The present invention relates to an apparatus for printing closure bodies of containers.

Apparatuses for printing closure bodies of containers, such as for example closures for vessels or containers made of plastic or metal, are known and widely used.

Traditionally, the printing of closure bodies intended to close containers is performed by means of printing cylinders or pads by virtue of rotogravure, tampographic and offset printing processes.

Specifically, the closures are picked up from a cooling and storage magazine to be fed to a belt or chain which supports pins, also known as “flights”, onto which the caps to be printed are fitted.

Another printing method provides for the use of a wheel to the peripheral region of which said flights or pins are applied in a radial direction.

The chain or wheel then conveys the closure bodies toward a printing station constituted, for example, by printing cylinders or pads which make contact with the upper surface of the closure.

Such apparatuses are scarcely flexible if one wishes to change the formats or the images to be printed, since it is necessary to change the printing cylinders or the printing plates.

This problem is currently very strongly felt, since users require extreme flexibility and frequent format changes increasingly often.

An apparatus for printing closure bodies of containers is known from EP3024660B1, filed by this same Applicant, which comprises a transfer device associated in input with a feeder and in output with an unloader; the transfer device defines a plurality of seats for a respective closure body to be printed which are provided with at least one resting region for at least one abutment portion which is defined on the outer lateral surface of the respective closure body. The seats are mutually spaced apart at preset distances and are movable along a transfer trajectory; the apparatus comprises a device for digitally printing the closure bodies to be printed which is arranged along the transfer trajectory. This solution, while ensuring greater flexibility, has low productivity.

The aim of the present invention is to provide an apparatus for printing closure bodies of containers that is capable of improving the background art in one or more of the above mentioned aspects.

Within this aim, an object of the invention is to provide an apparatus for printing closure bodies of containers that ensures high productivity but which at the same time meets the requirements of flexibility currently required.

Another object of the invention is to provide an apparatus for printing closure bodies of containers that is highly reliable, relatively easy to provide and at competitive costs.

This aim and these and other objects that will become better apparent hereinafter are achieved by an apparatus for printing closure bodies of containers according to claim 1 , optionally provided with one or more of the characteristics of the dependent claims. Further characteristics and advantages of the invention will become better apparent from the description of some preferred but not exclusive embodiments of the apparatus for printing closure bodies of containers according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a schematic side view of the apparatus according to the invention;

Figure 2 is an enlarged-scale cross-sectional view of a peripheral portion of the apparatus of Figure 1 and in particular of a closure body engaged with a supporting element.

With reference to the figures, the apparatus for printing closure bodies of containers according to the invention, generally designated by the reference numeral 1, comprises a closed conveyance circuit 2 comprising a plurality of supporting elements 3 which are configured to support respective closure bodies 10.

The closure bodies 10 have a bottom surface 11 and a lateral surface (or skirt) 12 which cooperate in order to define a concave region 13.

The bottom surface 11 is advantageously substantially flat.

A device 20 for feeding the closure bodies 10 to be printed and a device 30 for unloading the printed closure bodies are arranged along the closed conveyance circuit 2.

According to the present invention, along the extension of the closed conveyance circuit 2, between the feeding device 20 and the unloading device 30 along the movement direction of the supporting elements 3, there are, in sequence, at least one first printing station of the analog type 42, at least one second printing station of the digital type 43 and at least one drying station 44.

The at least one first printing station of the analog type 42 and the at least one second printing station of the digital type 43 are adapted to print at least one portion of the face directed toward the outside of the bottom surface 11 of the closure body 10.

Preferably, as shown in Figure 1, the closure bodies 10, during their movement along the closed conveyance circuit 2, are arranged with the face of their bottom surface 11 directed outward, facing the at least one first printing station of the analog type 42 and the at least one second printing station of the digital type 43.

Conveniently, the apparatus 1 comprises, between the feeding device 20 and the at least one printing station of the analog type 42, a surface treatment station 41 configured to treat at least the portion of the closure bodies 10 to be printed.

In particular, the surface treatment station 41 is chosen from the group comprising:

- a treatment station of the flame type;

- a treatment station of the corona type;

- a treatment station of the plasma type.

The at least one printing station of the analog type 42 is chosen from the group comprising:

- a printing station of the offset type;

- a printing station of the pad type;

- a printing station of the rotogravure type.

