EP0465370A2 - Method for covering a palletized load with a hood of foil of plastic stretchable material - Google Patents

Abstract

Method for covering a palletised load (1) with a hood (2) of stretchable plastic film, characterised in that: - a non-gusseted sheath is employed; - the starting point is the flattened, non-stretched sheath (12); - the initial lower end (16) of the sheath (12) is brought over the palletised load (1); - the sheath (12) is opened progressively and is slipped over the corner supports (18) in the retracted state, while being folded transversely (19); - the sheath (12) is cut to length transversely; - the sheath (12) thus folded in the transverse direction is stretched; - the stretched sheath (12) and the palletised load (1) are moved relative to each other. <IMAGE>

Description

The invention relates to a method of overpacking a palletized load by means of a cover of stretchable plastic film.

Processes for overpackaging palletized loads are already known by means of stretchable plastic film covers. Such overpacking aims to ensure cohesion and protection of the palletized load (physical protection or against rain for example). It allows the storage and transport of such palletized loads. A palletized load typically comprises a lower pallet and resting on it several superimposed layers each comprising one or more individual loads or loads. Such elementary burdens or loads can be, for example, bags of materials or blocks of solid materials (brick, concrete blocks, plates or the like) or cardboard boxes filled with a certain container or containers, empty or filled, such as bottles, barrels, and .... Such a palletized load conventionally has a general external shape more or less parallelepiped limited by a horizontal lower face (pallet), a free horizontal upper face (roof) and four vertical lateral faces . However, the palletized load can have an external shape which is not exactly parallelepipedic but inscribed in a parallelepiped. This can for example be the case with bags which give the vertical lateral faces of the palletized load an accordion shape. Alternatively, also, the palletized load can be of the "without pallet" type, the pallet being replaced by one (or more) layer (s) of burdens or elementary loads located in the lower extreme part and coming laterally behind the others. layers placed above, on at at least two opposite side faces (and where appropriate the four side faces) thereby forming a "false pallet". Palletized loads overwrapped with covers or stretch plastic film have a width (in the horizontal direction) of between 50 cm and 150 cm, a length (also in the horizontal direction) of between 80 cm and 180 cm and a height (in the direction vertical) between approximately 50 cm and 250 cm. For example a typical palletized load has a length of 120 cm, a width of 100 cm and a height of 200 cm. The cover, once in place on the palletized load covers its horizontal upper face and its vertical side faces up to the pallet (or the false pallet). A stretchable plastic film constituting such a cover can, by stretching, be lengthened significantly even beyond its elastic limit and up to several times the latter. Once stretched, it loses some of the extra stretch given to it by stretching. By being dimensionally blocked before having lost the additional elongation which has been given to it before, it creates forces which are used to ensure the tightening of the palletized load.

The stretch film covers used for the overwrapping of palletized loads are, to date, delivered and used in the form of rolls of bellows sheath, flattened. Such a bellows sheath comprises two large facing walls, joined by their edges by two bellows which are themselves facing, the two middle folds of which are closest to each other and situated towards the inside of the sheath. In the "flattened" state, the two bellows are folded back on themselves, not deployed, and placed between the two large facing walls applied to one another. In this "flattened" state, the sheath can be wound on a spool, the width of which can be understood. between 20 cm and 120 cm. The use of a bellows sheath makes it possible to reduce the width of the flattened sheath coil, with all the advantages of space and handling which result therefrom. In addition, a bellows sheath is advantageous in that it allows the introduction, into the bellows and from the outside, of separators promoting the opening of the sheath for its implementation.

