US20110088359A1

US20110088359A1 - Method and device for wrapping products

Info

Publication number: US20110088359A1
Application number: US12/995,384
Authority: US
Inventors: Pierre BROCARD
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-06-27
Filing date: 2009-06-29
Publication date: 2011-04-21
Also published as: WO2009155713A3; CA2726209A1; WO2009155713A2

Abstract

There is described herein a wrapping machine for wrapping a web of at least two stretchable films around a product. The wrapping machine comprises a dispenser for dispensing the at least two stretchable films with a longitudinal overlap. Each of the at least two stretchable films has a film edge in a longitudinal direction. The wrapping machine further comprises a roper for roping the film edges of the at least two stretchable films; a stretching device for stretching, after the roping, the at least two stretchable films; and a frame structure on which is disposed the dispenser, the roper and the stretching device for delivering the web for wrapping around the product.

Description

FIELD

The present description is concerned with methods and devices for wrapping products. More particularly, it concerns the temporary wrapping of products for protection during transportation or other purposes.

BACKGROUND

It is very common to wrap and protect products which are piled on pallets for transportation by covering them helicoidally using a band of stretchable film extruded in multiple layers. This is performed manually or using an electronically controlled machine.
The thickness of the stretchable film as well as the number of revolutions performed by the film around the pallet and product assembly varies according to the nature of the product to be protected and contained for transport. For example, in the case of a 40″ by 48″ by 48″ pallet and product assembly, there could be used:

- 1. For cereal boxes stored in cardboard boxes, at least 6 turns of stretchable film having a thickness of 0.6 mil thickness;
- 2. For beer cases, at least 10 turns of wrappable film having a thickness of 0.7 to 0.8 mil; and
- 3. For crushed stone having cutting edges and packed in plastic bags, at least 15 turns of stretchable film having a thickness of 0.7 to 0.8 mil.

To reduce the cost of wrapping, there is a natural tendency to reduce the number of turns (to reduce wrapping material and to reduce wrapping time) and to reduce the thickness of the stretchable film (to reduce wrapping material).

SUMMARY

According to an embodiment, there is described a wrapping machine for wrapping a web of at least two stretchable films around a product. The wrapping machine comprises a dispenser for dispensing the at least two stretchable films with a longitudinal overlap. Each of the at least two stretchable films has a film edge in a longitudinal direction. The wrapping machine further comprises a roper for roping the film edges of the at least two stretchable films; a stretching device for stretching, after the roping, the at least two stretchable films; and a frame structure on which is disposed the dispenser, the roper and the stretching device for delivering the web for wrapping around the product
According to another embodiment, there is described a wrapping machine for wrapping a web of a stretchable film around a product. The wrapping machine comprises a dispenser for dispensing the stretchable film having two film edges in a longitudinal direction and a roper for roping the two film edges of the stretchable film. The roper comprises at least two pulleys such that each one the two film edges is introduced in a corresponding one of the at least two pulleys when the stretchable film is dispensed thereby roping the two film edges. The wrapping machine further comprises a stretching device for stretching, after the roping, the stretchable film and a frame structure on which is disposed the dispenser, the roper and the stretching device for delivering the web for wrapping around the product.
According to another embodiment, there is described a method for wrapping a web of a stretchable film around a product. The method comprises: dispensing the stretchable film; introducing each one of the two film edges of the stretchable film in a pulley for roping the two film edges; after the introducing, stretching the web; and wrapping the web around the product.
According to another embodiment, there is described a method for wrapping a web of at least two stretchable films around a product. The method comprises: dispensing each of the at least two stretchable films with a longitudinal overlap, each of the at least two stretchable films having a film edge in a longitudinal direction; roping the film edges of the at least two stretchable films; after the roping, stretching the at least two stretchable films; and wrapping the web around the product.
According to another embodiment, there is described a method for wrapping a stretched web around a product set on a pallet. The method comprises: dispensing the stretched web having an end; holding the end on the product above the pallet; and wrapping the stretched web around the product.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

FIG. 1 is a partial schematic front view of a wrapping machine according to an embodiment;

FIG. 2 is a graph showing the mechanical characteristics of webs produced by different combinations of the wrapping machine of FIG. 1;

FIG. 3 is a partial schematic front view of a wrapping machine according to another embodiment;

FIG. 4 is a graph showing the mechanical characteristics of webs produced by different combinations of the wrapping machine of FIG. 3;

