinal direction of the screen printing cylinder. Extends outside the screen printing cylinder and parallel to the backup roller a pinch roller, which is at a distance from the backup roller. By the The gap between the support roller and the squeeze roller is tangential to the screen printing cylinder a die can be passed through, the plate-shaped and with is provided with a pattern. Pattern is determined by this matrix Masking material applied to the surface of the screen printing cylinder to to close this area. The screen printing cylinder rotates, which is rotatably mounted on the cross member on the bundles, when the die is transported through the gap between the pinch roller and back-up roller. Acting according to British Patent 1,050,649 the screen printing cylinder is one in which the inner cylinder relatively firm and the outer cylinder is relatively flexible, for example made of nylon consists.

To be able to print on tiles or ceramics, a. covered with gauze Screen printing cylinder for use. Gauze can be nylon or plastic sieves with different mesh sizes. To form the screen printing cylinder the gauze is on two stable and for example metallic End rings with a certain diameter glued on. However, they would be thus produced screen printing cylinder completely unstable, so that between the two or possibly three spacer rods are arranged on both end rings, to keep the end rings at a distance. These spacer bars are exclusive for transporting and storing and if necessary when developing the Screen printing cylinder used. For coating, sampling and printing these spacer bars are removed again, as with these steps the fixation of the screen printing cylinder or its end rings from the respective Machines is accomplished.

Such a screen printing cylinder is horizontal on one of the machines mentioned arranged, the gauze constricts in the middle. With others Words, the outside diameter of the screen printing cylinder increases Middle down. This can be done by stretching the gauze lengthways Screen printing cylinders can only be partially compensated for by the end rings be moved apart.

Should one with a light-sensitive lacquer, for example, inside and outside coated gauze, which is attached to opposite end rings is patterned in an exposure machine, it becomes conventional around the gauze a film with the pattern to be printed laid around, through which the gauze is exposed. So that Film lies exactly on the circumferential surface of the gauze to make hollow copies avoid, a cylindrical plexiglass shell on the outside Circumference of the gauze stretched out while an inner tube roller inflates the screen printing cylinder formed by the gauze and its Press the jacket against the plexiglass shell, with the film between the To lie outside of the gauze and the inside of the plexiglass shell comes. Then the photosensitive material lying on the gauze becomes Layer exposed through the film, including the plexiglass shell through, with suitable radiation and over a predetermined Period.

After exposure, the plexiglass shell and film are removed from the screen printing cylinder removed and the screen printing cylinder itself from the exposure machine away. Then the exposed photosensitive layer developed, dried, possibly retouched and cured, so that the screen printing cylinder is then ready to print.

When printing with the help of the screen printing cylinder, using an inner squeegee the printing ink through to the now patterned gauze Example tiles pressed. The gauze in the area of the doctor blade is about the diameter of the end rings expanded or deformed.

The conventional method is relatively cumbersome because u. a. the plexiglass bowls must be used to the cylinder peripheral wall when patterning or exposing via film in a radial position to keep the radial position of the peripheral wall in the area of Squeegee corresponds to later printing. Otherwise they will be distorted Received samples.

The invention has for its object a method of the aforementioned Kind in such a way that the handling of the screen printing cylinder is improved especially in the patterning. There should also be one suitable device created for performing this method become.

The procedural solution to the problem is set out in claim 1. In contrast, the device-side solution is the task called in claim 8. Advantageous embodiments of the invention can be found in the subordinate claims.

• ein Mantel des Siebdruckzylinders wird nur durch eine von zwei Endringen gehaltene flexible Gaze gebildet, die für Flüssigkeiten bzw. pastöse Massen durchlässig ist;
• die Endringe sitzen koaxial auf einer drehbar gelagerten Welle, von der sie bei Drehung mitgenommen werden;
• durch Verschieben der Endringe voneinander weg wird der Mantel gespannt;
• eine auf einer Seite der Welle sitzende und sich wenigstens annähernd über die gesamte Länge des Siebdruckzylinders erstreckende Anlage drückt den Mantel von innen in eine parallel zur Welle liegende Position;
• bei Drehung der Welle wird die Anlage raumstabil gehalten; und
• eine Bemusterung des Siebdruckzylinders von außen erfolgt bei dessen Drehung nur im Bereich dieser Anlage mittels einer Bearbeitungsstation, die parallel zur Welle verschoben wird.

