FR2468506A1 - METHOD AND APPARATUS FOR PACKAGING MULTIPLE ELEMENTARY LOADS IN A SINGLE PACKAGE - Google Patents

Abstract

at. Method and apparatus for packaging in the form of a one-piece package 130 of a commodity consisting of several elementary charges placed on a turntable 120. b. Method and apparatus characterized in that they use a mounting frame for unwinding and pre-stretching rollers 40, 42, 44 of a plastic film carried by a roll 32 and a turntable 120 carrying a load 130 to be wrapped, the pre-stretching of the film being intended to increase its strength. vs. The invention applies to automatic packaging machines.

Description

The invention relates to a method and apparatus for packaging a plurality of

  elementary charges in a single packet, and more specifically a method and apparatus for making one-piece packets containing a plurality of objects or elementary charges, each packet containing

  a load wrapped in a sheet of stretchable material.

  Packaging or canning are processes conventionally used to ensure the shipment of goods in the form of multiple elementary charges. These multiple elementary charges are generally stacked in a box containing splines, or wrapped in wrapping paper whose ends are glued or tied together,

  Another method of packaging these

  to prepare for shipping, involves placing a sleeve or coating of a hot-stretched sheet around the goods and stretching the sleeve to form a

one-piece package.

  The use of a sheet of heat-shrinkable material is described in U.S. Patent Nos. 3,793,798.

  3,626,645, 3,590,509 and 3,514,920. A description of this

  prior art technique is given in U.S.A.

No. 3,867,806.

  The invention requires no sealing structure and can therefore use any type of extensible material. The invention is designed to work with

  thin sheets of materials such as nylon, polypropylene,

  pylene, P.V.C. (polyvinyl chloride), polybutylene, polyethylene or any copolymer or mixture of the extensible thin films above. The apparatus according to the invention utilizes a mechanism for effectively securing a softened film winding to an adjoining adjacent film while simultaneously cutting off the rear edge of the film to separate it from the merchandise after the film has been filmed.

  been spiraled to form a bundle.

  The use of a spiral wrapping machine is well known in the prior art. One of these machines is described in U.S. Patent No. 3,863,425 wherein a film is guided from a roll and wound around a cylindrical commodity to form a spiral. A cart drives the roll of film to the vicinity

  the surface of the goods so as to deposit a roll-

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  wrapping around it and back in the opposite direction

  to lay another spiral layer around the merchandise.

  say. U.S.A. 3,788,199 has previously described spirally wound strips so as to overlap each other, leaving a suitable gap between them when the goods are to be aerated. In this patent a very strong bag is prepared by spirally winding synthetic resin stretchable strips in opposite directions so that they cut into one another.

  number of superimposed cylindrical bodies glued together to form

  sea a cylindrical network. The inner and outer strips of the superimposed layered cylindrical body intersect at a suitable angle depending on the intended application, the preferred embodiment having transfer strength.

  substantially constant in the longitudinal direction.

  In this preferred embodiment the strips intersect at an angle of about 900. The angle defined by the strips constituting the cylindrical network can be determined by varying the relationship between the speed of advancement of the endless belts carrying the strip. and the rotational speed of the reel carriers which rotate a number of web reels so as to deposit the web on a moving belt. The aforementioned patents use heat-shrinkable adhesive materials, hot bonding, or the sticky nature of the film, to hold in place

  fixedly the outer layer of the winding.

  In U.S. Patent No. 3,003,297 a complex cutting and holding mechanism is used to place the strip on a box and to cut it by repeating this pattern.

process for each box.

  Additional interesting references relating to rotary drives for wrapping packages may be found in U.S.A.

  3,820,451; 3,331,312; 3,324,789; 3.309.?39; 3,207,060;

  2,743,562; 2,630,751; 2.jqU629; 2,054,603; and 2,244,770.