FIG. 5 is a partial schematic front view of a wrapping machine according to another embodiment;

FIG. 6 is a partial schematic front view of a wrapping machine according to another embodiment;

FIG. 7 is a partial schematic front view of a wrapping machine according to another embodiment;

FIG. 8 is a partial schematic front view of a wrapping machine according to another embodiment;

FIG. 9 is a partial schematic front view of a wrapping machine according to another embodiment;

FIG. 10 is schematic front view of a wrapping machine according to another embodiment;

FIG. 11 is a schematic side view of the wrapping machine of FIG. 10;

FIG. 12 is a schematic side view of the wrapping machine of FIG. 11 adapted for delivering a different stretched web;

FIG. 13 is schematic front view of a wrapping machine according to another embodiment;

FIG. 14 is a schematic top view of the wrapping machine of FIG. 12;

FIG. 15 is a schematic top view of the wrapping machine of FIG. 12 before being engaged by a fork lift;

FIG. 16 is a schematic top view of the wrapping machine of FIG. 12 engaged by a fork lift wrapping a tool machine;

FIG. 17 is schematic top view of a wrapping machine according to another embodiment;

FIG. 18 is a schematic axonometric view of a holding and cutting arm according to an embodiment shown in an upright position holding a end of the web;

FIG. 19 is a schematic axonometric view of the holding and cutting arm of FIG. 18 after one complete turn around the product and with its pegs retracted;

FIG. 20 is a schematic axonometric view of the holding and cutting arm of FIG. 18 showing the arm in an escaped position;

FIG. 21 is a schematic axonometric view of the holding and cutting arm of FIG. 18 shown in an upright position with its cutting means ready to cut the web;

FIG. 22 is a partial schematic axonometric close up view of the holding and cutting arm of FIG. 18 with its pegs in a extracted position;

FIG. 23 is a partial schematic axonometric close up view of the holding and cutting arm of FIG. 18 with its pegs in a retracted position;

FIG. 24 is a schematic axonometric view of a holding and cutting arm comprising an upper and a lower arm according to another embodiment shown holding an end of the web;

FIG. 25 is a block diagram of a method for wrapping a web of a stretchable film around a product according to an embodiment;

FIG. 26 is a block diagram of a method for wrapping a web of at least two stretchable films around a product according to another embodiment; and

FIG. 27 is a block diagram of a method for wrapping a stretched web around a product set on a pallet according to another embodiment.

DETAILED DESCRIPTION

According to an embodiment, the wrapping machine described herein offers a considerable reduction in the cost of wrapping by using a curtain comprising a plurality of stretchable films, which are stretched in a conventional manner, in substantially a single revolution without reducing protection or containment of the products on the pallet.
For a 48″ high pallet, the film dispenser uses three 20″ film rolls.
In another embodiment, all film rolls are modified by introducing roping at the edge of each film and/or overlapping the ropings to increase: film stretch, puncture resistance, and force to load.
2″ roping is performed at the bottom of the bottom film roll. 2″ roping is performed at the top of the top film roll. A 4″ overlap is obtained using the middle roll to cover 4″ of the end of the bottom roll and another 4″ overlap is obtained using the middle roll to cover 4″ of the top roll.
The 48″ curtain therefore comprises:

- 1. 2″ film roping;
- 2. 1 film layer for 14″
- 3. 2 film layers for 4″
- 4. 1 film layer for 12″
- 5. 2 film layers for 4″
- 6. 1 film layer for 14″
- 7. 2″ film roping.

