EP1266829B9 - Method for wrapping articles, particularly stacks of articles, in a stretchfoil - Google Patents

Abstract

Device for surrounding a load has a roller (14) arranged in a hook (1) in the horizontal moving path of the roller (13) on the upper edge section (17). Preferred Features: The roller is arranged in the known manner central to the hook and/or the roller (14). The roller (14) has the cross-section of the edge section of the hook. The roller (14) can be reversibly driven.

Description

The invention relates to a method described in the preamble of Ansprüches 1 for wrapping sharp-edged Piece goods units, in particular cuboid or cube-shaped stacks of pieces, which, for example, from (i.a. stacked on a pallet) palletized bricks or the like. exist, with a plastic one (As in particular polyethylene) existing, schlaüch- or Haübenförmigen stretch film, which is a ready-wrapped cargo unit each at least at its (i.a., four) side surfaces under it embossed by transverse strain Inner horizontal hoop stress completely enveloped, preferably (esp. In the film during the coating over the unit to be wrapped in each case in addition to the horizontal Transverse stretch embossed vertical longitudinal stretch) on its underside (of the Edges ago) with a so-called. "Understretch" at least partially covered, and thus possibly also the underside of the cargo unit at least partially enveloped, and which the cargo unit in hood-like design of the stretch film wrapping also on its upper side completely covered, as this is always provided when a stack of pieces not just one over its uncoated state due to the stretch film wrapping increased stacking strength (dimensional stability) is to be awarded, which is a relative slippage of general cargo or whole piece goods prevented, but if the cargo unit It also provides protection against the effects of weather and / or pollution should / must.

Such weather protection is regularly required by the practice, but is in Exceptional cases dispensable, for example. If it concerns the to be wrapped cargo units around palletized (brick) stone stacks or the like. does not affect the weather by rain or snow, nor against dust or other pollution are sensitive. In such cases, therefore, often for cost reasons on a dome-shaped design of the stretch film wrapping dispensed with, and accepted, that on the only partially covered by foil top of the cargo units if stored and transported, if necessary, moisture and dirt particles under the foil packaging penetrate only on their side walls completely wrapped cargo units can, because you waive a hood-like design of the Stretchfolienumhüllung resulting in a significant savings of film material, and from a profitability point of view Since ever tried, the necessary use of for a Packaging required amount of relatively expensive plastic on the unconditionally to reduce the required level. That is why we work in film packaging technology even with the thinnest possible films.

Regardless of whether you have a Stretchfolienumhüllung for a cargo unit dome-shaped forms or tubular leaves, a film wrapping already subject at their attachment (but also when converting finished enveloped loading units or at their transport) on sharp edges and corners, (hereinafter also referred to as "critical points") of the general cargo units a risk of tearing. This is easily understandable, considering that the film used for such purposes from those already mentioned above Cost reasons i.a. has only a material thickness of fractions of a millimeter, namely currently only about 80 - 150 μ, but also already considerably thinner Films (e.g., 40 μ) have been successfully tested and used.

One could risk this danger at the entire critical points of a to be enveloped Although reduce unit load unit by a significant increase in the film thickness or but would be eliminated, for example, by doubling the film thickness (e.g., 100 μ 200 μ) inevitably leads to a doubling of the material used, and thus to a doubling of packaging material costs, which is unacceptable in practice.

In the method concerned by the present invention, a stretch film is used existing wrapping section of an i.a. trained as a so-called gusseted tube Plastic film tube, the one in its fed initial state (i.a. has smaller circumference than the piece goods to be wrapped in each case, at his in each case the free (feed) end section facing away from the piece goods unit to be wrapped (i.a. four) bow-shaped (also as "stretch bar", "stretch bar" or "reef bar" designated) multifunction elements (hereinafter also referred to as "bracket") taken and after taking his pre-opened (flat in the stocking state folded) supplied free end portion (i.a., completely or at least i.w. unstretched), then preferably in i.w. concentric with the hose or General cargo longitudinal center axis extending folds on the multifunction elements aufrifffft to become.

Regardless of whether a cargo unit with a tubular or hood-shaped plastic wrap is to be provided by the multifunctional elements (pre-opened) recorded, (at least still unstretched) spread and aufaufffffte on this (Enveloping) hose section at its from the each to be wrapped cargo unit abgekehrten upper end of the hose supply separated (in the case of a hood formation optionally after its welding with a Quemaht at its upper end), and means the multifunctional elements stretched in a covered state in which each hose section or hood side wall in a common projection plane a safety distance (from, for example, 15 cm) to the cargo sidewall associated with it during coating has, so that when coating the (possibly hood-shaped) wrapping Hose section on each piece to be wrapped cargo unit not to a collision the wrapping film holding multi-functional elements due to any irregularities laterally projecting portions of the cargo unit to be wrapped can come, and finally in his cross-stretched overcoat state over each wrapped unitary unit pulled.

In the course of the coating process, either the transverse weld is applied Closed hood bottom ("hood cover") or else on the multifunction elements after landing as planned upwardly projecting edge portion of the tubular Serving hose section to the top of the general cargo unit, and can support this in the manner of an abutment, so that aufgereffte on the multi-functional elements Foil thus further lowering the i.a. on a common lifting frame arranged multifunctional element successively derived from these, and under (i.a. significant) circumferential strain ("cross-stretch") and complete wrapping of the side surfaces the piece goods unit firmly attaches to the piece goods unit, i.a. so that these on the edge portions of its lower side from the lower end portion of the wrapping hose portion with a so-called sub-stretch is under attack. This substretch is in the finished Envelope state may not be complete over the underside of its side surfaces wrapped unit load unit (possibly one arranged under the parcel parts of a cargo stack Paletie) i.w. vertically downward in front, but lies down because of him too impressed Circumferential expansion i.w. (horizontal) flat to the peripheral edge portion of the bottom the piece goods unit.

Such a sub-stretch, as he insb. DE 40 19 127 Al expedient and effective is to be realized is esp. Required, if to be enveloped cargo units with wrapped in a stretch film hood, which in the finished investment state not only in horizontal Transverse transverse direction is, but gem. EP 0 344 815 in addition also slid longitudinally in the vertical longitudinal direction, ie in the finished wrapping state biaxially stretched, because the vertical (in the hood longitudinal direction) longitudinally stretched hood side walls must be prevented, after the complete sliding of the film of the multifunctional elements (due to the longitudinal stretch imprinted on them inner vertical longitudinal tension) to over the underside of each wrapped unit load unit pull up (in practice and literature also referred to as "half moon formation", since the film while i.a. being held at the bottom corners of the stack / pallet, their bottom Edge but between two adjacent corners takes a crescent-shaped course). Because this would be the case when coating (preferably i.w. alone by friction of Foil on the multifunctional elements) embossed vertical longitudinal stretch (at least partially) lost again, the intended thereby considerable advantages would (at least partially), and a targeted weather protection would be on the side walls to reach only imperfectly.

