EP0738224B1 - Cylindrical container with a collapsible peripheral wall - Google Patents

Abstract

The container has a plastically deformable peripheral wall (1), a closed base at the bottom and a device at the top for opening it. The peripheral wall (1) can be axially collapsed and has at least one row of linear, peripheral and colinear notches (7) running at one or both ends of the container circularly around its peripheral wall (1). Only one part of the peripheral wall (1) has rows of notches (7) running around the container. The remaining part of the peripheral wall (1) is smooth. The distance between neighbouring notches (7) in a row is so short that the space between them disappears when the peripheral wall (1) is compressed in the longitudinal direction of the container and a new row of notches (9) is formed parallel to the previous ones (7).

Description

The invention relates to a cylindrical, in particular cartridge-like container with a plastically deformable peripheral wall, a closed bottom at the rear end of the container and an element provided for opening the container at its front end, in particular a threaded connector or a nozzle. The peripheral wall is compressible in the axial direction and has at least one row of linear notches running in the circumferential direction and colinearly running on the peripheral wall at only one end or at both ends of the container on the peripheral wall.

The container can be a conventional cartridge, but it can also be a beverage can, keg, and other containers. The invention and the state of the art on which it is based are explained below with the aid of cartridges, without the invention being restricted to this type of container.

For packaging reactive, pasty masses, e.g. B. joint sealants, cartridges have been in use for a long time, which are made of plastic, for. B. HDPE, but also consist of aluminum. The cartridges are sealed with a slidable plastic piston that can move within the circumferential wall and can also be secured with an additional metal lid on the floor to prevent humidity. In such containers, reactive masses, e.g. B. the under the influence of humidity curing joint sealants, typically up to 12 months. With unfavorable storage, e.g. B. high humidity and elevated temperatures, this time is reduced. However, storage stability of more than 12 months is desirable and desirable.

Another general goal is to reduce the volume of waste empty cartridges. Conventional cartridges have the disadvantage, after the residual emptying, of taking up the same volume as for the filled container. A solution to this problem is achieved by the known tubular bags, which on the other hand, however, require complex tools for emptying. Thus, the cartridge known from DE 4201064 A1, intended for use in a deodorant pen dispenser, consists of a tubular sleeve which is closed on one side with a cover and on the other side with a pressure base and an inner piston. In use, the tubular casing forming the jacket wall is folded into annular folds, thus reducing the volume of the partially and also completely empty cartridge. The disadvantage is the high expenditure in the manufacture and filling of the cartridge. Pasty masses cannot be packed with it without additional stabilization being provided. There are also known problems with the piston sliding in the cartridge. This plunger cannot be sealed against the inner wall of the cartridge, or can only be sealed with an extremely high outlay, so that in systems reacting with air or air humidity, hardening and solidification of the mass in the interior of the cartridge occurs in the region of the plunger. This partial hardening of the mass also complicates the residual emptying of the cartridge.

It is also known to use cartridges, the peripheral wall of which is a preformed bellows. No piston sliding inside the cartridge is required here. However, the manufacture of such a cartridge is very complex. In addition, such a cartridge with pasty masses can be filled without bubbles without difficulty, since voids can remain in the beads of the bellows. A further disadvantage is the lateral breaking out when the laterally unsupported container is compressed due to the poor stability of the peripheral wall.

Another attempt to achieve a high storage stability even with reactive materials and at the same time a low waste volume is described in DE 3200542 A1. Here a cartridge is shown, which consists of a substantially cylindrical peripheral wall, a nozzle provided at the front end and a closed rear end. The cartridge consists of metal or an aluminum-clad polyethylene foil of such a thickness that the peripheral wall of the cartridge can be compressed in the direction of the front end of the container. With this cartridge, a high storage stability with reactive materials can be achieved, since the cartridge is a completely closed container before it is used. To empty the cartridge, it is placed in a full-shell cartridge gun. When the gun is actuated, the peripheral wall is compressed so that it collapses into annular folds. This cartridge therefore also fulfills the requirement to reduce the volume of waste.

A disadvantage of the known pistol is the need to use a full-shell cartridge pistol or at least one cartridge pistol, the middle parts of which have axially extending struts distributed in the circumferential direction. The tubular middle part or the struts distributed in the circumferential direction are necessary in order to prevent the circumferential wall of the cartridge from buckling when it is pressed together. Even a slight irregularity in the distribution of the pressure on the bottom of the cartridge is sufficient to cause the peripheral wall of the cartridge to break out laterally.