The total film height of the curtain is therefore 48″ (14″+4″+12″+4″+14″). This is called a re-enforced curtain of film for wrapping.
According to an embodiment, the curtain of film is mechanically pre-stretched and mechanically powered around the load for best dispensing.
For light loads, 1 turn or 2 turns are performed. For heavy loads, 3 turns or 4 turns are performed.
Referring to FIG. 1, there is shown a part of a wrapping machine 100 dispensing a web 102 of a stretchable film 104 for wrapping a product, not shown. FIG. 1 depicts conditions of experiments A conducted in a laboratory. The wrapping machine 100 comprises a dispenser 106 loaded with a roll 108 of the stretchable film 104 which is dispensed toward pulleys 110. Each of the pulleys 110 is free to rotate around a rotation axis 112 substantially parallel to a width 114 of the stretchable film 104. The width 114 is in the vicinity of the pulleys 110. The pulleys 110 form a roper. The stretchable film 104 has two film edges 116 which are introduced in the pulleys 110 and are thereby roped. The two film edges 116 are in a longitudinal direction 117 of the stretchable film 104. Two roped edges 118 are produced before the stretchable film 104 is received by a braking roller 124. Each of the roped edges 118 are made by gathering each of the film edges 116 in the pulleys 110. Each of the film edges causes rotation of one corresponding of the pulleys 100 without longitudinal friction. This produces well roped edges 118 while the film between the two roped edges 118 is kept tight. The braking roller 124 rotates around a braking axis 126 dispensing the stretchable film 104 to a free roller 120 which is free to rotate around a free axis 122. The free roller 120 and the braking roller 124 are disposed so that a portion of the stretchable film 104 being in contact with braking roller 124 is great enough to be firmly engaged by the braking roller 124 by friction. The braking roller 124 is pivotally coupled to a brake 128 which can be adjusted to apply a braking torque to the braking roller 124, to selectively block the rotation of the braking roller 124. The free roller 120, the braking roller 124 and the brake 128 form a stretching device. The dispenser 106, the roper and the stretching device are disposed on a frame structure, not illustrated here, but shown in subsequent figures.
Before beginning experiments A, the brake 128 is released to dispense the web 102 around a traction bar 130 positioned at a distance L0 from the braking roller 124. Then the brake 128 is switched to a blocked status for immobilizing the portion of the stretchable film 104 which covers the braking roller 124. Then a continuously increasing force S is applied to the middle of the traction bar 130 away from the free roller 120 according to a normal to the free axis 122. While the force S increases, the traction bar 130 moves away from the free roller 120. Experiments A are conducted until the web 102 breaks. During experiments A, values of force S and corresponding distance Ls are recorded in real time. Distance Ls is a distance of the traction bar 130 from the free roller 120 while a force S is applied to the traction bar as described above. A stretch percentage is defined as equal to (Ls−L0)/L0 %.
Referring now to FIG. 2, there is shown the variation of the force S according to the stretch percentage during experiments A as described above. A first experiment A was conducted exactly as described above including a 0.7 ga thick stretchable film, having two roped edges 118 gathering each one of the film edges 116, each roped edge being 1 inch wide. The continuous curve 132 corresponds to the first experiment A. A second experiment A was conducted with the same 0.7 ga thick stretchable film, but this time without the two roped edges as in the prior art. The discontinuous curve 134 corresponds to the second experiment A.
It has been unexpectedly discovered that a web of a stretchable film including two roped edges formed by pulleys before the stretching, is much more resistant than a web of the same stretchable film without the roped edges. Moreover, a unit of a fully stretched stretchable film will cover more area if the stretchable film is roped than if it is not roped. It has been also discovered that a half inch wide roped edge is enough to increase the resistance of the web.
Referring now to FIG. 3, there is shown a part of wrapping machine 300 ready for experiments B. The dispenser 106 is adapted to receive two rolls 108 of stretchable film for dispensing two identical stretchable films 104 fully overlapped. The two film edges 116 of a front stretchable film 104 are introduced in front pulleys 110 to produce front roped edges. Similarly, the two film edges 116 of a back stretchable film 104 are introduced in back pulleys 110 to produce back roped edges. The process of the experiments B is the same as for experiments A, which consists in applying a force S on the traction bar 130, away from a free roller 120.