Although the stretch film packaging technology despite in technical as well as more economical In terms of their highly satisfactory results, especially in their training as Stretch hood packaging technology can cause significant problems of all kinds, the present invention focuses i.w. on the issue briefly mentioned above, the stretch film packaging technology due to "critical areas" such as sharp edges and / or sharpening Corners on the top and / or bottom to be packaged cargo units arises because it is attached to such critical areas of piece goods to be wrapped with stretch film (eg Stack top edges and the upper corners of brick stacks or the like.) In the Contact with the slipped from the multifunction elements, i.a. under a considerable Hoop stress (or even a biaxial stress that puts even greater stress on the foil) standing film to a punctiform penetration or a linear incision come under considerable tension, relatively thin plastic film can.

This problem has increased rather than decreased in recent years progressive further development of the plastic films used Foil compressible strains have increased enormously, so that in the meantime a transverse stretch of 50% and sometimes even considerably more is quite feasible. there the stresses imposed on the foil during the wrapping process are correspondingly large, see above that the risk of damage to critical cargo areas has risen accordingly. But it comes in such a tense, thin plastic film with a thickness of, for example. 100 μ (or even for example only 40 μ) even only to a punctiform hole formation, so breaks the film - starting from their punctate injury - immediately on. At an initial line-shaped cutting a correspondingly stretched film hood or a tubular wrapping hose section, for example, on the sharp-edged top a stack of blocks consisting of bricks is the packaging result i.a. yet devastating.

From DE-A-38 32 557 a method for the complete wrapping of palletless formed, cuboid or cube-shaped cargo stacks (whose - in the finished state of use - Lowest cargo as a special layer on two opposite sides having elongated receiving tables for suspension means of a lifting device) by means of two counter-rotating Known over a stack drawn stretch film hoods, in which in the upper Edge region of a fully wrapped loading unit results in a single-layer film reinforcement.

In this process, when stacking before laying the special layer on the top the hitherto topmost cargo a possibly formed as a flat film, web-shaped Laying material portion which projects laterally beyond the stack contour. After hanging up the special layer, a first stretch film hood is pulled over the stack so that the Hood edge the stack on its underside with a sub-stretch engages below, where the protruding edge portion of the flat film on the sides of doing under the special layer present second highest cargo. After that, the hood is in the area of niches einprofiled in this and there connected to the flat film, that they the niche contour follows.

Subsequently, the stack is turned by 180 ° in its position of use, so that the special layer now forms the lowest piece goods, and - again from above - with a coated second film hood, which either over the special layer above bottom edge portion of the now second lowest piece goods under engages or already above ends. This results in the former case in the lower edge of the second lowest Piece goods through the flat film and through the first hood a two-layer film reinforcement and in the latter case by the flat film, a single-layer film reinforcement. The one of the Special layer formed lower edge region of the stack is not foil-reinforced.

The present invention is based on the object, the method of the above described genus in both technical and economical satisfactorily to improve that also unit load units, the sharp edges in its upper and / or lower edge region and / or have pointed corners, with as few working steps and the Ubersiehen of the Envelope hose section already existing facilities or elements can be wrapped in their critical Zweichen properly covered by means of a Verstünkungs hose section, without that there is damage to the wrapping film.

The solution of this starting takes place erfindungsmäß by the characterizing features of Ansprüches. 1

This could be done (from a purely technical point of view) by using a dikkeren and thus more resistant sheet material happen, or by two- or multiple coating a film hood, but these ways of working or that would be with them the result to be achieved is not acceptable from a cost point of view.

The same applies in the result for the attachment of any kind of edge protection by hand between the machine cycle times, and / or an elaborate extension of the Packaging machine by additional edge protection mounting means, which not only increase the capital expenditure accordingly and the vulnerability would increase the machine, but above all, to a significant reduction Machine performance (throughput of finished load units per unit time) lead.

The reinforcing tube section can be considerably shorter than the wrapping tube section be because he only as a reinforcement for the sheath hose section at a critical location of each For example, in the case of a piece-goods unit to be wrapped, it serves, for example, in the case of a fairly uniform, qaderförmiger Masonry pile, as with a good palletizer readily on a flat pallet are to be formed, if necessary, only for the sharp-edged circumferential upper edge of the stone pile with its four corners, so it's entirely for reinforcing this "critical spot" sufficient if such a cargo unit on both sides of its peripheral upper edge (ie on the one hand on its four side surfaces, and on the other hand on its upper side) with one in proportion is provided to the stack height relatively narrow, annular film section, the formed at least two layers is.

Even though is practicable, though a reinforcing hose section in his supplied initial state has a scope that i.w. equal to the scope which is to be wrapped in each piece unit, that is - unlike the wrapping hose section - Is barely stretched or not stretched in the final wrapping state, since the reinforcing tube section yes, nothing to increase the dimensional stability of the general cargo unit contribute needs, but only a reinforcement of the film wrapping at a critical Intended to serve the unit of unit is such a design not to be regarded as optimal in many ways.

A major reason for this is already in the fact that the sheath hose section on the one hand and the reinforcing hose down on the other hand then each from a different hose stock must be fed, of which alternating at each wrapping process Schlauchmatenal must be supplied, which inevitably complicates the Machine and lead to an avoidable reduction in throughput.

It should be added that it is already for frictional-anchoring a not as a hood formed reinforcing hose section at the top of a cargo unit to be wrapped most expedient, although he - as well as the wrapping tube section - In its unstretched initial state, a smaller extent than the respective has to be wrapped stack of goods, because he at the Top of the unit to be wrapped cargo unit to be held during the coating process, in such a circumferential dimensioning of the tubing with his the to be wrapped piece goods away from the upper edge portion, the top when coating over the upper ends of the multi-functional elements protrudes, when tightening automatically fixed under adhesive friction applied to the top of the unit to be wrapped unit, and on further lowering of the multifunction elements - as an abutment - allows, that of the multi-functional elements (in a raised form) held sheet material Gradually from the multifunctional elements slips off and on the side surfaces of the Packaged goods with appropriate circumferential expansion and thus under this strain corresponding tight internal tension. It therefore requires neither separate anchoring measures, nor any additional elements or other means.

Already under these aspects is therefore provided that everyone Reinforcing hose section in its unstretched initial state a smaller one Scope as each having to be wrapped cargo unit, namely the the same extent as the tubing for the wrapping tube section, and that he is made of the same material as the wrapping tube section, so that all hose section can be supplied from the same hose supply and separated from this.

That has result that Also each Vestärkungs hose section in the finished mounting state under the same Circumferential expansion (= transverse stretch) is applied to the unit load unit. This may seem prima facie be regarded as disadvantageous because the film in a (esp. considerably) stretched state not only thinner accordingly, but also vulnerable for other reasons as in the unstretched or less stretched state, but you can do this less first at least then translate beneficial effect into a (further) advantage, when you stack the height of a reinforcing tube section when wrapping piece goods trained so that it includes at least two cargo items in the attached state. Because then he carries - in addition to its gain function - also to further increase the Stacking strength at, and arranged at one in the upper portion of a cargo stack Reinforcing hose section in that area of the stack, because of its lowest Overload and demgem. the lowest frictional force between two superimposed General cargo items with regard to mutual slippage of individual general cargo or even whole cargo conditions at the occurrence of lateral accelerations particularly endangered is.