From US-PS 2,139,143 a cylindrical container of the type mentioned is also known. The notches distributed over the entire lateral surface of the container also lead to a lateral breaking out into an S-shape when the container is compressed, if the lateral surface is not supported, for example by a firm covering with a stable solid jacket.

The invention is therefore based on the object of improving a container of the type mentioned at the outset so that it can be compressed using simple devices without breaking out laterally. If the container is designed as a cartridge, storage stabilities of more than 12 months and a substantial reduction in the waste volume are to be achieved and the cartridge can be emptied with a conventional, simple half-shell gun without any problems. Furthermore, the manufacture and filling of the container should be possible without major effort.

This object is achieved in the container of the type mentioned in that only a part of the peripheral wall around the container carries rows of notches and the rest of the peripheral wall is smooth and that the distance between adjacent notches in a row is so small that the space between adjacent notches in a row disappears when the circumferential wall is compressed in the longitudinal direction of the container, and a new row of notches running parallel to the previous rows of notches and at an axial distance therefrom is formed.

Surprisingly, it has been shown that only a single row of these notches is necessary so that when the peripheral wall of the container is compressed, a completely regular fold is formed. Minor irregularities in the distribution of pressure on the rear end of the container do not disturb the regularity of the wrinkling. There is no fear of the peripheral wall of the container breaking off during the compression. Therefore, in the case of cartridges, the usual, low-cost cartridge pistols in half-shell form can be used for processing.

It is optimal for the regular folding of cartridges or beverage cans if each row of notches contains at least 4 and preferably exactly 6 notches.

The container, which is often deep-drawn from metal, has a stable shoulder at its front end due to the deep-drawing, which carries the threaded connector or the nozzle for emptying the container. The rear end is weakened compared to the front end. It is therefore advantageous if the notches are only provided at the rear end of the container. This starts the wrinkling at the rear end and continues towards the front as the container is emptied. A particularly defined and uniform formation of folds can be achieved if at least two parallel rows of notches are provided which run around the circumferential wall, the notches of adjacent rows being offset by approximately half the notch length in the circumferential direction. The notch length is preferably about one sixth of the circumference of the container. In particular, it is suggested that adjacent rows of notches have a spacing of approximately one have half the notch length. This distance enables extremely regular wrinkling. The new folds that arise automatically during the compression are also at the same distance as the two predetermined rows of notches.

A further improvement of the container according to the invention can be achieved if the rear end of the container is closed with a cup-shaped fitting, the bottom of which protrudes into the interior of the peripheral wall and the cup opening points outwards. The piston-like shaped piece compensates for non-uniformities in the pressure on the bottom of the container and, in particular, enables residual emptying, since the folds formed when the peripheral wall is pressed together create around the peripheral wall of the shaped piece.

In a preferred embodiment, the height of the shaped piece is dimensioned such that the front end of the completely emptied container lies against the bottom of the cup-shaped shaped piece. This ensures complete residual emptying.

However, it is also within the scope of the invention if, in addition to the shaped piece or instead of this shaped piece, a flat bottom is used to close the rear end of the container.

An additional advantage results from a circumferential shoulder on the peripheral wall of the shaped piece, on which the first row of folds is supported when the container is compressed. If a cartridge gun is used for compression, its piston is automatically centered when it is inserted into the fitting.

A compensation for the thermal expansion of the mass in the completely closed container for different storage temperatures is achieved if the bottom of the fitting is flexible, for example in the form of a membrane. For this purpose, it is further proposed that the bottom of the shaped piece is corrugated and additionally domed, the waves in particular forming concentric circles. This special geometric shape of the waves also enables pressure equalization, e.g. B. at an oblique placement of the piston of the cartridge gun on the bottom of the fitting. This compensates for the irregular pressurization that occurs particularly when using inexpensive cartridge guns.

The shaped part, in particular 3 to 5, can advantageously have guide lugs which absorb any tilting moments by being supported on the container wall.

In order to make the emptied container particularly easy and economical to recycle, the molded part is made of the same material as the peripheral wall and the front end of the container. It is therefore an advantageous single-substance packaging in terms of environmental protection.

The fitting can be connected to the peripheral wall of the container in different ways, e.g. B. by flanging, welding, gluing. It is important in the case of containers, for example cartridges, for reactive materials that gas diffusion is excluded with certainty. For example, water vapor diffusion must be prevented for silicone and polyurethane jointing compounds in order to avoid premature crosslinking. In a number of connection methods, e.g. B. the flanging, however, a shock or impact on the cartridge leads to a leak. It is therefore proposed for the shockproof connection that the shaped piece is welded to the peripheral wall of the container.