Referring now to FIG. 4, there is shown the variation of the force S according to the stretch percentage measured during several experiments B as described above. A first experiment B was conducted exactly as described above including two identical 0.70 ga thick stretchable films, each having two roped edges 118 gathering each one of the film edges 116, each being 2 inches wide. A first curve 136 corresponds to the first experiment B. A second experiment B was conducted with only one stretchable film, absolutely identical to each of the two stretchable films of the first experiment B, including the two roped edges. A second curve 138 corresponds to the second experiment B. A third and a fourth experiment B were conducted as described above each including respectively three and four identical stretchable films including the two roped edges. A third curve 140 and a fourth curve 142 respectively correspond to the third and the fourth experiment B.
These curves 136, 138, 140, 142 show an unexpected phenomenon: for a given resistance, a single revolution of two roped films stretched together uses less film than two revolutions of a single roped films stretched alone. Let us look at points A and B. On point A with one film, the stretch rate is 350% and the tension 15 Lbs. On point B with two films, the stretch rate is 475% and the tension 30 Lbs. That shows that two revolutions of one film stretched at 350% are necessary to obtain the same strength as a single revolution with two films stretched together at 475%. It also shows that a single revolution with two films can use 36% less film than two revolutions of a single film.
Using one of the two previous phenomena or combining them more or less, contribute to sustainable development and cut costs.
Referring now to FIG. 5, there is shown a part of a wrapping machine 500 equipped with a stretching device comprising a slow roller 144 and a fast roller 146. The dispenser 106 is adapted to receive two rolls 108 of stretchable films. Pulleys 110 are disposed for roping two film edges 116 so that the two longitudinal web edges 148 of the web 102 are each roped. The dispenser 106, the roper and the stretching device are disposed on the frame structure, not illustrated, for delivering the web 102 having a longitudinal overlap 150. The overlap 150 comprises two film edges 116. The combination of the roped longitudinal web edges 148 and the overlap 150 results in a higher resistance of the web 102 and a wide web for wrapping a product with almost a single revolution.
The slow roller 144 is moved into rotation by a standard motor, not shown. The slow roller 144 receives the stretchable films and controls a slow speed of the web 102. The fast roller 146 is moved into rotation too by a standard motor, not shown. The fast roller 146 receives the web 102 coming from the slow roller 144 and controls a fast speed of the web. The fast speed is greater than the slow speed and has an opposition direction than the slow speed. The web 102 is stretched thereby.
Referring to FIG. 6, there is shown a part of a wrapping machine 600 equipped as depicted on FIG. 5. The roper further comprises a middle front pulley 110 a and a middle back pulley 110 b for roping two adjacent film edges 116 and increasing the resistance of the web.
Referring to FIG. 7, there is shown a part of a wrapping machine 700 comprising a dispenser 106, a roper, a stretching device and a frame structure, not shown. The dispenser 106 is adapted for receiving three rolls 108 of stretchable films. The roper comprises two edge pulleys 152 having an edge rotation axis 154. Pulleys 152 are disposed for roping two film edges 116 so that the two longitudinal web edges 148 of the web 102 are each roped. The stretching device comprises a braking roller 124 and a stretching roller 156. The braking roller 124 receives the stretchable films 104 forming the web 102. The stretching roller 156 receives the web 102 coming from the braking roller 124 and pulls on it to stretch the web 102. The braking roller 124 controls the tension of the web 102. The dispenser 106, the roper and the stretching device are disposed on the frame structure for delivering the web 102 having two longitudinal overlaps 150. At least one of the film edges 116 of the overlaps 150 can be roped for increasing the resistance of the web 102.
Using three rolls 108 allows wrapping taller products with less than two revolutions of the web 102. Each one of the edge rotation axis 154 is substantially normal to a width 114 of the corresponding stretchable film 104. The width 114 is in the vicinity of corresponding edge pulley 152. In some cases, the edge pulleys 152 may be a bit less efficient than the pulleys 110 depicted on FIG. 1, but they are some times easier to position when there are many rolls 108 of stretchable film on the wrapping machine 700 or when the space dedicated to the roper is really narrow.
Referring to FIG. 8, there is shown a part of a wrapping machine 800 designed like the wrapping machine depicted on FIG. 7 and adapted to receive three rolls 108 of stretchable film and to produce two separate webs 102, each of the four longitudinal web edges 148 being roped. Such arrangement allows wrapping products which need to be ventilated such as fruits or vegetables.
Referring to FIG. 9, there is shown a part of a wrapping machine 900 designed like the wrapping machine depicted on FIG. 1 and adapted to produce a web 102 further having a longitudinal strip 158 which is roped and located between the two longitudinal web edges 148. One pulley 110 is added between the two film edges 116. This additional roped longitudinal strip 158 allows increasing the resistance of the wrapping. Producing such a roped longitudinal strip 158 is possible with such a pulley 110 but is not possible with an edge pulley 152 as depicted on FIG. 7.
