This invention refers to a process and a system for wrapping palletised loads.
As is common knowledge, the palletised loads consist of one or more goods distributed in a more or less orderly manner on a pallet so it can be moved and transported in a practical and easy way.
The palletised loads are normally covered with a stabilising wrap that immobilises the loads on the pallet so they can then be transported without any risk of falling or tipping over.
To make such a stabilising covering the usual way is to tightly wrap the sides of the load and pallet with a plastic covering film that is unwound from a dispensing reel.
Wrapping is normally done by means of either automatic or semi automatic wrapping stations, which use one or more machines, intended to move a wrapping head which supports the reel of plastic film.
The moving machine is normally composed of a jointed robot arm that, to wind the covering film around the load to wrap, operates the wrapping head with a lifting and rotating motion around the palletised load which, on the contrary, substantially remains still.
Alternatively, the moving machine works by moving the wrapping head vertically, simultaneously winding the covering film around the palletised load that turns on a rotating platform.
The reel is mounted on the wrapping head in a rotating way around its own axis and, while wrapping, is kept substantially vertical and parallel to the lateral sides of the load to wrap.
The plastic film which unwinds from the reel, therefore, has two opposing longitudinal edges, one top and one bottom, which extend crosswise to the axis of the reel.
To increase the adhesion force of the plastic film on the pallet, the wrapping head has particular means to roll up, fold and wrap the bottom longitudinal edge on itself as the plastic film is dispensed.
Due to the effect of rolling up, the bottom longitudinal edge gets thicker, becoming a particularly strong reinforcement border that can be wound around the pallet without breaking.
Such wrapping stations make it possible to wrap palletised loads of different shapes and sizes.
To this end, the fact is underlined that, for logistic management reasons, smaller pallets are increasingly resorted to in medium and big distribution chains, conventionally called "demi-pallets" or "semi-pallets" due to the fact their standard dimensions are equivalent to half the size of traditional pallets.
Unlike traditional pallets, e.g. the so-called "euro-pallet", it is often impossible to use traditional forklift trucks (normally used to load and unload goods) to pick up demi-pallets.
In fact, the size of traditional pallets is such that both forks of a forklift truck can be inserted either through the long side or the short side of the pallet. Whatever direction the forks are inserted, therefore, the load is lifted with both forks in stable and safe conditions.
But the width of the demi-pallets on their short side allows just one fork of a traditional forklift truck to be inserted which means that lifting a palletised load under such conditions is particularly awkward and dangerous.
To overcome such drawbacks and to stabilise the loads on the demi-pallets, two demi-pallets with their loads are normally put on a traditional size auxiliary pallet that can hold both demi-pallets side by side.
The loads, demi-pallets and auxiliary pallet, thus assembled, are then wrapped together.
The auxiliary pallet has the purpose of allowing the movement and transport of the two demi-pallets up to the point of delivery where the two loads resting on the demi-pallets can be separated from each other.
This load wrapping method, however, has some drawbacks among which is the fact that using auxiliary pallets leads to a big increase in overall transportation costs.
In this regard, the fact is underlined that in some cases the actual cost of the auxiliary pallets has a considerable effect on the final price of the products transported, especially when the goods are particularly bulky and not all that expensive in the first place.
The necessity to place the demi-pallets and relative loads on top of an auxiliary pallet, furthermore, means that particular types of additional equipment have to be used to lift the demi-pallets and position the auxiliary pallet under them. Inconveniently, said additional equipment constitutes a supplementary cost in terms of installation, maintenance and overall system management.
To overcome such inconveniences, a particular wrapping process is known where two palletised loads are placed side by side so the two demi-pallets they are put on are placed side by side, and then the plastic film is wrapped around the palletised loads, tightening the reinforcement border of the covering sheet which is folded over itself around the demi-pallets.
The reinforcement border, in effect, not only allows the stabilising wrap to adhere to the pallets but also makes the demi-pallets integral with each other so they can be transported without using the auxiliary pallet.
To actuate this process, two consecutive wrapping stations are normally used, each with a rotating platform and a machine to move the reel of plastic film. One wrapping station is for winding single palletised loads, while the other is for wrapping two palletised loads, one against the other.
In this case, however, the wrapping system becomes particularly complex and costly, both in terms of installation expenses and in terms of the high running, labour and maintenance costs.
As an alternative to using two wrapping stations in series, the above mentioned wrapping process can be done with just one station, with just one rotating platform and with just one reel moving machine.
