RU2235643C2 - Method of making compensating pad for forming press - Google Patents

Abstract

FIELD: presses.

SUBSTANCE: method includes preparing reaction mixture and making rigid perforated frame. The frame is then coated with the reaction mixture and pressed between shafts. The pad cloth is then cut and thermally treated.

EFFECT: enhanced wear resistance.

5 cl, 3 dwg, 6 tbl

Description

Compensation press pillow is used for pressing in a forming press in the manufacture of foil and non-folded dielectrics, fiberglass, getinaks of all grades and thicknesses in electrical, chemical production, for pressing multilayer printed circuit boards in electrical, radio engineering, electronic and other industries, as well as for pressing layered building materials [1, 2, 4].

There are no analogues of the method of manufacturing a press compensation pillow (hereinafter referred to as the press pillow) in the Russian Federation and the CIS countries.

At enterprises manufacturing dielectrics and multilayer printed circuit boards, a press pad is made by cutting cable paper of the KM-120 brand into sheets of the required length. These sheets are collected in a bundle of 25-35 sheets, and this bundle is used as a press pad in a forming press [1, 2, 4].

A known method of manufacturing a multilayer press pillow for a forming press, consisting of a solid (dense) needle-punched non-woven fabric with a thickness of 4 mm, impregnated with a binder based on synthetic resins by dipping or spot coating. Then, by gluing, layering on top of each other, a multilayer construction of the press pad is assembled. On both sides of the impregnated sheet heat-resistant adhesive is glued on a steel sheet 0.3-0.5 mm thick. These sheets are glued with the same adhesive on a sheet of the same non-woven needle-punched but soft cushioning fabric, the surface of which is melted to form a thin porous surface layer, and then a release layer of silicone or fluoroplastic resin is applied to it.

The disadvantages of this method:

1. Piece-wise manual assembly of the multilayer construction of the press pad; it is necessary to prepare all materials, cut into the required dimensions, and then assemble the press pad,

2. The manufacturing method does not provide important qualitative indicators of the press pad, such as heat resistance, thermal conductivity, uniform distribution of temperature throughout the volume of the pad, since the impregnation by the binder method of dipping, and even more so by the method of spot coating, does not provide high-quality binder impregnation of a hard layer of needle-punched non-woven fabric a thickness of 4 mm, a density of 200-300 needles / cm ² , in addition, the binder does not contain heat-conducting components (such as, for example, metal powder).

SUMMARY OF THE INVENTION

The technical result of the invention is expressed in a method for manufacturing a press compensation pillow for a forming press.

Salient features of a method of manufacturing a press compensation cushion for forming press, characterized in that

the reaction mixture is made, an adhesive layer is applied, a rigid framework is made, a rigid framework is coated with the reaction mixture, a release layer is applied, the press pad web is transversely cut, and the press pad is heat treated;

in addition, the rigid sheet of the carcass is subjected to perforation, guiding the protrusions on both sides of the plane of the sheet, thereby providing additional springing properties to the rigid carcass;

use perforation protrusions to secure and prevent the displacement of the elastic layer over the surface of the sheet;

perforation holes have 13-16 pieces per 1 cm ² ,

overall dimensions of perforation holes: length 1.0-1.7 mm, width 0.8-1.0 mm;

in addition, a rigid frame is wrapped around the reaction mixture, followed by pressing between the shafts;

conduct heat treatment of the reaction mixture in a drying-vulcanization unit or in a hydraulic press.

Summary of drawings.

Figure 1 is a cross section of a press pad manufactured by the method described in this invention.

Figure 2 is a cross section of another type of press cushion made by the method described in this invention,

Figure 3 is a cross section of the next type of execution of the press pillows made by the method described in this invention.

A method of manufacturing a press pad

The technological process of a method of manufacturing a press cushion is a set of technological operations that establishes the sequence and procedure for performing technological operations of manufacturing a press cushion.

The list and sequence of technological operations:

- manufacture of the reaction mixture;

- application of an adhesive layer;

- manufacture of a rigid frame;

- lining the frame of the reaction mixture;

- application of a release layer;

- transverse cutting of the web of the press pad;

- heat treatment of the press pad.

Raw materials, reagents, materials used in the manufacture of press pillows.

Table 1 shows a list of feedstock and reagents used in the manufacture of press pillows.