Concurrently referring now to FIG. 10 and FIG. 11, there are respectively shown a front view and a side view of a wrapping machine 160 according to an embodiment. The wrapping machine 160 comprises a frame structure having a gantry frame 162 and a rotary arm 164. The rotary arm 164 is linked to the gantry frame 162 with a ring gear bearing 166 which allows the rotary arm 164 to turn around an arm axis 168. The ring gear bearing 166 is fixed to the gantry frame 162 which is fixed to the ground 170. A rotary actuating means 172 controls the rotary arm 164 around the arm axis 168. A dispenser, a roper and a stretching device, as previously described are disposed on the rotary arm 164 for delivering a web 102, pre-stretched or not, around a product 174 disposed on a pallet 176.
In such a configuration, for a person skilled in the art, it is easy to expect that when the web 102 will be delivered around the product 174, the film edge 116 will be substantially included in a given plane 178. It is also easy to expect that less than two revolution of the web 102 around the product 174 will be enough for completely wrapping the product 174.
Referring to FIG. 12, there is shown a wrapping machine 161 according another embodiment. The wrapping machine 161 is adapted for delivering a stretched web 103 having a width 175 smaller than a height 177 of a product 174 being wrapped. The stretched web 103 comprises three stretchable films which were roped and stretched together by a dispenser, a roper and a stretching device as previously described. The stretched web 103 comprises six roped edges 118 for conferring a high resistance to the stretched web 103. The wrapping machine 161 comprises a frame structure 182 fixed to the ground 170. The frame structure 182 comprises a moving frame 183 able to be moved according to a vertical axis. The dispenser, the roper and the stretching device are disposed on the moving frame 183 for delivering the stretched web 103 at a varying height, not shown, according to the ground 170. The product 174 is disposed on a pallet 176 on a rotating table 173 for receiving the stretched web 103. The rotating table 173 rotates around an axis 171, hence rotates the product 174 and thereby wraps the stretched web 103 around the product 174.
At the beginning of the wrapping, the stretched web 103 is held to the top or upper portion of the product 174, above the pallet 176. Then the rotating table 173 rotates the product 174 and thereby wraps the stretched web 103 around the upper portion of the product 174. It has been discovered that with stretched webs as previously described, many products 174 do not need to be wrapped with the pallet 176 and need to be wrapped only at its upper portion (e.g. pallet of beer cases which are temporally glued together). This allows to cut costs and to contribute to sustainable development.
Concurrently referring now to FIG. 13 and FIG. 14, there are respectively shown a front view and a top view of a wrapping machine 180 according to another embodiment. The wrapping machine 180 comprises a frame structure 182 and a dispenser, a roper and a stretching device, as previously described. At the bottom of the frame structure 182 there are two openings 184 for receiving forks of a fork lift or other vehicle.
Turning to FIG. 15 there is shown a top view of the wrapping machine 180 depicted on FIG. 13 and FIG. 14 and a fork lift 186 disconnected from the wrapping machine 180. Turning to FIG. 16, there is shown the forklift 186 which has introduced its forks in the openings of the wrapping machine 180, thereby embedding the wrapping machine 180 via its frame structure. Equipped as such, the forklift 186 is wrapping a machine tool 188 with the web 102, driving around the machine tool 118. It is possible to maintain a given level of the web 102 during the wrapping. It is also possible to vary the level of the web 102 for increasing a height of the wrapping. Such a wrapping machine 180 is a low cost solution for wrapping expanded product or when the need of wrapping is occasional.
Referring now to FIG. 17 there is shown a top view of a wrapping machine 190 according to another embodiment. The wrapping machine 190 comprises a frame structure 192, a dispenser, a roper and a stretching device, as previously described. The wrapping machine 190 further comprises a moving device 194 for driving on a floor and for wrapping a product as depicted on FIG. 16. The moving device 194 comprises a motorization 196 for rotating a directional driving wheel 198, two un-directional free wheels 200, a control handle 202 for controlling a speed and a direction of the wrapping machine 190 and a standing platform 204 for receiving an operator.
Referring now to FIG. 18, there is shown a holding and cutting arm 206 of a wrapping machine according to an embodiment. The holding and cutting arm 206 is for holding a web 102 of stretchable film at the beginning of the wrapping of a product 174 and for cutting the web 102 at the end of the wrapping. The holding and cutting arm 206 is pivotally coupled to a portion of a frame structure 192 so that when the holding and cutting arm 206 rotates, it moves along a side wall 208 of the product 174. The portion of the frame structure 192 is substantially fixed with respect to the product 174 during the wrapping. If the product 174 rotates, the portion of the frame structure 192 rotates as well, possibly embedded on a compression plate, not shown, for maintaining the product, which is compacted during the wrapping. If the product 174 is static with respect to the ground, the portion of the frame structure 192 is static as well. In any case, the portion of the frame structure 192 can be disposed at the base of the product 174, as shown, or at the top of the product 174, not depicted.
