JPH02121874A - Multi-color offset printing - Google Patents

Abstract

PURPOSE: To enable accurate registration of two colored prints by a method wherein a transfer pad with a first print put thereon is made to engage with an intermediate surface with a second print put thereon, the transfer pad is made to engage with the surface of an article, and the first and second prints are put on the surface of the article. CONSTITUTION: In the course of the operation of a printing machine, a first print is formed with a first color on a platen 18 of a first print supply unit 14 and a second print is formed with a second color on the platen of a second print supply unit 16. Each platen is rotated at an angle of 180 deg. and the print is positioned just under one of transfer pads of a pad support 12. (1) The pad is lowered to be engaged with the platen 18 of the first print supply unit 14 and the pad is lifted to take up the first colored print. (2) The pad is lowered to be engaged with the platen of the second print supply unit 16 and the pad is raised to take up the second colored print laid over the first print. (3) The pad is lowered to be engaged with a plate of a product support 10 and, the pad being raised, the first print and the second print are put on the surface of the plate together.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention uses a transfer pad to apply two or three colors to the surface to be decorated with a design, such as a ceramic or glass article. This relates to offset printing (i.e., multicolor printing) of the above design.

(Prior Art) Offset printing of ceramic products is based on a repetitive manufacturing process.
Or pick up an ink design from a flat intermediate surface,
It is well known to apply such designs to the surface of articles. The affinity of the ink for the pad and article ensures that the design is completely transferred to the article and that virtually no residual ink remains on the pad.

In the past, metal and glass-type intermediate surfaces have been used to transfer screen printed designs from intermediates, rather than designs taken from etching or engraved intaglio. However, these surfaces required cleaning with a blade between designs. This was because when the design was picked up by the pad, it was not possible to prevent ink residue from remaining on the surface. Recently, the use of other materials for intermediate surfaces has been introduced, which, together with proper selection of inks and control of the viscoelasticity of such inks, allows complete transfer of ink designs from the surface to the pad. Ta. Therefore, it was possible to eliminate the need to clean the intermediate surface between designs. Such a method is described in patent specification GB-B211890
0 and European Patent Application No. 83302297.3, according to which a silicone rubber material is used for the intermediate surface and the transfer pad.

Such offset printing techniques using transfer pads are used to perform multicolor printing, and typically layers of ink are applied to the article in succession, one color at a time. Machines that perform such work are disclosed in patent specifications CB-A-1247001 and GB-A-1432355, for example.
is explained in. In these machines, the article of manufacture is moved between successive printing stations of the machine, with transfer pads at each station applying a layer of ink to the article as the multicolored design is formed on the article. .

A multicolor printing machine operating in such a manner, as described below,
Carry the design from an intaglio or from a screen intermediate surface.

To make the process more efficient, in the past, the entire design was assembled into a collection surface at the same time, and then the assembled design was applied to the article one color at a time in a multicolored design. Attempts were made to transfer the image onto an article by attaching it to the image. One such method is patent specification CB-A-8.
04751. According to this proposal, different colors could be printed one after the other on a flat stainless steel surface with a stencil, and then such assembled designs could be transferred from the stainless steel surface to the article with an elastic pad. Later, Patent Specification G proposed printing multiple colors one after another on a silicone rubber diaphragm using a stencil.
B-A-1273621. The diaphragm is then turned over and pressed against the article to transfer the design to the article. However, none of these proposed methods were satisfactory and therefore none could achieve practical success.

It is an object of the present invention to provide an improved multicolor offset printing method.

One of its objects is to provide a method of repetitive offset printing for applying two or more color designs to the surface of an article in one cycle of operation, wherein the cycle comprises at least the first of a predetermined pattern. placing ink of a color on the intermediate surface to form a first print, engaging the transfer pad with the intermediate surface bearing the first print;
removing the transfer pad from the intermediate surface and picking up the first print on the pad, placing a predetermined pattern of ink of a second color on the intermediate surface to form a second print, and moving the transfer pad with the first print onto the pad; 2, the transfer pad is moved away from the intermediate surface to pick up the second print, the transfer pad with the first and second prints is engaged with the surface of the article, and the transfer pad is removed from the intermediate surface. A repetitive offset printing method is provided that includes the steps of: applying a first print and a second print to a surface of an article at a distance from the article.

Usually associated with precise alignment of the two colored prints, as the entire design consisting of the first and second prints (and three or more prints) is brought together on the surface of one transfer pad before being applied to the article. This problem has been alleviated. Furthermore, since each print is applied to a clean intermediate surface (i.e., any print previously formed on the intermediate surface has already been removed from such surface), unrelated inks are printed by the equipment used to form the print. There is no risk of being exposed. Since the design is attached to the item in one printing, we take the prints that make up the design,
The number of pad movements when printing and applying is less than in the multi-print method (3 times instead of 4 for 2 colors)
, the cycle time is correspondingly shortened.

To apply a multicolored design to an article, simply press the transfer pad onto the surface of the article (for example, when decorating a plate), or use a suitable pad configuration to apply the design to progressive lengths. It may also be applied along the length (for example, on the outside of the cup or cup substantially from handle to handle).

There follows a description of the machine and its use, explaining the invention by way of example, and which should be read with reference to the accompanying drawings.

