ITPD20120046A1 - EQUIPMENT FOR PRINTING ON PAPER FOR PAPER BAGS - Google Patents

Description

PAPER PRINTING EQUIPMENT FOR MAKING PAPER BAGS

DESCRIPTION

The present invention relates to an equipment for printing on paper for making paper bags.

Nowadays the automatic production of paper bags, so-called 'shoppers', requires that first a paper reel is mounted on a printing machine known as 'flexographic', for printing on the paper reel of characteristic, distinctive and ornamental images and signs. that you want to appear on sight once the paper bag is made.

As the printed paper tape exits the flexographic printing machine, it is rewound to define a printed paper reel, which reel is ready to be loaded onto a paper bag packaging machine.

Inside such a packaging machine, the pre-printed ribbon is processed, that is folded, glued, cut and equipped with handles, to define, in fact, a paper bag.

The use of a flexographic machine for pre-printing a paper tape, although widespread, has some drawbacks.

Flexography is a direct rotary printing method, which uses raised matrix plates of rubber or photopolymer materials, called clichés; the letterpress matrix, flexible and soft, is wound on a cylinder; the cliché transfers the ink directly to the substrate to be printed thanks to a slight pressure exerted by a pressure cylinder.

As many master plates are used as there are primary colors necessary to achieve the desired printing, and in particular, one or more colors are generally used for paper printing for the production of paper bags, and consequently as many master plates.

This implies that whenever the image to be printed on the paper needs to be changed, it is necessary to replace the master plates in use with as many new and different master plates, with consequent additional costs and downtime in which the flexographic machine is stopped.

These flexographic machines, due to the aforementioned peculiarities, although they can be integrated with a machine for the production of paper bags, involve the drawback that every stop of the flexographic, due to plate replacement, also requires the packaging machine to stop, with obvious negative repercussions on production rates.

Therefore, the use of similar flexographic machines does not allow the printing data to be varied online, ie images, codes, symbols, dates, addresses and the like which are intended to appear printed on the paper.

Furthermore, normally, in order to be convenient, the preparation of new matrix plates is designed and carried out for the production of batches of paper bags of at least five thousand units.

The object of the present invention is to provide an equipment for printing on paper for making paper bags, capable of obviating the aforementioned drawbacks of the known art.

Within this aim, an object of the invention is to provide an equipment which allows to print continuously even in the event of a modification or a change of the image to be printed on the paper, and which allows to vary in line the print data, i.e. images, codes, symbols, dates, addresses and the like that you want to appear printed on the paper.

Another object of the invention is to provide a more flexible and economical equipment with respect to known flexographic printing machines.

Another object of the invention is to provide an equipment which can be integrated with a machine for the continuous production of paper bags.

Not least object of the invention is to propose an equipment for printing on paper for making paper bags, which can be produced with known systems and technologies.

This task, as well as these and other purposes which will become clearer hereinafter, are achieved by a paper printing equipment for the packaging of paper bags, which is characterized in that it comprises a reel of paper tape for the packaging of paper bags, printing means of the ink jet type, for continuous printing on said paper web, means for moving and tensioning said paper web, drying means for the printed paper web, means for return of the printed and dried ribbon to a subsequent automatic packaging machine for paper bags.

Further characteristics and advantages of the invention will become clearer from the description of a preferred but not exclusive embodiment of the equipment for printing on paper for packaging paper bags according to the invention, illustrated, by way of non-limiting example, in the accompanying drawing table, in which: - Figure 1 illustrates a schematic side view of an apparatus for printing on paper for packaging paper bags according to the invention.

With reference to the diagram of the aforementioned figure, an equipment for printing on paper for packaging paper bags is indicated as a whole with the number 10.

This equipment 10 comprises an axis 11 for a reel 12 of paper tape 13 for packaging paper bags.

It also comprises printing means 14 of the ink jet type, for continuous printing on said paper web 13, and means for moving and tensioning the paper web 13 during the printing operation.

There are also means 15 for drying the printed paper web 16, and means 17 for returning the printed and dried web 18 to a subsequent machine 19 for the automatic packaging of paper bags, the latter being possibly also of a known type, and it is not intended to be the subject of the present invention.

The ink jet printing means 14 are preferably, but not exclusively, provided by a piezoelectric technology printing head. The drying means 15 are provided by infrared radiation emitters, such as for example infrared lamps.

The means for moving and tensioning the paper web 13 are given, in the present embodiment, to be understood as not limiting the invention, by two pairs of drawing rollers, 20 and 21 respectively.

Each pair of drawing rollers 20 and 21 comprises a drawing roll, 22 and 23, and a pressure roll, 24 and 25, with adjustable thrust.

The traction roller 22 and 23 is fixed to a supporting frame, not shown for simplicity, while the pressure roller 24 and 25 is carried between two opposite brackets, one of which 32 and 33 is shown in figure 1, which brackets are pivoted to the supporting frame and subjected to the action of a corresponding fluid-dynamic actuator 34 and 35, for example with compressed air, which is therefore responsible for determining the thrust of the pressure roller on the traction roller.