Concurrently referring now to FIG. 22 and FIG. 23, there is shown an end of the holding and cutting arm 206 which comprises a releasable holding means 210 and a cutting means 212. The releasable holding means 210 comprises an arm bar 214 equipped with a bank of pegs 216, both logged into the holding and cutting arm 206. The pegs 216 pass through arm holes 218 of the holding and cutting arm 206. The arm bar 214 is movable inside the holding and cutting arm 206 so that the releasable holding means 210 can be active for holding a web as shown on FIG. 22 and the releasable holding means 210 can be released for releasing a web as shown on FIG. 23. In another embodiment, not shown, the releasable holding means comprise gripping fingers which can escape the web. The cutting means 212 comprises a wire 220. The wire 220 is activated with an electric current which heats the wire and thereby cuts a web located proximate the wire 220.
Returning now to FIG. 18, FIG. 19, FIG. 20 and FIG. 21, concurrently referred to, there are shown steps of use of the holding and cutting arm 206 during a wrapping of a product 174. At the beginning of the wrapping depicted on FIG. 18, the releasable holding means of the holding and cutting arm 206 is activated, the pegs are extracted and the web 102 is held along the holding and cutting arm 206. The web 102 is wrapped around the product 174 for more than one revolution as depicted on FIG. 19. Then the releasable holding means is released and the holding and cutting arm 206 rotates, escaping between the web 102 and the side wall 208 as depicted on FIG. 20. The more the web 102 is stretched, the easier it is to move the holding and cutting arm 206 before the web 102 naturally tenses. On FIG. 20, the holding and cutting arm 206 is down. The web 102 can be wrapped around the product 174 for many revolutions as necessary. At the end of the wrapping, the holding and cutting arm 206 is risen as depicted on FIG. 21, the cutting means is activated for cutting the web 102 and the holding means is activated to for holding the end of the web 102 to be ready for a new wrapping cycle.
Referring now to FIG. 24, there is shown a holding and cutting arm 206 of a wrapping machine according to another embodiment. The holding and cutting arm 206 comprises a lower arm 222 and an upper arm 224, each pivotally coupled to a portion of a frame structure 192 for escaping between the web 102 and a side wall 208 of the product 174 during a wrapping cycle as previously described.
It should be understood that any combination is allowed according to the wrapping product requirement; i.e., combining: number of revolution, no roped film edge, single roped film edge, double roped film edges, roped longitudinal strip, single stretch films, two stretch films or three stretch films or more, identical films or different films in width, thickness or composition, partial overlap or full overlap, etc. For each given wrapping product requirement, it is possible to define a convenient wrapping plan which represents one combination of the foregoing elements.
Referring now to FIG. 25, a block diagram provides steps of a method 226 for wrapping a web of a stretchable film around a product according to an embodiment. The method 226 comprises the steps of: Dispensing the stretchable film (step 228); Introducing each one of the two film edges of the stretchable film in a pulley for roping the two film edges (step 230); After the introducing, stretching the web (step 232); and wrapping the web around the product (step 234).
Referring now to FIG. 26, a block diagram provides steps of a method 236 for wrapping a web of at least two stretchable films around a product according to another embodiment. The method 236 comprises the steps of: Dispensing each of the at least two stretchable films with a longitudinal overlap, each of the at least two stretchable films has a film edge in a longitudinal direction (step 238). The method 236 further comprises the steps of: Roping the film edges of the at least two stretchable films (step 240); After the roping, stretching the at least two stretchable films (step 242); and wrapping the web around the product (step 244). Optionally, the step of wrapping the web around the product is such that one film edge is substantially included in a given plane when the web is wrapped around the product. The method 236, optionally further comprises a step of defining a wrapping plan according to wrapping requirements of the product (step 246).
Referring now to FIG. 27, a block diagram provides steps of a method for wrapping a stretched web around a product set on a pallet, according to another embodiment. The method comprises the steps of: Dispensing the stretched web having a end (step 250); holding the end on the product above the pallet (step 252); and wrapping the stretched web around the product (step 254).
While embodiments the invention have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made therein without departing from the essence of this invention. Such modifications are considered as possible variants comprised in the scope of the invention.

