DE2012649B2 - SLEEVE USED AS A COVER FOR PAINT APPLICATION ROLLERS AND METHOD FOR PULLING THE SLEEVE ON - Google Patents

Description

3 4

Use point on a mandrel that is always used is provided with means for evacuation, one of which is a flange held at both ends closed air space between the outer wall (U.S. Patent 2,814,855). This especially one of the sleeve and the inner wall of the cylindrical Directional rolls are generally more expensive, and the shape is created to operate with trapped air is evacuated with no facilities for renewal 5 space is evacuated, whereby the sleeve expands of rollers provided that will not be this particular until the inside diameter of the sleeve is greater than Have construction. the outside diameter of the print roller onto which the

The sleeves of the type described consisted of sleeve is drawn that the sleeve in the extensively elastic Rubber (US Pat. No. 1,926,312), th state is drawn onto the pressure roller made of vulcanized rubber (USA.-Paientschrift i ° and that the vacuum is released, after which the 3 184 355) and made of a polyester resin (USA. Patent Specification 3,090,106). The invention will now be described in detail.

From the German Auslegeschrift 1 071 950 and ben. In the drawing is

of British Patent 803 160 are method F i g. 1 a partially drawn as a section

become known, with which curable liquid 15 side view of a pressure roller according to the invention,

Masses are poured onto a carrier and which shows the arrangement of the components of the roller,

thus form a printing or inking roller. F i g. 2 is a cross-sectional view showing the sleeve in

A renewal of the paint application surface in which a cylindrical shape is enclosed in front shows

known rollers would cut off the F i g. 3 is a longitudinal section through a sleeve, which the

cast roller body from the axis and one ²⁰ ends of a cylindrical shape for sealing

subsequent re-casting of the roller body overlaps, and

require. A replacement of the paint application surface F i g. 4 is a longitudinal section showing the effects of

according to the present invention only requires the vacuum expanded sleeve with a sleeve therein

shows a removal of the used sleeve and an inserted pressure roller.

pulling a new core after the Inventions ² 5 As shown in the F i g. 1 can be seen, has the printing process. wal / c an axial shaft 1 with a widened

The laid-open specification 1471 715 describes a cylindrical part 2 in the middle, which has a rubber coating for a dampening roller in Fo; m a coating with a paint application surface. To Sleeve made of a certain hydrophilic, wear and tear on this layer, the sleeve 3 is nonwoven Material is made. This sleeve pulled 3 °.

is mechanically widened when wet and the F i g. 2 to 4 show the different Verim expanded state dried, after which they move steps when pulling the sleeve onto the only then again on its original through-roller with Ve -wandung a cylindrical shape. knife contracts when re-moistened. According to the illustration in FIG. 2 will the will. As a result, the sleeve in the expanded sleeve 3 can be inserted into a cylindrical shape 4 which, without the use of additional devices, is fitted with a tube attachment 5 for evacuation, can be drawn onto a roller body. After that is. The diameter of the pressure roller 2 is larger, the sleeve is shrunk on by simply moistening it in a relaxed manner than the diameter of the sleeve 3. This briefly indicated process state, as shown in FIG. 2 shown,
cannot be used with resilient materials such as polyurethane 40. According to FIG. 3, the ends of the sleeve 3 are used, which would not remain in the stretched state at 6 around the ends of the cylindrical form 4, but immediately put in a tensioned state, whereby an air space 7 is closed, the loose state returns when there is no more force which acts connected to the pipe socket 5 with the help of a. NEN suction pump is evacuated.

