FI93190B - A load wrapped in a stretchable film, placed on a pallet, and a method and apparatus for making the load - Google Patents

Abstract

Disclosed are palletized loads (2) formed by a plurality of packages (21) and wrapped in stretchable film (1) as well as a related process and apparatus to produce such palletized loads (2). The stretchable film (1) has strengthened sections (111, 112, 113, 211, 212) generated by folded or rolled edges (11, 12) or folded central parts and, where said film (1) connects the load (2) to the pallet (3), it has a roped lower edge (115). <IMAGE>

Description

931 90

This invention relates to a load formed of a plurality of units assembled on a pallet and helically wrapped in a stretchable film, and to a method and apparatus for making such a load.

In particular, the invention relates to an extensible film having folded or rolled edges and helically wrapping around a load, combined with securing the load to a pallet by rope the lower edge of the film where it wraps around the pallet, thereby increasing the stability of the entire package while reducing material wear and tear. at the same time handling the load placed on the 15 pallets.

Many different packing materials are available for multi-unit pallets. A widely used packaging material is a stretch film which is wrapped around a load and a pallet. The loads wrapped in stretch film, as well as the methods for providing this and the large number of machines capable of performing such a method, are known in the art, but overall package stability problems have so far often been solved using additional material such as cardboard packing corners and extra layers of stretch film.

The principle of stretch wrapping is that the stretchable film is guided from the unwinding and stretching point around the load by a relative rotation in the form of a spiral between the load and the film feed. In one embodiment, the load is mounted on a table that rotates about a vertical axis and thus wraps film around the load. At the same time, the film feed stock moves along a vertical path so as to provide a wrapper helically rotating around the load. The vertical path of the film 2 931 90 usually begins at one end, top or bottom of the load, moves to the other end of the load and returns to the starting point to allow the next load to be wrapped in the same manner. Rotation and vertical up and down movement 5 create double layers of film which spirally rotate in opposite directions. However, more than two layers or partially overlapping over a wide area are often required, especially to secure the load to the pallet but to ensure adequate stability of the package. Good examples of such packages, methods and devices are found, for example, in U.S. Patent 3,863,425, GB Patent 2,063,809, DE Patent 2,724,100 or EP Patents 306,573 and 22,135.

15 As another application method, the load is stationary and the entire unwinding and stretching means is rotated around the load. This alternative application is called a satellite application and is particularly useful if rotating the load causes problems or is impossible. A description of this and similar alternatives are disclosed in DE 3 414 964, US application 411 995 or EP-A 279 871 and are commonly used in industry.

Further improvements revealed in the technical field pe-25 are based on these two basic applications of stretch wrapping. However, they all suffer from high film consumption and often require packaging aids to obtain the necessary stability.

Developments towards more economical use of film have been described in US-4,497,159 and GB-2,083,002 by increasing the lengthening of the film and thus reducing the amount of film per package.

Similarly, development steps were taken that allowed the use of different stretch film materials.

35 U.S. Patent 4,432,185 discloses a non-adhesive stretch k.

93190 3 Assembling the front and back ends of the film into a single rope to facilitate the attachment of the back and front ends of the film. EP-A 32 140 describes an improvement in the attachment of the front end of the stretch film by guided wrapping over the front end of the film with successive layers of 5 stretch wraps.

In U.S. Patent No. 4,807,427, the rope of the stretch film material is described as adhering to the basiloid container, thereby securing the top and bottom flaps to the stretch-wrapped load.

For loads formed from materials stacked on top of each other in layers, U.S. Patent 4,845,920 discloses tying the edges of a stretch film and orienting it to horizontal wrappers such that one wrap joins the two layers together. This is done to take advantage of the ease of use of the stretch film, but to allow the load to breathe because the ties are spaced vertically apart. A similar layer connecting the wrappers is disclosed in EP-177 413 without rope edging.

Finally, EP-A 298 799 discloses means for stretching an adhesive film to the extent that the fracture resistance of the edges requires an increase by wrinkling the edge of the film somewhat together. It further describes adjusting the amount of wrinkled film at the edges to provide narrow portions of the film that allow the load to be breathable.

A common disadvantage in stretch film applications is that, in order to ensure stability, the layers of the helically wound stretch film overlap substantially vertically on top of each other. In addition, to firmly secure the load to the pallet, the stretch film is wrapped several layers horizontally around a portion of the pallet and the lowest layer of the units. Despite this attempt, sufficient stability was often not achieved, leading to consumer and customer dissatisfaction with disordered loads on the pallet that use excessive stretch film. In addition, the film securing the load to the pallet also covers the holes 5 in the pallet for fork-lift trucks to handle the pallets. These parts of the stretch film are often pierced with fork cranes, which further reduces stability, creates another aesthetic disadvantage, and is often unsuitable for automated storage.

