EP1208996A2 - Apparatus for the production of sleeve type printing blankets - Google Patents

Abstract

The apparatus with a carrier sleeve transport unit (11), for producing a sleeve shaped printing cloth, comprises at least one continuous strip casting unit (20) for applying a flowable material which forms a layer (34, 42, 45) on the carrier sleeve. Also claimed is a resultant sleeve shaped printing cloth.

Description

The present invention relates to a device for producing a sleeve-shaped Printing blanket according to the preamble of claim 1.

The present invention further relates to a method for producing a sleeve-shaped printing blanket according to the preamble of claim 14 and a method for producing a printing blanket according to claim 30.

Furthermore, the present invention relates to a sleeve-shaped printing blanket for the Offset printing according to the preamble of claim 23 and according to the preamble of Claim 32.

A web offset printing press typically includes a plate cylinder, one Blanket cylinder and an impression cylinder, which are stored for rotation in the machine are. The plate cylinder carries a pressure plate with an inelastic surface, which defines an image to be printed. The blanket cylinder carries a printing blanket with a elastic surface, which the pressure plate at a gap between the Plate cylinder and the blanket cylinder touched. A web to be printed moves through a gap between the blanket cylinder and the impression cylinder. On the Paint is applied to the surface of the printing plate on the plate cylinder. A colored one Image is from the printing blanket at the gap between the blanket cylinder and the Plate cylinder and is picked up by the blanket between the Transfer blanket cylinder and impression cylinder to the web. The impression cylinder can be another blanket cylinder for printing on the opposite side of the web.

A conventional printing blanket is produced as a flat cover. A blanket this Art is attached to a blanket cylinder by placing the coating around the Blanket cylinder wrapped and the opposite ends of the coating on Blanket cylinder in an axially extending channel in the blanket cylinder be attached. The adjacent opposite ends of the coating define a channel that extends axially along the blanket. The channel moves each time the blanket cylinder is rotated through the gap between the Blanket cylinder and the plate cylinder and also through the gap between the Blanket cylinder and the impression cylinder.

When the leading and trailing edges of the channel run through the blanket Gap will move between the blanket cylinder and an adjacent cylinder Pressure between the blanket cylinder and the adjacent cylinder built up. One speaks here of a "channel blow". The repeated dismantling and The build-up of pressure on the channel causes vibration and shock loads in the Cylinders and throughout the printing press. This vibration and shock loads have an adverse impact on print quality. For example, to that Time when the channel pressure at the gap between the blanket cylinder and the Plate cylinder builds up or builds up through the gap between the Blanket cylinder and the printing cylinder moving web are printed. each Movement of the blanket cylinder or the blanket, which at this time by the reduction or build-up of pressure can cause smearing of the Guide image that is transferred from the printing blanket to the web. Likewise, if there is the channel in the blanket through the gap between the blanket cylinder and the Printing cylinder moves, an image that is just at the other gap through the blanket of the Pressure plate is picked up, smeared. The result of through the channel Vibration and shock loads caused in the printing blanket are undesirable low speed limit when printing presses with acceptable Print quality can be operated.

In order to eliminate these disadvantages in conventional flat film printing blankets, canal, sleeve-shaped blankets by the assignee of the present invention developed. These channelless, sleeve-shaped printing blankets are, for example, in the US 5,768,990, US 5,553,541, US 5,440,981, US 5,429,048, US 5,323,702 and US 5,304,267 described.