The object of the invention is therefore to provide an improved, 45 FIG. 4 shows the sleeve 3 after evacuation, serving as a cover for inking rollers sleeve which now has a clear width that the and a method for pulling up the sleeve in front of the circumference of the pressure roller 2 exceeds. The outside watch side of the pressure roller 2 is exactly cylindrical -

According to the invention, the object is achieved by grinding. The pressure roller is then pushed into the expandaß the sleeve in the unpulled state a 50 dierte sleeve 3. After the lifting has an inner diameter that is at least 10% smaller than the vacuum looking for the sleeve in the relaxed than the diameter of the pressure roller, the condition will return and attach itself to the outside of the roller with a solid sleeve made of a hardened, with a filler sit / whose through-missed, plasticized polyurethane elastomer knife is greater than the inside diameter of the sleeve in which is completely relaxed when a pressure of 55 is applied. The overlap about 0.984 at a radial elongation of 10 to 35% on 6 (Fig. 3) is then removed and the cylinder having a tear strength of at least 8.8 kg / drum 4 is peeled from the roller.
cm ² (according to ASTM D 624-54-Die C) and a holding The ends of the sleeve 9 extend beyond the tensile force of at least 7.0 kg / cm ² (according to ASTM ends of the pressure roller 2 (Fig. 1 ), so that D 624-54-Die C), a tensile strength of 140 kg / cm ² 6o, no dye can collect on these edges (according to ASTM D 624-54-Die C), a compression that can occur in the space between the sleeve availability of less than 25% (according to ASTM D 395- and the roller body could penetrate. A 61-Lt) and a tensile strength of at least such a pressure roller is therefore also easier to 400% (according to ASTM D 624-54-Die C ) Has. clean.

The invention also provides a method for producing the sleeve according to the invention A grindable solid polyurethane gas is used to pull printing sleeves onto the roller body characterized in that the sleeve is thoroughly broken in elastomer and in a rubber band cylindrical shape is included, with mill or similar device with a

Plasticizer and a curing agent between these two diameters is so mixed, after which the mixture becomes a material- better the seat of the sleeve on the roller, as long as web is rolled out. Depending on when the sleeve can be expanded radially so far, The properties desired by the sleeve can mean that the roller can be used. This expansion is allowed mix fillers, thinners, pigments, cat- 5 of course only as far as it is carried out lysers and modifiers to stiffen the strength of the sleeve. With this wind-up reinforcement, To increase the abrasion resistance, care must of course be taken and added to tensile strength. By on the one hand a firm seat of the sleeve on the roller winding this web of material on a metal mandrel and, on the other hand, the physical strength a hollow cylinder is then made and thereafter the sleeve is maintained. In general cured under pressure which can expand from 10 to about 35% and Outside with the help of a hardening fabric tape, preferably from 15 to 30%, and by heating from the inside by means of steam, The rollers of lithographic offset presses those passed through the hollow metal mandrel have diameters from about 3.8 to more than will, or the entire arrangement will be in a 15 10 cm on and lengths of the rubber surface of less Autoclave heated until a complete extension than 25 to more than 200 cm. With other pressure hardening is reached. procedures can exceed these limit values

After curing, the will be carried by the mandrel. In the diameter range from 5 to 9 cm

Rubber sleeve ground to an exact cylindrical shape. After that, the sleeve has a thickness of approximately 0.125 cm

the sleeve is turned inside out, so that its inner 20 has proven to be suitable. It can of course

unprocessed side can be used for the new paint application surface for other thickness dimensions. However

becomes a pressure roller. are the requirements for the strength of the

The drawing up of this height on the pressure roller sleeve, the greater the thinner the sleeve wall

is carried out in such a way that it is in a cylinder. The upper limit for the thickness is thereby

drical form is used, which is fixed with a tube 25 that the sleeve according to the invention

approach or some other means is no longer expandable with appropriate processes in a vacuum.

that an evacuation can be carried out. can be dated. The minimum thickness of the sleeve