As in the case of corresponding experiments (especially with relatively thin film material, and / or esp. With relatively large Querstretchwerte of 50% and more) has been found (esp the sheath hose section prior to its detachment from the hose supply by welding a Quemaht is formed as a hood, and if it in addition to coating to the transverse stretch still a vertical longitudinal stretch is impressed, the film hood that is biaxially stretched in the finished wrapping state, and demgem. under appropriate internal stresses on the wrapped cargo unit abuts), it is sufficient in esp. Hard and sharp-edged piece goods such. Clinker bricks often not off, the stack of goods its peripheral top edge (and thus also at its particularly dangerous upper corner) circumferentially with a single-layer reinforcing hose section of the same material thickness to provide, but offered and therefore according to the invention, provided that the film material of the film reinforcement (at least) is formed in two layers.

For this one could successively two or more single-layer reinforcing tube sections successively attach at a critical point of the piece goods unit to be wrapped. Considerably more appropriate is However, the procedure according to the invention in which one at a critical point the ring-shaped reinforcing tube section to be attached to the unit to be wrapped Although it is attached in two or more layers, however consists of a one-piece tube section.

Therefor become the multifunction elements at the beginning of a A packaging process for receiving a reinforcing tube section first each moved into an approximated receiving position, and from this receiving position relative to the supplied hose end portion in the open free end process, as this from the known stretch hood packaging technology is known without film reinforcement, and also here later in the sheath hose section is practiced. After that, the taken reinforcing tube section through the multi-functional elements in turn in itself known manner with the tube end portion received by them by diagonal Spread apart (i.w. unstretched) spread, and then a hose section given length in i.w. concentric to the hose or piece goods longitudinal axis extending wrinkles on the multifunction elements auffrefffft.

After impact, the reinforcing tube section is spaced from the free Hose end in predetermined length separated from the supplied hose supply, and possibly so nachgerefft on the Multifunlaionselemente (i.e., further auffffften), or possibly by means of Reverses the reefing driven reefing as far as the multifunctional elements abgerefft (i.e., released upwards) that the upper free edge of the rest on the multifunction elements aufuffften reinforcing tube section to a predetermined Dimension protrudes beyond the upper end of the multifunction elements. This over the multifunction elements upwardly projecting edge portion of the reinforcing tube section is (in analogy to the common term "sub-stretch") below also referred to as "upper stretch section" or short as "upper stretch" when he is at Covering the reinforcing tube portion in the manner of an abutment for the subsequent successive sliding of film from the multifunction elements on the cargo top supported / anchored under stiction. For this he needs a certain minimum length or height.

If a general cargo unit at its i.a. special critical surrounding upper edge (including its particularly critical corners) with a reinforcing tube section should be provided, drive through the multifunction elements when lowering from their Overshoot an intermediate position in which they held transversely held reinforcing hose section with its upwardly projecting edge portion as (single-ply) "Upper stretch" (as it were as an abutment) on the cargo top to the plant comes, and is under static friction at this supports, until the reinforcing hose section in a first lower working position as far as gliding from the multi-functional elements is that he is in the intended height of the film reinforcement single-layered to the side walls the piece goods unit (fixed) has created.

To form a one-piece, two-ply reinforcing tube section in the upper edge region of the cargo unit, the multi-functional elements of this first lower working position - With further sliding of film material, which is an outer second Reinforcement on the already located on the side walls of the cargo unit first Reinforcement layer sets - raised to a (higher) second lower working position, in which they have fully released the reinforcing tube section, with its originally lower end portion under the tube material embossed circumferential expansion as (upper) second upper stretch on the already on the edge portion of the cargo top deposited (lower) first upper stretch.

After this two-ply attachment of a one-piece reinforcing hose section the (subsequently to be wrapped with the wrapping hose section) unit load unit the multifunction elements are driven together again upwards into their starting position, now in a known manner a wrapping hose section (i.a. as a film hood) from picking up the hose stock, spreading it, keeping it reefed, in the stall position crosswise, and finally to pull over the unit to be wrapped unit.

If, on the other hand, the i.w. a reinforcing reinforcing hose section of particular use Be formed three-layered or multi-layered, so must in the raised second lower working position, in which the reinforcing sheet already double-layered on the side walls of the cargo stack, not only a sufficient annular film portion on the multi-functional elements available but it must continue to be ensured that in the second lower working position again - as already at the beginning of the attachment process for the reinforcing tube section - a (initially still on the multifunction elements aufgereffter) Foil section (as another later "upper stretch") upwards over the multifunction elements protruding, which in the following for the purpose of further anchoring the film also in the Type of "top stretch" (as third and fourth upper stretch layer) to the top of the cargo unit create firm and thereby anchor frictionally. This annular film section is now apparent two layers, and must before a new lowering of the multi-functional elements from the second lower working position first of these abgerefft become.

It will therefore be approximately in the second lower working position the reversible drivable Reffrollen - if in between have been driven by the multi-functional elements to the outside in a rest position are - again from the outside to the multifunction elements with the still aufgerefften by these Moved up film, and in the sense of a meeting in the reverse direction as in (Refreshing) reefing until it scoops up so much foil from multifunctional elements have this as (one-part) second and third upper stretch when lowering again the multi-functional elements has placed firmly on the first upper stretch, and under Friction of the second upper stretch to the first upper stretch and the third upper stretch for the second upper stretch again forms an abutment, against which in the again further lowering the multi-functional elements slide further slide of these and as a third reinforcing layer from the outside firmly to the already existing second reinforcing layer the reinforcing hose section on the side walls of the cargo unit can create.

If a three-layer film reinforcement is provided, then the multifunction elements from the second lower working position to the first lower working position lowered until the film is completely separated from the multifunction elements, and they can be moved back to their original position. Is against a four- or provided about even higher-layer film reinforcement, so this process is analogous repeated until, in the second lower working position or in the first lower working position the annular tube material of the reinforcing tube section completely from the Multi-functional elements is slipped, and then immediately back into their upper Starting position to the actual wrapping process in conventional Way to perform.

It is to be examined case by case whether, for example, in four-ply Attachment of a one-piece reinforcing hose section the above-described inventive variant of the method appears appropriate, or whether it is not - esp. In Hin view on the throughput of the packaging machine - under certain circumstances is more convenient, a four-layer reinforcing hose section (without otherwise required intermediate meeting) by repeated Attachment of a two-layer reinforcing hose section to realize the second tube section so possibly of two or more annular To form hose sections, which after each other at a critical Place the each to be wrapped piece goods unit attached become.

A preferred embodiment of the present invention is in claim 2 described.