Such an overpacking of palletized loads by means of covers of stretchable plastic film can be produced in the following manner: the palletized load to be overpacked is brought into a hood intended for the implementation of this overpackaging. Such a hood includes a frame, a support for one or more coils of flattened bellows sheath, of horizontal axes, located in the lower part and outside the hood. The flat bellows sheath is guided and brought to the upper part of the hooder. It is then directed vertically and downwards in line with the palletized load. The sheath is unwound, pre-opened and then completely opened by deployment of the bellows losing its "flattened" state. To this end, pre-opening separators and opening means such as belts or drive fingers of the sheath going away from each other from top to bottom are used. As it is unwound, the sheath is threaded on a support trolley then located in the upper middle part of the hood, above the palletized load. This carriage has, in horizontal elevation, a substantially homothetic contour of that, opposite, of the palletized load but at this time of the process smaller than the latter. The carriage comprises, in its four angles, four vertical direction angle supports. These four corner supports are placed inside the open sheath and it came to crease using, by example, motorized rollers carried by the frame and supported on the sheath outside of the latter and in line with the angle supports. This pleating can be qualified as transverse since the successive plies extend in transverse direction relative to the longitudinal direction of the sheath. In practice, the folds extend in a horizontal direction relative to the vertical longitudinal direction of the load. This pleating of the sheath has the effect that the size of the pleated sheath in the unwinding direction (axis of the sheath) is very small compared to that of the sheath deployed or unfolded. This makes it possible to store a large length of sheath, in the pleated state, on angle supports of limited and smaller length. Where appropriate, the carriage is associated with the means for opening the sheath such as two suction boxes with opposite and horizontal reciprocal movements. When a suitable length of sheath has been unwound, the sheath is cut transversely and a transverse weld is made in order to close the upper free end of the cover. At this time, the sheath then forming a cover, pleated on the carriage is stretched in the transverse direction. For this purpose, the corner supports are moved horizontally to the outside of the hood. This displacement has an amplitude which on the one hand determines the degree of stretching of the film of the cover and on the other hand causes the angle supports to be located, in vertical direction, outside the palletized load. The carriage is then moved with vertical sliding downwards around the palletized load in the stationary position, up to the pallet or the false pallet. The closed end of the sheath where the transverse weld is located is applied to the horizontal upper face of the palletized load. The folds of the bellows extend vertically parallel to the vertical edges of the palletized load and the transverse weld extends parallel to two edges, notably longitudinal and horizontal of the horizontal upper face. the rest of the sheath is gradually applied to the vertical lateral faces of the palletized load. The movement of the carriage is continued until the sheath is completely on the palletized load and released from the carriage. the carriage can then be slid vertically and upwards and brought back to the upper waiting and starting position. The palletized load with the overwrapped stretch film sheath can then be removed from the hood. A new cycle can then be performed.

Reference may be made to documents DE-A-2 706 955, DE-A-3 918 311 and US-A-4 546 598 which relate to such an overpack, from a flattened bellows sheath.

Reference may also be made to document FR-A-2 473 985 which also relates to the pleating of a bellows cover.

• La gaine mise en oeuvre est indifféremment de type à plat ou à soufflets.
• La gaine mise en oeuvre a un périmètre sensiblement égal au périmètre de la charge à emballer.
• Une fois la gaine plissée en soufflet elle est directement appliquée sur la charge sans étirage transversal.

Le document US-A-3 8592 937 concerne également l'emballage d'une charge au moyen d'une gaine en matière plastique et, selon ce document :

• La gaine est également indifféremment de type à plat ou à soufflet.
• La gaine mise en oeuvre a un périmètre plus grand que celui de la charge à emballer ce qui génère l'espace libre (loose) entre-eux.
• La gaine n'est jamais plissée.
• Il n'y a aucun étirage transversal de la gaine avant application sur la charge.

According to document FR-A-2 300 009, there is provided a method and a machine specifically for laying a strip of stretch film around a group of objects such as a group of a few bottles placed side by side . However, the process and the machine according to this document are not intended for palletized loads: they deliver a strip and not a cover, the group of objects concerned has dimensions and characteristics very different from those of a palletized load, the final degree of tightening sought is very limited.
Document FR-A-2 230 549 relates to the packaging of a load by means of a plastic sheath, like the invention. According to the document :

• The sheath used is either flat or bellows type .
• The sheath used has a perimeter substantially equal to the perimeter of the load to be packaged.
• Once the bellows pleated sheath is applied directly to the load without transverse stretching .