The invention initially relates to a method for producing a screen printing cylinder, comprising the following steps:

• a jacket of the screen printing cylinder is formed only by a flexible gauze held by two end rings, which is permeable to liquids or pasty masses;
• the end rings sit coaxially on a rotatably mounted shaft, from which they are carried when they rotate;
• by moving the end rings away from each other, the jacket is stretched;
• a system seated on one side of the shaft and extending at least approximately over the entire length of the screen printing cylinder presses the jacket from the inside into a position lying parallel to the shaft;
• when the shaft rotates, the system is kept stable; and
• The screen printing cylinder is sampled from the outside when it is rotated only in the area of this system by means of a processing station which is displaced parallel to the shaft.

The method according to the invention permits a considerably simpler one Handling the screen printing cylinder when sampling, since this is only needs to be placed on the sampling device without it is necessary to surround it with additional pressure elements or inflate a hose roller lying in it. The touchdown and Losing weight on the device or from the device thus takes place relatively easy. In addition, the system and the sample in Area of this system ensures that always flawless and undistorted Also receive prints when printing on tiles or ceramics if the printing area or squeegee is there during the printing process where the system was previously located.

According to an advantageous embodiment of the invention, a Roll used, the longitudinal axis of which is parallel to the cylinder longitudinal axis. Since the roller itself can rotate freely about its longitudinal axis, Rotation of the screen printing cylinder about its cylinder axis and runs on the inner peripheral surface of the screen printing cylinder. By this rolling process is avoided that additional tensions in the Circumferential wall of the screen printing cylinder are transferred, resulting in a leads to even better print quality.

The jacket of the screen printing cylinder can be used in many different ways be sampled. The sampling process always takes place from the outside, thus on the outer peripheral surface of the screen printing cylinder.

For example, the sampling of the jacket can be carried out that a masking liquid is applied directly to this according to the pattern becomes. It can be a curable liquid, wax, a Metal alloy, and the like.

It is also possible, however, to lay one on top of it to sample the coat expose the photosensitive layer according to the pattern and then to develop. The exposure can take place directly, for example with the help of a laser beam that can be switched on and off. The exposure could also be done over a large area using a film that is tangential is guided along the outer peripheral surface of the jacket and itself also based on the system.

On the other hand, it is also possible to spray the above-mentioned. Art first with a light-sensitive film lying on the coat opaque masking liquid to cover according to pattern in this way to produce a mask, through which subsequently is exposed.

Finally, there is another way to sample the jacket in it, a layer lying on it directly according to pattern by irradiation abrasion, for example by burning away with a focused Laser beam. Here, however, the layer material must be compared to The material of the jacket must be chosen so that the jacket does not burn through done itself.

A gauze is used as the coat, the pores or Has openings with a certain mesh size. The gauze can also consist of nylon or another plastic. It's relatively flexible in order not to damage tiles or ceramics in particular when printing and so as not to harm yourself.

• auf einer drehbaren Welle angeordneten Maschinenendringen zum stirnseitigen Halten des Siebdruckzylinders koaxial zur Welle;
• einer Spanneinrichtung zum Spannen des Siebdruckzylinders in Längsrichtung der Welle;
• einer innen und nur an einer Seite der Welle liegenden und sich wenigstens annähernd über die gesamte Länge des Siebdruckzylinders erstreckenden Anlage, die den Mantel des Siebdruckzylinders in eine parallel zur Welle liegende Position drückt, wobei
• die Anlage über ein Getriebe auf der Welle sitzt, das sie bei Drehung der Welle raumstabil hält; und
• einer Bearbeitungsstation zur Bemusterung des Siebdruckzylinders von außen, die der Anlage gegenüberliegend positioniert und parallel zur Welle verschiebbar ist.