Gas diffusion is avoided particularly safely if the container is made of metal, in particular tinplate or aluminum.

Even with a, e.g. B. during transport, pressed peripheral wall of the container can achieve a defined folding during emptying, if the peripheral wall of the container consists of a sufficiently elastic material so that a bulging peripheral wall smoothes during compression. In this case, the pressure on the elastic peripheral wall causes these dents to pop out. Tinplate in particular is proposed here as the elastic material.

The container according to the invention can be used particularly advantageously for receiving joint sealant. There are also particular advantages if the container is a beverage can. In the case of the large number of beverage cans produced and used, there is the problem, despite the relatively easy recyclability, that the volume of waste is of the order of the original volume. This disadvantage can be eliminated with the invention.

Thus, a device can be provided in an automatic machine for taking back beverage cans, which first presses one or two rows of notches into the returned, empty can and then compresses them.

Figur 1

einen Längsschnitt durch eine mit Fugendichtungsmasse gefüllten Kartusche entsprechend der Erfindung,

Figur 2

einen Ausschnitt aus der Ansicht auf die Umfangswand der Kartusche nach Figur 1,

Figur 3

die Kartusche nach Figur 1 nach deren Entleerung,

Figur 4

eine seitliche Draufsicht auf einen Behältermantel vor dem Zusammendrücken gemäß einem weiteren Ausführungsbeispiel der Erfindung und

Figur 5

einen Schnitt entlang der Linie A-A in Figur 4.

In the following an embodiment of the invention is described in more detail with reference to drawings. Show it

Figure 1

2 shows a longitudinal section through a cartridge filled with jointing compound according to the invention,

Figure 2

2 shows a section of the view of the peripheral wall of the cartridge according to FIG. 1,

Figure 3

1 after it has been emptied,

Figure 4

a side plan view of a container jacket before compression according to a further embodiment of the invention and

Figure 5

a section along the line AA in Figure 4.

The peripheral wall 1 of the cartridge shown in Figure 1 is closed at its rear end with a cup-shaped fitting 2, which is welded to the edge 3 of the peripheral wall 1. At the front end of the cartridge, a threaded connector 4 is attached, on which a nozzle can be screwed in the usual way. In the area of the threaded connector 4, the cartridge is closed with a membrane 5 which is pierced before use.

Above a circumferential shoulder 6 of the molding 2, two rows of notches 7 are attached, the arrangement of which is shown particularly clearly in FIG.

The notches run in two rows, each row of notches having the same number of notches and being offset from one another by half a notch length. 4 to 10 notches per row have been found to be particularly favorable with commercially available cartridges.

If pressure is exerted on the molded piece 2 in the direction of the threaded connector 4, the notches deepen and sharp peaks 8 form between the notches, the height of which increases with increasing pressure. At the same time, new notches 9 appear in dashed lines in FIG. 2. This process is explained in detail below. The rows of notches thus automatically generate new rows of notches during compression until the entire circumferential wall 1 has folded in folds 10 around the cup-shaped shaped piece 2 (FIG. 3). During the compression, the annular folds are supported on the shoulder 6 of the molding. The height of the cup-shaped fitting 2 is dimensioned such that the base 11 lies against the inside of the front end of the cartridge, which carries the threaded connector 4. This enables complete residual emptying to be achieved.

The individual sub-steps in the compression are described below with reference to FIGS. 4 and 5.

In this example, a cylindrical cartridge made of thin-walled aluminum with a diameter of the cylinder of 40 mm and a length of the cylinder of 155 mm is used. The compressible part, i.e. the outer surface without the cup-shaped fitting on the base of the cartridge, has a length of 120 mm.

First, two rows of 6 notches 7, 23 each running in a plane perpendicular to the cylinder axis are pressed in at one end of the cylindrical cartridge casing. The distance between the rows is 5 mm, the length of the notches is 19 mm and the space between the notches of the same row is 1 mm.

In this example, the rows of notches are made in the area of the outlet opening of the cartridge. However, the position of the notches in the opposite, lower part of the cartridge casing is preferred.

The ends of the notches have the same radius as the original cartridge casing and form tips 8 which are connected to one another by folding edges 15, 22 running in a straight line. For the sake of clarity, only a few elements are provided with the respective reference symbols in FIG. The terms “above” and “below” used here refer to the position of the individual elements in FIG. 4. The notches 23 of the lower row of notches are shown in broken lines in FIG.

The surfaces 16, 17, 18 are essentially flat and run obliquely between the folded edges 15, 22 and the notches 7, 23. This creates a waffle-iron structure.