Document US-A-3 8592 937 also relates to the packaging of a load by means of a plastic sheath and, according to this document:

• The sheath is also indifferently of the flat or bellows type .
• The sheath used has a larger perimeter than that of the load to be packaged , which generates the free space between them.
• The sheath is never wrinkled .
• There is no transverse stretching of the sheath before application to the load.

The technique of overwrapping palletized loads with covers made of stretchable plastic film has certain advantages compared to the different competing technique using heat-shrinkable plastic film. In particular, it makes it possible to dispense with the heat shrinking phase and means. In addition, the palletized load is not subjected to the action of heat shrinking heat.

However, the technique of overpackaging of palletized loads with covers of stretch plastic film as it is currently implemented has a certain number of drawbacks or limitations: the upper part of the cover has several film thicknesses due to the presence of bellows and transverse weld simultaneously. This results in an unsightly character of the sheath; an unsatisfactory size of the bellows at the top; wind protection possible in the two pockets formed by the bellows flattened. The perimeter quantity of film is smaller at the upper part of the cover than in the remaining part below. Combined with the several thicknesses of the upper part already mentioned, this results in an uneven stretch between the upper part of the cover and the lower part remaining, the stretch at the upper part being higher than in the lower part remaining . This results in either an excessive stretching of the upper part with the risks of tearing which result therefrom, or an insufficient stretching of the remaining part below with the subsequent consequence of insufficient cohesion of the palletized load. This also results either in a risk of tearing of the cover, especially towards the upper part mainly if the palletized load has sharp or pointed angles, or increased efforts on these angles. In total, it can be seen in practice that the residual stretching is less than a limit of the order of 10 to 25%.

• l'on met en oeuvre une gaine sans soufflet ;
• on part de la gaine aplatie non étirée ;
• on amène l'extrémité initiale inférieure de la gaine au dessus de la charge palettisée ;
• progressivement on ouvre la gaine et on l'enfile sur des supports d'angle à l'état rétracté en la plissant transversalement ;
• on coupe transversalement la gaine à longueur ;
• on étire la gaine ainsi plissée en sens transversal en écartant réciproquement les supports d'angle, jusqu'à ce que ceux-ci soient à l'état étiré et situés en direction verticale à l'extérieur de la charge palettisée ;
• on assure un déplacement relatif de la gaine étirée et de la charge palettisée de manière que la gaine échappe progressivement aux supports d'angle et soit déplissée et appliquée progressivement sur la charge palettisée du haut vers le bas.

The invention therefore aims to solve these problems and to this end, it provides a process for overpacking a palletized load by means of a cover made of stretchable plastic film characterized in that:

• a sheath without bellows is used;
• we start from the flattened, unstretched sheath;
• the lower initial end of the sheath is brought above the palletized load;
• gradually the sheath is opened and it is threaded on angle supports in the retracted state by pleating it transversely;
• the sheath is cut transversely to length;
• the sheath thus pleated is stretched in a transverse direction, reciprocally drawing aside the angle supports, until these are in the stretched state and located vertically outside the palletized load;
• a relative displacement of the stretched sheath and of the palletized load is ensured so that the sheath gradually escapes the angle supports and is unfolded and applied progressively to the palletized load from top to bottom.

According to another characteristic, the sheath is stretched with a drawing rate at least equal to 80%.

According to another characteristic, the stretching of the sheath is distributed in the transverse direction and the sheath is applied to the angle supports while allowing free transverse relative movement.

The use of a sheath without bellows makes it possible to avoid the direct or indirect drawbacks which result from the existence of the bellows. The extra thickness is avoided at the top of the cover, the perimeter length of film is the same including in the vicinity of the top, the degree of stretching can be greater which allows better clamping forces of the film on the palletized load therefore better cohesion thereof, the aesthetics of the cover is improved. On the other hand, the invention allows both film savings, overwrapping in the same dimension of increased palletized loads having certain dimensional tolerances. Finally, it allows excellent control of the stretching, therefore of the compressive and cohesion forces of the palletized loads. From another angle, it should be noted that the invention makes it possible to envisage different variants of implementation, in an automatic, semi-automatic or even manual manner, with or without removal of protruding "horns", with or without reversal of the rise. , with or without lower bead, etc ...