US 5,304,267 deals with a method for producing a channelless, sleeve-shaped blanket. This patent describes a preferred method for Production of a channelless, sleeve-shaped printing blanket described as "coating a compressible thread with a mixture of rubber solution and microspheres and Wrap the coated thread in a helix around the cylindrical sleeve " to form a compressible layer, "coating an inextensible thread with a Rubber solution containing no microspheres and wrapping the coated thread in a helix around the compressible layer underneath ", to a to form an inextensible layer, and "wrapping an unvulcanized elastomer over it the inextensible layer and its fastening with tape "and vulcanizing" the wound structure ... thus the superimposed layers of elastomeric material take the form of a continuous, seamless sleeve ". There will be more Manufacturing process described, including the manufacture of a canalless, sleeve-shaped printing blanket with an inextensible underlayer counts, which comprises a continuous piece of plastic film which spirals through the elastomeric material of an inextensible layer and around a compressible layer extends. The plastic film preferably has a width which is approximately the length of the sleeve-shaped blanket, and a thickness of only 0.00254 cm (0.001 Inches) so that the narrow hem that is defined by the 0.00254 cm (0.001 inch) wide edge of the top layer of it the smooth, continuous cylindrical contour one above lying print layer does not interrupt.

DE 197 20 549 A1 describes a method for producing a cylinder carrier by winding a continuous strip on the surface of a carrier mandrel. The Strip is unwound from a spool attached so that it can rotate so that the winding angle of the strip can adjust itself. The Strip tension is maintained during the winding process. A Pretreatment and coating of the strip with an adhesive takes place between the Unwind and wind up the strip. The pre-treatment stations are at one Attached wall that is installed so that it is in relation to the Cylinder surface can rotate. The cylindrical carrier sleeve comes with an integrated Layer of plastic material coated. The carrier sleeve is called a solid sleeve Length shown.

The methods described above for the production of channelless, sleeve-shaped printing blankets have the disadvantage that they have blankets in series (i.e. only one at a time) with one Establish a fixed axial length. Series production increases production costs and the production times and leads to series-related differences in the produced printing blankets occur.

The US 6,257,140 describes channelless, sleeve-shaped printing blankets, which are in flow production can be produced and cut to the desired length. Sleeve and printing layer are formed "continuously" by the sleeve-forming station continuing one to form additional section of the sleeve while the printing layer forming station is on the previously formed section of the sleeve applies the printing layer. For application different layers, winding tapes or crosshead extruders are used.

The invention is accordingly based on the object, a channelless, sleeve-shaped To create printing blanket. The printing blanket can have different layers.

This object is achieved according to the invention by the features of claims 1, 14, 23, 30 and 32 solved. Further features are contained in the subclaims.

The present invention provides a method for casting materials Production of tapes ready to form different layers of a sleeve To form printing blanket. "Belt casting process" or "belt casting device" as here defined, can mean a liquid material from a stationary source on a rotating and moving substrate is applied, or that a Liquid from a rotating source onto a moving substrate is applied. In this way, a continuous band of liquid material be applied to the substrate.

As defined herein, "liquid material" can be any flowable material, including one semi-solid material counts. The liquid material is preferably a polymer that does not requires a separate level of hardness, i.e. a self-curing material. Because the liquid is out can be delivered to a single mouthpiece of the source is the application of the Material for forming the printing blanket easier than with a crosshead extruder, in which Material is pressed outwards so that the entire circumference of the substrate touches becomes. In addition, liquid materials are easier to use than Strip materials.

A device according to the invention for producing a sleeve-shaped printing blanket a sleeve conveying device for moving a carrier sleeve stands out from at least one belt casting device applying a flowable material, wherein the applied flowable material is a layer arranged over the carrier sleeve forms.

The present invention provides less expensive and faster production of Printing blankets. The cost of sleeve-shaped printing blankets is a big factor in the Total cost of ownership of a printing press that uses sleeve-shaped blankets.

The at least one belt casting device preferably comprises a belt casting device for producing a compressible layer with a first feed area for a flowable material and a compressibility generating device, the for example a feed area for compressible microspheres or a blowing or Can be a foaming device. The foam structure or the microspheres can be used for the compressible layer provide the desired compressibility.

The at least one belt casting device preferably further comprises one Belt casting device for producing a reinforcing layer and a Tape casting device for producing a printing layer.