The mode of the technological process of manufacturing a press pad

Table 2 shows the mode of the manufacturing process of the press cushion.

The reaction mixture is used to form an elastic layer of the press pad, the composition of the mixture determines the quality of the elastic layer of the press pad.

Table 3 shows the composition of the mixture.

The reaction mixture is made in a mixer.

Before loading into the mixer preliminary preparation is subjected to fibrous filler, liquid rubber. The remaining components of the mixture are used without prior preparation.

The liquid rubber is heated to 80 ° C and then fed to the mixer.

The fibrous filler is subjected to stretching on runners and fluffing on disintegrators. The fibrous filler is loaded by pneumatic transport into the bowl of the runners, where it is pressed by rotating rollers to mash it, split the fibers and weaken the cross-links between the fibers. Warm-up time on runners is 5-20 minutes at a vertical shaft rotation speed of 20 rpm, and a horizontal shaft rotation speed of 100 rpm. The treated fibrous filler with an elevator is fed to a disintegrator, where it is subjected to fluffing with rotating disks. The disk rotation speed is 650 rpm. Drying mode - 1 bag of filler weighing 25 kg is processed in one minute. The purpose of the flare is to separate the fiber bundles into thin fibrils, to separate it from adhering gangue or dust. The fibrous filler thus prepared is fed to the mixer for the preparation of the reaction mixture.

The reaction mixture is made in a mixer, where the working body is a stirrer - two Z-shaped rotors rotating in opposite directions. The rotation speed of one rotor is 38 rpm, the rotation speed of the other rotor is 27 rpm. Close the cooling of the mixer, load in mass fractions,%: 62-73 powder filler, 0.25-1.0 sulfur, 0.25-1.0 zinc oxide, 10.0-20.0 fibrous filler, 0.125-0, 5 2-mercaptobenzothiazole, mix for 5-15 minutes, load 3.0-12.0 liquid rubber, 3.0-12.0 chloroparaffins CP-470, mix 40-60 minutes, 0.375-1.5 emulsifier, mix 40- 50 minutes. The total production time of the reaction mixture is 85-125 minutes. Since the reaction proceeds with the release of heat, cooling is started 15-20 minutes before unloading.

The quality control of the manufactured reaction mixture is carried out according to the indicator Rashig fluidity at a temperature of 20-25 ° C and a specific pressure of 185 kg / cm. The fluidity must be at least 60 mm.

The finished reaction mixture is fed to the automatic production line of the press compensation pillow in the hopper for feeding on the calender. The rigid frame of the press cushion is simultaneously fed onto the calender - continuous perforated steel tape.

A press pad is made on an automatic line.

The automatic production line of the press pad includes an unwinding device, an adhesive layer application machine, a hard sheet punching machine, a calender, an anti-adhesive layer application device, a cross cutting machine, a drying-vulcanization unit, and a hydraulic press.

Adhesive coating

The adhesive is applied to the rigid frame of the press pad on the device for applying the adhesive layer. The goal is to increase the adhesion of the elastic layer to the surface of the frame of the press pad.

Before perforation, a layer of glue on the basis of epoxy resin is applied to the steel strip with special rollers, the adhesive is poured into the bath into which the roller is dipped. The thickness of the adhesive layer on the rigid frame 0.02-0.05 mm is controlled by the level of adhesive in the bath. After application, the adhesive is dried by blowing air on the steel strip. Air temperature 30-40 ° С. Next, the steel tape is fed to the perforation.

Hard frame manufacturing

The frame of the press pad consists of one or two rigid sheets, which have high thermal conductivity. The most preferred materials for this are sheet steel, copper, aluminum or their alloys, sheets of heat-resistant resins such as polyimide, polysulfone and others, with metal fibers or metal powder. The thickness of the hard sheet is 0.05-2.0 mm.

Steel for the manufacture of press pillows is used in the form of a roll. The thickness of the steel is 0.25 mm, the width is 1100-1200 mm.

The unwinding of a roll of steel tape is carried out on an unwinder. The free end of the roll is threaded through the pulling rollers of the unwinding device into the perforating machine.

The fabrication of the frame of the press pad is carried out as follows: a steel sheet is passed between two perforating rolls formed by stitching discs worn on the shaft. The steel tape is perforated, guiding the perforation protrusions on both sides of the sheet plane, which provides additional springing properties to the rigid steel sheet. The perforation protrusions fix and prevent the displacement of the elastic layer over the surface of the sheet. The number of holes 13-16 pieces / cm ² , the size of the holes: length 1.0-1.7 mm, width 0.8-1.0 mm. The speed of the steel tape is not more than 0.235 m / s.