This cylindrical shape must be designed so strong must be dimensioned so that this together with

that they do not have a tear strength when evacuating the material composition

is pressed. Everting the sleeve ends 30 results in greater than about 8.8 kg / cm ^2. These

over the ends of the cylindrical form a desired thickness is of course depending on the one used

closed air space between the inner walls of the polymer differently and depending on the particular

formation of the cylindrical shape and the outer wall, their conditions during printing and the

created the sleeve. The cylindrical shape is under which the sleeve is made,

of course shorter than the rubber sleeve, so that its 35 .mu.m a sufficiently strong fit of the sleeve

Ends can be turned inside out. on the roller, the sleeve should have a minimum

To create this closed air space tension of approximately 5.3 kg / cm ² in the sleeve

there are of course other options. Have on yourself and this longer on the reel

one end of the cylindrical shape could retain time. The sleeve must also have a certain

Overlap processes are applied while having 4 "degrees of toughness in order to keep them in use

at the other end of the mold a cap is used on the press and not at some overload

will. The cap is torn in the middle with an opening. The sleeve drawn onto the roller must

provided, through which the sleeve in the friction fit with smooth, abrasion-resistant and resistant to ozone

the inner edge of the opening extends therethrough. and a suitable adhesion to the upper

The closed air space will then have an area of less than 45.

Use of a vacuum pump or another The holding tensile force is evacuated according to the 25% modulus device, which is determined via a pipeline, which is a measure of the stress with the pipe attachment on the wall of the cylindrical 25% expansion. At most operational thresher form it is related. During the evacuation conditions on the printing presses and for the ver ization, the sleeve expands radially and has 50 turned printing inks, a tensile strength of a greater clear width. Evacuation is desired to be at least 7.0 kg / cm ^2. The upright continues until the clearance is greater than the retention of the holding force is related to the circumference of the pressure roller on which the sleeve has been drawn, compression or tension achieved after curing. At the final com-

Before pulling on the sleeve, the pressure roller should be 55 pression, a value of less than 25% is desired,

be ground exactly cylindrical. The pressure of the ASTM-D 395-61 test method B be

The roller is then inserted into the expanded sleeve, a 22-hour treatment at a temperature

pushed, and the atmospheric air is determined in the of 70 ° C. The toughness is a grain

closed evacuated air space again combined from tensile strength, elongation unc

calmly. The sleeve returns to the relaxed 60 of the tear strength. The sleeve should preferably eim

State back and lies close to the outside tensile strength of at least 140 kg / cm ² , a stretch

the roller on. Because the diameter of the roller is greater tensile strength of at least 400% and a tear

is than the inner diameter of the relaxed sleeve, strength of at least 8.8 kg / cm ² and preference

a fixed friction coefficient of 10.5 kg / cm ² according to ASTM D 624-54-Die (

seat made with the roller. Show in a relaxed atmosphere. When the tear strength is the wet

If the sleeve was to have an inner diameter of at least 8.8 kg / cm ² , this would create difficulties

at least 10% and preferably 15% smaller speeds. The fluctuations in tear strength depend

than the roll diameter. The greater the difference from the particular polymer chosen and de

7 8

special conditions of use. There is a glass-paper made to cool; however, it can also

like smooth exterior desired to be used or the possible a removable surface

Difficulties in transferring the printing ink.

as a result of uneven contact with the be hung.

