DE2116366A1 - Pressure roller and method of manufacture - Google Patents

Description

Giovanni Colombo, Como (Italy), Via Giustizia Libertä 25, Ezio Malservigi ^ ernobbioCComo-Italy), Via Aquileia, Amedeo Bozzone, Appiano Gentile (Como-Italy), Viale Italia 12.

Printing roller and method of manufacture «

The invention relates to a printing roller, in particular for printing of fabrics, paper, plastic, metal, ceramics, glass, silk screens, curtains and the like β as well as a process for the production of such rolls,

The previously known pressure rollers generally consist of aua information is engraved on a metal cylinder on its circumference are. In addition, wooden rollers are known, the surface of which has a number of holes for the printing ink to pass through.

The known rollers are complex and expensive to manufacture. The perforated wooden roller in particular has certain disadvantages. Because the holes obviously cannot be very close together, because this reduces the strength of the roller and thus Precise work can be adversely affected by the printing ink insufficient quantities of it get through the holes on the roller circumference.

The invention avoids the disadvantages of the known printing rollers. It is based on the task of a thin-walled, hollow pressure roller with holes in the jacket for the passage of the printing ink to be designed in such a way that it is economically feasible Manufacture, in addition to one for sufficient ink passage provided sufficient number of holes in the roll shell, the required mechanical strength, elasticity and Abrasion resistance are present.

The invention solves the problem posed in that the pressure roller consists of a lextile cylinder, the threads of which are completely are encased with a metal coating that gives the cylinder the required gives mechanical strength, elasticity and stability

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and the mesh openings for sufficient ink leakage releases »

Such a pressure roller is simple and inexpensive to manufacture. It also has the necessary elasticity and strength Hollow cylinders can be made from fabric of the desired denier, onto which the metal coating is electrodeposited will·

The invention is illustrated by way of example in the drawing. Show it:

Pig.l a pressure roller, the left half of which is a certain Execution of the roller cylinder made of fabric can be seen, while the right half another version reproduces the meshes are shown enlarged for better explanation;

2 shows, on an enlarged scale, a schematic front view of the printing roller with the counter roller and the web to be printed between the two, in section?
Fig. 3 enlarges a piece of tissue before application

of the metal coating;

FIG. 4 shows a section in the direction 4-4 through FIG. 3; Fig.5 the same piece of tissue according to Fig.3 after the

Applying the metal coating;

FIG. 6 shows a section through FIG. 5 in the direction 6-6; 7 shows an enlarged cross-section through part of a metallized yarn of the roller.

The pressure roller consists of a hollow cylinder l, which is attached to both Ends seated on flanged end pieces 2 and has a distributor 3 on the inside, which extends in the longitudinal direction of the roller Wave 4 sits and presses the printing ink through the holes or mesh openings in the roller shell, so that the underneath lying, to be printed web 5 is printed with the information in the roller circumference.

The pressure roller 1 according to the invention consists of a cylinder made of natural threads such as cotton, hemp, jute, silk or synthetic

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table fibers, such as polyester, polyamide, polyacrylic, polychlorovinyl, polypropylene fibers, and the like. The fabric has warp and weft threads Ιο, ΙΙ (Fig.3,4), which are known in the art are connected to a net-like fabric with a number of meshes 12. The threads of the fabric are covered with a metal coating 13 (Fig _e 5> 6), whereby the roller cylinder receives sufficient mechanical strength, elasticity and stability. The coating can consist of one or more layers according to the required strength.

7 shows enlarged in cross section a part of a warp thread Io with a metal coating 13, which advantageously consists of a first layer 13 'which is formed from an electrolytically deposited metal deposit, e.g. copper deposit, which forms an elastic cushion for the subsequent electrochemical deposit , the "represents and the required strength and resistance to abrasion ensures .This position 13", the second layer 13 may zBaus nickel, chromium, bronze or similar metal or suitable metal alloys _e the total coating 13 is such that it the mesh 12 The thickness of the coating 13 depends on that of the individual layers, which is a function of various parameters, such as the diameter of the fabric threads, the diameter and length of the roller, the density of meshes 12. The person skilled in the art can easily determine the corresponding values on the basis of his experience For example, some values are given below. With a conventional pressure roller of 64 cm circumference and a length of 128 cm and a mesh density of 42 meshes per cm, the thickness of the copper layer 13 'is approximately 30 microns and that of the nickel layer 13 "is approximately 10 microns.