EXAMPLE A multicolor offset printing machine is configured to backprint a two-color design onto a dinner plate.

The machine has a rotatable product support IO, which support 10 is configured to hold three plays (horizontal but upside down) evenly spaced around its vertical axis of rotation. has been done. The product support has conventional types of means for placing each plate in its correct position. The support is configured to be indexed in a uniform 120° rotation about its axis of rotation.

Similarly, a rotatable pad support 12 supports three silicone rubber transfer pads T above the level of the product support 10, which also have a uniform 12
It is configured to be indexed by a rotation of 0°. The transfer pad is of a conventional dome shape of the type well known when offset printing ceramic products. Pad support 12
has an axis that is offset from the axis of the product support 10, so that between the indexing of the two supports, each transfer pad T is positioned directly above each play P of the product support, as shown in the drawing. .

Each transfer pad T is attached to pad support 12 by a vertically aligned roller unit. This allows each pad to be raised and lowered on the support, and the three cylinder units are configured to operate in unison.

The printing machine also has a first print supply unit 14 and a second print supply unit 14.
It has a print supply unit 16.

Each of the units 14.16 includes a platen 1 providing a flat, horizontal top surface constituting an intermediate surface for the printing process.
It has 8. The platen 18 is rotatably mounted with a vertical rotation axis in the middle, and is configured to be indexed at 180 degrees around the axis, with both ends of the platen being rotated alternately.
It is provided below the transfer pad T of the pad support 12 and the screen printing device 20 of the print supply unit. Each printing device 20 is configured in a conventional manner to deposit a predetermined pattern of ink onto the top surface of a platen below it.

The surface of each platen 18 is formed with a layer of a suitable silicone rubber material. This material, in conjunction with the material of the silicone rubber transfer pad T and the appropriate ink formulation, is generally selected as disclosed in patent specification GB-B 2118900 and European patent application 833022973. Both the platen 18 and the screen of the printing device 20 are heated to maintain the ink in the proper condition.

During operation of the printing machine, the first print supply unit 14 is set up to form a first print (indicated in the drawing in the drawing by a circle) on its platen in a first color, and the second print supply unit 16 is
and set the second platen (indicated by a cross in the drawing)
Form a print in a second color. Rotate each platen 180°
Rotate the print onto the transfer pad T of the pad support 12.
Position it directly below one of them.

Product support 10, pad support 12, and platen 18 are such that indexing movements occur together in synchronization each time transfer pad T is lifted, so that each pad can: (1) lower the pad; the pad to engage the platen 18 of the first print supply unit 14 and lift the pad to pick up the first colored print on the surface of the platen 18 (2).
) lowering the pad to engage the platen of the second print supply unit 16, raising the pad to pick up the second colored print superimposed on the first print, and (3) lowering the pad to pick up the second colored print superimposed on the first print. plate P and raising the pad to apply the first print and the second print together to the surface of the plate.

In this manner, the design formed by the combination of the first print and the second print is assembled on the surface of the transfer pad and applied to the product in - impressions. In general, there is no reason why designs of three or more colors cannot be similarly clustered and applied.

[Brief explanation of the drawing]

The drawing is a schematic plan view of a printing machine. 16...Second print supply unit 18...Platen 20. Screen printing device 10・ l　2　・ 14・ @0 pad ··plate ・Product support ・Pad support ・First print supply unit

Claims (6)

[Claims] (1) A repetitive offset printing process in which a design of two or more colors is applied to the surface of an article in a single cycle of operation, the cycle including at least placing ink of a first color in a predetermined pattern on an intermediate surface. forming a first print and engaging a transfer pad with the intermediate bearing the first print;
removing the transfer pad from the intermediate surface and picking up the first print on the pad, placing a predetermined pattern of ink of a second color on the intermediate surface to form a second print, and moving the transfer pad with the first print onto the pad; engaging the intermediate surface bearing two prints, moving the transfer pad away from the intermediate surface to pick up the second print, engaging the transfer pad bearing the first print and the second print with the surface of the article, and moving the transfer pad away from the intermediate surface; First, away from the item.
A repetitive offset printing process that involves the steps of applying a print and a second print to the surface of an article. (2) A method according to claim 1, wherein the first print is placed on the first intermediate surface and the second print is placed on the second intermediate surface. (3) A method according to claim 1 or claim 2, wherein the print is formed on the intermediate surface or each intermediate surface by screen printing. (4) a plurality of print supply units each having a printing machine and a platen providing an intermediate surface configured to receive ink from the printing machine when a print is formed on the intermediate surface; and at least one print supply unit; a pad configured to support a transfer pad so that the pad can be pressed against a platen to pick up a plurality of prints and pressed against an article to apply the assembled prints to the article in a single impression; An apparatus for carrying out the method according to claim 1, comprising: a support. (5) The platen of each print supply unit is 180°
5. The apparatus according to claim 4, wherein the platen is arranged to be rotated with a rotational index of 1, and wherein the opposite ends of the platen are alternately projected under the printing machine and pad support of the unit. (6) the pad support is configured to support a plurality of transfer pads, the pad support being rotated at a uniform index to sequentially counter-align each pad with the article on each platen and article support; Apparatus according to either claim (4) or claim (5), configured to perform.