Fig. 1

eine etwas schematisierte Teildraufsicht auf wesentliche Bestandteile (bügelförmige Multifunktionselemente; zugeordnete Reffeinheiten) einer Stretchfolien-Verpackungsmaschine in Richtung des Pfeiles I in Fig. 2 gesehen;

Fig. 2

eine gegenüber Fig. 1 erheblich vergrößerte Teildarstellung eines Bügels in einer Seitenansicht von außen gem. dem Pfeil II in Fig. 1 gesehen;

Fig. 3

einen mittleren vertikalen Teilschnitt durch die Darstellung gem. Fig. 2 in Richtung der Schnittlinie III-III gesehen;

Fig. 4

eine stark schematische und vereinfachte Teildarstellung (in einer Seitenansicht von vom, teilweise im Schnitt) auf einen mit Stretchfolie zu umhüllenden Stückgutstapel kurz nach Beginn eines Verpackungszyklus, wobei ein aus Stretchfolie bestehender Verstärkungs-Schlauchabschnitt bereits auf die Multifunktionselemente aufgerefft ist, und der obere Randabschnitt des Umhüllungs-Schlauchabschnittes über die oberen Enden der Multifunktionselemente (nach innen) vorsteht;

Fig. 5

die Anordnung gem. Fig. 4 beim Absenken der (gemeinsam an einem nicht dargestellten Hubrahmen angeordneten) Multifunktionselemente in deren Überziehzustand, wobei sich der nach oben über die Multifunktionselemente vorstehende obere Randabschnitt des Verstärkungs-Schlauchabschnittes gerade (als "Oberstretch") auf die Oberseite des (auf einer Flachpalette abgestützten) zu umhüllenden Stückgutstapels auflegt;

Fig. 6

die Anordnung gem. den Fig. 4 und 5 in einer ersten unteren Arbeitsstellung, in der sich der Verstärkungs-Schlauchabschnitt gerade über die vorgesehene Höhe an die Seitenwände des Stückgutstapels einlagig angelegt hat, wobei der zunächst bis in diese Stellung abgesenkte Hubrahmen danach zunächst wieder begrenzt angehoben wird;

Fig. 7

eine Zwischenstellung beim Hochfahren der Multifunktionselemente aus der ersten unteren Arbeitsstellung in eine angehobene zweite untere Arbeitsstellung, wobei eine zweite Folienlage des Verstärkungs-Schlauchabschnittes gelegt wird;

Fig. 8

den fertigen zweilagigen Anlagezustand des Verstärkungs-Schlauchabschnittes am oberen Endabschnitt des Stückgutstapels, nachdem der Verstärkungs-Schlauchabschnitt vollständig von den Multifunktionselementen abgeglitten ist, die danach aus dieser Arbeitsstellung nach oben in ihre Ausgangsstellung verfahren werden, um nachfolgend den Umhüllungs-Schlauchabschnitt vom Schlauchvorrat aufzunehmen, aus dem bei dem dargestellten Ausführungsbeispiel durch Abschweißen einer Quernaht eine Folienhaube gebildet und vom Schlauchvorrat abgetrennt wird, mit welcher der bereits mit dem zweilagigen Verstärkungs-Schlauchabschnitt an seinem oberen Endabschnitt verstärkte Stückgutstapel sodann in bekannter Weise überzogen wird;

Fig. 9

die fertig umhüllte Ladeheit; und

Fig. 10

ein Zwischenergebnis einer weiteren Verfahrensvariante, bei welcher die gesamte Ladeeinheit (einschließlich Palette) oder nur der Stückgutstapel mit einem zwar einteiligen, jedoch zweilagigen Verstärkungs-Schlauchabschnitt umhüllt werden soll, jedoch nicht am oberen; sondern am unteren Endabschnitt der Ladeeinheit bzw. des Stapels.

The invention will be explained below with reference to exemplary embodiments with reference to a drawing, wherein the statements made are in some cases not only specific to the example, but sometimes also quite generally refer to the present invention. It shows:

Fig. 1

a somewhat schematized partial plan view of essential components (bow-shaped multifunction elements, associated Reffeinheiten) of a stretch film packaging machine in the direction of arrow I seen in Figure 2;

Fig. 2

a comparison with FIG. 1 considerably enlarged partial view of a bracket in a side view from the outside gem. seen the arrow II in Figure 1;

Fig. 3

a middle vertical section through the representation acc. Fig. 2 seen in the direction of the section line III-III;

Fig. 4

a highly schematic and simplified partial view (in a side view of, partially in section) on a stretchable to be wrapped stack of goods shortly after the start of a wrapping cycle, wherein an existing stretch film reinforcing hose section is already aufgerefft on the multifunction elements, and the upper edge portion of Enclosing tube section protrudes over the upper ends of the multi-functional elements (inwards);

Fig. 5

the arrangement acc. Fig. 4 when lowering the (arranged together on a lifting frame, not shown) multi-functional elements in their stall condition, with the above the multi-functional elements projecting upper edge portion of the reinforcing hose section straight (as "upper stretch") on the top of (on a flat pallet supported) hangs up to be wrapped cargo stack;

Fig. 6

the arrangement acc. Figures 4 and 5 in a first lower working position, in which the reinforcing tube section has just created the single height over the intended height to the side walls of the stack of pieces, wherein the first lowered to this position lifting frame is then initially limited again raised;

Fig. 7

an intermediate position during the raising of the multifunction elements from the first lower working position into a raised second lower working position, wherein a second film layer of the reinforcing hose section is laid;

Fig. 8

the finished two-ply system state of the reinforcing tube section at the upper end portion of the stack of pieces after the reinforcing tube portion is completely slipped from the multi-functional elements, which are then moved from this working position up to their original position to subsequently receive the wrapper tube section from the tube supply, from in the illustrated embodiment by welding off a transverse seam a film hood is formed and separated from the hose supply, with which the already reinforced with the two-ply reinforcing hose section at its upper end portion stack of goods is then coated in a known manner;

Fig. 9

the completely wrapped cargo; and

Fig. 10

an intermediate result of a further variant of the method, in which the entire loading unit (including pallet) or only the stack of pieces is to be wrapped with a one-piece, but two-layer reinforcing tube section, but not at the top; but at the lower end portion of the loading unit or the stack.

Fig. 1 shows in a simplified partial plan view exemplary essential components of a Apparatus for wrapping unit load units 1, namely cuboid or cube-shaped Piece goods stack with square cross-section, with one of plastic (eg / in. Polyethylene) existing, hood-shaped Stretchfolienumhüllung 2, which finished a wrapped (Packaged) unit load unit 1 each at its four side surfaces under it by transverse stretching embossed inner hoop stress completely enveloped, the cargo unit 1 at whose underside engages from the edges with a so-called. Understretch, and thus also this partially wrapped, and due to a hood-like design of the stretch film wrapping also the top of the cargo unit 1 completely covered.

For this purpose, the device is designed with a gusseted tube (not shown) Hose supply of plastic stretch film provided in folded flat Supply state is reeled to a hose reel, from which, if necessary Tube film is supplied. The device therefore has a (not shown) i.w. out Support and deflection rollers existing feeder, by means of which in each case for wrapping one of the device supplied cargo unit 1 a hose section from Pulled off hose supply and the unit to be wrapped cargo unit 1 is supplied so that at the beginning of a packaging cycle, the free end portion of the film tube above the each to be wrapped cargo unit 1 freely depends.

Since the tubing is folded flat in the storage state, and the case Adhering to one another by "adhesion" to each other due to adhesion forces The film tube must first be pre-opened suitably at its free end portion so that he can subsequently record and continue recording can be treated so that he finally pulled over the cargo unit 1 as a hood can be. This pre-opening can, for example, by suction cups or the like. done that by moved to the outside of the free hose end portion, and / or e.g. by wedge-shaped, sword-like Voröffnungselemente in the feed path of the film tube and, when putting the hose over these elements, ensure that that it is opened so far at least at its free end portion that suitable receiving elements can be moved into the free end of the hose.