Between the pairs of drawing rollers 20 and 21 there is a support and sliding platform 26 for the paper web 13, in correspondence with which said ink jet printing means 14 and the subsequent drying means are placed.

The means for moving and tensioning the paper web also comprise an oscillating roller 27, also known as a 'dancer roller', for recovering the correct working tension of the paper web 13.

The oscillating roller 27 is carried between two opposite brackets, one of which, indicated by 36, is shown in figure 1, pivoted to the supporting frame and subjected to a tension load of the belt 13; such load is for example determined by a pneumatic actuator 37 whose thrust is suitably controlled and regulated by a corresponding sensor apparatus, in turn interconnected with an electronic control and management unit capable of also intervening on the pairs of traction rollers 20 and 21 .

The return means 17 for the printed and dried paper web 18 comprise a series of return rollers, indicated with 28, 29, 30, 31 in figure 1, suitable for preparing the printed and dried paper web 18 for entry into a subsequent machine for packaging paper bags 19. In the embodiment of the equipment according to the invention 10 described here, a first return roller 28 is arranged to deflect the paper web 13 coming out of the reel 12 upwards, while the first pair of traction rollers 20 deflects the belt 13 in a direction of travel which is opposite to the direction of output of the same belt 13 from the reel 12.

The printed and dried web 18 is then returned upwards by the second pair of traction rollers 21, and subsequently returned by the return rollers 29, 30 and 31 so as to assume again the same position that the belt 13 has just come out from coil 12.

In this way, the paper tape 13 is printed on that side of it which is facing downwards at the entrance to the packaging machine 19.

The return rollers are therefore to be understood as being predisposed according to the operation of the packaging machine, which may require the paper web to have the printed face facing downwards.

The paper bag packaging machine 19 is to be understood as of a known type, for example a machine capable of implementing a paper bag production system as described and claimed in the international patent application PCT / IT2008 / 000214 in the name of Giacometti Fernando.

In practice it has been found that the invention achieves the intended aim and objects.

In particular, the invention provides an equipment which allows, thanks to the ink jet printing means, to print continuously even in the event of a modification or a change of the image to be printed on the paper. In fact, inkjet printing does not require matrix plates, and therefore does not require replacement costs and times, and it is instead sufficient to modify the image to be printed through the electronic control and management unit, therefore quickly. , without additional costs and without interrupting the operation of the associated packaging machine.

Furthermore, the invention provides a more flexible and cheaper equipment than known flexographic printing machines, thanks precisely to the ease of use of the ink jet printing means, which allow the printing data to be varied online. that is, images, codes, symbols, dates, addresses and the like that you want to appear printed on the card.

In addition, the invention has developed an equipment that can be used with economic advantage even for production batches of paper bags much lower than five thousand units, a reference number for obtaining an economically advantageous printing process with flexographic machines. of a known type.

Furthermore, with the invention an equipment has been developed which allows the reduction of manpower, since the assembly operations of a reel of pre-printed paper tape on the packaging machine are no longer foreseen, much less the operations of removal of a pre-printed paper reel from a flexographic machine and subsequent storage or shipment, with further savings in terms of storage space.

The equipment according to the invention can be easily integrated with a machine for the continuous production of paper bags of a known type.

Last but not least, the invention has developed an equipment for printing on paper for making paper bags, which can be produced with known systems and technologies.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; moreover, all the details can be replaced by other technically equivalent elements.

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

Where the features and techniques mentioned in any claim are followed by reference marks, these marks have been affixed for the sole purpose of increasing the intelligibility of the claims and consequently such reference marks have no limiting effect on the interpretation of each element. identified by way of example by these reference signs.

Claims (6)

CLAIMS 1) Equipment (10) for printing on paper for packaging paper bags, which is characterized in that it comprises a reel (12) of paper tape (13) for packaging paper bags, printing media (14) of the ink jet type, for continuous printing on said paper web (13), means for moving and tensioning said paper web (13), drying means (15) of the paper web printed paper (16), means (17) for returning the printed and dried ribbon (18) to a subsequent machine (19) for automatic packaging of paper bags. 2) Equipment according to claim 1, characterized in that said ink jet printing means (14) are given by a piezoelectric technology printing head. 3) Equipment according to the preceding claims, characterized in that said drying means (15) are given by infrared radiation emitters. 4) Equipment according to the preceding claims, characterized in that said means for moving and tensioning said paper web (13) are given by two pairs of drawing rollers (20, 21) each comprising a traction roller (22 , 23) and a pressure roller (24, 25) with adjustable thrust, between said pairs of drawing rollers there being a support and sliding platform (26) for the paper web, in correspondence with which said means are placed to operate inkjet printing (14). 5) Equipment according to the preceding claims, which is characterized in that said means for moving and tensioning said paper web comprise an oscillating roller (27) for recovering the tension. 6) Equipment according to the preceding claims, which is characterized in that said means (17) for returning the printed and dried paper web (18) comprise a series of return rollers (28, 29, 30, 31) suitable for preparing the printed and dried paper ribbon (18) for entry into a subsequent paper bag packaging machine (19).