DE742083C - Method and device for monitoring the etching process when producing etched rotogravure or embossing rollers (molettes) - Google Patents

Description

Method and device for monitoring the etching process during manufacture Etched intaglio printing or embossing rollers (motets) The invention relates to the Manufacture of. etched 'intaglio printing or embossing rollers (motets) and aims the continuous monitoring of the etching process, such that the detection and monitoring the amount and uniformity of what can be expected from an etched copper rotogravure roller Ink application is enabled before printing.

It is known that the surfaces to be etched according to the pattern on the rollers divided by bars. These bridges are called hashurs. The number of hashurs to the centimeter can vary between about io to 5o. the less hashurs one uses, the deeper the etching can be held - and the greater it is the outline of the printed area, and the greater the number of hashurs, the more so the etched area will be flatter and the finer. the contours. The number the hashour is given before the production of the pattern and depends on it the type of material to be printed, the manufacturing process to be used for the printing form and also according to the form of the individual samples. The manufacture of the Motets as well as the etchings of the rollers after the pantograph process was so far only in the emotional assessment of the caustic. Depending on the type of copper used, the temperature and concentration of the etching solution and taking other factors into account, the etching occurred to a greater or lesser extent quickly, and it came that way using the same number of hashurs the most diverse end effects. out. The case was similar with the manufacture of the motet, w o e it to the worker was left to his tools and his personal understanding of shaping the form and depth of the individual hashour. Even if the ratios were apparently the same, the fluctuations were in the Rolling considerably. The paint application fluctuated in part at a desired value up to ioo% and up to. 500; o down. Except for the big difference In terms of color consumption, there was a risk of insufficient color, especially with surface samples Covering or excessive accumulation of paint on the surface of the fabric, which then caused accumulation of the color and thus irregular printing. It had to so in very many cases the rolls that have already been manufactured are reworked, without. that in this way one would have achieved something other than the eradication too much gross mistake.

As: the only test method for the shape and depth of the hashurs So far, a pure depth measurement was used in the manufacture of etched rollers, which, however, cannot adequately fulfill its purpose because of the amount of the to be raised The color does not depend primarily on the depth of the etching, but on the shape of the hashur cross-section, which one had not grasped in the previous way. Also those in other branches Test methods of a similar type known to the technology could serve the purposes the invention cannot be made directly serviceable.

In order to remedy this deficiency, it is proposed according to the invention, to the L`t> er, wake up the etching process when producing etched gravure or embossing rollers (Moletten ') to interrupt the etching from time to time, from suitable points of the -, - etched roller surface by means of an image hardening mass an impression to take a cross-section through this and a photographic one from it Produce enlargement, which with one the optimal cross-sonality form for the respective intended purpose is compared.

This makes it possible to capture the hashur cross sections and them set enlarged in the picture, and can then determine through experience. Which To address the shape of the hashur cross-section as the best for the respective desired purpose is. On this basis one can then use the form and Determine the depth of hash for each item beforehand.

In the case of the etching process, a fast one interposed in the etching process is possible Examination of the form of the hash, the determination of whether and to what extent the positive effect has already been reached. It is then necessary to carry out the etching process in several stages to be carried out, but this relatively small amount of work is still going on out of proportion to. the advantage achieved, the etching of the roller also the shape to give, di ° both according to the amount of color to be applied and according to the Uniformity of the print application for the respective: pattern represents an optimum.

Although it is known per se, it is used to test surface structure Impression method to apply, taking from the surface of the object under examination an imprint by means of a pictorial. Mass made and a section of the pressure body miki-oskopiseb is examined.

It is also used in conjunction with screws or threads and track flanks finit \ orinalprofile become known. the test object in the projection image with the Compare image of a normal form.

But in contrast, is home inventive subject matter a fundamentally new task before that is in the manufacturing position of etched Ku @ horse smoothly rolling schedule appropriate means to apply to the etch # irbeit arising @ .- rKupfcrdruck "- <ilzeii planned to monitor and manage , ind:; # m it is interrupted in suitable sections by including a follow-up test.

Also keeping models ready for comparison "with the ones won _ltzbildern, so the previous statement opt: mal: r cross-sectional shapes for the the purpose pursued in each case has not become known in copperplate printing.

The device for carrying out this process comprises, in addition to equipment of the general kind. like Formrahin (-ii and a projection apparatus, even more special Facilities that ensure that the required impressions of parts can be properly taken the copper pressure roller or the b2ün Mole ttierverfhnen used Molette to back up.