In this case, the wrapping station works as follows: a first palletised load is wrapped on the rotating platform and then temporarily transferred to an adjacent parking roller unit; a second palletised load is placed on the rotating platform and then wrapped; the first and second palletised loads, both wrapped individually, are then put side by side on the rotating platform and wrapped together.
Even this solution has several drawbacks, one of them being that system production output is greatly limited by the lengthy down times when no palletised load is being wrapped.
This is mainly due to the time it takes to place the palletised loads on the rotating platform.
In fact, the movement of palletised loads that have not yet been stabilised is risky and has to be done slowly so the loads cannot fall or turn over accidentally.
Summing up then, a great deal of total processing time is required for handling the loads, during which the machine to move the reel of plastic film and the rotating platform are substantially at a standstill.
The patent document
The column is provided with suitable: rotational means and is displaced automatically from one platform to the other when packaging is completed on one of them.
The main aim of this invention is to provide a process and a system for wrapping palletised loads that allow to wrap the demi-pallets and the loads on top of them in a practical, easy, quick and functional way and, at the same time, to reduce the overall transportation costs significantly both in terms of less pallets used and in terms of less money spent on installation, maintenance and management of the wrapping station.
Another object of this invention is to provide a process and a system for wrapping palletised loads that allow to overcome the mentioned drawbacks of the known technique as part of a simple, rational, easy, effective use and low cost solution.
The objects mentioned above are reached with this process for wrapping palletised loads, characterised by the fact that it comprises the following phases:
The above mentioned objects are reached with this system for wrapping palletised loads, comprising at least a first rotating platform suitable for receiving in succession at least a first palletised load and at least a second palletised load to wrap, at least a second rotating platform suitable for receiving simultaneously said first and second palletised loads, and a single movement machine. for moving a covering sheet suitable for cooperating with said first rotating platform to wrap in succession said first and said second palletised loads with a first stabilising wrap and for cooperating with said second rotating platform to wrap together said first and said second palletised loads with a second stabilising wrap in a double wrapping configuration where said first and second palletised loads are substantially side by side and together on top of said second rotating platform, characterised by the fact that it comprises at least one forward movement line of said palletised loads along which said first and said second rotating platforms are arranged.
Further characteristics and advantages of this invention will appear more evident from the description of a preferred but not only embodiment of a system for wrapping palletised loads, illustrated indicatively by way of non limiting example in the accompanying drawings, wherein:
With particular reference to such figures, a system for wrapping palletised loads has been globally indicated by 1.
The system 1 comprises a first rotating platform 2 and a second rotating platform 3.
The first rotating platform 2 is suitable for receiving in succession a first palletised load 4 and a second palletised load 5 to wrap and make them turn around a vertical axis.
In this regard, note that when, in this paper, it is stated that the first and the second palletised loads 4, 5 are received in succession on the first rotating platform 2 it is meant that the second palletised load 5 does not engage the first rotating platform 2 until the first palletised load 2 is on it and vice versa.
On the first rotating platform 2, therefore, one palletised load 4, 5 is made to turn at a time.
The second rotating platform 3, on the other hand, is suitable for receiving simultaneously the first and the second palletised loads 4, 5 and to make them turn simultaneously around a vertical axis.
The first and the second palletised loads 4, 5 are composed of, respectively, a first load to wrap 4a and a second load to wrap 5a placed, respectively, on top of a first pallet 4b and on top of a second pallet 5b.
The pallets 4b and 5b consist of two demi-pallets of standardized shapes and dimensions.
In proximity of the first and of the second platform 2, 3 is arranged a movement machine 6 for moving a dispensing reel 7 of a covering sheet 8.
The movement machine 6 is suitable for cooperating with the first rotating platform 2 to wrap in succession the first and the second palletised loads 4, 5 with a first stabilising wrap.
The movement machine 6 is also suitable for cooperating with the second rotating platform 3 to wrap together the first and the second palletised loads 4, 5 with a second stabilising wrap in a double wrapping configuration where the first and the second palletised loads 4, 5 are substantially side by side and together on top of the second rotating platform 3.
In the embodiments illustrated in the figures, the movement machine 6 comprises an articulated arm 9, the free end of which has a working head 10 that supports the dispensing reel 7.
The articulated arm 9 is hinged according to a vertical axis to a fixed base 11, so as to be able to rotate around said axis to bring the dispensing reel 7 close to the first rotating platform 2 or, alternatively, to the second rotating platform 3.
In proximity of the rotating platforms 2, 3 are arranged respective presser elements 12, 13 suitable for lowering and pressing the palletised loads 4, 5 which are on the first rotating platform 2 or on the second rotating platform 3 respectively so as to keep them stable during wrapping.