Four i.a. arranged on a common drivable lifting frame 14, bow-shaped receiving elements ("strap") 3, but during the further process sequence have several other functions, and therefore as "multifunctional elements" can be designated. They are not just for recording of the free hose end portion, for which they are diagonal in one to the longitudinal axis of symmetry moved together recording state in the free end of the tube, but then initially for the expansion-free spreading of the free hose end portion, from her recording position (i.a., synchronously) horizontally in a Spreading be driven apart.

This Aufspreizstellung also forms the Reffstellung the bracket 3, in which Hose material of the required length in i.w. concentric folds to the tube longitudinal axis Refurbished by means of 7 refring on the bracket, which as an abutment and holding means serve. This encounter is carried out by so-called. Reffeinheiten 5, each a bracket 3 are assigned, at their respective bracket 3 facing end portion a reversible have drivable Reffrolle 7, and from an outer rest position so horizontally the stirrups 3 are to be moved in that the refining rollers 7 are each under an adjustable pressure on the outside of her associated bracket 3 rests. In this case, the recorded by the brackets 3, unstretched spread film 2 between the outside of each bracket 3 and the Reffrolle 7 of this associated refining unit 5 arranged / clamped so that the in Aufreffrichtung 8 driven Reffrolle 7 each under frictional film on the assigned her Can meet 3 bracket. The Reffrollen 7 suitably have an elastic Coat 7 '.

Fig. 1 shows in its middle part over a direction indicated by dotted lines Piece goods unit 1, whose longitudinal center axis is designated by M, four such bow-shaped Multifunction elements (bracket) 3 in their Aufspreiz- or Reffstellung. In terms of on the cube-shaped configuration of the stack of pieces 1 with a square cross-sectional area are also the bracket 3 in each working position symmetrical to the longitudinal central axis M arranged, in their in Fig. 1 shown in solid lines Spreading and Auflagestellung each in a corner of the recorded by them and stretched unexpanded film tube, as the film hood 4 on each to wrapping stack 1 is to be pulled. Because the film hood 4 is supposed to finished Enveloped state with considerable horizontal (circumferential) transverse strain on the side surfaces abut the stack 1, so that they accordingly in the still unexpanded Aufspreizzustand a correspondingly smaller extent than the stack 1 must have.

Before the brackets 3 esp. With reference to Figs. 2 and 3 are explained in detail further, it should be noted with reference to Fig. 1 that the refraction units 5, which are still in their outwardly driven when picking and spreading the film tube Rest position are, as shown in Fig. 1 bottom left, according to the there drawn double arrow 6 translationally horizontally moved back and forth, namely from that rest position, in which their Reffrolle 7 each have a distance a to each associated bracket 3, in a Reffstellung (= Aufspreizstellung), as shown in Fig. 1 bottom right exemplified. In this Reffstellung are therefore all four refining units 5 with their Reffrolle 7 on the outside of the film tube / the film hood 4, and this in turn with its inside on the outside of the respective bracket 3. Are the Reffrollen 7 in the direction indicated by an arrow 8 Driven direction of rotation, so hose material is therefore withdrawn from the hose supply and aufgerefft in concentric with the longitudinal center axis M extending folds on the bracket 3. In this case, the contact point of each Reffrolle 7 is at a distance f below the upper hoop edge 15 ', because the film 2 could not otherwise be drawn by the friction rollers 7 centrally generated at the respective bracket 3 frictional forces on the side portions 3 "of the bracket 3, which are located on both sides of the central bow-crown portion 3 '(see in particular Fig. 1): It would already be stuck to the outer edge regions of the curved central peak area 3'.

As soon as a sufficient amount of film material has been aufgerefft on the bracket 3, drive two (not shown) welding jaws of a (not shown) above the stack of pieces. 1 arranged welding device under pinching the film tube together, and weld this with a transverse seam 11, since in the present in Fig. 1 embodiment the item stack 1 not only wrapped with a wrapping tube section should be, which the top of the stack in the finished wrapping state not (at most partially covered), but with a closed at one end of the film hood. 4

To the formation of the provided with a transverse weld seam 11 tube section above the previously formed transverse weld 11 with a (not shown) cutting device separated from the hose supply, so that the closed hood end then between the four brackets 3 falls down, and there sags down first bag-like. Since it is often not only very useful to create optimal loading units, but i.a. indispensable that the closed hood end 10 (i.a. referred to as "hood cover") in the finished wrapping state not unstretched or even in folds on the upper side of the Stack of goods 1 rests, but - as the hood side walls - biaxially taut, takes place after the separation of the hood 4 from the hose supply nor a so-called. Follow-up means the reef rolls 7 driven in the reef sense picked up until the hood lid 10 (at least i.w.) Tightened, and the bracket 3 are then from their spread and reff gem. the arrows 9 (also synchronously) diagonally moved to the longitudinal center axis M outward in an overdrawing, in which they each a safety distance s of i.a. about 10 - 15 cm to the stack of goods 1 have to them when coating the film hood 4 collision-free by means of the lifting frame 14 lower down to be able to. This coating state is exemplified in Fig. 1 at the top left on one of four bracket 3 shown in the neck.

When coating therefore sets the hood lid 10 on the top 39 of the stack of articles 1 and thus forms an abutment against which the hood 4 when lowering the Strap 3 can successively slide off the bracket 3 / can be deducted.

If the hose material as in the embodiment shown in FIG a gusseted hose, so the transverse seam 11 formed in the welding is in its middle region 11 'two layers and in its two outer regions 11 "respectively four layers. The hood cover 10 has two mutually mirror-symmetrically opposite V-shaped or triangular multi-layer film areas 12, which are also known as film pockets can be designated, since they each to their the baselines of the rectangular Triangular forming edge 13 are open.

Hereinafter, the brackets 3 are esp. With reference to Figs. 2 and 3 by way of example described. All four brackets 3 are attached to a common lifting frame 14, at the beginning of each packaging cycle in an upper end position (starting position) is located, and controlled from this is lowered. The hangers 3, which in the pioneer period of the Stretch hood packaging technology i.a. were trained in each other's fingers mean (crest) area 3 'curved, and have on both sides of the curved middle section 3 'then each one i.w. stretched or in plan view i.w. linear side portion 3 ". The upper edge portion 15 of each bracket 3 has one circular cross-section with a diameter d. He is centered on one in the top view I. W. welded in the same way bow-shaped support portion 17 with welds 18. Since the thickness b of the support portion 17 is smaller than the diameter d of the upper Edge portion 15 of each bracket 3, the upper edge portion 15 is therefore inwardly and esp. Also outwardly on the support portion 17 via, so that so that on the outside of each Hanger 3 below its upper edge portion 15 an undercut 19 created is because the hood 4 when coating over the stack 1 in addition to the horizontal Querstretch means of the bracket 3, a vertical longitudinal stretch to be impressed, for which the mentioned undercut 19 in order to increase the frictional force between the film and the ironing 3 is highly appropriate.