In the case of manufacturing a press pillow with two rigid frames, two unwinding devices, two installations for applying adhesive, two machines for perforating the rigid frame in parallel and simultaneously are used.

Covering the frame with the reaction mixture

The frame in the form of a steel perforated continuous tape enters the gap of the calender. At the same time as the frame, the reaction mixture is fed into the calender gap from the hopper using a conveyor belt.

The level of the reaction mixture in the calender gap is automatically maintained by a level switch. The perforated frame is passed through the gap between the upper and lower calender rolls, the reaction mixture is encircled on both sides at the same time, the mixture is pressed through the shafts and pressed through the holes in the frame. This forms the fabric of the press cushion, which is fed to the installation of applying the release layer. The required thickness of the press pad is achieved by adjusting the calender clearance.

The thickness of the web of the press pad after the calender is 1.5-3.5 mm, the speed of the web of the web of the press pad is not more than 0.235 m / s.

Application of a release layer

To reduce the adhesion of the press pad to the steel cushion sheets when pressed in a forming press, a release layer - talc is applied to the outer surface of the elastic layer of the press pad, the layer thickness is 0.02-0.05 mm. At the unit for applying the release layer, the web tape passes through a talc bunker, where both surfaces of the web are spray-coated with talc and then polished to clean the surface and calibrate the thickness of the web of the press pad with special rolls. The speed of the web of the press pad is not more than 0.235 m / s.

Cross cutting the web of the press pad

Next, the web of the press pad is fed to the transverse cutting device of the tape on the sheets of the press pad of a predetermined length. The length of the pillow, depending on the purpose, can be from 500 to 2500 mm.

The finished press pad is a rectangular product with a length of up to 2500 mm, a width of 1100-1200 mm, and a thickness of 1.5-3.5 mm.

The weight of 1 m ^{2 of a} press pad with a thickness of 1.5 mm is 3.8 kg.

Heat treatment of the press pad is in the drying and vulcanization unit.

To form the reaction mixture, the cut sheets of the press pillow are stacked one by one on a shelf of a chain frame conveyor located inside the chamber of the drying-vulcanization unit in an elastic layer.

Inside the chamber, the sheets are moved by a conveyor and blown with hot air, which is fed into the lower part of the chamber. The air is first heated with steam, and then with an electric air heater to a temperature of 180 ° C. In the upper part of the chamber, the sheets of the press pad are dried, and in the lower part, they are vulcanized. The temperature in the drying-vulcanization unit is 120-180 ° C. The heat treatment time is 70-80 minutes. In the drying-vulcanization unit, as a result of the vulcanization reaction, the reaction mixture acquires the elastic properties necessary for the press pad

2RH- + S _x + ZnO → RS _x-1 -R + ZnS + Н ₂ О,

where RH is the radical of the rubber chain.

The vulcanization reaction proceeds in the presence of an accelerator - 2-mercaptobenzothiazole.

Heat treatment of a press pad in a hydraulic press.

Heat treatment in a hydraulic press with electric heating is carried out at a temperature of 145-160 ° C for 3-6 minutes at a pressure of 135-180 kg / cm ² .

The combination of technological operations, their sequential order and the conditions for their implementation ensure the manufacture of a press cushion that meets the requirements for a press cushion, namely: uniform thickness over the entire surface of the cushion, increased wear resistance, high elastic properties, high thermal conductivity, the ability to evenly distribute temperature and pressure throughout the volume of the press pad.

Description of a preferred method for manufacturing a press pad.

Example 1

The press pad shown in figure 1 consists of one rigid frame (1), an elastic layer (2), a release layer (3).

Table 4 shows the composition of the reaction mixture.

Liquid rubber in barrels in a special installation equipped with electric heating, heated to 80 ° C, and then served for loading into the mixer. Asbestos, chrysotile pneumatic transport is loaded into the bowl of runners, where it is kneaded by the pressure of rotating rollers, the run time on runners is 5 minutes at a vertical shaft rotation speed of 20 rpm, and a horizontal shaft rotation speed of 100 rpm. Then asbestos is fed by an elevator to a disintegrator, where it is subjected to fluffing with rotating disks. The disk rotation speed is 650 rpm. Drying mode - one bag weighing 25 kg is processed for 1 minute. Thus prepared asbestos is fed by an elevator to a mixer for the manufacture of the reaction mixture.