  Other applications to packaging examples are described in U.S. Patent Nos. 3,514,920 - and 3,793,798 in which a heat-shrinkable film is wrapped around a pallet supporting a number of

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  cartons. A solid sheet analog apparatus employing a tensioned adherent film is disclosed in U.S. Patent No. 3,986,611, another apparatus employing a tacky PVC film (polyvinylchloride) as described in U.S. Patent No. 3,795,086. The elasticity of the film or network keeps the products under tension greater than that of shrink wrapping or paper wrapping, particularly when

  we use products that "take" once packaged.

  The effectiveness of a plastic film stretched to hold goods together depends on the tensile force that can be applied to these goods and the maximum strength of the goods.

  the total winding constituted by the film. These two characteristics

  are determined by the hardness modulus of the film after application of the tension, and the maximum film fastness of the film

after application.

  The force applied to the package is commonly obtained by pulling up to the maximum elongation,

  it is just before the breaking point of the film.

  In fact all the currently available tense films on the market, among which the products of the "Mobil Chemical Company" (Mobil X, Mobil C, Mobil H), the "Borden Resinite Division (PS-26)," Consolidated Thermoplastics "," Presto ", PPD, and others do not stretch by more than 30% in most applications because of the irregularities of the film braking systems, which depend on the friction applied to the film either directly by a bar device such as that used by the "Radient Engineering Company", either indirectly as in the case of patents

No. 3,867,806 and 4,077,179.

  All these devices according to the prior art have a significant disadvantage related to the cost per unit package, due to unused film falls. In addition, friction braking devices do not maintain a constant force. These brakes are subject to variations due to their physical construction and sensitivity to variations.

  speed produced by the passage of the corners of the driving package.

  sudden increases and decreases in the film's progress. A typical pallet package of 6.4 x 7.6 cm leads to surface velocity variations of over 40% at each

quarter turn.

  Higher turntable speeds, reaching 12 to 18 rpm, produce

  additional resonance forces that vary with the

  rolling of the roll causing a change in weight thereof. Additional limitations to maximum film elongation are due to imperfections of the film roll and to variations in size that accentuate force variations.

  above by causing breaks in the film.

  Although all the films described above are capable, according to manufacturers' specifications, of achieving elongations greater than 300%, these elongations

  However, they are very far from being reached as a result of

  imposed by constant-force devices of type

friction.

  Another problem presented by the packaging by means of retractable and non-adherent stretched films, besides the

  they do not allow the packaged goods to breathe

  is that the initial strength and reliability of the

  are determined by the quality of the seal. These seals depend on the care with which the seal lips are maintained and are never as strong as the film itself. The time required to make the boundary joints

  the maximum possible speed of most retractable systems

  ble. Moreover, with some shrinkable materials such as shrinkable films, or with narrow films, it is not

  possible in practice to make hot joints. -

  In view of the above characteristics of the films, the tender machines mentioned above, such as the machines manufactured by "Lantech Inc.", "Infra-Pak", "PS and

  D, "Radient Engineering, I.P.M." and "Mima", have possibilities

limited resources.

  When one seeks to achieve great elongations the forces used frequently reverse stacking packets or pull them out of the turntable. In addition, the non-vertical sides and the irregularly shaped corners of goods or packages result in very large forces applied to very small film surfaces during the tension, which causes

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  causes partial breaks at certain points for forces much lower than those which can be applied on a plane face. These partial ruptures lead to a transfer of force on the remaining part of the film and this force is very often sufficient to cause the tearing of everything.

the film.

  The object of the invention is to create a

  and a method of pre-stretching the film prior to wrapping it around a package so as to stretch the film between 40% and 300% before wrapping it around the package while keeping it in place under the package. action of compressive forces. Most plastic films, when stretched above their yield point, have their resistance modulus significantly increase. The maximum strength in Kg / cm of a typical polyethylene section is multiplied by three after an elongation of about 300%. This very large increase in strength begins approximately when the elongation exceeds the elastic limit point. This point of maximum elasticity is reached for a tension of 15% to 40%

  in the case of virtually all films currently used.