• Les figures 1A et 1B sont deux vues schématiques en coupe transversale de deux demi-gaines de film étirable respectivement avec soufflets comme dans l'état de la technique et sans soufflet ainsi que mis en oeuvre dans la présente invention.
• Les figures 2A, 2B, 2C, 2D, 2E et 2F sont six vues purement schématiques des étapes de mise en oeuvre du procédé selon l'invention.
• Les figures 3, 4, 6 sont trois vues schématiques en perspective d'une charge palettisée suremballée au moyen d'une housse en film plastique étiré obtenue par la mise en oeuvre de l'invention.
• Les figures 5A et 5B sont deux vues schématiques en perspective, partielles, illustrant les modalités de suppression des cornes saillantes de la gaine.
• Les figures 7A, 7B, 7C, 7D, 7E sont cinq vues schématiques en perspectives partielles illustrant des étapes successives de constitution de la partie supérieure de la housse dans une variante possible permettant de supprimer les cornes saillantes qu'elle comporte.
• La figure 8 est une vue schématique dérivée de la figure 7E illustrant une variante de réalisation.
• Les figures 9A, 9B, 9C sont trois vues schématiques en perspectives partielles illustrant des étapes successives de la réalisation d'une housse dépourvue de cornes saillantes à sa partie supérieure.

The other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings in which:

• FIGS. 1A and 1B are two schematic cross-section views of two stretch film half-sheaths respectively with bellows as in the prior art and without bellows as used in the present invention.
• FIGS. 2A, 2B, 2C, 2D, 2E and 2F are six purely schematic views of the steps for implementing the method according to the invention.
• Figures 3, 4, 6 are three schematic perspective views of an overpacked pallet load using a stretched plastic film cover obtained by the implementation of the invention.
• FIGS. 5A and 5B are two schematic perspective views, partial, illustrating the methods of removing the projecting horns from the sheath.
• FIGS. 7A, 7B, 7C, 7D, 7E are five diagrammatic views in partial perspective illustrating successive stages of constitution of the upper part of the cover in a possible variant making it possible to remove the projecting horns which it comprises.
• Figure 8 is a schematic view derived from Figure 7E illustrating an alternative embodiment.
• FIGS. 9A, 9B, 9C are three schematic views in partial perspective illustrating successive stages in the production of a cover devoid of projecting horns at its upper part.

The invention relates to the overpacking of a palletized load 1 by means of a cover 2 made of stretched plastic film.

The general characteristics (notably dimensional) of palletized loads are well known those skilled in the art and for this reason they are not described again here. Such palletized loads comprise a plurality of elementary bundles or bundles 3 juxtaposed in layers 4 stacked one on the other and on a lower pallet 5. As a variant, the pallet 5 is replaced by a false pallet, in the case of a load called "without palette". The lower layer or layers 4 then have recessed lateral free spaces for the passage of the forks of a transporting carriage. Such a palletized load 1 has a general external parallelepiped shape or included in a parallelepipedic envelope. It is limited by an upper face 6 generally horizontal, four lateral faces forming two opposite pairs 7a, 7b, and a lower face 8, horizontal, at the location of the pallet 5. the upper face 6 is limited by four edges or two opposite pairs 9a, 9b corresponding to the lateral faces 7a, 7b. These four edges 9a, 9b also define four corners 10 where the upper face 6 and two lateral faces 7a, 7b meet. The lateral faces 7a, 7b define between them four vertical edges 11 adjoining the corners 10. The lower face 8 has a structure derived from that of the upper face 6. It should be understood that the edges and corners 9a, 9b, 10 and 11 are more or less straightforward, sharp or acute or, on the contrary, rounded, depending on the elementary burdens or packages 3.

The cover 2 is made from a sheath 12 devoid of bellows (s), originally flattened. Such a half-sheath is shown in Figure 1B slightly deployed for better understanding. Such a sheath 12 without bellows comprises two main walls 13 opposite and facing one another, joined one at a time. the other by a longitudinal fold 14. Such a sheath without bellows differs from the bellows sheaths of the state of the art shown in FIG. 1A. In such bellows sheaths, the main walls have a narrower width (or width) and they have a junction bellows placed inside.