The invention also relates to a device for producing a screen printing cylinder, comprising:

• machine end rings arranged on a rotatable shaft for holding the screen printing cylinder on the end face coaxial to the shaft;
• a tensioning device for tensioning the screen printing cylinder in the longitudinal direction of the shaft;
• a system lying inside and only on one side of the shaft and extending at least approximately over the entire length of the screen printing cylinder, which presses the jacket of the screen printing cylinder into a position lying parallel to the shaft, wherein
• the system sits on the shaft via a gearbox, which keeps it stable when the shaft rotates; and
• a processing station for sampling the screen printing cylinder from the outside, which is positioned opposite the system and can be moved parallel to the shaft.

The machine end rings, the clamping device, the system and the processing station can all be on one bed of a processing machine are located, which is approximately lathe-shaped. The screen printing cylinder can be easily applied to the machine for the purpose of sampling put on and take it off again, so that the processing step the sampling overall considerably simplified.

As already mentioned, the system is preferably as about its longitudinal axis rotatable shaft which is fixedly positioned in its angular position and rests via a gear on the axis on which the end rings are seated and which is rotated to rotate the screen printing cylinder. In this respect it follows a compact unit.

The processing station sits on a carriage of the processing machine, the carriage in turn on a guide rail is slidable, which rests on the machine bed and extends parallel to the longitudinal direction of the shaft on which the screen printing cylinder has been put on.

According to one embodiment of the invention, the processing station can be used as Spray head for spraying liquids or other viscous media be trained. The spray head can also be designed that it is suitable for spraying liquid metal alloys, for example for spraying out woody metal. It can move other processing units behind an ejection opening have, such as a heat source for hardening the sprayed liquid by applying heat.

On the other hand, the processing station can also have an exposure head have to light-sensitive layers for example with focused To be able to expose radiation or around other layers with more focused To be able to remove radiation. With focused radiation it can be focused laser radiation, for example.

A spray head with one behind it in the direction of movement could also be used Exposure source to be provided so that after spraying a Area of a mask has an underlying photosensitive layer can expose large areas immediately through the mask.

Figur 1 eine Draufsicht auf eine Vorrichtung zur Bemusterung eines Siebdruckzylinders;

Figur 2 eine Seitenansicht der Vorrichtung nach Figur 1, teilweise im Schnitt; und

Figur 3 einen Axialschnitt durch die Vorrichtung nach Figur 1.

An embodiment of the invention is described below with reference to the drawing. Show it:

Figure 1 is a plan view of a device for patterning a screen printing cylinder;

Figure 2 is a side view of the device of Figure 1, partly in section; and

FIG. 3 shows an axial section through the device according to FIG. 1.

Figures 1 to 3 show a device according to the invention for sampling a screen printing cylinder in accordance with the invention Method.

According to Figure 1, the screen printing cylinder 1 consists of two end rings 2 and 3, which carry a gauze 4 on the circumference. Opposite margins the gauze 4 are along the peripheral edges of the end rings 2 and 3 with these glued, the abutting edges of the gauze 4 also preferably connected by gluing, so that the End rings 2 and 3 together with the gauze 4 form the screen printing cylinder 1.

A central longitudinal axis 5 of the screen printing cylinder 1 or End rings 2 and 3 are coaxial with a rotatably mounted shaft 6 with shaft sections 6a and 6b. The shaft sections 6a and 6b are rigid with each other connected. The shaft section 6b is suitable coupled with a rotary drive.