As the drawing Fig. 1 shows on the left, the warp threads Io run parallel to the roller axis and the weft threads 11 perpendicular to it. In this case, the so-called ⁿ moire "can occur. Therefore, the threads are advantageously oriented differently. For example, the roller cylinder is rotated around twisted its longitudinal axis so that the warp and weft threads are essentially helical

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2116386

run moderately, as the right side Mg.l shows. To divide the pressure roller can be a G-eweberoiir or else a flat piece of fabric can be used, which is bent and then sewn, glued or on other with the then abutting edges connected in a suitable manner.

The tissue pipe is cleaned or cleaned to remove all dirt and foreign matter, then it is pushed onto a cylindrical mandrel, whereupon, depending on the type of thread, it is subjected to a temperature of 160 to 22o ° C . After this heat treatment, the tube is immersed in a catalytic bath containing precious metals in the colloidal state. This prepares it for a deposit of electrically conductive material run to the longitudinal axis of the roll. After the catalytic treatment, a chemical precipitate made of electrically conductive material, e.g. copper, is applied so that the fabric becomes electrically conductive. The tube or cylinder is then immersed in an electrolyte bath in order to coat the threads with a metal precipitate, e.g. copper elastic padding for the following layer to be applied results in «This layer, the one in Figo? is denoted by 13 ^f and is considered to be the first layer, can have a thickness of 20 to 100 microns, according to the diameter and length of the roller and the density of the fabric.

After the first layer 13 'forming the electrolytic or galvanic applied metal deposit has been generated, the deposit for the second layer 13 ″ is applied electrolytically which gives the roller the required mechanical strength, Has elasticity and surface hardness against abrasion, this second Layer 13 ″ is advantageously made of nickel, but can also be made of any other suitable material, such as bronze, chrome or a metal alloy The layer 13 "has a thickness of 5 to 50 microns, depending on the parameters of the roller in question. The roller produced in this way can be used in a known manner »

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Claims (1)

- 5 claims. 6-β, ¹ ) Printing roller with thin-walled roller body, which has a number of openings in its jacket for the passage of the printing ink to the outside, characterized in that the printing roller consists of a textile cylinder, the threads of which are completely covered with a metal coating, which the roller cylinder ensures the required mechanical strength, elasticity and stability and leaves the mesh openings free for sufficient ink discharge 2 ·) pressure roller according to claim 1, characterized in that the Metal coating (13) from a first, the desired elasticity securing layer (l3 ') and a second layer (l3 ") consists of the has the required rigidity and surface hardness as well as flexibility. 3.! Printing roller according to claim 1 and 2, characterized in that the first layer (13 ') consists of copper. 4.) Printing roller according to claim 1 to 3, characterized in that the second layer (13 ") made of nickel, bromine, chromium or their alloys consists" 5.) Printing roller according to claim 1 to 4, »characterized in that the textile cylinder has warp and weft threads, some of which parallel and the others are perpendicular to the roller axis. 6.) Pressure roller according to claims 1 to 5, characterized in that the jetted and weft threads are inclined obliquely to the longitudinal axis of the roll. 7.) Printing roller according to claim 1 to 6, characterized in that the roller cylinder made of natural or synthetic threads or fibers consists· 8.) A method for producing a printing roller according to claim 1 to 7 »characterized in that a cylinder made of textile or Fabric material is formed and a layer of electrically conductive material is catalytically placed thereon, onto which electrochemically a layer of a metallic deposit enveloping the threads of the fabric is applied in such a way that a sufficient mechanical strength, elasticity and surface area hardness and the mesh openings for sufficient 109844/1085 211636R the escape of the printing ink remain free, 9.) The method according to claim 8, characterized in that a colloid bath made of noble metal is used as the catalyst
Io ·) Method according to claim 8 to 9 »characterized in that, following the application of electrically conductive material to the textile fabric, a metal deposit is applied electrochemically, which consists of at least one layer, which forms a sufficient base for a further layer to be applied, that of the roller has the required mechanical strength, elasticity
and ensures surface hardness. 11.) The method according to claim 8 to lo, characterized in that the textile cylinder is rotated about its longitudinal axis that
the weaving threads run helically to it. 10.9 8 4:47 1Q8 5