Since in stretch film packaging technology increasingly worked with greater cross-stretch is because the film manufacturers in the meantime provide slides that without further tolerated an elongation of 50% and sometimes significantly more harmless, the Mode of operation with such a high transverse stress in the system state to a clearly higher transverse strain in the overdrawing state, the film but yes in the stall position of Strap 3 is to slide off successively from the brackets 3 during the coating process, and this At such high strains leads to significant problems when the film in the curved Slip off the middle apex areas of the bracket 3 with sliding friction of them must, special measures are provided according to the invention to solve these problems.

The generally designated 3 temple acc. Figs. 2, 3, in a plan view of above an isosceles L-shape with a rounded middle vertex area 3 ', on each of which an i.w. straight outer side section 3 "connects, and from its opposite the bracket support portion 17 thickened upper Edge section 15 an i.w. planar support portion 17 is directed downwards, on the Lifting frame 14 (horizontally movable) is held, is in its middle (crest) area 3 'with a - gem in the embodiment. Fig. 2 by no means over the entire curved apex region 3 'extending - designated as a whole by 50 (film conveyor) device provided, by means of which (in each case in cooperation with the assigned Reffrolle 7) is not only aufzureffen foil on the respective bracket 3, but by means which esp. Also aufgerechte on the bracket 3, transversely interlaced wrapping film in the Pull-over position of the bracket 3 during the coating process above the center of the respective Clamp 3 moved up and driven in the opposite direction to the direction of rotation during reefing Reffrolle 7 until leaving the upper bracket edge 15 'controllable via the bracket. 3 to move.

For this purpose, the bracket 3 gem. Figs. 2 and 3 below its upper edge 15 'and also still significantly below the upper edge portion 15 in his from the associated Reffrolle 7 acted upon, the central area a reversibly driven, vertical (Small) belt conveyor 51 with a self-contained flat belt 52 as a conveyor belt, at its upper end from the upper bracket edge portion 15 and at its lower end is deflected by a lower deflecting element 53 so that its outer one strand ("Obertrum") 54 on the outside and its inner otherwise strand ("Untertrum") 55 on the inside the flat strap support portion 17 extends.

The endless flat belt 52 is formed by a below the upper bracket edge portion 15 in Support section 17 centrally provided, window-like recess 56 out (and only afterwards made endless), the downwardly rounded upper edge of the lower deflecting element 53 for forms the flat belt 52. The f with a greater distance to the upper hoop edge 15 'provided window-like recess 56 has a width g, which is slightly larger than the width h of the flat belt 52, and a height j which is slightly larger than the thickness k of the flat belt 52, the rest in Fig. 3 (in relation to the other dimensions) for better For clarity, thicker than shown in reality.

To / when film on the bracket 3 are by means of a program-controlled Total control device, the refractions 5 synchronously gem. the arrow 27 in Fig. 3 against the respective associated bracket 3 driven so that their refresher 7 with predetermined, set pressure applied to the associated bracket 3. Here are the Reffrollen 7, the while gem. The arrow 8 are driven in Aufreffrichtung, but not directly against the bracket support portion 17, since its axis of rotation 28 thereby at a distance f below of the upper hoop edge 15 ', which is slightly smaller than the distance f' of the window-like Recess 56 to the upper edge 15 'is. Because the bracket 3 facing outer end of Reffrolle 7 is still in the height range of the belt 52, but is not immediately pressed against these, but to the before the reefing of the temples 3 at the free supplied end portion recorded and stretch-free spread film.

When later removing film from the brackets 3 during the coating process are the Conditions - as has already been stated above - completely different: Since the removal of the Foil of the brackets 3 in the overdrawn position of the bracket 3 takes place, in which the film on strongest horizontally transversely, then it lies then already because of their large inner Peripheral stresses with considerable pressure on the temples 3 - and thus also on the Flat belt 52 of their (small) belt conveyor 51 - to. The opposite during the coating process the Reff-Drehsinne (contrary to the arrows 8) driven Reffrolle 7 mark on the flat belt 52 tight-fitting film again under pressure a - now vertical upward friction force. But since the friction between the film and Flat belt 52 accordingly due to the considerably higher pressure in the overshoot position larger than the reef, the flat belt 52 of the (small) belt conveyor 51 are doing from the Reffrollen 7 (as it were by "external drive") driven over the film and move according to the arrows 57 about their deflection points 15 and 53, each foil section, which has left the contact area with the refining roller 7 upwards, without relative movement the belt 52 is taken from the upper run 54 and the bracket 3 am Upper bracket edge 15 'leaves free of friction. This is even true for the tubular lower edge portion of the film when the free bottom edge of the film from the contact point with the refresher 7 has moved up. Because even then he remains in intimate Haftreibungskontakt with the flat belt 52, which successively friction friction above the refining roller 7 him moved up until finally the lower edge of the film, the upper bracket edge 15 'after a has left completely controlled sliding movement.

While the foregoing teachings apply to both the attachment of the sheath tubing section (optionally in the form of a film hood 4) and the attachment of a reinforcing hose section 40 refer, can now be exemplary first procedures when attaching a reinforcing tube section 40th described on a general cargo unit 1 to be wrapped, (with reference to the 4 to 9), an exemplary method sequence for attaching a one-piece, two-ply reinforcing tube section 40 at the upper end portion of a cargo stack 1, the sharp-edged top 39 a "critical point" in the sense of the introductory Designs forms at which the risk of cutting the (non-reinforced) serving hose section exists, and therefore at this "critical point" before coating of the film hood 4 formed as a sheath hose section by a Reinforcing hose section 40 - the critical point across - to be covered, before the envelope serving foil hood 4 is pulled over the stack 1.

FIG. 4 shows-very schematically-an intermediate state shortly after the start of a packaging cycle, FIG. in which the four bow-shaped multifunction elements 3 (of which in the Side view acc. Fig. 4 only two are visible) a reinforcing tube section 40th already in concentric folds to the longitudinal center axis M hold after they at the beginning of the Packing cycle from its initial position moved inwards, in the pre-opened free end portion of the supplied side gusseted tube in, from this receiving position in their Aufspreiz- or Reffstellung procedure, and after the arrival of Foil and the separation of the reinforcing tube section 40 from the hose supply gem. the arrows 9 in Fig. 1 with simultaneous horizontal transverse expansion of the reinforcing tube section 40 have been moved to the overshoot position shown in Fig. 4.

In this coating position, the reinforcing tube section 40 is therefore under a considerable horizontal transverse stretch on the outer sides of the bow-shaped multifunction elements 3, and he stands with his upper end portion 41 on the same bead-shaped upper edge portion 15 of the multi-functional elements 3 via. Since the reinforcing hose section 40 is under considerable transverse stretch, its upper end portion 41st but not (like the rest of the reinforcing tube section 40) through an abutment is supported, the upper end portion 41 of the reinforcing tube section is pulled 40 due to the elasticity of the film material thus together towards the center, such as this can be seen in Fig. 4.

