Patent ID: 12208590

The longitudinal direction is defined with reference to the direction of travel or transport of the plate elements in the packaging manufacturing line, along their longitudinal centerline. The transverse direction is defined as the perpendicular direction in a plane that is horizontal to the direction of travel of the plate elements. The upstream and downstream directions are defined with reference to the direction of movement of the plate elements, following the longitudinal direction throughout the packaging manufacturing line, from the line entrance to the line exit. The proximal and distal edges of the plate element are defined in this non-limiting example with respect to the driver side and the side opposite to the driver side of the machine and the plate element shaping unit as the plate element travels forward.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

With reference toFIG.2toFIG.4, a particular embodiment 2 of a line for manufacturing packagings according to the invention from plate elements in the form of corrugated cardboard sheets is here described by way of example.

The plate elements in their different states of processing are globally referred to by the reference mark4inFIG.2toFIG.4, with index letters a, b, c and d associated with the reference mark4to indicate the state of processing of the plate element in question. The plate element4is shown inFIG.3in different states of processing, explained below, with the reference marks4a,4b,4cand4d.

The direction of transport of the plate elements4from upstream to downstream in the packaging manufacturing line2is indicated by the arrow FD in all ofFIG.2toFIG.4.

As visible inFIG.2, the packaging manufacturing line2comprises a plurality of units and devices20to33that are synchronized on a single machine step, and that consecutively perform the various operations required for the manufacture of packagings in the form of folding boxes. All of the units and devices of the packaging manufacturing line2are synchronously controlled by one or more control units32provided with man-machine interfaces.

Thus, in the direction of transport FD of the sheets, the packaging manufacturing line2substantially comprises, in the example, an automatic plate element feeding station20, a feeder21, four flexographic printing units22ato22d, a shaping unit33with a plate element processing unit23and a cutting unit24, a stripper-vibrator25, a folder-gluer26, a counter-ejector27, a double tying machine28, a unit for separating folding boxes29and a palletizer30.

The plate element processing unit23in combination with the cutting unit24form a plate element shaping unit33(FIG.2andFIG.4).

Two conveyor tables31are arranged one after the other in this packaging manufacturing line2, in order to achieve a 180 degree change of direction of the line to allow its implementation in a limited floor area. Other configurations are possible, for example without any table, so as to keep the tied stack1ein the same rectilinear direction up to the unit for separating folding boxes29, or with a single table for a 90 degree change in direction of the tied stack1e.

The automatic plate element feeding station20has the function of feeding plate elements4ato the packaging manufacturing line2. The plate elements4aare the blank plate elements to be processed by the line2to form the packagings. As is visible inFIG.3, the plate element4ais typically a rectangular sheet of cardboard.

In station20, the plate elements4aare successively inserted, one by one, into the packaging manufacturing line2at a cadence corresponding to the machine step on which the various units of line2are synchronized.

After being inserted into the line2, the plate element4ais fed into the feeder21. The feeder21performs an alignment operation and corrects, for example, a position of an edge of the plate element4ato achieve the desired positioning for printing operations performed by the four printing units22ato22d.

The printing units22athrough22dperform four-color flexographic printing on the plate element4a, with the printing units22athrough22deach printing a different color on the plate element4a. The printing units22a-22doutput a printed plate element4b, visible inFIG.3, which is fed into the plate element shaping unit33.

With reference toFIG.4, the plate element shaping unit33is associated with the cutting unit24to manufacture a cut plate element4d, formed of two layers P1and P2, respectively referred to as “front layer” and “back layer”, from the printed plate element4b. In the cut plate element4d, the layers P1and P2are arranged in juxtaposition, with respect to the direction of transport FD, and are connected to one another by attachment points45. The attachment points45are aligned with a transverse central axis AL of the plate element4d. Each layer P1and P2corresponds to a folding box packaging.

The plate element processing unit23processes the printed plate element4band provides a cut plate element4c. In the cut plate element4c, slitting and scoring operations have been performed to form box sides40and box flaps41for each of the layers P1and P2. Other cutting operations were also performed, such as an edge cut on a distal side edge42of the plate element and tab cutouts, on the proximal opposite side edge43, to form a box tab441and442for each of the layers P1and P2. The plate element processing unit23performs all of the processing operations on the printed plate element4bin a single machine step, to obtain the cut plate element4c.

The cutting unit24is typically a rotary cutter with rotating cylindrical shafts. The cutting unit24has the function of making the attachment points45between the layers P1and P2in the cut plate element4cprovided by the plate element processing unit23, to obtain the cut plate element4d.

In accordance with an embodiment example of the invention, the plate element processing unit23is formed by the association in series of two so-called slotter plate element processing units23aand23b, which preferably have the same general architecture. The first unit23ais traversed before the second unit23bby the plate element moving in the direction of transport FD.

The performance of the processing operations on the plate element is optimized, by distributing these processing operations judiciously between the two units23aand23b.

The plate element processing units23aand23b, are of the type with four pairs of rotating cylindrical shafts. The double plate element processing unit23formed by the combination of units23aand23bthus has eight pairs of rotating cylindrical shafts,230ato233afor unit23aand230bto233bfor unit23b. The eight pairs of rotating cylindrical shafts,230ato233aand230bto233b, are spaced apart from each other at the same center distance AX, as shown inFIG.4. The length of the center distance AX typically corresponds to a minimum size of plate element that can be processed in the packaging manufacturing line2.