In the first case one uses vorztigswc isc. to take the prints a mold frame open at the bottom with a Prussst that can be moved vertically against spring pressure: empel, on which a two-armed lever for pressing down the Prel ':) stamp is articulated is that by pressing down a di ° pressure roller ° encircling retaining strap, its Ends on the one hand attached to the mold frame, on the other hand detachable and adjustable on the lever are tensioned at the same time. This facility ensures perfect fixing of the mold frame on the curved surface of the rollers and the sharp pressure of the mold frame to the roller while taking the impression given the Smallness of the etchings to be printed is absolutely necessary. Likewise made possible di ° s ° facility with little effort to take the device of the footprints to adapt to any roller diameter.

A similar device is used to take the impressions of the motet in the Molett? .er process. Here, an @open Mold frame. .the stamp compressing the impression material on one leg of his Articulated pliers, the other leg of which engages around the molette as an abutment. Through this evasion of the motet during the printing is definitely avoided.

The practical implementation of the method can be readily seen from the drawing. Shown in a schematic view: Figure i an etched platen with attached @offenem flask, Fig.2 cast the bitter presented from or imprint the body as well as-laid by him.. Section, Fig.3 the projection device used from the side and from the front, with the image of the section appearing enlarged on the projection surface, Fig. Q. the device for holding the push-off device on a copper pressure roller, Fig.5 a similar device for molettes.

When performing the procedure, the top and bottom will be open Formralunmen i, the lower surface of which is adapted to the curvature of the pressure roller 2, astride placed on the point of the roller to be pressed. The molding compound 3 is pressed in upwards or poured. The result is the shaped piece shown in Fig. 2 on the left, Make a flat cut from the one shown in Fig. 2 on the right by cutting or sawing and filing 4 is made with sharp edges. At 5- are the wells to be tested or hashurs can be seen. The section produced q. is now shown in Figure 3 in. the projection device 6 clamped in such a way that on the matt screen: be 7 the Enlarged image of the hashur to be tested 5 appears.

This picture can now be further developed with the examples given by bean Compare in order to then carry out improvements to the Haschurenfo @ rm. Is the has reached the optimum condition of the hashurs, one can take a photograph of the image appearing on the screen of the projection apparatus create that can be kept ready for future use.

The device according to Fig. Q., Which is mainly used for taking the impressions using soft metal as the impression compound consists of the one already described Form frame i, in which a Preßstempe18 is used, which is down against spring pressure can be pressed and thereby compresses the molding compound in the mold frame and presses into the unevenness of the lower abdomen. Used to operate the press ram a two-armed lever 9 which is articulated to an arm io of the mold frame i. By When the lever 9 is depressed, the ram: 8 is moved downwards.

To now the structure described above on the outer surface of the pressure roller to hold, is a retaining strap, preferably a steel strap i i, one of which End on the one; n side of the mold frame i is attached and that when the Form frame is pulled onto the roller under this. The other end will by means of the clamping device 12 on the lever arm protruding beyond the articulation point the. two-armed lever 9 clamped. Press the lever to take the impression 9 downwards, it increases the tension of the steel belt i i at the same time, whereby ie Form is pressed down more and more firmly on the roll shell.

A similar device for taking impressions of the motet is shown in FIG. Here the in the mold frame i against the spring pressure movable up and down press ram 8 is hinged to one leg 14 of a pincer-shaped structure, the other leg 1 5 from below. M! Olette grasps. Here, it is advisable to make it angled to prevent the molette from deviating.

It goes without saying that the new process also applies analogously to production such etched rollers are applicable that are not directly intended for the application of paint are, but are also provided with an etching, for example embossed rollers.

Claims (3)

PATENT CLAIMS: i. A method for monitoring the etching process when producing etched gravure or embossing rollers (molettes), characterized in that the etching is interrupted from time to time, an impression is taken of suitable points on the etched roller surface by means of a malleable hardening compound, a cross-section is made and a photographic enlargement is produced by him, which is faded with a model having the optimal cross-sectional shape for the respective intended purpose. 2. Apparatus for carrying out the method according to claim i for gravure rollers, characterized in that a mold frame (1) open at the bottom with a press ram (8) which is vertically displaceable against spring pressure and on which a two-armed lever (9) is used to take the impressions ) to the N: ederrückeii des Prel.) st ° mpels (8) is articulated so that a dic pressure roller (2) spanning retaining strap (1 1 j, whose end is on the one hand on the mold frame (1 ) , on the other hand releasable and adjustable on the lever (12 are attached, is tensioned at the same time. 3. Device for implementation of the method according to claim 1 for embossing rollers (halets @, characterized. that the impression material compressing stamp (S ') on one leg 1.i) one Pliers is articulated, the other leg (15) of which the embossing roller 12 ') as an abutment encompasses. To distinguish the subject of the registration from the state of the art The following publications were considered in the granting procedure: American Patent No. 1,703933; Schmaltz, Technische Obertläch @ nkunde, 1936 # p.71, para. z.