This invention relates to systems for producing labels comprising an adhesive base coated with a layer of resin and to the respective production method.

More particularly, the base of these labels has a lower face which removably adheres to a flexible support, in particular paper treated with a release agent, and a printed upper face which bears the desired written information and/or images. The resin layer has a decorative/protective function and may further highlight that which is printed on the base.

According to a known technique, the flexible support is comprised of a paper sheet — typically rectangular or square — on which a plurality of labels is fixed in a removable way, usually arranged according to a pattern ordered in rows and columns.

Consequently, each sheet must be produced separately from the others, which makes the respective production process somewhat complex. This complication, if not particularly burdensome for batches including a small number of labels, becomes annoying for numerically larger batches. Moreover, having a very large number of separate label sheets also makes the management of subsequent processing steps very complex, as the labels must be detached from the respective support and applied to the items to be labeled.

Additionally, DE 10 2010 001 794 A1 discloses a system for producing a roll of flexible material with a plurality of labels, including a fixed table for supporting the roll during the production process.

An object of this invention is therefore to remedy the drawbacks highlighted above in the prior art.

According to the invention, this object is achieved by a machine for producing a roll of flexible material carrying a plurality of labels each comprising an adhesive base coated with a layer of resin, said machine comprising:

- a first motorized shaft for unwinding the roll carrying a plurality of adhesive bases, - a conveyor belt adapted to support said flexible material along a direction of travel in a flat configuration,

- at least one nozzle for casting the resin on the base of the labels, located above the conveyor belt,

- at least one UV lamp located above the conveyor belt downstream of said at least one nozzle, for crosslinking the cast resin, and

- a second motorized shaft for winding the roll carrying a plurality of labels, each of which comprises an adhesive base coated with a layer of crosslinked resin.

Advantageously, the aforesaid at least one UV lamp is provided with means for moving along the direction of travel of the conveyor belt.

A further subject of this invention is a method for producing the aforesaid roll, comprising the subsequent steps of:

- unwinding a roll carrying a plurality of adhesive bases,

- adhering the flexible material unwound from the roll to a surface of a conveyor belt, so that it assumes a flat configuration,

- casting a predetermined quantity of resin onto each adhesive base,

- crosslinking said predetermined quantity of cast resin by UV radiation, and

- winding the flexible material, so as to form a roll carrying a plurality of labels, each of which comprises the adhesive base coated with the layer of crosslinked resin.

Advantageously, the movements with respect to the conveyor belt of a resin casting nozzle are controlled by a PUC device on the basis of signals received from a camera which detects the position of the adhesive bases on the conveyor belt.

The machine of the invention allows for the production of a very large number of labels adhering to the same flexible support in the form of a roll, simplifying both the respective production process and the subsequent steps of detaching the labels from the roll and applying them to the items to be labeled.

All the aforesaid procedures may in effect be carried out in a substantially continuous rather than discontinuous mode, with the consequent advantages in terms of speed and standardization: in particular, the fact that the labels are supported by a roll allows them to be manipulated by automated devices.

Overall, the machine of the invention is therefore able to resin labels placed on a pre-printed roll, cure the resin deposited on the labels, and subsequently roll up the resin-coated roll on a reel, making it ready for subsequent processing. Optionally, the machine of the invention may also work on sheets, rather than on a roll.

Further advantages and features of this invention will become apparent from the following detailed description, given by way of non-limiting example with reference to the accompanying drawings, wherein:

Fig. 1 is a schematic perspective view of a machine of the invention,

Fig. 2 to 5 are perspective views on an enlarged scale of respective details of the machine of Fig. 1,

Fig. 6 is a view of a length of roll entering the machine illustrated in the previous figures, and

Fig. 7 is a view of a length of roll exiting the machine illustrated in Fig. 1 to 5.

A machine (illustrated in Fig. 1 to 5) makes it possible to obtain, from a roll 10 of flexible paper support material carrying on one of its faces a plurality of adhesive bases 12 (Fig. 6), the same roll 10 carrying a plurality of labels, each comprising the adhesive base 12 coated with a layer of crosslinked resin 14 (Fig. 7). The labels are arranged according to an ordered arrangement of linear rows which follow one another along the longitudinal extension of the roll 10 and once detached from the roll 10 may be used to adhere to a respective item to be labeled. For greater clarity, the labels and their bases 12 are not shown in Fig. 1 to 5.

The machine (Fig. 1) comprises a support frame 16 and is equipped with a PLC device 18 for controlling the operation of its components in the various operation phases.