  Limitations of conventional friction type tension devices prevent packaging by

  conventional wound strips to take advantage of the maximum resistance

  Male available from most plastic films. The use according to the invention of greater elongation levels reduces the number of film turns for the same holding force. These higher levels of elongation and tension not only reduce the number of turns of film but also use a smaller weight of film each turn. The invention thus makes it possible to easily carry out

  cost savings of more than 50%.

  If we are dealing with irreversible goods

  gules, unstable or likely to crash, it is possible to adjust the surface velocity of the film leaving the pretensioning mechanism at a speed equal to or slightly greater than the

  average surface velocity (or tangential velocity) of the pallet.

  A considerable reduction in the force applied to the film makes it possible to obtain most of the advantages of high elongation levels without the risk of crushing. This reduction of the force is due to the fact that one finds an inelastic stress because the point of maximum elasticity has been exceeded, and the fact that the stress is relaxed

  quickly for high levels of elongation.

  Very stable packages that do not risk crashing can thus be obtained by taking advantage of the maximum strength of the film because the speed of the film leaving the pre-tensioning mechanism is slowed down to a surface speed less than average speed of the load of the

  pallet so as to obtain additional tensile forces

  beyond the forces obtained during the initial elongation. The object of the invention is to provide a method and apparatus for applying stretched plastic film to palletized goods for packaging thereof, using two associated sets of driven rollers driven at different speeds to lengthen the pallet.

  plastic film beyond its elastic limit point

  and simultaneously connecting the film to a rotating pallet whose vertical surface is moving at about the same speed as the surface of the fastest final roll of the two sets of rolls. When wrapping irregular or unstable goods one can increase the surface speed of the final roll over. the surface speed of the merchandise constituting the load, so as to avoid the efforts of deterioration of this load or tearing of the film. For relatively rigid and regular loads the maximum film strength can be used by slowing the final roll surface speed below the surface velocity

  pallet load for additional elongation

  shut and a greater pulling force. It is also possible to use a film accumulator driven by a motor or subjected to a force, in order to compensate for the effects of the corners in

  the case of large differences between length and width, this accumula-

  filmeur may for example be constituted by a jumping bar. A film width reduction device may be placed upstream or downstream of the rolls to reduce

  risk of edge tearing in the case of

  very important. The termination of the ends of the film can be done very effectively by means of a mechanism of

mechanical termination.

  To achieve the above goals, the

  relates to a method of packaging in the form of a one-piece package, of a goods consisting of several elementary charges placed on a turntable, characterized in that it comprises the different steps of drawing the end of a roll of stretchable material film mounted on a reeling device and passing the film through a drawing mechanism; maintaining the front end of the film in a locking device mounted on a turntable; passing the film through a first set of rollers of the stretching mechanism with a first speed and increasing this film speed by passing it into a second set of higher speed rolls so as to stretch the film of 50 about% above the elongation obtained at the limit point

  elasticity of this film, so as to modify its characteristics

  and increase its resistance modulus per section unit; winding the stretched film a number of times around the load; and to fix the back end of the film to

  an underlying layer of it.

  According to another characteristic of the invention, this relates to an apparatus making it possible to implement the above method and comprising a frame, unwinding means mounted on this frame, these unwinding means making it possible to maintain a film roll of stretch plastic and having driving means; a turntable for receiving and supporting a load comprising a number of elementary charges stacked in the vicinity of the chassis; driving means connected to the turntable so as to rotate the latter with the load which it carries pre-stretching means placed at a distance from the turntable; the film unwinding means moving in the vicinity of the pre-stretching means so that the rotating film roll which they carry comes into contact with the pre-stretching means to be driven by them so as to debit the plastic film, the pre-stretching means comprising spaced apart driven rollers driven at different constant speeds so as to engage the plastic film discharged by the roll, which film is drawn from the first-time unwinding means velocity and then moving to a higher speed downstream, so as to produce a

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  elongation of the material beyond its elastic limit point so that this stretched material wraps around the load when

it turns.