The shaft section 6b is rigidly connected to it Machine end ring 7. This machine end ring 7 sits firmly on the shaft section 6b and when the shaft section 6b rotates therefrom taken along accordingly. Sitting on the other shaft section 6a another machine end ring 8, which rotates when the shaft section 6a is rotated accordingly by the latter, but on the shaft section 6a is displaceable in its longitudinal direction. To postpone of the machine end ring 8 along the shaft section 6a is used Set screw 9, when it rotates in one direction or the other the machine end ring 8 along the shaft section 6a accordingly is moved forward or back.

As will be explained further below, the machine end ring 7 is included the end ring 3 rigidly coupled, while the machine end ring 8 with the End ring 2 is rigidly coupled. The coupling takes place via clamping rings 10 and 11, as will be explained. The clamping rings 10 and 11 exist each made up of a pair of half shells that overlap at one end Hinge are connected together and at the other end one Have clamp closure, so that when closing the respective Clamp closures, the clamping rings 10 and 11, the respective end rings 3, 7 or 2, 8 holding together.

The screen printing cylinder 1 is mounted so that it is removed with the machine end ring 8 is first placed on the shaft 6, after which the End ring 3 with the machine end ring 7 using the clamping ring 10 are interconnected. Then the machine end ring 8 pushed onto the shaft section 6a, and it will be under Using the clamping ring 11, the end rings 2 and 8 are clamped together. The set screw 9 is turned so that the machine end ring 8 removed from the machine end ring 7, in this way the between the end rings 2 and 3 lying gauze 4 in the longitudinal direction of the shaft 6 tighten.

A gear housing 12 is located on shaft 6. This gear housing 12 is fixed in space and is not when the shaft 6 rotates taken. This is described in more detail below. With the gearbox 12 is connected to a bracket 13 which extends in the longitudinal direction the shaft 6 extends and in the direction of the cylinder longitudinal axis 5 a length has, which corresponds approximately to the inner distance of the end rings 2 and 3. The Gear housing 12 is located approximately in the longitudinal direction of the shaft 6 in the middle of the screen printing cylinder 1, so that the bracket 13, the gear housing 12 in The longitudinal direction of the shaft 6 projects approximately equally far on both sides. To move the bracket 13 perpendicular to the cylinder axis 5 there are radial longitudinal slots 14 and 15 in the holder the screws 16, 17 are passed, which are firmly in a shoulder 18th are screwed in, which is firmly connected to the gear housing 12. By loosening the screws 16, 17, the bracket 13 can be radially Adjust cylinder longitudinal axis 5. Then the screws 16 and 17 tightened again.

The bracket 13 has a bearing device at each of its two free ends 19 and 20 on towards the inner wall of the screen printing cylinder 1 point. Between the bearing devices 19 and 20 is a roller 21 freely rotatably supported on their end faces. The roller 21 has one constant diameter over its length and extends in the longitudinal direction also seen practically over the entire length of the bracket 13 can be seen from that required for the storage facilities 19 and 20 Space off. The roller 21 or its longitudinal axis 22 is parallel to the cylinder longitudinal axis 5. Mispositioning can be done with the help of the above described adjustment mechanism from the elongated holes 14 and 15 and the screws 16 and 17 are balanced. The diameter of the Roller 21 is selected so that the bearing devices 19 and 20 in the direction a little overhanging the inside of the gauze 4. Through the roller 21 is thus achieved that the gauze 4 in the region of the roller 21 parallel to the longitudinal axis of the cylinder 5 is held. The roller 21 can radially so far be pressed outwards that the gauze 4 also the end rings 2 and 3 slightly overlooked in the radial direction. It is important that the gauze 4 with her patterning surface practically over the entire length of the roller 21st and thus practically parallel over the entire length of the screen printing cylinder 1 comes to rest on shaft 6 or cylinder longitudinal axis 5.