The process for overpacking a palletized load by means of a stretched plastic film cover according to the invention comprises the following steps:
We start with a sheath 12 without flattened bellows not stretched. Such a sheath can be wound to form a coil 15.

We bring a palletized load 1 in a situation of being overwrapped. In this situation, the palletized load 1 is at rest on a table of a hooding machine for use in stretch plastic film, resting on the pallet 5.

The lower initial free end 16 of the sheath 12 is brought above the palletized load 1, facing the upper face 6, by means, for example, of a guide and deflection roller 17 with a horizontal axis.

Gradually, the sheath 12 is continued to unwind from the reel 15 and the sheath 12 is opened from its end 16. The sheath 12 is thus opened, by its initial free end 16, on angle supports 18 (in particular four in number). These angle supports 18 are, in this situation, directed vertically and upwards. They are in a state called "retracted" as opposed to a state called "stretched" later. The unstretched sheath 12 has a smaller perimeter than the perimeter of the palletized load 1 defined by the lateral faces 7a and 7b. It follows that in the retracted state, the angle supports 18 define a smaller footprint than the footprint opposite the palletized load 1 (see figure 2). The angle supports 18 are carried for this purpose by an appropriate frame. In this situation, the angle supports 18 are in their upper position above the palletized load 1. The retracted state is that where the angle supports 18 are closest to each other. Their distance is such that the open sheath 12 can be threaded onto the supports 18 without being stretched transversely. Thanks to locking projections placed at the bottom of the angle supports 18 and directed horizontally outwards, the initial free end 16 is blocked while the sheath 12 is unwound from the reel 15 and that an additional quantity of this sheath 12 is accumulated on the angle supports 18. With, if necessary, additional means such as rollers or pleating rollers coming to be applied on the sheath 12, outside of the latter and in line with the angle supports 18, the sheath 12 is pleated transversely on the angle supports 18 (FIG. 2B). the pleating is qualified as "transverse" since the pleats 19 which constitute it extend substantially parallel to the initial free end 16, that is to say orthogonally to the longitudinal direction 20 of the sheath 12. In the case Figures 2A to 2F, the longitudinal direction 20 is the vertical direction and the folds 19 are placed horizontally.

When a sufficient longitudinal length of sheath 12 is unwound, taking into account the height of the palletized load 1 including taking into account either a subsequent stretching of the cover in longitudinal direction 20, or the production of a lower bead of film, the sheath 12 is cut transversely above the folds 19. It then follows on the one hand to form a free upper end portion 21 of the sheath and, on the other hand, a new initial free end 16 intended to be used, later, for another cover.

The sheath 12 carried by the angle supports 18 is then stretched in the transverse direction and for this purpose the angle supports 18 are reciprocally moved in the transverse direction (in this case horizontal) to make them pass from the retracted state to a stretched state where these are located, in a vertical direction, outside the palletized load 1 (Figures 2C and 2D). The importance of the transverse, horizontal sliding of the angle supports 18 determines the degree of transverse stretching of the film, which induces the value of the tightening forces of the cover 2 on the load 1 and therefore the cohesion of the latter.

Then, a relative displacement of the sheath 12 thus pleated and stretched transversely and of the palletized load 1 is ensured so that the sheath 12 gradually escapes the angle supports 18, is unfolded and applied progressively to the palletized load 1, starting by the upper part then going to the lower part, so as to cover the desired height of the palletized load 1 (Figures 2E and 2F). For example, the angle supports 18 are moved vertically and downwards and the palletized load 1 vertically and upwards.

The angle supports 18 are moved transversely over a stroke such that the sheath 12 is stretched with an initial stretch rate at least equal to 80%, which allows the cover 2 once placed on the palletized load 1 to have a residual stretch of at least 30%. This stretching rate and this residual stretching are made possible by the use of a sheath 12 without bellows. In addition, due to the absence of a bellows, the rates of stretching and residual stretching are constant or vary little from the initial free end 16 to the end part. upper 21. Indeed, the perimeter length of the sheath 12 without bellows is substantially the same over its entire longitudinal direction 20.