  The invention will be better understood at

  3 reading the following detailed description of an example

  preferred embodiment thereof with reference to the accompanying drawings in which: - Figure 1 is a perspective view of the apparatus according to the invention, in which a part of the apparatus is cut off, - Figure 2 1 is a plan view of the apparatus according to the invention of FIG. 1; FIG. 3 is an elevational front view in reduced scale of the apparatus of FIG. 2; FIG. a partial side view, in elevation, of the apparatus according to the invention and of the pallet; - FIG. 5 is a partial plan view from above, on a larger scale and partly in section, of the locking device and the device; for packaging the apparatus according to the invention; - Figure 6 is a side elevational view of the locking device shown in Figure 8, showing in dashed position of the device when turned,

  FIG. 7 is an isolated view, in

  and on a larger scale, the locking device in the open position, - Figure 8 is a side elevational view of the locking device of the device, - Figure 9 is a partial perspective view of the mechanism of change of the device. film width of the apparatus according to the invention, in open position of full width of the film, - Figure 10 is a partial perspective view of the film width change mechanism when it has rotated to reduce the film to Figure 11 is an enlarged side view, in elevation and partly in section, of the cutting mechanism and the packaging device of the apparatus according to. in ion and Figure 2 is a side view in

  elevation of the housing of the cutting mechanism.

  The wrapping and winding apparatus 10 according to the invention is preferably set forth in FIGS. 1 to 12, the preferred embodiment of FIG. nvention being shown in Figures 1 to 4 and the mechanical closure device of the invention being shown in Figures 5 to 12. The

  functioning and the description of the different parts

  of the apparatus according to the invention are explained in

the following description.

  The winding and wrapping apparatus

  under 10 powered by an engine comprises, according to the

  In the preferred embodiment of the invention, a carriage 16 is mounted to move in a conventional manner on the frame 12 and is driven by a rack and pinion device. chain or other suitable means Figure 3 shows a rack-type drive. Such tensioned packaging machines are well known in the prior art and are described in the Templates of our SVS-80, SVSME 80, STVS = 80, SrVSM = 80

  and SAHS-80 corresponding to the manufactures of ILantech Inct. "

  The apparatus 10 may also be

  It is arranged by a continuous apparatus without a carriage, as is also well known in the prior art. Examples of these machines are provided by Models Nos. S-65 SP-65 and SAH-70 manufactured by Lantech Inc. A typical example of the state of the art concerning continuous film machines is also described in UoS3, A. No. 3867,806 Other machines capable of using the invention are machines which rotate the film around the load rather than the turntable carrying the same. Such apparatuses are described in U.SoAo Nos. 4,050, 220 and 41010957 filed by "Lantech Co.". These patents are hereby given by reference. In the present embodiment, and as best seen in Figures 1 and 2, a support bar 20 is attached to the walls of the carriage 16 and 18. Support arms 22 and 24 are pivotally mounted the respective brackets 26 and 28 themselves attached to the side wall 17 of the carriage or again to a vertical upright 13 of the frame 12. A rotary shaft 30 is mounted at the ends of the pivoting support arms and serves to receive and To maintain a roll of film 32 - The roll of film is preferably constituted by a rolled sheet 32 of stretchable material.

  Stretchable films which can be used satisfactorily

  in the apparatus according to the invention are the films "Mobil XI" Mobil C "" Mobil H "the Mobil Y", "Borden" PS-26, "Consolidated Thermoplastics EVA" ', "" Presto "'," St Regis "and PoPoD. We can still use them in the camera of the movie "Bemis Stretch

  Net "', and excellent results have been obtained with polyethylene

Linear linear low density.

  A compressed air cylinder 34 is mounted on the support bar 20 and has an associated piston rod 36 connected to the arm 22 by a connecting element 38. The compressed air cylinder 34 is intended to drive the arm 22 forwardly. and the roll of film 32 so as to support this

  roll of film against a drive roller of elastic type

  rubber follower 40 9 made of polyurethane hardness 42 to 52. Next to the roller 40 is a second set of two identical rollers 42 and 44. The roller 40 has a toothed wheel 46 and the roller 42 has a toothed wheel 48. The first roller 40 and the second roller 42 have toothed wheels of different sizes so that the surface speed of the first roller 40 is at least 40 less than this.

  at the surface speed of the second set of rollers 42, 44.