Claims

1. A wrapping machine for wrapping a web of at least two stretchable films around a product, the wrapping machine comprising:

a dispenser for dispensing the at least two stretchable films with a longitudinal overlap, each of the at least two stretchable films having a film edge in a longitudinal direction;

a roper for roping the film edges of the at least two stretchable films;

a stretching device for stretching, after the roping, the at least two stretchable films; and

a frame structure on which is disposed the dispenser, the roper and the stretching device for delivering the web for wrapping around the product.

2. The wrapping machine of claim 1, wherein dispenser, the roper and the stretching device are disposed such that one of the film edges is substantially included in a given plane when the web is wrapped around the product.

3. The wrapping machine of claim 1, wherein the dispenser, the roper and the stretching device are adapted to deliver a web having a web width and a web resistance such that the wrapping comprises less than two revolutions of the web around the product.

4. The wrapping machine of claim 1, wherein the dispenser, the roper and the stretching device are adapted for simultaneously wrapping the web and another stretchable film around the product, the web and the other stretchable film being separate on the product.

5. The wrapping machine of claim 1, wherein the roper is adapted for roping at least one of film edges included in the longitudinal overlap.

6. The wrapping machine of claim 1, wherein the roper comprises a pulley such that one the at least two film edges is introduced in the pulley when the corresponding one of the at least two stretchable films is dispensed thereby roping the one of the at least two film edges.

7. The wrapping machine of claim 6, wherein the pulley has a rotation axis substantially parallel to a width of the corresponding one of the at least two stretchable films, the width being located proximate the pulley.

8. The wrapping machine of claim 1, wherein the stretching device comprises a braking roller for receiving the at least two stretchable films and controlling the tension of the web.

9. The wrapping machine of claim 8, wherein the stretching device further comprises a stretching roller for receiving the web coming from the braking roller and pulling on to stretch the web.

10. The wrapping machine of claim 1, wherein the stretching device comprises a slow roller for receiving the at least two stretchable films and controlling a slow speed of the web, the stretching device further comprises a fast roller for receiving the web coming form the slow roller and controlling a fast speed of the web, the fast speed being grater than the slow speed so that the web is stretched.

11. The wrapping machine of claim 1, wherein the frame structure is adapted for wrapping the web around the product fixed with respect to the ground.

12. The wrapping machine of claim 11, wherein the frame structure is adapted to be embedded on a vehicle for driving around the product.

13. A wrapping machine for wrapping a web of a stretchable film around a product, the wrapping machine comprising:

a dispenser for dispensing the stretchable film having two film edges in a longitudinal direction;

a roper for roping the two film edges of the stretchable film; the roper comprising at least two pulleys such that each one the two film edges is introduced in a corresponding one of the at least two pulleys when the stretchable film is dispensed thereby roping the two film edges;

a stretching device for stretching, after the roping, the stretchable film; and

14. The wrapping machine of claim 13, wherein the stretchable film further comprises a width in the vicinity of the at least two pulleys and wherein each one of the at least two pulleys has a rotation axis substantially parallel to the width.

15. The wrapping machine of claim 14, wherein one of the pulleys is disposed between the two film edges so that the web further has a longitudinal strip which is roped and located between the two longitudinal web edges.

16. A method for wrapping a web of a stretchable film around a product, the method comprising:

dispensing the stretchable film;

introducing each one of the two film edges of the stretchable film in a pulley for roping the two film edges;

after the introducing, stretching the web; and

wrapping the web around the product.

17. A method for wrapping a web of at least two stretchable films around a product, the method comprising:

dispensing each of the at least two stretchable films with a longitudinal overlap, each of the at least two stretchable films having a film edge in a longitudinal direction;

roping the film edges of the at least two stretchable films;

after the roping, stretching the at least two stretchable films; and

wrapping the web around the product.

18. The method of claim 17, wherein the step of wrapping the web around the product is such that one film edge is substantially included in a given plane when the web is wrapped around the product.

19. The method of claim 17, further comprising a step of defining a wrapping plan according to wrapping requirements of the product.

20. A method for wrapping a stretched web around a product set on a pallet, the method comprising:

dispensing the stretched web having a end;

holding the end on the product above the pallet; and

wrapping the stretched web around the product.