Belt casters preferably each have a single nozzle through which the flowable material flows onto the respective substrate.

Preferably, the belt casting devices are stationary, while the Sleeve conveying device is a moving and rotating device is on which an endless support sleeve is formed, for example by using a Metal strip.

Alternatively, the tape casting devices can rotate in a circular motion rotate the substrate while the sleeve conveyer is a sleeve substrate can continuously move past the strip casting devices.

The inventive method for producing a sleeve-shaped printing blanket, wherein a carrier sleeve is conveyed in a first direction is characterized by tape casting a compressible layer, a reinforcing layer and / or a printing layer the carrier sleeve while the carrier sleeve continues to move.

The method preferably further comprises rotating the carrier sleeve during the Forwarding step. The band casting step preferably includes this Band casting a compressible layer, a reinforcement layer and / or one Printing layer.

Alternatively, the tape casting step may involve rotating a tape caster around the Include carrier sleeve while the carrier sleeve continues to move.

Although rubber could be used for tape casting, it is common then hardened in a separate step. It is extremely beneficial if in Belt casting process a polymer is used that does not require a separate hardness level, such a polymer being defined herein as a "self-curing polymer". At the It is most advantageous if urethane for forming printing blankets according to the invention is used. The advantage of urethane is that it flows well during strip casting and hardens quickly. However, the self-curing polymer could also be a be self-vulcanizing rubber, such as a one that cures at room temperature Rubber.

The tape casting step therefore preferably comprises tape casting urethane um to form the at least one layer.

The printing blankets are preferably produced continuously so that they are a have indefinite length. The process also includes a step in which the Sleeve is cut to the desired length to form the blanket.

The present invention also provides a sleeve-shaped printing blanket with a Carrier sleeve, a compressible layer and a pressure layer, the compressible Layer and / or the printing layer are made of urethane.

Both the compressible layer and the printing layer are preferably made from Urethane is made and there is a reinforcing layer between the compressible Layer and the printing layer arranged. The reinforcement layer is preferred also made from urethane.

Preferably, the compressible layer is made of urethane foam, which by Bubbles of carbon dioxide, air, or other blowing agent are formed in the urethane is before it exits the nozzle of a belt caster. However, it can also compressible microspheres can be embedded in the urethane to increase compressibility receive.

The reinforcement layer is preferably made of urethane with high hardness test values of manufactured more than 80 Shore A or better from about 100 Shore A. The Reinforcement layer is preferably thinner than the compressible layer.

The print layer preferably consists of a urethane with hardness test values of less than 80 Shore A, with values of about 60 Shore A being most preferred.

Similar hardness test values can be provided for printing blankets according to the invention, which are made from self-curing polymers other than urethane.

The layers are preferably made by a tape casting process, the one creates a spirally wound shape that is used to form uniform, channelless Layers.

The carrier sleeve is preferably made of steel, preferably in a continuous one Process shaped by a band.

The present invention is described in the following with reference to the drawings preferred embodiments described in more detail.

Fig. 1

eine Vorrichtung zum Herstellen eines erfindungsgemäßen hülsenförmigen Drucktuchs, wobei das Ende des Drucktuchs nur aus Gründen der Anschaulichkeit schematisch dargestellt ist;

Fig. 2a, 2b

Einzelheiten der Dreh- und Weiterbeförderungseinrichtung zum Herstellen eines endlosen, hülsenförmigen Drucktuchs;

Fig. 3

eine alternative Ausführung der Herstellungsvorrichtung der vorliegenden Erfindung, bei der sich die Bandgießvorrichtungen um das Substrat drehen;

Fig. 4

eine Querschnittsansicht eines erfindungsgemäßen Drucktuchs.