The stretching of the sheath 12 is distributed in a transverse direction over the whole of a cross section of the sheath, in a uniform manner or a distribution is as uniform as possible and for this purpose the sheath 12 is applied to the supports d angle 18 by allowing the free transverse relative movement of the sheath 12 relative to the angle supports 18. For this purpose, this relative movement is carried out without substantial friction of the sheath 12 on the angle supports 18.

In a first alternative embodiment (FIGS. 2C, 3 and 4), the cross section of the sheath 12 is produced and, practically simultaneously, the transverse welding of the sheath 12 near and below the cutting line 22 thus produced thus constituting a welding line 23.

In a first sub-variant, the sheath 12 is placed on the palletized load 1 with the transverse weld line 23 placed substantially diagonally on the upper face 6. For this purpose, reference may be made to FIG. 3 in which the transverse weld line 23 connecting two diametrically opposite corners 10 of the upper face 6 of the load 1. This arrangement makes it possible to eliminate the presence of projecting horns 24 (see FIG. 9A) of the sheath placed adjacent and on either side of the transverse weld line 23. For this purpose, the stretched sheath 12 is suitably arranged from the outset with respect to the palletized load 1 or a relative rotation of the palletized load 1 / cover 2 is carried out around the longitudinal direction 20 with respect to an initial angular relative position where the weld line 23 is parallel to an edge 9a, 9b, to the final relative position thus angularly offset.

In a second sub-variant, the sheath 12 is placed on the palletized load 1 with the transverse weld line 23 placed substantially parallel to an edge 9a or 9b of the upper face 6. And, in this case, the protruding horns 24 on and to the remaining part of the sheath 12.

Several methods can be implemented to ensure this application and association. For example, in one embodiment (FIG. 4) the projecting horns 24 are external but folded down and glued or welded to the sheath, in particular that located either on the upper face 6 (right part of FIG. 4) or that lying on the lateral faces 7a, 7b (left part of FIG. 4). Or we gather and glue or weld the projecting horns 24 (Figures 5A and 5B). Or the protruding horns 24 are heat-shrunk. In the latter case, the heat-shrinking is very localized and limited to the horns 24 alone, so that it can be implemented by means of a light and energy-saving heating device, without the risk of heating the entire palletized load 1. In another embodiment (FIGS. 9A to 9C), the cover 2 pleated and stretched with the transverse weld line 23 is turned upside down, the free end 16 initially placed at the bottom and the end part 21 where the transverse weld line 23 initially placed at the top is located (FIG. 9A) being reversed by 180 ° around a horizontal axis and then being located respectively at the top and at the bottom (FIG. 9B ). This can be obtained, for example, by turning the frame supporting the angle supports 18 by half a turn around the horizontal axis in question. The projecting horns 24 adjoining the end portion 21 are placed below the cover and are the first to come against the palletized load 1 during the covering (Figure 9C). They are then trapped between the palletized load 1 at its upper part and the cover 2 without being able to interfere. It should be noted that in this embodiment there is, during the covering not only unfolding of the cover 1, but also progressive sliding reversal since, finally, the extreme free part 21 is found in the upper part and the initial free end 16 in the lower part. In this embodiment, the horns 24 are interior.

In a second variant (FIGS. 4, 6, 7A to 7E and 8), the upper end part of the sheath is grouped together in the form of a central tail 25 which is secured and held together. For example, stapling, ligation or welding of the tail 25 is carried out. In this variant, there is therefore no continuous transverse weld line 23. In one possible embodiment, when the sheath 12 is pleated on the angle supports 18, a transverse section is made using, for example, long and continuous cutting jaws 26 and, at the same time, the cover is taken 2 just below the cutting line 22 thus produced at points or zones 27 spaced along the cutting line 22 (FIGS. 7A to 7C). Then, the cutting jaws 26 being able to be moved apart, the points or zones 27 of gripping between two reciprocal jaws can be brought together (see arrows in FIG. 7D) which makes it possible to group the upper end part 21 along a segment more short than the cutting line 22. While maintaining the upper end part 21 thus, it is possible to bring, just below, the welding jaws 28 which ensures welding on a short welding segment where the cover is pleated in the longitudinal direction. In the variant of FIG. 8, the jaws 28 ensure the clipping and not the welding.