It is therefore an object of the present invention to provide a load wrapped in a stretch film and secured with a stretch film to a pallet while having improved stability.

It is a further object to provide a load wrapped in a stretch film with a minimum amount of stretch film material and without or with a minimum amount of packaging aids.

Yet another object of the invention is to reduce the packaging material, thus satisfying the increasing consumption needs of the packaging material and improving the ecological suitability.

Yet another object of the invention is to provide a load secured to a pallet by an extensible film while keeping the pallet handling recesses free of such a film while achieving an increased degree of stability.

A further object of the method of the invention is to reduce the time required for wrapping the load in the stretch film and attaching it to the pallet.

The set object is achieved by a load according to the invention, characterized in that both edges of the film are folded or rolled where the film wraps around the load and that the lower edge of the film forming the wrappers at the bottom of the load 35 is rope, the lowered edge being 931 90 5 more film than the folded or rolled bottom edge.

In a preferred embodiment, the rope bottom edge comprises 2-10, more preferably 5-10 times the amount of stretch film compared to that used for the folded or rolled portions of the edges.

In a preferred embodiment, the folded or rolled edges of the film are also made to a stretch film width of less than 30 mm, more preferably 10 to 20 mm.

In another preferred embodiment, the load is characterized in that the rope lower edge is located high enough around the top of the pallet to prevent, for example, fork cranes generally used to lift pallets from damaging the stretch film rope or the stretch film film extending towards the load.

In general, packages may include some of the usual packaging aids, such as, but not limited to, top or bottom covers, layer separating plates, angle stabilizers, or soft covers around sharp corners, although these can be removed in most cases.

A method according to the invention comprising unwinding and stretching a stretchable film and; orienting the film 25 to the load placed on the pallet in the form of a spiral by rotating the load placed on the pallet relative to the unwinding and stretching of the film and simultaneously; moving the film up and down, is characterized in that in the path of the film, preferably before the stretching process, the edges of the film are folded or rolled, and the lower edge of the film is rope as the wrappers are directed around the bottom of the load and the top of the pallet.

A device according to the invention comprising a load station, a film unwinding unit, a film stretching unit 35, a drive for rotating the load station or 6

9 6 1 9 O

the drive for rotating the unwinding and stretching unit around the load, in turn, characterized in that it further comprises control means for folding or rolling the edges of the film, and; guide means for rope-lowering the film 5, which is operated by a guide (regulator) so that the rope-edge is wrapped only around the pallet.

In the following, the invention will be explained in more detail with the aid of the accompanying drawings.

10 In the drawings;

Figure 1 shows a truncated, flat part of a stretch film 1 with an upper edge 11 and a lower edge 12.

Figure 2 shows a load 2 formed of a plurality of units 21 assembled on a pallet 3 and 15 helically wrapped in a stretch film 1 according to the prior art, but only after the first wrapping half from top to bottom. The edges 11, 12 of the stretch roll are flat and the fastening between the load 2 and the pallet 3 is achieved by wrapping the lower belts 123 of the stretch film 1 several times horizontally over the change zone between the load and the pallet, thus covering the pallet recesses 31.

Figure 3 shows a truncated part of a stretch film 1 with a folded upper edge 2511 and a lower edge 121 to be wrapped around a load as used in the invention.

Figure 4 shows a truncated part of a different stretch film 1 used in the invention, with a folded top edge 111 and a rope bottom edge 115 for securing a load to a pallet.

Figure 5 shows a preferred embodiment of the invention, in which, however, only the first half of the wrapping is made from top to bottom. The load 2 is wrapped in a stretch film 1 having folded edges as shown in Fig. 3 and the fastening between the load 2 and the pallet 3 is obtained by the stretch film 1 shown in Fig. 4.

il 7 v o i 90

Figure 6 shows an alternative to the stretch film shown in Figure 3 with a rolled top edge 211 and a rolled bottom edge 212.

Figure 7 shows another alternative to the stretch film shown in Figure 3 or 6, with a folded top edge 111 and a Z-fold 113 in the middle of the film.