Show it:

Fig. 1

a device for producing a sleeve-shaped printing blanket according to the invention, the end of the printing blanket being shown schematically only for reasons of clarity;

2a, 2b

Details of the rotating and conveying device for producing an endless, tubular printing blanket;

Fig. 3

an alternative embodiment of the manufacturing device of the present invention in which the tape casting devices rotate around the substrate;

Fig. 4

a cross-sectional view of a printing blanket according to the invention.

Fig. 1 shows a device 1 for producing a channelless, sleeve-shaped Printing blanket 100 in a continuous process. In this context, the Term "continuous process" means that the process is an endless, tubular Blanket of indefinite axial length produced.

Device 1 comprises a rotating and conveying device 11 for continuous movement of the blanket 100 from right to left in Fig. 1. Die Device 11 has a drive section 300 which has movable rods 201, 202, 203, 204, 205, 206, etc. continuously rotates and is conveyed as with reference to Fig. 2a and Fig. 2b described below.

In a first station 110, a strip 32, which is preferably made of steel, and two may have overlapping pieces of tape fed to the device 11, the tape so unwinds that a carrier sleeve 33 is formed.

At a second station 120, a first one belonging to device 1 comprises Tape casting device 20 for producing a compressible layer of urethane 21 and a blowing device 22. The urethane feed 21 can be a plurality of separate ones Sections include, for example, an isocyanate section Vulcanization section and a mixing chamber, as well as other material sections. Urethane from the feed 21 is through the blowing device 22 in the mixing chamber foamed and emerges from a nozzle 23 with an end mouthpiece. The foamed In this way, urethane is applied to the carrier sleeve 33 in order to make it compressible Form layer 34, which is illustrative with the applied liquid tapes is shown in the form of a spiral. In reality, the applied liquid flow Straps together and become hard to form a seamless, channelless compressible layer 34 to build.

A squeegee or scraper knife 55 may contact urethane layer 34 and one Grinder 56 can smooth layer 34 to remove imperfections, such as For example, to reduce curls in layer 34.

A second belt casting device 30 is used to compress the compressible layer 34 Device 1 includes a reinforcement layer 42 in section 130 of a third station applied. The tape casting device 30 may have a urethane feed 31 and a nozzle 36 to apply the urethane. The hardness test value of the urethane is preferably about 100 Shore A. Again the applied urethane flows together and becomes hard to form a seamless and channelless reinforcement layer 42. To the A scraper knife 57 and can reduce imperfections in layer 42 a grinder 58 may be used.

A third belt casting device 40, similar to device 30, pulls out a belt Urethane to form a pressure layer 45 over the reinforcement layer 42. The urethane the printing layer preferably has a hardness test value of about 60 Shore A. The applied print layer forms a seamless and channelless layer during hardening. If , a scraper knife 51 and a grinder 50 can be used for correction or reducing imperfections, such as curls, in the Print layer 45 can be used.

As soon as the printing layer 45 is finished, the printing blanket begins its movement in the direction of the Arrows 5 continue until a desired length is reached and cut the blanket is, for example by a rotating knife or a rotating saw.

In section 110, the sleeve is from rods 201-210 (see FIGS. 2a and 2b) held, and can be supported in sections 120, 130 and 140 by bottom brackets become.

2a is a closer view of the operation of the rods 201, 202, 203, 204, 205, 206, 207 rotating in the direction of 218. When the bars turn, nine become at the same time of the ten bars moved towards 5. If a rod is in the most axially distant position Reached direction 5, it is pushed back in the opposite direction 5, as for Rod 201 shown in Fig. 2a. This movement hampers the transfer of the sleeve in Direction 5 not, because the other nine rods continue to push the sleeve in direction 5. As soon as the rod 201 is pushed back, it begins to move in the direction 5 again move.

2b shows a cross-sectional view of the rods 201, 202, 203, 204, 205, 206, 207, 208, 209 and 210 together with the drive device 300 which rotates the rods and forwarded, for example through warehouse 260.

