EP0496062B1 - Folded box package made from a liquid-tight, heatsealable cardboard composite material, especially an Al-laminated cardboard composite material - Google Patents

Abstract

The invention relates to a folding box of composite cardboard material coated heat sealably at least on the inside, which has a flat bottom to which two pairs of opposite triangular folding pockets are sealed lying flat. To prevent bubble formation on the inside of the package, more particularly those areas of the triangular folding pockets which are to be sealed to one another over their complete surface, due to steam forming in the composite cardboard material during the heat activation of the areas, the heat sealable coating is perforated right into the cardboard in the areas.

Description

The invention relates to a folding box pack made of a liquid-tight, at least internally heat-sealable coated cardboard composite material, in particular Al-laminated cardboard composite material, with an integrally folded flat bottom, which is closed by at least one flat seam, in particular a seam, and two pairs of opposed flat and full-surface sealed triangular folding pockets.

Folding box packs of this type with differently shaped bottoms are known (DE-C-25 20 401; EP-A-0 093 849; EP-B-0 133 863). These folding boxes are made from a blank or from a roller conveyor or from a jacket, with the floor being heat-sealed by means of ultrasound, induction, heat pulses, infrared radiation or hot air. If such folding box packs are intended for the aseptic packaging of goods, it is customary to apply a full surface area of liquid or vapor sterilizing medium to them before filling. This sterilizing medium must then be completely removed from the package. In order for this to be possible, the triangular folding pockets must be sealed over the entire surface to avoid nests in the pack. This sealing can best be achieved with IR radiation or hot air. The areas to be sealed with each other must be because of the well over 100 ° C lying melting point of the heat sealable coating with hot air of well over 100 ° C.

This activation of the areas to be sealed with hot air has shown that there is a bubble formation on the inside of the cardboard composite material which is activated with heat, which entails the risk of leaks. This phenomenon is particularly pronounced in the case of cardboard composite material laminated with Al on the inside, because in this case the bubbles are warped and, as a result, leaks in the packaging base increase. It was found that the blistering occurs particularly strongly in the inner fields, that is, the fields lying at a distance from the cut edges, and less strongly in the outer fields, that is, the fields adjacent to the cut edges. It has also been found that the extent of such errors can be kept low if the activation temperature is as low as possible. A low activation temperature makes it difficult to seal the activated areas over the entire surface.

In order to keep the error rate during heat sealing as low as possible on the one hand and on the other hand to guarantee a safe full-surface sealing of the activated areas, a relatively high activation temperature, at which bubbles do not yet form, can be used if the Keep activation temperature within narrow tolerances. Adhering to such tolerances means an increased effort in production.

The invention has for its object to provide a folding box pack of the type mentioned, in which there is no blistering of the inside of the cardboard material when the bottom is activated with heat even if the activation with a higher temperature than for the heat seal is essential required.

This object is achieved according to the invention in a folding box pack of the type mentioned at the outset in that the inside heat-sealable coating of the inner fields forming the triangular folding pockets is perforated right into the carton. In addition, the outer fields adjacent to these inner fields can also be perforated.

The invention is based on the knowledge that the formation of bubbles is due to moisture present in the cardboard composite material, which increases the vapor pressure in the cardboard material in particular at an activation temperature that is well above 100 ° C. in such a way that with a dense outer coating, as is the case, for example, with the purpose of Better printability on the outside with a cardboard box equipped with a line or, in the case of a cardboard coated on both sides, water vapor escapes to the inside of the composite and leads to the formation of bubbles and leaks. The inner fields are particularly affected by this formation of bubbles, i.e. the large areas to be activated that are not are directly delimited by a cutting edge, while in the case of outer fields, i.e. the areas to be activated, which are located directly on a cutting edge, they are significantly smaller and do not occur in the case of correspondingly narrow outer fields running parallel to the cutting edge and adjacent to it, since in These outer fields allow the steam to escape through the open cut edges. In the invention, such a vapor pressure cannot generally build up because the water vapor which forms when the fields are activated with heat can escape to the outside via the perforation which is initially still exposed. The activation temperature is not critical, which means that it is not important to keep the temperature within narrow limits. Experiments have shown that there is no blistering on the inside of the cardboard composite material even if the activation temperature even exceeds the current activation temperature of, for example, 160 ° C. by more than 15 ° C. The perforation on the finished package does not interfere with its use, since it can be chosen so that it is folded in and sealed in, so that it is protected from dirt and, through it, no moisture can penetrate into the composite material.

If necessary, for example if the cardboard composite material comprises coated cardboard and / or the inner or outer coating has little adhesion to the cardboard, it may be advantageous to perforate the outside of the composite material in the area of the fields to be sealed as far as the cardboard, to prevent blistering on the outside.

In the following the invention is explained in more detail with reference to a drawing, which shows the cut and the bottom of a folding box pack with a seam for the shows various types of folding box packs mentioned at the beginning, to which the invention extends. The hatched fields represent the fields to be activated with heat.