Figure 8 shows the principle of the method typically used in the known prior art, the film 1 stretching by controlling the rollers 41, 42 of the pair 10 around which rotate at different peripheral speeds of the downstream side of the roll 42 being faster than the upstream roller 41. The other rollers that guide the aukikelausosasta per 401 entering or load directed 402 film is also shown.

Figure 9 shows a method for providing a folded or rolled top edge 111, 211 and a bottom edge 112, 212. The folding or winding means 51, 52 forces the film edge 11, 12 to bend into folded or rolled film edges 111, 112, 211, 212. Positioning the means 51, 52 upstream of the stretch rolls 41, 42 is a preferred embodiment. The rope means 6 are shown in the disengaged position.

Figure 10 shows a method for providing a folded top edge 111 and a rope bottom edge 115. The rope spacing 6 ropes the stretch film 1 to the extent that the folding 25 or winding means 52 do not extend to the lower edge 12.

The load 2 consists of several units 21, which themselves are often packages of several subunits. The load 2 is wrapped in a helical form in a stretchable film 1 to protect and stabilize the contents. To accomplish this, the individual wraps of stretch film directed around the load 2 partially overlap the previous wrap, often more than 50% of the width of the film, providing a uniform whole package.

The load 2 is also further attached to a handling and transport aid, most often a pallet 3, to add stability with a rigid support structure for easy handling and transport. This is accomplished when the wrappers are oriented horizontally at the bottom 123 of the load 2, extending over the load 2 and over the pallet 3.

According to another part of the invention, the load 2 is helically wrapped in a stretch film 1, both edges of which are folded or rope 111, 211, 112, 212, thus increasing its stability while allowing the partial overlap of successive wraps or a combination thereof 10 to be reduced. Another part of the invention is to fasten the tightly stabilized load 2 to the pallet 3 by rope the lower edge 115 of the horizontal wrapping film 1 at the base 123 of the load. This rope lower edge 115 is separated from the folded or rolled bottom 112 by making 15 more film material than folded or rolled.

In a preferred version, the folded or rolled film edges 111, 211, 112, 212 are formed by folding or rolling less than 30 mm, preferably 10 mm to 20 mm. This combines the advantage of improved stability and minimizes the reduction in stretch film width per edge.

In another preferred embodiment, the lower edge 115 of the rope stretch film 1 does not extend beyond the openings 31 of the pallet 3. This ensures that the stretch film 1 and the rope 25 edge 115 are not damaged when handling and transporting the pallet 3, e.g. using a fork crane or similar device.

The edges 111, 211, 112, 212, 115 of the stretch film can be folded or rolled or rope to the inside or outside of the load 2.

It is also possible to direct the stretch film 1 onto the load 2 when only a part of its total length has been folded or rolled or rope. For example, the first part of the film may have flat edges 11, 12 to cover the package once with a flat film and in the latter

II

93190 9 may have folded or rolled and rope edges 111, 211, 112, 212, 115 according to the invention or vice versa.

Another alternative to obtain a stabilizing effect 5 on the load 2 is to fold one or more film centers into a Z-shape, resulting in a Z-fold 113. This would require a more complex method but has the advantage of eliminating successive helically twisting, partially overlapping belts. upper 10 and / or lower The folded or rope edges 111, 211, 112, 212 and thus apply a particularly high partial pressure to the load 2. It is particularly preferred that the upper edge 111, 211 and one Z-center fold are folded or rolled.

The benefits of stability or reduced material consumption or combinations thereof are independent of the particular load 2 or its particular assembly method. Precisely sorted or randomly stacked hard or soft or even compressible units 21 forming the load 2 can benefit from the invention.

Breathable loads 2 can also be packaged using the invention. For example, a sufficiently steep helical twist can be used to eliminate partial overlap, or fold or rope enough of the width of the stretch film to prevent partial overlap of successive wraps of stretch film 1 to allow breathability.

The choice of a particular film material is also not critical to the invention. The invention can be practically obtained from any of the commonly available stretch film materials. Film materials with one-sided self-adhesion are preferred because they help stabilize the folded or rolled and rope edges.