  The dimensions of the toothed wheels are chosen according to the

desired degree of stretching of the film.

  Thus the surface movement of the first roller 40 may be about 40%, 75%, 200% or 300 c slower than the surface movement of the second set of rollers.

  to obtain pre-stretches of 40%, 75%, 200% or 300 '.

  Although stretching is normally in a range of 40 to 300%, excellent results have been obtained for narrower pre-stretching ranges, for example, according to requirements, stretching the material between 40 and 300%. % and 73 eo, 73 fc and 200 f,

  % and 300 /%, and at least 100% o In some cases the pre-

  stretching has been achieved successfully at over 300%. The rollers and 42 are connected by a drive chain or a

belt 50.

  As can best be seen in FIG. 3, the two sets of rolls are driven by a variable speed DC motor 52 through a gearbox 54 mounted on the shaft 55 of the roller 42. It is obvious that the reducer 54 can be mounted on any of the rollers, these rollers are provided with drive gears

56 and 58.

  Variations of realization can be

  the mechanically driven rollers producing the stretching of the film by differences in surface velocities, instead of the preferred embodiment of the invention described in FIGS. 1 to 3. For example, two driven individual roller assemblies can be used. and connected by a belt or by any other suitable means. The film 33 coming out of the roll 32 can also pass around the intermediate roll under the action of the drive rollers, so as to effect traction and elongation of the film. In yet another variation, a motor roll can pull the film 33 directly from the roll 32, with a brake pressing the roll of film to hold it back so that the film stretches over the intermediate rollers. It can thus be seen that the film is stretched between symmetrical round rolls rather than between the film roll and a rectangular pallet, as was the case in the prior art, to stretch this film appropriately beyond the point of elastic limit in order to enjoy his

  increase in breaking strength.

As we can see it better on

  FIGS. 1 to 3, a battery mechanism 90 oriented vertically.

  horizontally movable, is mounted at the side of the second set of rollers. This accumulator mechanism comprises two pivoting support arms 92 and 94 respectively mounted on consoles 96 and 98. These consoles are fixed to the side wall 19 of the frame. A compressed air cylinder 100 is

  attached to a support bar 102, the piston rod 104 of the cylinder

  The rotating shaft 108 rotatably supports the roller 110 so that the film can decompose before a wedge to pass around the load on the pallet. The roller is connected to the support arm by a connecting member 106. is placed so as to deliver additional film after the passage of the corner 131 of the load 130, and retrieves the film in

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  This is done in practice by the use of limit switches.

mounted on the turntable.

  The accumulator can also maintain a constant force through a spring or air cylinder lo, so as to soften the passage of the corner. An alternative mechanism for obtaining the same result uses means for detecting the passage of a corner of the pallet and for producing an electrical signal which changes the speed of a

  DC motor. This simultaneously modifies the

  its two sets of rollers so as to synchronize the speed of the film coming out of the rollers to compensate for the

passage of a corner.

  During operation of the apparatus 10 the film 33 spirals around the first roll 40 and then passes between the second set of rollers 42 and 44 to wind around the accumulator roll 110 and finally connect to the load on pallet 130 or a fixation of the turntable (not shown but well known in the prior art). The turntable 120 and the drive rollers are operated simultaneously to unroll the film 33 from the roll 32 with a suitably controlled speed. The second set of rollers 42, 44 is mechanically connected to rotate

  with a faster surface speed than the roller 40.