• On étire également la housse 2 en direction longitudinale 20.
• On réalise un houssage incomplet sur une partie seulement de la charge palettisée 1.
• On réalise deux houssages tête-bêche sur les deux faces d'extrémités 6 et 8 de la charge palettisée, séparés par un retournement tête-bêche de la charge palettisée autour d'un axe horizontal.
• On réalise, notamment au voisinage de l'extrémité libre 16 un bourrelet constitué par plusieurs plis de housse 2.
• On met en oeuvre le procédé de façon automatique, semi-automatique voire manuelle.

According to variant embodiments:

• The cover 2 is also stretched in the longitudinal direction 20.
• An incomplete covering is carried out on only part of the palletized load 1.
• Two head-to-tail covers are produced on the two end faces 6 and 8 of the palletized load, separated by a head-to-tail reversal of the palletized load around a horizontal axis.
• A bead consisting of several cover folds 2 is produced, in particular in the vicinity of the free end 16.
• The method is implemented automatically, semi-automatically or even manually.

All these variants should be considered as included in the invention.

According to another variant, not shown, a transverse cut and weld is made, not rectilinear and perpendicular to the longitudinal axis of the sheath but curved with a concavity facing the load. This rounded shape is able to remove or reduce the protruding parts in the shape of horns. This results in the existence of excess sheath parts, towards the bottom of the pallet. These parts are not annoying in this place.

The invention also relates to a palletized load which is overwrapped by means of a cover made of stretched plastic film which covers the upper 6 and lateral faces 7a, 7b of the palletized load 1. The cover 2 is devoid of bellows including its upper end part 21.

The residual stretching of the cover 2 placed on the load 1 is at least 30%, which ensures suitable tightening of the load and therefore the effective maintenance of its cohesion.

According to a first alternative embodiment, the cover 1 has a transverse weld line 23 and the latter is placed either parallel to the edges 9a, 9b of the upper face 6, or diagonally by joining two diametrically opposite corners 10. Where appropriate, the horns 24 of the cover 2 are applied to and associated with the remaining part of the cover 2, where are wedged between the palletized load 1 and the cover 2.

According to a second variant (Figure 6), the cover has at its upper end 21 a tail 25 secured to itself.

The projecting horns 24 are either external and secured by gluing, heat shrinking, pleating, or internal and wedged between the cover 2 and the palletized load 1.

• La housse 2 est également étirée en direction longitudinale.
• La housse 2 a un bourrelet périphérique constitué de plusieurs plis de housse 2 situé au voisinage de l'extrémité libre 16.
• La charge comporte deux housses tête-bêche à recouvrement venant s'appliquer respectivement sur la face supérieure 6 et la face inférieure 8.

According to possible variants:

• The cover 2 is also stretched in the longitudinal direction.
• The cover 2 has a peripheral bead made up of several folds of cover 2 located in the vicinity of the free end 16.
• The load comprises two head-to-tail covers with overlap which apply respectively to the upper face 6 and the lower face 8.

Claims (27)