The reaction mixture is made in a mixer, where the working body is a stirrer - two Z-shaped rotors rotating in opposite directions. The rotation speed of one shaft is 38 rpm, the other is 27 rpm. Before loading the reagents into the mixer, the cooling of the mixer is closed. Download,%: 73 iron minium, 0.25 sulfur, 0.25 zinc oxide, 20 chrysotile asbestos, 0.125 2-mercaptobenzo-thiazole, mix for 5 minutes, load 3.0 liquid rubber, 3.0 chloroparaffins CP - 470, mix 40 minutes, load 0.375 emulsifier, mix 40 minutes. The total reaction preparation time is 85 minutes. Since the reaction proceeds with the release of heat, 15 minutes before unloading, cooling is opened. In this case, the Rashig fluidity is 67 mm. The finished reaction mixture is fed into the hopper for feeding on the calender, where at the same time the rigid frame of the press pad is fed.

Steel for the manufacture of press pillows is used in the form of sheet metal with a thickness of 0.25 mm and a width of 1100 mm. The unwinding of the tin roll is carried out on an unwinder. The free end of the roll is threaded through the pulling rolls of the unwinding device into a perforating machine, a metal tape is passed between two perforating rolls formed by stitching discs worn on the shaft. The speed of the metal tape is not more than 0.235 m / s. The number of holes is 13-16 pieces / cm ² , the size of the holes: length 1.0-1.7 mm, width 0.8-1.0 mm.

A rigid frame in the form of a steel perforated tape enters the calender gap, where, simultaneously with the frame, the reaction mixture is fed from the hopper using a conveyor belt.

The level of the reaction mixture in the calender gap is automatically maintained by a level switch. The perforated frame is passed through the gap between the upper and lower calender rolls, encased with a mixture at the same time on both sides, the rollers are pressed and pressed through the holes of the frame. The required thickness of the web of the press pad is achieved by adjusting the calender clearance. The thickness of the web of the press pad after the calender is 1.5 mm. On the outer surface of the elastic layer of the press cushion, a release layer is applied by spraying - talc on the installation of applying the release layer. The layer thickness is 0.02 mm. Then, the thickness of the web of the press pad is polished and calibrated with special rolls. The speed of the web of the press pad is not more than 0.235 m / s.

Then the web of the press pad is fed to the transverse cutting device of the tape and cut into sheets according to the size of the press pad, which is sent for heat treatment in the chamber of the drying-vulcanization unit.

Heat treatment is carried out at a temperature of 120 ° C for 80 minutes.

A press pad (Fig. 1) made by the described method was tested in the manufacture of foil dielectrics at a temperature of 155-170 ° C and a specific pressure of 60-90 kg / cm ² and withstood more than 100 pressing cycles without visible defects of the press pad - delamination. Foil dielectrics meet the requirements of technical documentation.

The finished press pillow is a rectangular product with a length of up to 2500 mm, a width of 1100 mm, a thickness of 1.5 mm.

Example 2

The press pad shown in figure 2 consists of two rigid frames (1), an elastic layer (2), a release layer (3). Table 5 shows the composition of the reaction mixture.

The liquid rubber in barrels in an installation equipped with electric heating is heated to 80 ° C and fed to the mixer.

Asbestos chrysotile pneumatic transport is loaded into a bowl of runners, where it is carried out by the pressure of rotating rollers. Warm-up time on runners is 15 minutes, vertical shaft rotation speed 20 rpm, horizontal shaft rotation speed 100 rpm. Treated asbestos with an elevator is fed to a disintegrator, where it is subjected to fluffing with rotating disks. The disk rotation speed is 650 rpm. Blending mode - 1 packet weighing 25 kg is processed in 1 minute. Asbestos thus prepared is fed by an elevator to a mixer.