A processing station 23 is arranged opposite the roller 21. This processing station 23 is in the longitudinal direction of the cylinder longitudinal axis 5 slidably mounted and can therefore be parallel to the screen printing cylinder 1 in the area in which the gauze 4 the roller 21 is applied tangentially. Over the entire length of the roller 21 is thus an equal distance between the gauze 4 and the processing station 23 ensured. Keeping this distance constant over The length of the screen printing cylinder is important in the later printing process create perfect patterns using the screen printing cylinder 1 to be able to.

The processing station 23 is mounted on a carriage 24 which runs along is slidable by guideways 25, which on a machine bed 26 of the device are mounted. The guideways 25 run parallel to the cylinder axis 5. Guideways 25 and Machine bed 26 can best be seen in FIG.

The processing station 23 can be any suitable station act with which the gauze 4 can be sampled. For example the processing station 23 be a spray head with which a liquid Medium or a viscous medium sprayed onto the gauze 4 to Close through openings according to the pattern. With the liquid Medium can be curable ink, wax or even one act liquid metal alloy. The processing station is accordingly 23 designed. The processing station 23 can also be an optical one Station, such as one for emitting a laser beam, with which a light-sensitive layer located on the gauze 4 is exposed leaves, which is then developed to make the photosensitive Open layer according to pattern. A laser beam could also be emitted be directly with him a closure layer located on the gauze 4 to remove according to the pattern, i.e. to burn it away. Not least the processing station 23 could also have several in the longitudinal direction the cylinder longitudinal axis 5 processing areas lying one behind the other exhibit. A first processing area could be, for example on the gauze 4 lying photosensitive layer with a liquid and sample opaque medium during a second editing area the processing station 23 the patterned photosensitive Layer exposed. Further exemplary embodiments would be conceivable. It is only important that the processing or Sampling of the gauze always in Area of tangential contact between gauze 4 and roller 21 in Longitudinal direction of the roller 21 and at the same distance from the processing station 23 to the roller 21. Only in this way is a good reproduction the pattern in the later printing process.

Figure 2 shows the device according to the invention seen from the side and partly in the cut. The same elements as in Figure are the same Reference numerals and are not described again. It can be seen that the gauze 4 is only patterned where it rolls the 21st touches tangentially. In this area there is a perfect sample ensures that only there the gauze 4 is always a constant distance from Processing station 23 has. The gauze 4 is sampled in such a way that with the screen printing cylinder 1 rotating, the processing station 23rd moves in the longitudinal direction of the roller 21.

FIG. 3 shows an axial section through the screen printing cylinder 1 in the area the wave 6.

The shaft sections 6a and 6b carry over the machine end rings 7 and 8 the screen printing cylinder 1, as already mentioned. Thereby embrace the Clamping rings 10 and 11 or their respective half shells radially outwards standing approaches 3a, 7a and 2a, 8a of end ring 3 and machine end ring 7 or end ring 2 and machine end ring 8, so that in this way the screen printing cylinder 1 is held on the shaft 6. The half shells of the Clamping rings 10 and 11 can be swung out around the screen printing cylinder 1 to release. It can then be removed after removing the machine end ring 8 are deducted from the shaft section 6a from the entire shaft 6.

The shaft 6 is supported on the right side in FIG. 3 on a bearing block 27 which is firmly mounted on the machine bed 26. The machine bed 26 is in Figure 3 only indicated schematically. A firmly connected to the shaft 6 Axle shoulder 28 serves to drive the shaft 6 and is not shown Pulley firmly connected, driven by a belt becomes.

Inside the shaft section 6b is an outside of the cylinder longitudinal axis 5 mounted drive rod 29. This drive rod 29 has a fixed with it at its two opposite ends connected gear 30 or 31. When the shaft 6 rotates the drive rod 29 moves around the cylinder longitudinal axis 5 at a distance. During this movement, the gears 30, 31 mesh with each Internal toothing of a ring gear 32, 33. The ring gear 32 is fixed in the gear housing 12, while the ring gear 33rd is fixedly arranged in the bearing block 27. So the shaft 6 over the axis approach 28 rotated, the drive rod 29 rotates on the one hand Longitudinal cylinder axis 5 at a distance, while on the other hand the drive rod 29 performs an additional self-rotation because the gear 31 meshes with the internal toothing of the ring gear 33. The latter is firm arranged. Since here the gear 30 is also carried accordingly is and meshes with the internal teeth of the ring gear 32, it remains with the ring gear 32 fixedly connected gear housing 12 fixed in space, and so that the bracket 13 connected to the gear housing 12 and the with the bracket 13 connected roller 21, which is only about their Longitudinal axis 22 can rotate freely.