Fig. 3 shows an alternative embodiment, in which the sleeve from a transport device 400 is transported through three revolving belt casting devices 220, 230, 240, which each the compressible layer, the reinforcement layer or the pressure layer Instruct. The layers can be made of materials of the same type as those shown in FIG. 1 Layers 34, 42 and 45.

4 shows a cross-sectional view of the printing blanket 100 with the carrier sleeve trained sleeve 33, the compressible layer 34, the reinforcing layer 42 and the Print layer 45.

As used herein, the term "compressible layer" refers to a polymeric one Material that has been made compressible by one of the known methods, for what for example the use of microspheres, blowing agents, foaming agents or Wash out count. Examples of these materials are described, for example, in US Pat. No. 5,768,990, US 5,553,541, US 5,440,981, US 5,429,048, US 5,323,702 and US 5,304,267.

As used herein, the term printing layer or elastomeric image transfer means Material on a polymeric material such as urethane that is transferable an image from an offset printing plate or other print image carrier onto a Roll or sheet material in a print quality that meets the requirements of corresponds to the respective printing application.

Although the preferred embodiments of the continuous process manufactured offset printing blanket according to the present invention shown here that they have a compressible layer, a reinforcement layer and a Print layer, it can be assumed that in the event that this is for a Certain application is required, the blanket also has a base layer may include between the support sleeve 33 and the compressible layer 34.

In addition, it can be assumed that - although the printing blanket according to the invention preferably comprises a compressible, a reinforcing and a pressure layer - it it is also possible to produce printing blankets with fewer or with additional layers. Thus, a printing blanket according to the invention, if this is for a specific application it makes sense to have a carrier sleeve and a printing layer, or a carrier sleeve include compressible layer and a pressure layer. Beyond that assume that a printing blanket according to the invention also has several compressible layers, could comprise several construction layers or several reinforcement layers.

Although the reinforcement layer is preferably formed from urethane, the Reinforcement layer also made of wrap or plastic tape, cord or thread to be formed around the work piece. Can also cross-spray extruder heads Strips are used to form some of the layers that are not cast by tape getting produced.

The temperature of the flowable material can vary from the respective Belt casting devices are checked. The nozzles can also have mouthpieces have whose shape can be changed to change the To cause tape dimensions. Preferably the temperature and shape are Design nozzles so that a steady flow of flowable material onto the substrate flows. Flow speed, temperature, nozzle shape and speed of rotation of the Substrate can be changed to the desired properties for the to get different layers, for example the thickness of the layer.

List of reference numerals:

1

contraption

5

directional arrows

11

Turning and forwarding facility

20

first belt casting device

21

Urethanzufuhr

22

blower

23

jet

30

second belt casting device

31

Urethanzufuhr

32

tape

33

support sleeve

34

compressible layer

36

jet

40

third belt casting device

42

reinforcing layer

45

print layer

51, 55, 57

Schabmesser

50, 56, 58

grinder

100

blanket

110

first station

120

second station

130

third station

201 ... 210

rods

218

arrow

220,230,240

Bandgießvorrichtungen

260

camp

300

driving section

400

transport means

Claims (33)