The reaction mixture is made in a mixer, where the working body is a mixer - two horizontal Z-shaped rotors rotating in opposite directions, the rotation speed of one rotor is 38 rpm, the other rotor is 27 rpm. Download to the mixer in mass fractions,%: 62.0 iron minium, 1.0 sulfur, 1.0 zinc oxide, 10.0 chrysotile asbestos 0.5 2-mercaptobenzothiazole, mix 10 minutes, load 12.0 liquid rubber, 12 , 0 chloroparaffins KP-470, mix for 50 minutes, load 1.5 emulsifiers, mix for 45 minutes. The total production time of the reaction mixture is 105 minutes. 18 minutes before unloading, cooling is opened on the mixer. Rashig fluidity in this case is 74 mm. The reaction mixture meets the requirements of technology. The finished reaction mixture is fed to a calender feed hopper, where at the same time the rigid frame of the press pad is fed - a continuous perforated steel strip.

In example 2, the press pad consists of two rigid frames, therefore, in this embodiment, two unwinding devices are used, two perforating machines in parallel and simultaneously.

Steel for the manufacture of the frame of the press pillow is used in the form of rolled sheet with a thickness of 0.25 mm and a width of 1100 mm. The unwinding of tin rolls is carried out on an unwinder. The free end of the rolls is fed through the pulling rolls of the unwinding device into a perforating machine, a metal tape is passed between two perforating rolls formed by stitching discs worn on the shaft. The speed of the metal tape is not more than 0.235 m / s. The number of perforation holes 13-16 pieces / cm ² , the size of the holes: length 1.0-1.7 mm, width 0.8-1.0 mm. Two rigid frames simultaneously and simultaneously in the form of a continuous tape enter the calender gap, where the reaction mixture is simultaneously fed from the hopper using a conveyor belt. The level of the reaction mixture in the calender gap is automatically maintained by a level switch. Perforated frames are passed through the gap between the upper and lower calender rolls, wrapped in a reaction mixture, rollers are pressed and pressed through the holes of the frame. The thickness of the web of the press pad is controlled by the size of the calender clearance. The thickness of the web of the press pillow with a double frame after the calender is 3.5 mm. On the outer surface of the elastic layer of the pillow in the installation of applying the release layer by spraying, a release layer is applied - talc, layer thickness - 0.03 mm. Then, the thickness of the web of the press pad is polished and calibrated with special rolls. The speed of the web of the press pad is not more than 0.235 m / s. Next, a continuous web is fed to the device for transverse cutting of the tape onto the sheets according to the size of the press pad and sent to the heat treatment chamber of the drying-vulcanization unit. Heat treatment is carried out at a temperature of 180 ° C for 75 minutes.

The press pad (figure 2) made by the described method was tested in the manufacture of foil dielectrics at a temperature of 155-170 ° C and a specific pressure of 60-90 kg / cm ² and withstood more than 100 pressing cycles without visible defects of the press pad - delamination. Foil dielectrics met the requirements of technical documentation.

The finished press pad is a rectangular product with a length of up to 2500 mm, a width of 1100 mm, and a thickness of 3.5 mm.

Example 3

The press pad shown in Figure 3 consists of one rigid frame (1), an elastic layer (2), a release layer (3), an adhesive layer (4). Table 6 shows the composition of the reaction mixture.

The liquid rubber in barrels in a special installation equipped with electric heating is heated to a temperature of 80 ° C and fed to the mixer.

Asbestos, chrysotile pneumatic transport is loaded into a bowl of runners, where it is kneaded by the pressure of rotating rollers. The warm-up time is 20 minutes, the rotation speed of the vertical shaft is 20 m / min, and the horizontal shaft is 100 rpm. Treated asbestos with an elevator is fed to a disintegrator, where it is subjected to fluffing with rotating disks. The disk rotation speed is 650 rpm. Blending mode - 1 packet weighing 25 kg is processed in 1 minute. Thus prepared asbestos is fed into the mixer.

The reaction mixture is made in a mixer, where the working body is a stirrer - two horizontal Z-shaped rotors rotating in opposite directions. The rotation speed of one rotor is 38 rpm, the other rotor is 27 rpm. They are loaded into the mixer in mass fractions,%: 67.5 iron minium, 0.625 sulfur, 0.625 zinc oxide, 15 chrysotile asbestos, 0.312 2-mercaptobenzothiazole, stirred for 15 minutes, 7.5 liquid rubber, 7.5 chlorinated paraffin waxes CP-470 are loaded, mix 60 minutes, load 0.938 emulsifier, mix 50 minutes. The total production time of the reaction mixture is 125 minutes. Since the reaction proceeds with the release of heat, cooling is opened 20 minutes before unloading. The fluidity of the mixture according to Rashig - 78 mm. The prepared mixture meets the requirements of the technology, and it is used for the manufacture of press pillows. The reaction mixture is fed to a calender hopper.