  The difference in speeds of the associated rollers makes it possible to obtain a precise degree of elongation irrespective of the force required or gauge variations. Movie 33 is supported

  across its width by smooth parallel surfaces and elastic

  ticks rollers. The stretched film then passes around the accumulation mechanism 90 to reach the load 130 without it being necessary to provide additional tension or force. If uneven, unstable, or crashworthy loads are encountered, the second set of rollers 42, 44 can be adjusted at a surface speed equal to or slightly greater than the average load surface velocity. the force applied to the film provides most of the benefits of strong elongation without the risk of crushing. This reduction in force is due to the fact that we find a non-elastic stress because the film has exceeded its point of elastic limit and the stress is released very quickly at high elongation levels Stable loads or not risking s' crushing can take advantage of the maximum strength of the film if one slows the second set of rollers to a surface speed lower than the average speed of the load on

  pallet, so as to produce additional tensile forces

  above and below those obtained during

the initial stretch.

  In addition, some types of high strength films or stretched films substantially above their yield point may require corner compensation such as that provided by the accumulation device 90O. The roll 110 is positioned to output a additional film at the passage of a corner 131 and recover the excess film to the passage of a flat face 132. This is actually achieved by adjusting the position of limit switches on the turntable 120. This setting of This position is well known in the prior art. The accumulator can also maintain a constant force due to the presence of a spring or a cylinder.

  compressed air, so as to soften the passage of the corner.

  The end end 33 of the film can be brushed onto the underlying film layers wound on the load, then clamped, heat-sealed, or secured by a mechanical lock. In the preferred embodiment of

  the invention uses a mechanical locking device.

  We will notice that we use indifferently

  in the present description a film, a film material or

  When it leaves the accumulation mechanism 90, the film 33 passes through a rope shaping mechanism 50. As can be seen in FIGS. 9 and 10, this mechanism 50 comprises a support plate 152 fixed to the frame 12 and a rotatable support bar 154, one end of which is rotatably mounted on the support plate and the other end of which is attached to the width-reducing member of the support plate;

movie 156.

  The film reduction member 156 comprises a rectangular bar defining a rectangular opening 157. The length of this rectangular opening is greater than the width of the material film used for

  wrap the load, and the width of this rectangular opening

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  The film is larger than the thickness of the film. Preferably this width is also equal to the desired thickness of the film when it is returned in the form of a rope, so that when the element 156 rotates the film material 33 takes a rope shape of diameter substantially equal to or less than the width of the opening

  157, as can best be seen in Figure 10.

  A pneumatically actuated cylinder 158 is attached to the support plate 152 or to the frame, and an end 159 of its piston rod is rotatably connected to the drive bar 160 itself attached to the rotatable support bar 1540. cylinder 158 may be controlled by a conventional fluid circuit so as to drive the rotatable support bar so that it rotates about a pivot point 155 carrying the film reduction member 156 upwards or downwards. down to an arc of about 900. This gives the film a rope configuration 226 when the rectangular element is parallel to the ground, or on the contrary freely passes the film in the reduction element 156 when

  it is substantially perpendicular to the ground.

  When formed into a rope, the film passes through a blocking device 170 mounted on the edge of the turntable. The locking device 170 includes a fixed arm mechanism 172 and a rotatable locking mechanism 174 mounted on a shaft 176 rotated by a pneumatic cylinder 1780 The fixed arm mechanism 172 comprises a support block 180 mounted on a turntable, a seat support 182 attached to the support block 180 and a cylinder support subassembly 184 attached to the support block. The rear portion 185 of the support block is attached to the air cylinder, and its rear portion 186 is attached to the fixed seat support 1820 The seat support 182 has a "U" seat 188 provided with a friction member 190 made of rubber or any other suitable resilient material secured in the seat and protruding above the legs 200 and 208 of the U-shaped seat 182 to receive the locking arm 198 of the rotational locking mechanism 174. The rotary locking mechanism comprises an eccentrically shaped material guide member 192 having a circular opening 194 of suitable diameter surrounding the pneumatic cylinder 178 so that the guide member 192 can freely rotate around the pneumatic cylinder A curved surface notch 196 is cut internally from the outer edge of the material guide member 192, to a suitable depth allowing this notch to receive and guide the The locking arm 198 is attached to a spacer bar 210 itself attached to the guide member 192. The locking arm 198 is a rope-like material during the packaging and cutting operation of the apparatus. comprises a cut-off segment 202 in approximate shape of "L" curve, constituting the contact surface for receiving the elastic friction element e The segment 202 has a flat surface 204 for receiving the friction element 190 so as to receive between them the rope-shaped material. The outwardly facing branch 206 of the "L" is intended to be placed next to the foot 208 of the seat 188 so as to receive the material stretched under the

  smallest possible extension angle from the wrapped package.