In order to make the loads 2, as described above, the following method steps are required: unwinding the stretch film 1 95190, stretching it and directing it to the load. As has been shown in the prior art, many methods and machines perform the above. The method typically comprises an unwinding station from which a coil 5 is pulled about a guide roller 401, which is not rotated by an external power source, to a first externally powered rotation roll 41 which rotates at a lower circumferential speed than the second externally powered stretch roll 1. for example, by a second guide roller 402, which is not rotated by an external power source, and is directed to the load 2 placed on the pallet by the relative rotation of the load placed on the pallet and the stretchable film 1. According to the invention, this standard method 15 is terminated by folding or rolling and rope the edges 111, 211, 112, 212, 115 of the film to provide a stretched stretch film 1 for the invention. Obstructing portions of standard means, such as a roll or folding board or folding bar 51, 42, 6, in the path 20 of the film edge 11, 12 gradually bends the film edge 11, 12, thus achieving the desired result 111, 211, 112, 212, 115. Depth and angle, in which these parts of the standard means 51, 52, 6 are placed in the path of travel of the edge of the film, it is crucial whether folding, rolling or ropeing takes place. The desired shape of the edge of the film of its stars can be easily determined by taking into account the properties of the load 2, the film 1 and the handling needs.

To cause the edges 111, 211, 112, 212 of the film to be folded or rolled when wrapping the load 2 and 30 to provide the lower edge 115 of the rope film when attaching the load 2 to the pallet 3, the guide engages the rope means only while the bottom wraps are produced. The controller is not shown in the figures but may be, for example, a mechanical, electrical or magnetic sensor 11 9 61 90 connected to a suitable activating device 35 for moving the rope means. The preferred mode of operation is to use only a combination of a mechanical sensor and an activating device.

As will be better seen from the example, the use of the method and means 5 leads to the additional advantage that the time required to wrap the load 2 on the stretch film 1 is reduced due to the reduced number of wrappers around the load 2 and the partial overlap between successive wrappers.

10 It is irrelevant to the method at which point in the winding path the folding or winding and tying method is placed. However, it has been found that it is most preferred that the folding or winding devices 51, 52 are mounted upstream of the stretching rollers 41, 42 and the rope device 6 is mounted downstream of the stretching rollers 41, 42.

The method can be further supplemented by press rolls which press the formed edge, either folded or rolled 111, 211, 112, 212, 115, tightly together. Pu-rollers are not shown in the figures. They can be particularly useful where a stretching method with little or no adhesion (i.e., adhesion) is used.

In an embodiment of the preferred method and means according to the invention, the connection of the folding or winding step of the lower edge to the tying step is achieved by using means movable relative to the stretch film 1 or by mounting the means.

But it can also be useful, for example, for adjustable or movable winding or folding means 51, 52 for loads 2 requiring breathability.

Specific examples illustrating the use of the invention will now be described.

It is based on CEKA Dominant's standard satellite-type stretch packer. Loads consisting of soft multi-35 Sack loads are assembled on a pallet. Conventional cardboard corner pieces that were necessary to complete the loads in order to have acceptable stability are omitted. The rod is mounted with two rods perpendicular to the plane of the stretch film at a small angle to the flow direction of the film. The rods are mounted on a bracket upstream of the stretch rollers. The bars create an obstacle that extends 15 mm into the path of travel of the stretch film as measured from the edge of the stretch film. The bars bend the edges of the film 10 self-adhesive side of the film adhesive side of the thus formed fold is pressed together when the foil is stretched around the stretch rollers. Press rolls are not necessary because self-adhesiveness is sufficient to overcome the internal flexibility of the material.

15 Behind the stretching rollers, an hourglass-shaped rope roller is mounted on the support, which can be moved with a lifting magnet. The magnet is controlled by an electromagnetic switch that turns on when the horizontal wrappers securing the load to the load are produced. Alternatively, the hourglass-20 sin-shaped roll can be mounted on a bracket that secures it to the desired height by being mechanically limited to move further downward as horizontal wrappers are produced. When engaged, the hourglass-shaped rope roll extends 150 mm into the width of the film 25. The axis of the rope roll is approximately perpendicular to the plane of the film.

In the engaged position, the rope roller is flush with the top of the pallet but not flush with or below the pallet handling openings.

The following table shows the variables and in particular the improvements achieved by the embodiment according to the invention compared to the corresponding prior art embodiment. In both examples, the stretch film material is polyethylene and the alignment means are a CEKA Dominant satellite-type stretch wrapping machine.

ti, 13 95190

Stability has been evaluated in these examples by placing the products at an angle of 24 ° and measuring the deflection of a 2 m high load relative to a line perpendicular to the pallet. A positive rating was given for deflections less than 5 5 cm and a negative rating was given for deflections greater than 10 mm. Falling loads were excluded but mentioned separately.