Avoid printing plates or other rollers. 5 The sleeve is then placed on the hardening mandrel. The smoothness of the hardened mixture can be deformed to resemble a 48 cm long steel tube by expanding a thin test piece that is polished and has an outer diameter in the area of use of the sleeve (15 to from 4.699 cm. A 36 cm long 20 ° / o)> with any knot formation or wavy rubber sheet being cut to size and determined in two layers, which is shown on the surface. io with a small excess on the mandrel - a knot or curl is often - wound. A 0.005 cm thick corn is found on the rubber with reinforced and oil-resistant polyester film, in order not to protect the curing material, polymers such as chloroprene or nitrile, however, and to avoid sticking or an indentation of the curing tape according to the invention, which can be milled. Urethane. 15 The whole thing is wrapped in a spiral-like manner with a 2.4 m long hardening tape consisting of nylon in the following examples under tension over the production of the sleeves and their performance. The hardening takes place in given. The test data cited in the above description of an autoclave within 30 minutes for one were obtained at a vapor pressure of 4.4 kg / cm ² . After curing temperature of 20 ⁰ C and a relative Luftfcuch- 20 is cooled by the fact that through the mandrel Kühltigkeit of 50 ° / _n, unless otherwise specified. water is piped. After cooling down, this will be. I _{removed 1} tape and the polyester film. The exposed β e 15 ρ 1 e surface of the rubber sleeve is then exactly cylindrical. Sleeves for pressure rollers were made from the following materials with an outer diameter of 0.254 cm plus: ground to the outer diameter of the mandrel. To ..... " , . For this purpose, the mandrel is clamped in a lathe. Polyurethane that can be milled, using a conventional motor-driven grinding _{machine attached to the rotary elastomer 100.0 bench.}

Stean acid. 0.2 facility is used.

Halbverstarkender carbon black 25.0 _{3o Bey of phvsika} i n _ical examination of this gum

Calcified aluminum silicate 40.0 _{the following} values were obtained:

Tricresyl phosphate 13.0

Dicumyl peroxide (40% active) 7.5 Final tensile strength: 2430 kg / cm ²

The mixture was produced by means of final elongation 625% ^

a laboratory rubber mill with the dimensions 35 ". ^{/ o} , °; \, "'f. ^K8 ' ^c ! "

sungen 15 x 30 cm, which with internal water cooling » ^a " ^e (Durorneter) 60 Shore A

was equipped. The polyurethane elastomer was tear strength Il · ^ ¹ ™ '

through the gap with an opening of about Continuous compression on ... 14.75%
0.25 cm passed through without the polymer. The sleeve is turned inside out and after vacuum kneading. The gum was then left on a roller 40 for expansion onto an inking roller, and the opening was drawn onto a minimum of a Davidson printing press. The roller band with a diameter of 0.6 to 1.3 cm has an outside diameter of 5.634 cm, set. Stearic acid was added into the gap so that there is a difference of 0.935 cm between the diameters of the mandrel and and dispersed by alternately cutting off the roller, so the material from both sides. Thereafter, "the sleeve has an expansion of 19.9% compared to the gap of the calcareous clay slowly added to the molded dimensions,
and then about half of the plasticizer. The expansion device consists of a 31cm medium. After a good, even dispersion of long copper pipe with an inner diameter of, the tape is cut again from 6.4 cm and alternately cut from both sides with a hose soldered on the outside, 50 fitting for connection to a vacuum pump,
The sleeve is pushed into the tube and an even mixing within the ends of the strip is achieved at the ends of the tube. Then it is turned over, whereby a closed air space is slowly added carbon black and then the rest between the inner wall of the pipe and the part of the plasticizer, after which the outside of the sleeve is created. This mixing process described after addition of the clay, closed air space is evacuated up to 71 cm QS, is fetched. After having carried out a uniform mixture, the sleeve is expanded enough so that the hardening agent is added so that the pressure roller can be inserted into it, and mixed by cutting. The entire previously, however, the outside of the roller charge is then cut off 60 from the roller and ground cylindrically. After inserting and rolled up into a solid roll. The vacuum is released on this roller, the roller is then guided vertically through the gap, the sleeve shrinks again and is milled in order to achieve a good dispersion with certainty. a tight fit on the roller. The overlapping opening is then adjusted in such a way that a tape end of the sleeve is then rewritten with a thickness of 0.088 to 0.1 cm. Beat the material and cut it off so far that a small overhang remains on the material after it has left the processing device.
cut to a single sheet of material. The roller provided with the coating was then used on a silicone-coated press in a Davidson press, whereby dii