A first motorized shaft 20 is rotatably mounted on the initial part of the frame 16 for unwinding the roll 10 carrying the adhesive bases 12 (Fig. 6). In a manner known per se and not illustrated in the figures, the first motorized shaft 20 is provided with a rotary electric drive motor, for example of the brushless type, and with an expander device in the radial direction for example of the pneumatic type, so as to allow, when desired, to make the roll 10 rotating together with the shaft 20.

Downstream of the first shaft 20, the machine comprises (Fig. 2) a tensioner 22 for the flexible material unwound from the roll 10 and a plurality of idle rollers 24 which send the unwound flexible material toward an entry end of a conveyor belt 26. Said conveyor belt has a belt having a plurality of holes 28 and is provided with a suction device 30. The direction of travel (see arrow 31) of the conveyor belt 26 is substantially orthogonal to the longitudinal axis of the first shaft 20 and of the idle rollers 24.

Above an initial length of the conveyor belt 26 there is mounted (Fig. 3) a nozzle 32 for casting the thermosetting resin 14, which nozzle 32 is provided with movement means which include two rails 34 respectively mounted on the support frame 16 at the sides of the conveyor belt 26, and a bar 36 having respective ends sliding on the rails 34 and oriented transversely with respect to the direction of travel of the conveyor belt 26. In turn, the nozzle 32 is slidably mounted on the bar 36, is fed by a resin tank not shown in the figures and may be associated with a visual detection system of the bases 12, such as a camera 43.

The machine further comprises (Fig. 4) an apparatus for crosslinking by means of radiation (as will be explained in detail in the subsequent description of operation) of the resin 14 cast onto the bases 12, which apparatus is enclosed within a casing 38 located above a length of the conveyor belt 26 downstream of the nozzle 32. The crosslinking apparatus comprises a plurality of UV lamps 40 provided with a device 42 for moving along the direction of travel of the conveyor belt 26.

Downstream of the exit end of the conveyor belt 26 there are arranged a further tensioner 44 for the flexible support material of the roll 10 and a second motorized shaft 46 for rewinding the roll 10.

In a way known per se and not shown in the figures, the second motorized shaft 46 is provided with a rotary electric drive motor, for example of the brushless type, and with an expander device in the radial direction, for example of the pneumatic type, so as to allow, when desired, to make the roll 10 rotating together with the shaft 46.

The operation of the previously described machine is now illustrated.

Due to the rotation of the first motorized shaft 20, the roll 10 carrying a plurality of adhesive bases 12 is unwound and guided through the tensioner 22 and the idle rollers 24 at the entry end of the conveyor belt 26. Due to the suction action exerted by the device 30 through the holes 28, the flexible support material unwound from the roll 10 adheres to the surface of the conveyor belt 26 and assumes a flat configuration.

Then, the nozzle 32 casts a predetermined amount of thermosetting resin 14 onto each base 12 of a length of flexible roll material 10 adhering to the surface of the conveyor belt 26 after the nozzle is brought near to each base 12 as a result of its movement relative to the bar 36 and the movement of the bar 36 along the direction of travel of the belt 26. If necessary, it is also possible to adjust the height of the nozzle 32 with respect to the conveyor belt 26. The movements of the nozzle 32 are controlled by the PLC device 18 based on signals, for example received by a camera which detects the position of the bases 12.

The longitudinal movement of the nozzle 32 may be synchronized with the travel of the conveyor belt 26, so as to allow the resin 14 to be cast precisely on each base 12, or the travel of the conveyor belt 26 may be stopped intermittently to allow the resin 14 to be cast on all the bases 12 adhering to a length of the flexible support material.

This length is then directed toward the crosslinking apparatus for irradiation following the travel of the conveyor belt 26. Also in this case, the longitudinal movement of the lamps 40 of the crosslinking apparatus may be synchronized with the travel of the conveyor belt 26 so as to irradiate the resin 14 cast onto each base 12 for a time sufficient to cause complete crosslinking, or the travel of the conveyor belt 26 may be stopped intermittently for a time sufficient to allow one of the lamps 40 to irradiate the resin 14 cast onto each of the bases 12 adhering to a length of the flexible material, so as to cause its complete crosslinking. It goes without saying that in the steady state operation of the machine, the phases of casting and crosslinking of the resin 14 take place simultaneously on successive lengths of the flexible support material, so that the travel/stop times of the conveyor belt 26 are established in such a way as to allow the coordinated execution of both operations.

The flexible material leaving the conveyor belt 26 is then guided by the other tensioner 44 toward the second motorized shaft 46 which rewinds the roll 10 which now carries the finished labels ready for use (Fig. 7).

Of course, the principle of the invention being unchanged, the details of construction and the embodiments may vary widely with respect to that which has been disclosed purely by way of example, without thereby departing from the scope thereof.