The presser elements 12, 13, in detail, are mounted on corresponding supporting columns 14, 15 and operable sliding in a vertical direction so as to come into contact with the top of the palletised loads 4, 5.
The system 1 also comprises a forward movement line 16 of the palletised loads 4, 5 along which the first and the second rotating platforms 2, 3 are arranged.
In detail, the second rotating platform 3 is arranged downstream from the first rotating platform 2 in the direction of movement of the palletised loads 4, 5 along the forward movement line 16.
This forward movement line is composed of, e.g., a set of transfer means of the palletised loads 4, 5 suitable for placing the first palletised load 4 on top of the first rotating platform 2, for moving the first palletised load 4 away from the first rotating platform 2, for placing the second palletised load 5 on top of the first rotating platform 2, for moving the second palletised load 5 away from the first rotating platform 2, for positioning the palletised loads 4, 5 in the double wrapping configuration on the second rotating platform 3 and, lastly, for moving the palletised loads 4, 5 away from the second rotating platform 3.
In the particular embodiment of the invention illustrated in the figures, the transfer means 16 comprise: a conveyor belt 17 mounted on a fixed supporting frame arranged immediately upstream of the first rotating platform 2; a first motorised roller unit 18 mounted on the first rotating platform 2; a first roller conveyor 19 mounted on a fixed supporting frame interposed between the first rotating platform 2 and the second rotating platform 3; a second motorised roller unit 20 mounted on the second rotating platform 3; a second roller conveyor 21 mounted on a fixed supporting frame arranged immediately downstream from the second rotating platform 3.
Advantageously, along the forward movement line 16 is arranged a labelling machine 22 suitable for labelling the palletised loads 4, 5.
This labelling machine is arranged in proximity of the first roller conveyor 19 and is suitable for affixing one or more labels on the first stabilising wraps of the palletised loads 4, 5 coming from the first rotating platform 2.
Usefully, the wrapping of the palletised loads 4, 5 inside the system 1 is done by means of the process according to the invention which consists of the following phases:
Usefully, after the labelling phase the process according to the invention also contemplates an additional phase that consists of joining the pallet 4b of the first palletised load 4 and the pallet 5b of the second palletised load 5 together in the double wrapping configuration.
In the particular embodiment of the invention illustrated in the figures, this phase of joining occurs simultaneously with the wrapping together phase of the first and second palletised loads 4, 5 (
In fact, the joining phase consists of folding the bottom longitudinal edge of the covering sheet 8 over on itself with the aid of a wheel 23 so as to form a reinforcement border 24 and wrapping once or more times the covering sheet 8 around the first and the second palletised loads 4, 5 in the double wrapping configuration, tightening the reinforcement border 24 around the pallets 4b, 5b of the first and of the second palletised loads 4, 5 to form one or more holding coils of the pallets.
All the coils tightened around the pallets 4b, 5b make the pallets 4b, 5b practically integral with each other and confer to the palletised loads 4, 5 the stability and the stiffness necessary to be transported without being placed on top of an auxiliary pallet (
The number of coils tightened around the pallets 4b, 5b corresponds to the number of wrappings of the covering sheet 8 around the base of the loads to wrap 4a, 5a and can vary according to load type.
Alternative embodiments of this invention are not, however, excluded where the joining phase is different and consists of, e.g., an intermediate station placed in between the first and the second platforms 2, 3 and suitable for lifting the palletised loads 4, 5 and for placing them on top of an auxiliary pallet of a bigger size.
In this case, the phase of wrapping together the first and the second palletised loads 4, 5 on the second rotating platform 3 does not necessitate the application of a set of coils to hold the pallets 4b, 5b and consists of winding the covering sheet 8 around the auxiliary pallet.
In the particular embodiment of the invention illustrated in the figures, moreover, the palletised loads 4, 5 to wrap together on the second rotating platform 3 are only two.
Alternative embodiments of this invention are not, however, excluded where, on the first rotating platform 2, three or more palletised loads are wrapped in succession which, once transferred on to the second rotating platform 3, are wrapped together in exactly the same way as described and illustrated previously.
It has in point of fact being ascertained how the described invention achieves the proposed objects.
The invention thus conceived is susceptible to numerous modifications and variations, all of which falling within the scope of the inventive concept. Furthermore all the details can be replaced with others that are technically equivalent.
In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to requirements without because of this moving outside the protection scope of the following claims.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.