Method for overpacking a palletized load (1) by means of a cover (2) made of stretchable plastic film characterized in that: - a sheath without bellows is used; - We start from the flattened sheath (12) not stretched; - the lower initial end (16) of the sheath (12) is brought above the palletized load (1); - Gradually opening the sheath (12) and threading it on angle supports (18) in the retracted state by pleating it transversely (19); - The sheath (12) is cut transversely to length; - The sheath (12) thus pleated is stretched in a transverse direction, reciprocally drawing aside the angle supports (18), until these are in the stretched state and situated in a vertical direction outside the palletized load (1); - a relative displacement of the stretched sheath (12) and of the palletized load (1) is ensured so that the sheath (12) gradually escapes the angle supports (18) and is gradually unfolded and applied to the palletized load ( 1) from top to bottom. Method according to claim 1, characterized in that the sheath (12) is stretched with a draw ratio at least equal to 80%. Method according to any one of claims 1, 2, characterized in that the stretching of the sheath (12) is distributed in the transverse direction and the sheath (12) is applied to the angle supports (18) in allowing relative free transverse movement. Method according to any one of Claims 1 to 3, characterized in that the sheath (12) is welded transversely near the line of cut (22) and the sheath (12) is placed on the palletized load (1) with the transverse weld line (23) placed substantially diagonally on the upper face (6). Method according to any one of Claims 1 to 3, characterized in that the sheath (12) is welded transversely near the cutting line (22), the sheath (12) is placed on the palletized load (1 ) with the transverse weld line (23) placed substantially parallel to an edge (9a, 9b) of the upper face (6) and applying and associating projecting horns (24) of the sheath (12) placed adjacent and on the side and on the other side of the transverse weld line (23) on and to the remaining part of the sheath (12). Method according to claim 5, characterized in that the projecting horns (24) are folded down and glued or welded onto the sheath (12). Method according to claim 5, characterized in that the protruding horns (24) are gathered and glued or welded to the sheath (12). Method according to claim 5, characterized in that the protruding horns (24) of the sheath (12) are heat-shrunk. Method according to Claim 5, characterized in that the sheath (12) pleated stretched upside down is turned over and the sheath (12) / palletized load (1) is moved in this situation, the sheath (12) being turned over that the horns (24) are placed between the cover (2) and the palletized load (1). Process according to any one of Claims 1 to 3, characterized in that the upper end part (21) of the sheath (12) is grouped in the form of a tail (25) and the connection is secured and the maintenance of it. A method according to claim 10, characterized in that it secures and maintains the tail (25) by stapling, tying, welding. A method according to any one of claims 10, 11 characterized in that it ensures the grouping of the end part (21) of the sheath below the transverse section line (22). Method according to any one of Claims 1 to 12, characterized in that the cover (2) is also stretched in the longitudinal direction. Method according to any one of Claims 1 to 13, characterized in that a covering is carried out on only part of the palletized load. Method according to any one of Claims 1 to 14, characterized in that two head-to-tail covers are produced on the two faces (6 and 8) of the palletized load (1), separated by an inversion of the head palletized load - spade around a horizontal axis. A method according to any one of claims 1 to 15 characterized in that there is provided, in the vicinity of the free end (16) of the cover (2) a bead consisting of several folds of cover (2). A method according to any one of claims 1 to 16, characterized in that a cut and a transverse weld of rounded shape capable of removing the protruding parts of the cover are made. Palletized load overpacked by means of a cover (2) made of stretched plastic film covering the upper and lateral faces of the palletized load, characterized in that the cover is devoid of bellows including its upper end part (21). Palletized load according to claim 18, characterized in that the cover (2) has a residual stretch of at least 30%. Palletized load according to any one of claims 18, 19, characterized in that the cover (2) has a transverse weld line (23) placed substantially diagonally on the upper face (6) of the palletized load (1) . Palletized load according to any one of claims 18, 19 characterized in that the cover (2) comprises horns (24) placed adjacent and on either side of the transverse weld line (23) applied to and at associated or stuck on the remaining part of the cover (2). Palletized load according to claim 21 characterized in that the projecting horns (24) are external and secured by gluing, heat shrinking, pleating. Palletized load according to claim 21 characterized in that the projecting horns (24) are internal and wedged between the cover (2) and the palletized load (1). Palletized load according to any one of claims 18, 19, characterized in that the cover (2) comprises at its upper end part (21) a tail (25) secured to itself. Palletized load according to any one of Claims 18 to 23, characterized in that the cover (2) is also stretched in the longitudinal direction. Palletized load according to any one of claims 18 to 24 characterized in that the cover (2) comprises a bead made up of several cover plies (2) in the vicinity of the free end (16). Palletized load according to any one of claims 18 to 25 characterized in that it comprises two head-to-tail covers on the faces (6) and (8).

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