  A cutting mechanism 220 and a packaging mechanism 240 are attached to a movable arm 212 driving these mechanisms sequentially into the path of the material to perform the cutting and packaging steps. The arm 212 is rotatably mounted on the support structure 214 and

  driven by the pneumatic cylinder 216 fixed to the frame 222.

  The outlet of the piston rod 217 of the cylinder 216 brings the arm and the associated cutting and packaging mechanisms into the path of the material so that these mechanisms can play their part. At the cross arm 212 attach a perpendicular arm 218 holding the packaging mechanism 240 and

  a support structure 219 mounted at the top of the arm and supporting

both the cutting mechanism 220.

  This cutting mechanism 220 comprises a vertical support plate 222 and a cross member 224 attached to the support plate, and a piston 226 attached to the vertical support plate 222. A piston arm 227 exits the piston and the end The outer blade of this piston arm is attached to a cutting blade 228. This cutting blade 228 can move back and forth in a sheath or guillotine-shaped housing 230 attached to the end of the cross arm 212. The guillotine sheath 230

  has a plate structure with an indentation

  born inward 233 and cut in a corner so as to

  receive the rope material and guide it to the center of the

  check 2340 When held in the cutting notch 234 the rope material is cut by the reciprocating movement of the cutting blade 228 falling on this rope to sever it. A conventional looping or stapling device 242 such as that manufactured by the company "ATRO"; types I and C, is attached to the lower part of the arm 21.9. A magazine 244 is arranged perpendicular to the mechanism to bring staples or loops into the mechanism. During the operation of the conventional buckle or stapler device, the nose of the buckle engages in the merchandisers to be wrapped and a ring or staple is driven around the morning material into the nose of the buckle and secured around the goods by curvature

  the ring or staple around these goods to be wrapped.

  Thus the two layers of film transformed into ropes and placed side by side, are fixed together under the action of the stapler passing a staple or loop around the two ropes to fix and attach by contraction or curvature of the

  loop or staple around the goods.

  It may be noted that the various steps of the packaging process described above can be interchanged without departing from the scope of the invention. Moreover these

  different stages are interchangeable and equivalent.

17.-

Claims (18)