Device for producing a sleeve-shaped printing blanket with a sleeve conveying device (11) for moving a carrier sleeve (33),
marked by
at least one band casting device (20) applying a flowable material, the applied flowable material forming a layer (34; 42; 45) arranged above the carrier sleeve (33). Device according to claim 1,
characterized in that the at least one belt casting device (20) comprises a belt casting device for producing a compressible layer (34) which has a first feed region (21) for a flowable material and a device which generates compressibility. Device according to claim 2,
characterized in that the compressibility generating device is a foaming agent. Device according to claim 2,
characterized in that the at least one tape casting device (40) comprises a tape casting device (40) for producing a printing layer (45). Device according to claim 2,
characterized in that the at least one belt casting device (20) comprises a belt casting device (30) for producing a reinforcing layer (42) and a belt casting device (40) for producing a pressure layer (45). Device according to one of the preceding claims,
characterized in that the at least one belt casting device (20) has a single nozzle (23) through which the flowable material flows. Device according to one of the preceding claims,
characterized in that the at least one belt casting device (20) is stationary, and the sleeve conveying device is a conveying and rotating device (11). Device according to claim 7,
characterized in that the carrier sleeve (33) is an endless sleeve formed from a metal strip. Device according to one of claims 1 to 6,
characterized in that the at least one belt casting device (20) is rotatable about the sleeve (33). Device according to one of the preceding claims,
characterized in that the flowable material is a self-curing polymer. Apparatus according to claim 10,
characterized in that the self-curing polymer is urethane. Apparatus according to claim 10,
characterized in that the self-curing polymer is rubber curing at room temperature. Device according to one of the preceding claims,
which further comprises a grinding station (56) which is arranged downstream of the at least one belt casting device (20). Method for producing a sleeve-shaped printing blanket, a carrier sleeve being conveyed in a first direction,
marked by
Tape casting a compressible layer (34), a reinforcing layer (42) and / or a pressure layer (45) around the carrier sleeve (33) while the carrier sleeve (33) moves on. The method of claim 14
which further includes rotating the carrier sleeve (33) during the conveying step. The method of claim 14
characterized in that the tape casting step comprises rotating a tape casting device (20) around the sleeve (33) as the carrier sleeve (33) continues to move. Method according to one of claims 14 to 16,
characterized in that the compressible layer (34), the reinforcing layer (42) or the pressure layer (45) is made of urethane. Method according to one of claims 14 to 16,
characterized in that the compressible layer (34), the reinforcing layer (42) or the pressure layer (45) is produced from a self-curing polymer. Method according to one of claims 14 to 18,
characterized in that the carrier sleeve (33) is formed continuously. Method according to one of claims 14 to 19,
which further comprises cutting the sleeve (33) to a desired length. Method according to one of claims 14 to 20,
which further comprises grinding the compressible layer (34), the reinforcing layer (42) and / or the pressure layer (45). Method according to one of claims 14 to 21,
characterized in that the printing blanket (100) is formed continuously. Sleeve-shaped printing blanket for offset printing with: a carrier sleeve (33); a compressible layer (34) arranged above the carrier sleeve (33); and a pressure layer (45) arranged over the compressible layer (34), characterized in that the compressible layer (34) and / or the pressure layer (45) is made of urethane. Printing blanket according to claim 23,
which further comprises a reinforcing layer (42) arranged between the compressible layer (34) and the pressure layer (45). Printing blanket according to claim 24,
characterized in that the reinforcement layer (42) is made of urethane. Printing blanket according to claim 24 or 25,
characterized in that the reinforcing layer (42) has a hardness test value of more than 80 Shore A. Printing blanket according to one of Claims 24 to 26,
characterized in that the reinforcing layer (42) is thinner than the compressible layer. Printing blanket according to claim 25,
characterized in that the pressure layer (45) is made of urethane with a hardness test value of less than 80 Shore A. Printing blanket according to one of Claims 23 to 28,
characterized in that the carrier sleeve is produced from a spirally wound band (32). Method for producing a printing blanket, which comprises the following process steps: Applying a compressible layer (34) of urethane to a carrier sleeve (33); and Applying a urethane pressure layer (45) over the compressible layer (34). A method according to claim 30,
which further comprises applying a reinforcing layer (42) of urethane over the compressible layer (34). Sleeve-shaped printing blanket for offset printing with: a carrier sleeve (33); a compressible layer (34) arranged above the carrier sleeve (33); and a pressure layer (45) arranged over the compressible layer (34), characterized in that the compressible layer (34) and / or the pressure layer (45) is made of a self-curing polymer. Printing blanket according to claim 32,
characterized in that the self-curing polymer is rubber curing at room temperature.

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