So shaft 6 and screen printing cylinder 1 rotate about the cylinder's longitudinal axis 5, the roller 21 remains dimensionally stable, so retains with regard to it Longitudinal axis 22 at a predetermined angular position. So the roller 21 comes when the screen printing cylinder 1 is rotated about the cylinder longitudinal axis 5 always to lie opposite the processing station 23.

Claims (11)

1. Method of producing a screen-printing cylinder (1), having the following steps:

   a) a cover (4) of the screen-printing cylinder (1) is formed only by a flexible mesh which is held by two end rings (2, 3) and is permeable to liquids or pasty compounds;

   b) the end rings (2, 3) are situated coaxially on a shaft (6) which is mounted such that it can rotate and by which they are carried along during rotation;

   c) the cover (4) is tensioned by the end rings (2, 3) being displaced away from each other;

   d) a support (21) which is situated on one side of the shaft (6) and extends at least approximately over the entire length of the screen-printing cylinder (1) presses the cover (4) from the inside into a position lying parallel to the shaft (6);

   e) during rotation of the shaft (6), the support (21) is held in a physically stable manner; and

   f) the screen-printing cylinder (1) is patterned from the outside during its rotation only in the region of this support (21) by means of a processing station (23) which is displaced parallel to the shaft (6).
2. Method according to Claim 1, characterized in that the support (21) used is a roll, whose longitudinal axis (22) is parallel to the shaft (6) .
3. Method according to Claim 1 or 2, characterized in that in order to pattern the cover (4), a covering liquid is applied directly to the latter in accordance with a pattern.
4. Method according to Claim 1 or 2, characterized in that in order to pattern the cover (4), a light-sensitive layer situated on it is exposed in accordance with a pattern, and developed.
5. Method according to Claim 4, characterized in that before being exposed, the light-sensitive layer is patterned using an opaque covering liquid.
6. Method according to Claim 1 or 2, characterized in that in order to pattern the cover (4) a layer situated on it is removed by irradiation in accordance with a pattern.
7. Method according to Claim 1, characterized in that a mesh (4) consisting of nylon, polyester or another polymer is used.
8. Apparatus for producing a screen-printing cylinder (1), comprising:

   a) machine end rings (7, 8) arranged on a rotatable shaft (6) to hold the screen-printing cylinder (1) at the ends, coaxially with respect to the shaft (6);

   b) a tensioning device (8, 9) for tensioning the screen-printing cylinder (1) in the longitudinal direction of the shaft (6);

   c) a support (21) which is situated inside and on only one side of the shaft (6) and extends at least approximately over the entire length of the screen-printing cylinder (1), which presses the cover (4) of the screen-printing cylinder (1) into a position lying parallel to the shaft (6),

   d) the support (21) being seated on the shaft (6) via a mechanism (29, 30, 32) which holds it in a physically stable manner during rotation of the shaft (6); and

   e) a processing station (23) for patterning the screen-printing cylinder (1) from the outside, which is positioned opposite the support (21) and can be displaced parallel to the shaft (6).
9. Apparatus according to Claim 8, characterized in that the support (21) is a roll that can rotate about its longitudinal axis.
10. Apparatus according to one of Claims 8, 9, characterized in that the processing station (23) has a spray head for spraying out liquids or viscous media.
11. Apparatus according to one of Claims 8, 9, characterized in that the processing station (23) has an exposure head or irradiation head.

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