DK174651B1 - Method, for application of offset printing on plastic package, involves application of at least one basic color print on part/whole of package outer wall prior to application of print and hardening it by ultra violet radiation - Google Patents

Abstract

The method involves the application of at least one basic color print on a part or the whole of the package outer wall prior to the application of the main color print and hardening it by ultra violet radiation. This is immediately followed by the application of offset printing, which is likewise hardened by ultra violet radiation.

Description

in DK 174651 B1

The present invention relates to a method of applying dry offset to packages, preferably of plastic material.

5 When printing text, color printing, etc. on pages of packaging of the specified kind, for technical reasons colors used for curing with UV light illumination, whose curing time is very small, are used.

10 When printing color printing on packaging, a plurality of colors are often used to create a preferred appearance of the packaging, which is often transparent, so that the product in the packaging when it is at the point of sale can be viewed by the consumer.

15 Printing of colors and possibly text, takes place on a cloth. Using multiple colors, these outer surfaces of the packaging are applied individually via a color coating cloth, whereupon the respective colors desired to be applied to the packaging side are successively laid out and placed on the cloth, depending on where on the sides of the packaging the color printing is desired to be placed on the side wall of the packaging and the packaging. is rolled along the tablecloth, whereby the color is applied to the side of the packaging and the color is cured immediately after application by illumination of the color-coated packaging side.

When using transparent packaging, but also in color, it can be very difficult to obtain the desired color fastness for the colors printed on the packaging, just as text boxes containing the mandatory product declarations can be very difficult to read for the consumer, unless the text is somehow highlighted. It is to be understood that the printed color or text, by the light penetration which takes place in particular in transparent packaging, 35 means that the color does not appear uniform in any situation, just as printed text in the form of a declaration of goods of the item DK 174651 B1 2 can be difficult to read on the transparent background.

It is known to emphasize a printed text on a packaging item 5 by producing a cliche corresponding to the text, thus applying white color in the box between the individual letters or figures, where they are printed immediately after the application of the cliche. This provides an improvement to the readability of printed text to some extent, but places 10 great demands on the accuracy of the placement of the cliche print relative to the text, where a mere deviation of 1/10 mm will be sufficient to blur the text so that it almost becomes unreadable.

15 However, a cliche which is otherwise expensive to manufacture and use due to the very high accuracy requirements will not solve the problem of the lack of color fastness simply attributed to light or the lack of the same on the back of the printed text or the like on the packaging .

20 In addition, printing on a colored packaging can also result in a completely different end result than first assumed. An example of this could be the application of a blue color print to a yellow packaging, which will give the finished color print a greenish tinge, which cannot be considered satisfactory.

25

It is thus the object of the invention to provide a method for providing printing on plastic packaging wherein the printed color exhibits a greater color fastness than the color fastness obtainable by the known methods. / 30

This object is achieved by prior application of color printing to the packaging, on selected parts of the outer wall of the packaging, or all of it, at least a bottom color cured by illumination with a UV light source and In connection with this operation, the normal successive application of pressure to the same packaging side is applied offset pressure, after which it is also cured by illumination with a UV light source.

In this way, the colors 5 or text applied to the packaging are achieved more clearly, for example, they are applied on a background which, by text printing, contrasts with the printed text, and in the case of other color prints either contrasts with the colors. , or obstruct light from the back of the transparent container wall.

10

Experiments with printing different bottom colors on packaging, both transparent and non-transparent, have shown that an appropriate background color is a white color.

A machine for carrying out the method according to the invention comprises a carousel comprising radially protruding, rotatably mounted brackets for carrying and rotating packaged articles thereon against a color coating cloth in a color work, a color work for applying UV-curing colors to the packaging objects comprising: at least one color coating cloth having a feed unit for feeding the color cloth at a rate corresponding to the circumferential rate of rotation of the container items on the carousel, the width of the color coating cloth at least corresponding to the width of the field on the package 25 to be applied to color printing, a color extruder coating of colors, text or the like on the dye cloth, and which dye additionally comprises a UV light source for illumination of the dyed areas, characterized in that the machine comprises an extended dye cloth for applying a bottom color to the entire electricity clay parts of the packaging's side surface and cured by illumination with a self-contained UV light source before applying the other color / text or successively applied colors / textures to the color coating cloth.

35 DK 174651 B1 4

Hereby it is achieved that the printed color applied to the packaging side, where desired, is placed on a background consisting of a cured bottom color, thereby greatly improving the color fastness of the applied color. Especially when applying a 5 white background color to which color printing is applied subsequently will give a high degree of color fastness. The bottom color is applied in the same operation, at the same time as the normally occurring color print is applied and cured, and at practically the same process time, the packaging being simply rotated an extra 10 times in the color printing machine in connection with the application of the bottom color, after which the normal color application / pressure with subsequent UV light curing takes place. Thus, a significantly improved color fastness of printed colors can be achieved on the packaging, without this resulting in a noticeably increased process time for carrying out the associated operations.

A further advantage of using the background color is that text can be applied to it directly without the need for a cliche, which means that the production of the cliche can be omitted and thus it will be considerably easier to change the text that is printed. eg. a goods declaration if the composition of the product stored in the packaging is changed or if new requirements for the declaration arise, or the like.

25

Claims (2)

A method of applying dry-offset to packaging / preferably of plastic material, with UV-curing colors, and 5 where printing of colors and any. text, takes place on a laying cloth on which at least one color, preferably a plurality of colors, on which the respective colors desired to be applied to the packaging side are applied successively and placed on the tablecloth, depending on where on the sides of the packaging the color print is desired to be placed on the side wall of the packaging. and wherein the packaging is rolled along the tablecloth while simultaneously feeding the tablecloth, whereby the color is applied to the side of the package, and wherein the color is cured immediately after application by illumination of the color-coated packaging side, characterized in that prior to the application of color printing to the packaging, selected portions of the outer wall of the packaging, or all of it, is applied to at least a base color which is cured by illumination with a UV light source and that, in direct connection with this operation, the normal successive application of pressure to the same packaging side is applied offset pressure after which it is also cured by lighting with a UV light source. A machine for carrying out the method according to claim 1, comprising a carousel comprising radially protruding, rotatably mounted brackets for carrying and rotating packing blanks thereon against a color coating cloth in a color work, a color work for applying UV-curing colors to the packaging blanks comprising at least one color coating cloth having a feed unit for feeding the color cloth at a rate corresponding to the circumferential velocity by rotation of the container items on the carousel, the width of the color coating cloth at least corresponding to the width of the field on the packaging to be applied to color printing, for successively laying out colors, text or the like on the 35 color fabric, and which color additionally comprises a UV light source for illumination of the color applied areas, characterized in that the machine comprises an extended color coating fabric for applying a base color. inherit all or part of the packaging's side surface, and an independent UV light source for curing the bottom color, before applying the other 5 colors / text or successively placed colors / textures on the fabric.