The first plate element processing unit23amakes central slits4612in the sheet. As shown in the cut plate element4c, the central slits4612are aligned in a transverse central axis AL of the plate element and participate in the formation of the box sides40and box flaps41of the layers P1and P2. The central slits4612are made here by the second and fourth pairs of rotating cylindrical shafts231aand233awhich are equipped with suitable tools.

The first plate element processing unit23alikewise performs first complementary processing operations which include the operations of cutting of the box tab442of the layer P2and of pre-scoring operations4712for, in particular, the making of fold lines in the layers P1and P2. These first complementary processing operations are performed by tools mounted, for example, on the third pair of rotating cylindrical shafts232aof the first plate element processing unit23a. The first pair of rotating cylindrical shafts230aof the first plate element processing unit23ais used here for conveyance of the sheet.

The second plate element processing unit23bmakes front edge slits461and rear edge slits462. The slits461are made on a transverse front edge48AVof the plate element and participate in the formation of the box sides40and the box flaps41of the layer P1. The slits462are formed on a transverse rear edge48ARof the plate element and participate in the formation of the box sides40and the box flaps41of the layer P2. The front edge slits461and rear edge slits462are respectively made here by the fourth and second pairs of rotating cylindrical shafts233band231b, which are provided with suitable tools.

The second plate element processing unit23balso performs complementary second processing operations that include the operations of cutting of the body tab441of the layer P1and final scoring operations4712for the performance of, in particular, the fold lines in the layers P1and P2. These second complementary processing operations are performed by tools mounted, for example, on the third pair of rotating cylindrical shafts232bof the second plate element processing unit23b.

In the second plate element processing unit23b, the first pair of rotating cylindrical shafts230bperforms a third complementary processing operation which corresponds to a crushing of the cardboard at the box tabs441and442on the proximal side edge43, as well as a crushing of the cardboard at the opposite distal side edge42. This crushing of the box tabs441and442and the opposite distal side edge42allows for the reduction of the thickness and is intended to avoid excess thickness in the folded and glued assembly5(FIG.3), at the gluing of the flaps441and442to their respective opposite distal side edge42of the corresponding box sides.

The performance by the double plate element processing unit23of the aforementioned processing operations results in the cut plate element4cshown inFIG.3andFIG.4.

The cut plate element4cis then fed into the cutting unit24. Suitable tools are mounted in the rotating cylindrical shafts of the cutting unit24and make selective cuts in the plate element to obtain the attachment points45. The cutting unit24outputs the cut plate element4dcomprising the layers P1and P2connected solely by the attachment points45.

Referring once again, in particular, toFIG.2andFIG.3, the cut plate element4dis fed from the cutting unit24into the stripper-vibrator25. In the stripper-vibrator25, the plate element is cleaned up of dust and freed from the waste generated, in particular, by the slitting and cutting operations. The cut plate element4dis then fed into the folder-gluer26.

In the folder-gluer26, the cut plate element4dis folded and the box tabs441and442are glued to corresponding box sides to obtain the folded-glued assembly5formed by two folding boxes CA1and CA2connected by the attachment points45, the two folding boxes CA1and CA2respectively corresponding to the layers P1and P2.

The counter-ejector27recovers the folded assemblies5successively leaving the folder-gluer26, counts them and forms a stack of folded assemblies6comprising a determined number of folded-glued assemblies5stacked on top of each other. The stack of folded assemblies6is then fed to the double tying machine28.

The double tying machine28comprises two individual tying machines28aand28bentrusted with independently tying up the stacked folded boxes assembly CA1and the stacked folded boxes assembly CA2. Two strapping bands, or ties701and702are thus placed on the stack of folded assemblies6, the one701for the assembly of stacked folding boxes CA1and the other701for the assembly of stacked folding boxes CA2. In this manner, a stack of tied up folded assemblies7is obtained, which is then fed to the unit for separating folding boxes29.

The unit for separating folding boxes29is formed by the series combination of two separators29aand29bof folding boxes, also known as “breakers”. The two successive separators29aand29bof folding boxes are entrusted with separating the tied up stack of folded assemblies7into two batches of tied up and stacked folding boxes81and82, as visible inFIG.3. The separation into two batches81and82is achieved by breaking the attachment points45.

The breaking of the attachment points is achieved in the separators29aand29b, by an automatic process that involves, for example, while exercising pressure, maintaining the assembly of stacked folding boxes CA1and the assembly of stacked folding boxes CA2on two respective support panels and spreading, or inclination, between these support panels to cause the breakage.

The batches of folding boxes81and82are then taken over by the palletizer30, which automatically manages groupings9(FIG.2) on shipping pallets.

The series combination of the two separators29aand29b, forming the unit for separating folding boxes29, makes it possible to optimize and achieve the desired manufacturing rate for the manufacture of folding boxes, from cut plate elements, comprising two layers.

With the same machine step, this invention makes it possible to double the manufacturing rate of folding boxes when compared to the prior art packaging manufacturing line, described with reference toFIG.1. The packaging manufacturing line2according to the invention makes it possible to achieve a manufacturing rate of folding boxes of approximately 40,000 boxes/hour.

The invention is not limited to the particular embodiment which has been described herein by way of example. The person skilled in the art, depending on the applications of the invention, may make various modifications and variants falling within the scope of protection of the invention.