Steel for the manufacture of the frame of the press pillow is used in the form of sheet metal with a thickness of 0.25 mm and a width of 1200 mm. The unwinding of the roll is carried out on an unwinder. The free end of the roll is filled through the installation of applying an adhesive layer and with special rollers a layer of glue based on epoxy resin is applied to the frame. The adhesive is poured into the bath into which the roller is dipped, the thickness of the adhesive layer 0.02-0.05 mm is controlled by the level of adhesive in the bath. After application, the adhesive is dried by blowing air on the steel strip. Air temperature 30-40 ° С. Next, the steel tape through the pulling rolls of the unwinding device is sent to a perforating machine, a metal tape is passed between two perforating rolls formed by stitching discs worn on the shaft. The number of holes 13-16 pieces / cm ² , the size of the holes: length 1.0-1.7 mm, width 0.8-1.0 mm. The speed of the frame is not more than 0.235 m / s.

The perforated frame of the press pad is fed to the calender for lining the reaction mixture. The rigid frame enters the calender gap, where, simultaneously with the frame, the reaction mixture is fed from the hopper using a conveyor belt. The level of the reaction mixture in the calender gap is automatically maintained by a level switch. The perforated frame is passed through the gap between the upper and lower calender rolls, surrounded by a reaction mixture, the rollers are pressed through and pressed into the mixture through holes in the frame. The required thickness of the web of the press pad is achieved by adjusting the calender clearance. The thickness of the web of the press pad after the calender is 1.5 mm.

The speed of the web of the press pad is not more than 0.235 m / s. On the outer surface of the elastic layer of the press cushion, a release layer is applied by spraying — talc on the installation of applying the release layer. Layer thickness 0.05 mm. Then the web of the press pad is polished and the thickness of the web is calibrated with special rolls.

Web speed - not more than 0.235 m / s. Next, the web is fed to the transverse cutting device, the ribbon is cut into sheets according to the size of the press pads and sent for heat treatment in the chamber of the drying and vulcanization unit. Heat treatment is carried out at a temperature in the chamber of 160 ° C for 80 minutes. As a result of the vulcanization reaction, the reaction mixture acquires the elastic properties required by the press pad.

The press pad (figure 3) made according to the described method was tested in the manufacture of foil dielectrics at a pressing temperature of 155-170 ° C and a specific pressure of 60-90 kg / cm ² and withstood more than 100 pressing cycles without visible defects of the press pad - delamination. Foil dielectrics met the requirements of technical documentation.

The finished press pillow is a rectangular product with a length of up to 2500 mm, a width of 1100 mm, a thickness of 1.5 mm.

Sources of information

1. Technological processes for the production of foil and non-foil fiberglass and getinaks.

2. Technological processes for the production of multilayer printed circuit boards.

3. US patent 4461800, 29 D 17/00, 29 C 3/00, 32 V 5/32, 1984

4. O.V. Bobylev, N.V. Nikulin, N.V. Rusanov, V.I. Gypsies. Technology for the production of electrical insulation materials. - M .: Energy, 1997

Claims (7)

1. A method of manufacturing a press compensation cushion for a forming press, characterized in that the reaction mixture is prepared, a rigid perforated frame is made, the reaction mixture is wrapped around the frame, followed by pressing between the shafts, the press pad web is transversely cut and the press cushion is heat treated. 2. The method according to claim 1, characterized in that the rigid frame is made of perforated tape, while the protrusions from the perforation are directed on both sides of the surface of the tape. 3. The method according to claim 1 or 2, characterized in that the protrusions from the perforation are used to fasten and prevent the displacement of the elastic layer on the surface of the rigid frame. 4. The method according to claim 1, characterized in that the perforation holes are placed on a rigid frame of 13-16 pieces / cm ² . 5. The method according to claim 1, characterized in that the heat treatment of the press pad is carried out in a drying and vulcanizing unit or in a hydraulic press. 6. The method according to claim 1, characterized in that an adhesive layer is applied to the rigid frame. 7. The method according to claim 1, characterized in that a release layer is applied to the outer surface of the elastic layer of the press pad.

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