Of course, the not supported by the multi-functional elements 3 upper lies Edge portion 41 of the reinforcing tube portion 40 immediately adjacent Hose section 42 just as firmly on the upper edge portion of the multi-functional elements 3 on like the pleats 43 of the reinforcing tube section 40. If in Figs the hose section 42 and the upper edge section 15 of the multifunctional elements 3 a gap-shaped gap has been drawn, and when the folds 43 of the reinforcing tube section 40 have been drawn as a protruding fold package, so This was done in these systematic representations only for the sake of clarity.

Refresh rolls 7 of belonging refraining units 5 (not shown) are in the intermediate state not (anymore) driven. You can after the arrival of the reinforcing tube section 40 (and possibly a follow-up or a meeting of foil for adjusting the upper end portion 41 of the reinforcing tube portion 40) be moved back to the outside in their rest position, or even at a standstill (optionally idle) in contact with the outside of the reinforcing tube section 40th remain.

When lowering the arranged on a (not shown here) common lifting frame 14 Multifunctional elements 3 with the reinforcing hose section gripped on them 40 in the stall position of the multi-functional elements 3 is initially the upper End portion 41 with the piece goods to be wrapped stack 1 and engages - the sharp edges 39 'at the top 39 of the stack 1 cross-over - at the edge portion of Top 39 of the stack 1 circumferentially on the top 39. This results in between the underside of the upper end portion 41 of the reinforcing tube portion 40 and the stack top 39 a (adhesive) frictional engagement when the multi-function elements 3 gem. the Arrows 44 then from the state gem. Fig. 5 are further lowered.

In the intermediate state acc. 5, the reefing rollers 7 are driven again, namely in the reverse direction of rotation as the impact, so that when further lowering the Multifunktionselemente 3 successive slipping slide material of the reinforcing tube section 40 controlled by the multi-functional elements 3 and thus easily can be done. The Reffrollen 7 lie here (as in the schematic representation 5 can not be seen) each on an upper roller of each multi-functional element 3 under controllable pressure on.

When the multi-functional elements 3 are lowered into a first lower working position (FIG. 6) in which the reinforcing tube section 40 extends over (slightly more as) the height h has been applied to the four side surfaces of the cargo stack 1, the Lifting frame 14 stopped with the multifunction elements 3 arranged on it and again upwards to a second lower working position acc. Fig. 8 moves, in which the Reinforcing hose portion 40 completely separated from the multi-functional elements 3 is.

Fig. 7 shows an intermediate position after reversing the Hubrahmenantriebes. That I the film material of the reinforcing tube portion 40 due to the impressed him Circumferential expansion after the sliding of the multi-functional elements 3 below corresponding static friction firmly applies to the stack side surfaces, it is possible an intended two-layered design of the reinforcing tube section 40 at the upper end portion of the stack 1 with a one-piece hose section: As shown in FIG. 7, When reversing the Haubrahmenantriebes that of the multi-functional elements. 3 now gradually diverging slide material deflected by 180 °, and lays down two layers to the stack 1, and of course first on the side surfaces.

Reached the lifting frame 14 with the multi-functional elements 3 during further startup gem. the arrow 45 its second lower working position acc. Fig. 8, in which the reinforcing tube section 40 completely from the bow-shaped multi-functional elements. 3 is slid, so he has created two layers of the upper end portion of the stack 1, and is also two-ply with an upper stretch 46 on the outer edge portion of the Upside 39 of the stack 1 circumferentially, so that the sharp edges 39'am circulating Edge thus by a two-ply film reinforcement of a one-piece reinforcing hose section 40 are sheathed.

Subsequently, the lifting frame 14 with the multifunctional elements arranged on it 3 again moved to its initial position to now the sheath hose section (from the same hose stock) in a known manner to pick up, spread, etc., and ultimately to pull over the cargo stack 1, namely in the present embodiment as a hood 4. The wrapping ring tube section. 4 is therefore welded off with a transverse seam 11 for the purpose of hood formation, if sufficient much foil material withdrawn from the hose supply and on the multi-functional elements. 3 has been lifted, then separated from the hose supply, nachgerefft until the hood cover 4 '' in the unexpanded Aufspreizzustand runs approximately horizontally, and then by diagonal Moving apart of the multi-functional elements 3 in their overdrawing horizontal quergestretcht, wherein in the subsequent coating operation of the hood 4 through the multifunction elements 3 also a vertical stretch is impressed, and the hood lengthwise is dimensioned so that they are in the finished wrapping state (see Fig. 9) with an understretch 47 either at the bottom of the stack of goods 1 supporting pallet 48 create can (see left in Fig. 9), or to the bottom of the stack 1 (see Fig. 9 right).

When in Fig. 9 between the two layers of the reinforcing tube portion 40 and the reinforcing tube section 40 to the stack 1 or to the hood 4 and / or the individual Sections of the hood 4 and the stack 1 (on its upper side 39 and its side walls) a (sometimes even significant) distance is shown, this was done in this schematic representation, only for the sake of clarity. any Gaps between adjacent foil sections as well as these and the Of course, stacks are actually not present in the finished wrapping state. Rather, all film sections are in the final wrapping state due to considerable transverse and longitudinal stresses and thereby impressed the film material internal stresses very firmly against each other or on the stack 1.

Finally, FIG. 10 shows a further exemplary variant in which the "critical Steep "of the packaged unit 1 lies in the lower edge region of the pallet 48 (Left part of Fig. 4), or by sharp edges 49 'of the bottom 49 of the unit piece 1 is formed, so that - according to the charging unit acc. 9 - a one-piece, two-ply film reinforcement at a lower peripheral edge of the packaged Piece goods unit 1 is to be formed. The process steps are appropriate and in Knowledge of the above explanations readily ascertainable: The on the multifunction elements 3 grabbed reinforcing tube section 40 is thus aufuffffften on this that its upper edge portion 41 initially either not or only so little over the upper edge portions 15 of the multifunction elements 3 protrudes that it lowering the multi-functional elements 3 is not an anchorage of the upper edge portion 41 as an upper stretch on the upper side 39 of the to be wrapped Piece unit 1 can come, but that the upper edge portion 41 of the reinforcing hose section 40 with further lowering of the multi-functional elements 3 with after taken below.

Already during the further lowering or in a lower working position, like her is drawn lower right in Fig. 10, the upper end portion 41 of the on the multifunction elements 3 in the overshoot position under transverse stretch held reinforcing hose section 40 by means of the upper rollers 20 of the multi-functional elements. 3 moved up and driven in the sense of excitement Reffrollen 7 so much foil abgerefft that the upper edge portion 41 of the reinforcing tube portion 40 as a, first reinforcing layer firmly attach to the underside 49 of the stack 1 or the underside of the pallet 48 and thus can form an abutment against which during the subsequent startup of the Multifunctional elements 3 Slip foil off the multifunctional elements 3 and turn as lower first reinforcing layer can create on the side surfaces of the cargo unit 1.

Has the lifting frame 14 with the multi-functional elements 3 a raised working position reaches, in which the first film layer of the reinforcing tube section 40 firmly the stack and the pallet 48 has applied laterally so that they renewed in the subsequent Lowering the multifunction elements 3 down a (static friction) abutment for the further deducted from the multi-functional elements 3 film forms, which is as outer second reinforcing layer to the inner film layer firmly applies, so is the Hubrahmenantrieb reversed again, and the lifting frame 14 in turn moved down to a position, which the reinforcing tube portion 40 completely from the multi-functional elements 3 is slipped, with its lower edge portion after slipping from the Multifunction elements 3 as an outer lower reinforcing layer on the inner first reinforcing layer sets. Subsequently, the multi-functional elements 3 can then initiate the the actual wrapping process are again moved to their upper starting position, from this the wrapping process with the - possibly formed as a hood 4 - wrapping hose section initiate.