9 10

appropriate settings to compensate for the method described were made without difficulty on a larger diameter. Be drawn here. After mounting on the roller, pressure tests were carried out with various pa- showed the sleeve a very granular, knotty type of upper pier, whereby it was determined that the area with which no pressure in permissible quality could be achieved with the pressure roller 5 according to the invention,
at least equal to the roller with the original one

Surface was. A cleaning can essentially Example III

can be carried out more easily than with rollers with the 7-chlorobutadiene-l 3 100

conventional sanded outside. According to Magnesia '2

6 months of intermittent use with various Vaseline 2

the operating conditions showed no ver Zinc oxide 5

Pushing the sleeve on the roller. 2-Mercapto-f hiazoHn ". '.'. '.'. '.'. '.'. '.'. Υ. 0.5

The suitability of kneadable polyurethanes for calcined kaolin clay 45

Sleeves that can serve as a printing surface, i.e., semi-reinforcing carbon black 30

the sleeve can accept printing inks and with 15 di-butoxide-ethyl-sebacate 20

transferred with sufficient fidelity and remains in use

stationary on the roller, is in contrast to others.

elastomeric materials as made from the below mentioned procedures.

Examples 2 and 3 can be seen. When physically checking this rubber

20 the following values were obtained: Example II

Final tensile strength .... 95.5 kg / cm ²

Acrylonitrile-butadiene copolymer .. 100 Final elongation 330%

Zinc oxide 5.0 25% modulus 7.88 kg / cm ²

Stearic acid 1.5 hardness (durometer) 58 Shore A

Semi-Reinforcing Carbon Black 65 ²⁵ Continuous Compression 13.36%

Di-butoxide-ethyl-sebacate 15 tensile strength - C The 8.99 kg / cm ²

Para-Coumarone Resin 5 The mandrel used to make this sleeve

c wee, _{w there is an} outer diameter of 4.496cm,

Bentoth.azole disulfide 1,5 ^ ^^ _{the Wa] ze an} outside diameter of

The sleeve was measured as described in Example I 5.118 cm, so that the difference 0.622 cm

benign process. resulting in a 13.8% expansion of the sleeve

Led in the physical review of this rubber.

the following results were obtained: When using this sleeve as a forming roller

35 reference in an offset duplicating machine

Final tensile strength .... 130 ke / cm- _{dje h} , _se ;, j _ner half of 30 minutes of operating time than

Final elongation 400% _{due to the} stickiness of the outside of the sleeve

25% module, 8.8 kg / cm _roller, drifted off. With a subsequent upper hardness (durometer) 62 Shore A surface treatment of the sleeve, this tendency became apparent

Tensile strength - C 13.8 kg / cm ² _{4O verrn} i _n changed; however, a surface was created

Continuous compression .... 6.44% _{lacking the} desired properties, the

The sleeve produced was excellent in contact with the polished surface

Tear strength and could be produced according to the example I of the cathedral.

1 sheet of drawings

Claims (4)