embodiment according to the invention in general according to an embodiment of the invention but with a mucus folding, roll expression 1.1a rope lie 1. Load Cardboard boxes Cardboard boxes stretch film thickness 0.019 mm 0.023 mm 15 film elongation 172% 102 t film width 500 mm 500 mm per folded edge used film width 15 mm el folded edges 20 per rope edge not rope film used film width 120 mm edge number of film wraps. 9 12 index of the film used for full wrapping 25% 100% total start of wrapping of one pallet 1 min 33 s 1 min 50 s efficiency index 118 t 100% 30 pallet openings not covered covered and perforated with a stability rating of 2 positive (m. 2 negative hours After day) 93190 14 Execution of the invention in accordance with the invention in general in accordance with the invention but without folding, reeling or rope-mlsval lie _ 2. Load Soft Multi-Bags Soft Multi-Bags

D

stretch film thickness 0.019 0.023 mm film elongation 172% 102% film width 750 mm 500 mm 10 per folded edge width of film used 15 mm no folded edges per bound edge width of film used 120 mm no folded edge „r- no. 14 21 13 Index of the whole film used for wrapping 61% 100% openings in the pallet not covered covered and perforated 2q packing aids not necessary 4 cardboard corners in severity rating 2 positive (m. 2 negative, crashes after an hour) sometimes 2 ^ Although several inexpensive and optional performances have been described in detail and illustrated by drawings and examples, many variations are possible which still fall within the scope of the invention as defined by the claims.

Claims (12)

1. Cargo (2) consisting of several units (21) placed on a cargo pallet (3) and which is wrapped in a spirally extensible foil (1), characterized by covering the edges (111, 211, 112). , 212) is folded or rolled by the foil (1) in those places, the foil (1) being wound around the load (2) and the lower edge (115) of the foil (1) forming bandage 10 around the load (2). ) the bottom (123) is laced, the laced lower edge (115) formed by a larger number of foil (1) 8n the folded or rolled lower edge (112, 212). 2. A load pallet (2) placed on a pallet according to claim 1, characterized in that the folded or rolled edges (111, 211, 112, 212) of the foil (1) are formed by folding or rolling at least 30 mm, preferably 10 - 20 mm, of the width of the foil (1). 3. A load pallet (2) placed on a pallet according to any of the preceding claims, characterized in that the lower edge (115) of the foil (1) comprises foil (1) in a plurality of pS 2-10 threads, preferably 5-10 threads. , compared with the amount of weight or rolled foil at the lower edge (112, 212). A cargo pallet placed (2) according to any of the preceding claims, characterized in that the bonded lower foil edge (115) includes uncovered openings (31) in said cargo pallet (3). 5. A load of pallet placed (2) according to any of the preceding claims, characterized in that only part of the total length of the edges of the foil (11, 12.) has been folded or rolled or laced. A method of producing a load (2) according to any of the preceding claims, which method comprises 35. unwinding and stretching of the extensible foil (1) and line of the foil (1) in spiral form on a load (2) on a pallet by rotating the load (2) on the pallet in relation to the unwinding and stretching of the foil and simultaneously 5. moving the foil up and down, characterized in that along the thread path of the foil (1), preferably before the elongation process. , the edges of the foil (111, 211, 112, 212) are folded or rolled and the lower edge (115) of the foil is laced as bandages are guided around the bottom of the cargo (2) and the top of the pallet (3). Method according to claim 6, characterized in that the folded or rolled edges (111, 211, 112, 212) or the lined edge (115) of the foil are stabilized in a further step by compressing the folds or rolls or the laced portions. Apparatus for carrying out the method according to claim 6, which comprises a loading station, a unwinding unit for the foil, an extension unit for the foil, a drive for rotating the loading station or a drive for rotating the unloading or stretching unit around the load. (2), characterized in that it further comprises guide means (51, 52) for folding or rolling the edges (111, 211, 112, 212) of the foil (1) and guide means (6) for lacing the lower edge of the foil (1). (115), which is operated by means of a control device (regulator) such that the laced edge (115) is wound only around the pallet (3). 9. Apparatus according to claim 8, characterized in that the guide means (6) for lacing or the guide means (51, 52) for folding or rolling are made up of folding rods, drums or folding boards. Device according to claim 8 or 9, characterized in that the control device (regulator) is a mechanical lock. 931 90 Device according to Claim 8, 9 or 10, characterized in that the control means forming the folded or rolled edges (111, 211, 112, 212) are mounted on supports which permit coupling and friction of the control means (51, 52 , 6). Device according to claim 8, 9, 10 or 11, characterized in that compression drums are mounted after the control means (51, 52, 6) for forming the folded or rolled edges (111, 112). Hi