  l.- Packaging method, in the form of a   package of a single niece, of a good consisting of   a plurality of elementary charges (130) on a turntable (120) characterized in that it comprises the steps of pulling the end of a roll (32) of stretchable material film (33) mounted on a device unwinding (42, 44) and c doing   passing the film (33) in a drawing mechanism, to maintain the end   before the film in a locking device mounted on a turntable; passing the film through a first set of rolls (40) of the drawing mechanism at a first speed and increasing this film speed by passing it through a second set of higher speed rollers (42, 44), so as to stretch the film about 50% above the elongation obtained at the elastic limit point of this film, so as to thereby modify its characteristic and increase its resistance modulus per section unit; winding the stretched film a number of times around the load and attaching the rear end of the film to an underlying layer thereof. 2. A packaging method according to claim 1, characterized in that it comprises the additional step of cutting the plastic film (33) from the rest of the roll (32)   the unwinding device (42, 44) at the end of the fixing step.   3. Process according to any one of the   1 and 2, characterized in that the fixing is done in   mechanically laminating the upper film layers by fastening means.   4. Process according to any one of the   1 to 3, characterized in that the plastic film (33) is made of polyethylene.   5. Process according to any one of the   1 to 4, characterized in that the plastic is stretched in a range of 100% to 300% by drawing and drawing means. voltage (40, 42, 44).   6. Process according to any one of the   1 to 5, characterized in that the plastic material is a polyvinyl chloride film.   7. Process according to any one of the   1 to 6, characterized in that the plastics material is   consisting of a copolymer of polypropylene and polybutylene. 18. -   8. Process according to any one of the   1 to 7, characterized in that the material is constituted by a net of plastic material.   9. Process according to any one of the   1 to 8, characterized in that the plastic is stretched   in a range of about 200% to 300%.   10. Process according to any one of the   1 to 9, characterized in that it comprises the additional step   of stretching the stretched and stretched material through   to an accumulation mechanism (110) accumulating in advance the material stretched at the aperture of the passage of a corner (131) of the load   (130) so as to obtain a uniform covering.   11. A process according to any one of the   dications 1 to 10, for spiral winding a stretched and stretched wire   on a good (130) consisting of several basic charges   to form a single package, characterized in that it comprises the various steps of pulling the film (33) from a roll of film (32) by means of driving rollers (40, 42, 44). and maintaining the film (33) in the vicinity of the load (130); operating the drive rollers (42,44) to drive the film at a downstream speed greater than the upstream speed so as to produce stretching of the film beyond its elastic limit point and thereby increase the resistance modulus film while isolating the load from the tension force and simultaneously rotating this load; to wrap the spiral charge; setting the input width or the front end of the film to the output width or the rear end thereof; and cutting the film between the roll (32) of material and the fixed portion of the film.   12. The process according to claim 11, wherein   characterized in that the securing step includes attaching together the first and second rope-shaped configurations, by means of   of a piece of material surrounding these configurations.   13. Apparatus for carrying out the procedure   die according to any one of claims 1 to 12 consisting of   packaging a commodity (130) consisting of a plurality of elementary charges by means of a single plastic film forming a cover, characterized in that it comprises a frame (12) of unwinding means (42,44) mounted on this frame, these unwinding mcyens for maintaining a roll of film 19. -   of stretchable plastic material (32) and having means for   trailing (34, 22) a turntable (120) for receiving and supporting a load (130) comprising a number of loads   elementary piles stacked near the chassis; means of training   connected to the turntable so as to rotate it with the load it carries; pre-stretching means (40) placed at a distance from the turntable; the film unwinding means (42, 44) moving in the vicinity of the pre-stretching means (40) so that the rotating film roll (32) which they carry comes into contact with the pre-stretching means for being driven therefrom to deliver the plastic film, the pre-stretching means including spaced apart motor rollers (40) driven at different constant speeds to engage the plastic film being dispensed by the roll (32) this film being pulled from the feed means at a first speed and   then moving upstream downstream, so that   elongate the material beyond its elastic limit point so that this stretched material wraps around the load when it turns.   14. Apparatus according to claim 13, characterized   characterized in that the pre-stretching means are constituted by two rollers (40, 42) driven by a motor (52), one of these rollers being connected by connecting means (50) to the upstream roller (40). so that the speed of rotation of the upstream roll is directly   proportional to the rotational speed of the downstream roll (42).   15. Apparatus according to any one of the   13 and 14, characterized in that the ratio of the speeds of rotation between the downstream roller means (42) and the rolling means upstream (40) is at least 3 to 2.   16. Apparatus according to any one of the   13 to 15, characterized in that it comprises means of   cummlator (90) mounted on the frame, said storage means comprising a movable roller (110) for engaging the film and means for moving said movable roller (110) against the film to compensate for differences in speeds at the corners (131) of a rectangular load (130) by accumulating the film at the corners (131) and restoring the excess film on the walls planes (132) of the load.   17. - Apparatus according to any one of claims 13 to 16, characterized in that it comprises means (34,22) 20.- mounted on the frame (10) for bringing the roll of film (32) against   the first drive roller (40).   18. Apparatus according to claim 17, characterized   characterized in that the means consist of a fluid cylinder (34) associated with an arm (22).