Coating or wrapping, which covering is then vulcanized to patent claims: the point of use. Over time, this coating wears out and must either be replaced 1. Serving as a coating for inking rollers are used together with the roller, or the paint sleeve, characterized in that 5 application surface must be renewed, generally the sleeve in the unopened state by grinding. This grinding can only have an inner diameter which is at least 10% smaller once or twice, although is than the diameter of the pressure roller, whereby it is more economical than an etching in such cases, the sleeve from a hardened, with a nonetheless the The printing press must be put into operation for some time out of the plasticized polyurethane filled with filler. If the covering is not made of thanelastomer, which can be further abraded with the action, a pressure of about 0.984 at must have a radial pressure area, generally outside of operation, elongation of 10 to 35%, which replaces a tear . However, this requires an even higher strength of at least 8.8 kg / cm ² (according to ASTM costs and longer downtimes of the Druck-D 624-54-Die C) and a holding force of 15 machine than when grinding the rollers. For at least 7.0 kg / cm ² (according to ASTM D 624-54- renewal of this pressure area there are other die C), a tensile strength of 140 kg / cm ² (according to possibilities, which are generally unsuitable ASTM D 624-54- The C), a compression or too expensive to have practical value, availability of less than 25% (according to ASTM D 395- Besides natural rubber, 61-B have been used for several years) and a tensile strength of at least 20 for pressure roller bodies polyurethanes (Domestic 400% (according to ASTM D 624-54-Die C). Printers / American Lithographer, December 1966, 2. Sleeve according to claim 1, characterized in that p. 56 to 57, George Brawata, »Care and Main Drawings, that they mainly come from a tenance of offset press rollers "); however passed Polyurethane elastomer and, to a lesser extent, these materials from liquid cast polymers. the consists of fillers and plasticizers. 25 high adhesion achieved with these rollers is suitable 3. Sleeve according to claim 1, characterized in that it is used for letterpress printing with printing inks indicates that it consists essentially of lower adhesiveness. The clubs thermoset product from a turn of these rollers in lithographic printing Mixing 100 parts by weight of a pulverized one was unsuccessful, however, since it produced in the inking unit capable polyurethane elastomer, 7.2 Ge 30 heat to dry out the printing ink on the rollers parts by weight dicumyl peroxide, 0.2 parts by weight sought. Because of the high abrasion resistance of this Stearic acid, 25 parts by weight of semi-reinforcing materials, the surfaces are difficult to abrade. Carbon black, 40 parts by weight of calcined aluminum. Polyurethane roller bodies also exist miniumsilikates and 13 parts by weight tricresyl- the risk that the polymer liquefies, which phosphate. 35 There is less danger with abrasive polyurethanes 4. Method of mounting an elastomer is great. Sleeve on a pressure roller body, thereby around the grinding and renewal characterized in that the sleeve in a cylindrical of the pressure surfaces occurring difficulties Form used with a means of avoiding removable sleeves have been suggested. Evacuation is equipped, and between the 40. Before the invention, such sleeves had only one Outside of the sleeve and the inside of the limited success, mainly because of the labor-cylindrical Form an enclosed air space seed procedure that occurs when pulling up the pod is created, which is evacuated, which had to be applied to the roller body, Sleeve expands until the inside diameter and perhaps also because of the great difficulty the sleeve is larger than the diameter of the 45 the lateral position of the sleeve on the roller body Pressure roller on which the sleeve is drawn to maintain when in use lateral absoll, that shear forces occur when the pressure roller is pushed into the sleeve. To eliminate this becomes difficult and numerous attempts have been made to break the vacuum; whereby the sleeve rests against the pressure roller. however, the result was by no means complete 50 satisfactory. An older attempt was made to be elastic Rubber sleeve pulled onto a roller, the outside of which was sanded off again so that this The invention relates to a coating for dyeing was uniform (US Pat. No. 1,926,312). These sleeve used for application rollers and a method 55 roller was provided with tapered ends, for pulling the sleeve onto the roller body. thereby preventing longitudinal movement of the sleeve This sleeve is preferably made of solid, should be. In practice, however, it has been shown generally in the form of sheets or strips that this type of sleeve because of slipping in available polyurethane that was unsuitable in a lengthwise rubber grinder. Werk or a similar grinder crushed 60 rubber sleeves have been put together with some success can graze. This material is different from that used with special rollers. One of those rollers a liquid cast polymer, which as a liquid wedge had a rubber body, which is in a vacuum can be related and in the case of viscous liquid contracted radially, so that the sleeve on the roller is handled in the usual way. could be postponed and later The conventional inking or pressure roller 65 extension with which the roller was firmly seated consists of a shaft with a cylindrical wire and rope was no longer movable. At a Extension in the middle that is made with a rubbery other construction becomes a special roller 1-work surface covering is used, for example, by using a learning sleeve that is attached to the