Fig. 1a

einen Zuschnitt im Ausschnitt für den Boden mit schraffiert angelegten, innenseitigen Innenfeldern von dreieckigen Falttaschen,

Fig. 1b

den Zuschnitt gemäß Figur 1a mit schraffiert angelegten innenseitigen Außenfeldern für die Stegnaht,

Fig. 1c

den Zuschnitt gemäß Figur 1a mit schraffiert angelegten außenseitigen Innenfeldern im Bereich der dreieckigen Falttaschen,

Fig. 1d

den Zuschnitt gemaß Figur 1a mit schraffiert angelegten außenseitigen Außenfeldern im Bereich der Stegnaht,

Fig. 1e

den Zuschnitt gemaß Figur 1a mit schraffiert angelegten Innen- und Außenfeldern, die sowohl innen- als auch außenseitig mit Warme aktiviert werden,

Fig. 2a bis 2e

einen anderen Zuschnitt mit einer Feldaufteilung gemäß Figur 1a bis 1e vor der Faltung des Bodens,

Fig. 3a bis 3e

einen weiteren Zuschnitt mit einer Feldaufteilung gemäß Figur 1, 1c und 1e,

Fig. 4f, 4g, 4h, 4h' und Fig. 5f, 5g, 5h, 5h'

eine Faltschachtelpackung aus dem Zuschnitt der Figuren 1a bis 1e,

Fig. 6f, 6h

eine Faltschachtelpackung aus dem Zuschnitt der Figuren 2a bis 2e und

Figur 7f, 7g, 7h

eine Faltschachtelpackung aus dem Zuschnitt der Figuren 3a bis 3e.

In detail show:

Fig. 1a

a cut in the cutout for the floor with hatched inner fields of triangular folding pockets,

Fig. 1b

the cut according to FIG. 1a with hatched inner fields for the web seam,

Fig. 1c

the cut according to FIG. 1a with hatched outer inner fields in the area of the triangular folding pockets,

Fig. 1d

the cut according to FIG. 1a with hatched outer fields in the area of the web seam,

Fig. 1e

the cut according to FIG. 1a with hatched inner and outer fields, which are activated both inside and outside with heat,

2a to 2e

another blank with a field division according to Figure 1a to 1e before folding the bottom,

3a to 3e

another cut with a field division according to Figures 1, 1c and 1e,

4f, 4g, 4h, 4h 'and Fig. 5f, 5g, 5h, 5h'

a folding box pack from the blank of Figures 1a to 1e,

6f, 6h

a folding box pack from the blank of Figures 2a to 2e and

Figure 7f, 7g, 7h

a folding box pack from the blank of Figures 3a to 3e.

The rectangular blank for a cuboid folding box pack shown in the drawing FIGS. 1a to 1e consists of a cardboard composite material that is laminated on the inside of the packaging with an aluminum foil and has a heat-sealable plastic coating (PE) on the inside and outside. Before the folding box pack is formed, the blank is provided with folding lines 1, as shown in the drawing. The heat-sealable coating and the aluminum foil are perforated on the inside, at least in the inner fields 2 hatched in FIG. 1a for the formation of the triangular folding pockets 3, but preferably also in the hatched outer fields 4 for the web seam 5 in FIG. 1b. In the case of a dense coating on the outside, the composite material is also perforated from the outside in the inner fields 2 shown hatched in FIG. 1c and in the outer fields 4 shown hatched in FIG. 1d. From FIG. 1e the floor area of blanks with the inner and outer fields 2, 4 to be activated on both sides for the floor sealing, precedes this.

FIGS. 2a to 2e and 3a to 3e show different, different embodiments of blanks for folding box packs with a field division corresponding to FIG. 1.

FIGS. 4 to 7 show the bottom area of the different blanks in the individual manufacturing steps. FIGS. 4 and 5 correspond to the cut according to FIG. 1, FIG. 6 corresponds to the cut according to FIG. 2 and FIG. 7 corresponds to the cut according to FIG. 3.

The blank prepared in this way is first formed into a tube with a rectangular cross section, as shown in FIGS. 4f, 5f, 6f and 7f, which show the bottom area in the activation position. Then the hatched fields of the bottom in FIGS. 1 to 3 are activated and the bottom is formed by folding in the direction of the arrows from FIGS. 4f, 5f, 6f and 7f. The triangular folding pockets are formed, as can be seen from FIGS. 4g, 5g and 7g, and the hatched areas are folded in the bottom of the pack and sealed, if necessary, so flat that they are covered towards the inside and outside of the pack. Figure 4h shows the finished bottom of a blank according to Figure 1a to 1e, Figure 4h 'the finished bottom of a blank according to Figure 1b or 1d, Figures 5h and 5h' the finished bottom of a blank according to Figure 1b, Figure 6h the finished bottom of a blank according to FIGS. 2a to 2e and FIG. 7h the finished base of a blank according to FIGS. 3a to 3e. In FIG. 5h the triangular folding pockets 3 are folded out laterally and in FIG. 5h 'on the package bottom.

It goes without saying that the type of cutting according to FIG. 3 or FIG. 7 will only be used in the case of a folding box with a square base area.

Claims (5)

1. A folding box package made from a liquid-tight, at least internally heat-sealable coated cardboard composite material, more particularly an aluminium laminated cardboard composite, having a flat bottom which is folded on in one piece and is closed by at least one seam, more particularly a web seam (5) applied flat and has two pairs of opposite triangular folding pockets (3) which lie flat and are sealed over their whole area, characterized in that the internal heat-sealable coating of the inner areas (2) forming the triangular folding pockets (3) is perforated right into the cardboard.
2. A folding box package according to claim 1, characterized in that the inner and outer heat-sealable coating of the inner areas (2) forming the triangular folding pockets (3) are perforated right into the cardboard.
3. A folding box package according to claims 1 or 2, characterized in that the heat-sealable coating of the outer areas (4) adjoining the inner areas (2) is perforated right into the cardboard.
4. A folding box package according to one of claims 1 to 3, characterized in that the perforation is a needle perforation.
5. A folding box package according to one of claims 1 to 4, characterized in that the perforation is a cut perforation.

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