Preferably, the at least one station of the analog type 42 comprises a printing station of the offset type, so as to stress the closure bodies 10 less during ink transfer.

With reference to the embodiment shown in Figure 1, the apparatus 1 comprises a first printing station of the analog type 42a configured to transfer a base layer onto a portion to be printed of the closure body 10.

Advantageously, the first printing station of the analog type 42a is adapted to print a portion in a single color, typically white or a background color, for example neutral.

Conveniently, the apparatus 1 comprises a second printing station of the analog type 42b, which is configured to transfer onto a portion to be printed of the closure body 10 at least one imprint of at least one color.

Specifically, the second printing station of the analog type 42b is configured to provide imprints of at least two colors, and more particularly to provide four-color imprints.

The apparatus 1 comprises, between the feeding device 20 and the at least one printing station of the analog type 42, a station for the removal of static charges 46.

The apparatus 1 comprises, between the at least one printing station of the analog type 42 and the printing station of the digital type 43, at least one analog-type print drying station 45.

The drying station 44 and the analog-type print drying station 45 are of the type adapted to dry the type of inks used by the respective printing stations.

By way of example, if UV inks are used, the drying stations 44 and 45 will have UV lamps.

The analog-type print drying station 45 is arranged, conveniently, between the first printing station of the analog type 42a and the second printing station of the analog type 42b.

According to a possible constructive variation, the apparatus 1 comprises means for controlling the position of the closure bodies 10 at the at least one digital printing station 43.

The control means are, in particular, adapted to keep the portion of the closure bodies 10 to be printed by means of the digital printing station 43 at a distance comprised between a minimum distance and a maximum distance which are preset in order to ensure optimum printing.

The supporting elements 3 comprise respective elongated bodies 3a, also known as “flights”, which are designed to engage an engagement portion 10a defined on the surface directed toward the inside of the closure bodies 10.

According to a practical embodiment, shown in Figure 1, the closed conveyance circuit 2 is defined at the peripheral region of a carousel which can rotate about a respective axis of the carousel.

Preferably, the elongated bodies 3a are arranged along extension directions which extend radially with respect to the axis of the carousel.

Nothing forbids the closed conveyance circuit 2 from having a different configuration: for example, it might be defined along a chain which is wound around two or more guiding pulleys and supports the supporting elements 3 so that they are mutually spaced apart.

The closure bodies 10 comprise closures for containers, such as for example bottles.

In this respect, they can be made of plastic or metal and may be coupled to the container both by screwing and by deformation (such as “crown” caps).

The operation of the apparatus 1, according to the invention, is as follows.

The closure bodies 10 are fed by virtue of the feeding device 20 to the apparatus 1 so that each supporting element 3 can engage stably with a respective closure body 10 so as to move it along the closed conveyance circuit 2.

Advantageously, the supporting element 3 engages with the surface of the closure body 10 that is directed inward and which therefore does not need to be printed.

During its movement along the closed conveyance circuit 2, the closure body 10 is brought to a series of stations and in particular, if provided, at a surface treatment station 41 before it is brought proximate to a printing station of the analog type 42.

Preferably, at a first printing station of the analog type 42a, which comprises for example an offset cylinder, a base layer, typically white, is transferred to a portion of the closure body 10.

Subsequently, the closure body is brought to a drying device 45 of the first printing station of the analog type 42a and then is brought to the second printing station of the analog type 42b, which is adapted to provide an imprint in multiple colors, optionally also partially superimposed on the base layer.

At this point, the closure body is brought to the printing station of the digital type 43, which performs a printing that is customizable and on the configuration of which (shape and colors) it is possible to intervene in real time.

Once the digital printing has been performed, the closure body is brought to a drying station 44 and then, if provided, to an inspection station 47 arranged downstream of the printing station of the digital type 43.

The inspection station 47 can be functionally associated with an actuation and control system in order to provide feedback, if necessary, to the printing station of the digital type 43.

In practice it has been found that the invention achieves the intended aim and objects, by providing an apparatus 1 capable of ensuring high productivity, due to the possibility of providing the base layer and, if needed, colored imprints by analog printing, while allowing considerable flexibility in the customization of the printing, by virtue of the in-line use of the digital printing station.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims; all the details may furthermore be replaced with other technically equivalent elements.

In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

The disclosures in Italian Patent Application No. 102021000016298, from which this application claims priority, are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.