It is obvious that, if necessary, to a piece-unit to be wrapped several reinforcing tube sections 40 can be arranged when the piece goods to be wrapped 1 this requires or appear to be appropriate.

The process of the invention may prima facie relatively time-consuming act with the Result of a significant reduction in machine performance (throughput capacity). That is but in fact not so, since it has been shown that with appropriate control itself relatively complicated trained loading units with (possibly multiple) multi-layer reinforcement can be realized with surprisingly short cycle times.

In fact, one can the economics of the method according to the invention Altogether yes not synonymous with generic methods compare in which the ready-wrapped load units at critical points no protection against damage of the film, but must put it in relation to possible alternatives, where protection against film damage is otherwise provided must (for example, by a padding or similar action by hand). If you join one comes to such conceivable alternatives a profitability calculation a comparison calculation in the method according to the invention even taking into account a certain capacity reduction to surprisingly favorable values, because already the investment cost is hardly greater than with a conventional stretch hood packaging machine (It only needs a modified controller), as with the anyway existing elements and assemblies can be worked, and because the required Partial film reinforcement also made from one and the same hose stock can be.

In doing so, by skillfully passing through the cycle times required for the individual process steps Control minimized, and if you procedural steps as far as possible even overlap in time (for example, the feeding of tubing already during the drive out of a completely wrapped loading unit from the device, and the feeding of a load unit to be wrapped, if already preparatory above Process steps for attaching the / a reinforcing hose section made are), the loss of sales compared to packaging without film reinforcement Surprisingly and quite acceptable small, esp. If not only the / a reinforcing hose section 40 remains after removal from the hose stock as such, but also the subsequently applied wrapping hose section not as a film hood. 4 must be pulled over to the to be wrapped cargo unit except an elevated Form stability also to give a reliable weather protection, as this example. At Stacks formed from bricks is regularly the case.

Claims (2)

1. A method of wrapping article units (1), particularly cuboidal or cubic stacks of articles, with stretch film (4), which completely wraps each finish-wrapped article unit (1) at least at the side surfaces thereof, under internal peripheral tension imparted by transverse stretch, engages beneath said article preferably at its underside (49) and, in the case of a hood-shaped construction, also covers it at its top (39), wherein, in each case, a section of wrapping tube (4) from a supply of plastic film tube, which in its initial supplied state has a smaller periphery than the respective article unit (1) for wrapping, is picked up at its free end section and spread open by multifunction elements (3) in the form of brackets, is reefed on to the multifunction elements (3) substantially concentrically to the tube or article longitudinal central axis (M) and separated from the tube supply at its top end remote from the respective article unit (1) for wrapping, is welded by a transverse seam (11) at its top end before severance if required, transversely stretched into a pull-over state by means of the multifunction elements (3) and pulled in this state over the respective article unit (1) for wrapping, while before wrapping with the wrapping tube section (4), of hood-shaped construction if required, the respective article unit (1) for wrapping is continuously wrapped with a reinforcing tube section (40) in its top and/or bottom edge zone which comprises its top and bottom edge by moving the multifunction elements (3) into the free end of the supplied tube for the purpose of picking up a reinforcing tube section (40) in a pick-up position in which they are approached to one another and spread the same apart substantially unstretched by moving apart diagonally, a reinforcing tube section (40) of predetermined length is reefed on to the multifunction elements (3) in folds extending substantially concentrically to the tube or article longitudinal central axis (M) and is severed from the tube supply, and the multifunction elements (3) are moved outwardly out of their spreading open or reefing position into a pull-over position with horizontal transverse stretching of the reinforcing tube section (40) and are lowered, with the formation of a film reinforcement in the top edge zone of the article unit (1), into a bottom working position in which the reinforcing tube section (40) held in these conditions at its top end at the top of the article unit (1) has been applied to the article unit (1) as a single-layer film reinforcement, and in that the multifunction elements (3), after complete sliding of the reinforcing tube section (40) therefrom, are again raised into their top initial position, characterised in that for the purpose of and with the formation of an at least two-layer film reinforcement in the top edge zone of the article unit (1) the multifunction elements (3) are raised from the first bottom working position initially into a second bottom working position before being raised to their top initial position, in which second bottom working position their top edge is situated above the top of the article unit (1) and the reinforcing tube section (40) has either completely slid therefrom and has been applied by its bottom edge section to the top (39) of the article unit (1), or in which for the purpose of forming at least one other reinforcing layer before renewed lowering of the multifunction elements into their first bottom working position initially film is reefed upwards from the multifunction elements (3) to an extent such that the reefed off film on the subsequent renewed lowering of the multifunction elements (3) into their first bottom working position is anchored at the top (39) of the article unit (1) with adhesive friction, and in that the multifunction elements (3) are then raised from the first bottom working position into their top initial position; and in that for the purpose of forming an at least two-layer film reinforcement in the bottom edge zone of the article unit (1) the reinforcing tube section (40) is so reefed on to the multifunction elements (3) that its top edge section (41) does not project upwardly over the multifunction elements (3) or else only to an extent such that on the lowering of the multifunction elements (3) from their top initial position it cannot be anchored on the top (39) of the article unit (1); in that the multifunction elements (3) are first lowered from their top initial position into a bottom working position in which their top edge is situated beneath the bottom edge zone of the article unit (1) to be wrapped with the reinforcing tube section (40); in that in this bottom lowered position film is reefed off the multifunction elements (3) to an extent such that the top edge section (41) of the reinforcing tube section (40) on a subsequent raising of the multifunction elements (3) into a raised working position in which a first reinforcing layer has been applied to the article unit (1) is anchored at the underside of the article unit (1) by friction; and in that the multifunction elements (3) are lowered with the formation of a second reinforcing layer from the raised working position again into the bottom lowered position in which the reinforcing tube section (40) has either completely slid therefrom and has been applied by its top edge section to the underside of the article unit (1) or in which for the purpose of forming at least one further reinforcing layer before raising of the multifunction elements (3) into their raised working position again film is reefed off the multifunction elements (3) to an extent such that the reefed off film is anchored at the underside of the article unit (1) on the subsequent renewed raising of the multifunction elements (3).
2. A method according to claim 1, characterised in that for the purpose of forming a multi-layer film reinforcement in the top and/or bottom edge zones of the article unit (1) the multifunction elements (3) are repeatedly moved to and fro between the first and second bottom working positions or between the bottom lowered position and the raised working position before being raised into their initial position, with deposition of a film packing layer in each case, until the film has completely slid therefrom, while in the second bottom working position or in the bottom lowered position film is in each case reefed off the multifunction elements (3) to an extent such that on a renewed lowering or raising of the multifunction elements (3) it can bear with adhesive friction against the top and/or bottom of the article unit (1) as an abutment in the form of a top or bottom stretch.

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