The areas 19 below the lower row of notches are delimited towards the unchanged cartridge casing by an only slightly pronounced folded edge 20.

The following operations take place when the cartridge is compressed in the longitudinal direction.

If pressure is exerted from below, that is to say from the base of the cartridge, the cartridge casing folds together at the outwardly directed folded edges 15, 22 and at the inwardly directed notches 7, 23. The tips 8 lying between adjacent notches 7 of the upper row of notches move upward in the direction of the shoulder 14 until the tips 8 of the upper row of notches abut the edge of the shoulder 14, where the shoulder exerts a counter pressure. The tips of the lower row of notches with the notches 23 likewise migrate upward, namely in the direction of the center of the opposite notch 7 of the upper row of notches.

During this process, the initially weak folding edge 20 below the lower row of notches becomes increasingly stronger and sharper.

This process continues until the tips of the upper row of notches abut the edge of the shoulder 14 and the tips of the lower row of notches have migrated into the center of the respective opposite notches 7 of the upper row of notches. Up to this point, the folded edges 15, 22 could yield to the pressure exerted from below by stronger folding. Now, however, after the folding of the upper and lower row of notches has ended, the user feels that a much higher force is required for further compression.

After applying a significantly stronger force, a new effect appears. The even stronger force tries to press the lowermost fold edges 20 in the direction of the notches and fold edges 15 arranged above them. However, such a movement of the folded edges 20 is not possible because it would require the cartridge casing to be stretched along the dashed lines 21. Large tensile forces therefore occur along the dashed lines 21.

At this time, the cartridge casing has no folds, notches or other possibilities for absorbing the pressure exerted from below, apart from the new folded edges 20. The area of the previous rows of notches is also not suitable for absorbing the pressure due to deformation, because here the cartridge casing is already completely folded up and cannot deform any further while shortening the length of the cartridge casing. The only way to avoid the by acting downward pressure and move toward 22 of the lower notch row, the folding edges 20 of the notches and the folded edges, is in a convolution of the cartridge casing along the dashed lines 21 inwardly, so that thus forms a new notch row. In this way, the new row of notches 21 is created automatically. At the same time, a new row of slightly pronounced curved folding edges is created below the new row of notches 21.

Due to the new folding edges 20 already formed, the notches of the new row of notches 21 are offset by approximately half a notch length with respect to the notches 23 of the lower row of notches and lie parallel to it.

After the dashed lines 21 have been folded inwards, the counterpressure felt by the user decreases significantly. Now the newly formed row of notches folds up. The process already described is thus repeated until the entire cartridge casing is folded up.

The inventors suspect the cause of the effect described above, by means of which new notches and folded edges form automatically, in the interaction of the cylindrical shape of the cartridge casing with the straight shape of the notches running perpendicular to the longitudinal axis of the cartridge. The high stability of the tips 8 is probably also important in comparison to the other areas of the cartridge casing, in particular relative to the folded edges.

It is very important for the user that the major part of the peripheral wall of the container is designed as a smooth wall that is not weakened at any point. The notches are formed shortly before the corresponding wall area is folded. The cylindrical shape of the container is therefore retained even when strong pressures are exerted. In contrast to this, a cylindrical container with a completely weakened peripheral wall breaks out when already small axial pressures are exerted, so that the longitudinal axis of the container forms an S-shape.

In the case of the design of the container according to the invention as a cartridge, commercially available cartridge guns can be used for processing. Skeleton or full-coverage pistols are particularly suitable. Half-shell pistols can also be used.

• 1. Eine feuchtigkeitsdichte Verpackung, insbesondere für reaktive Systeme,
• 2. eine erhöhte Lagerstabilität für reaktive Systeme,
• 3. die Möglichkeit der Einstoffverpackung mit voller Recyclingfähigkeit,
• 4. eine starke Reduktion des Abfallvolumens durch die definierte Faltung der Umfangswand,
• 5. die Möglichkeit des Einsatzes üblicher, wenig aufwendiger Verarbeitungswerkzeuge und
• 6. die Restentleerbarkeit.

The advantages of the cartridge-like container according to the invention are summarized:

• 1. A moisture-proof packaging, especially for reactive systems,
• 2. increased storage stability for reactive systems,
• 3. the possibility of single-material packaging with full recyclability,
• 4. a strong reduction in the volume of waste due to the defined folding of the peripheral wall,
• 5. the possibility of using customary, less complex processing tools and
• 6. the residual emptiness.

Reference list

1

Peripheral wall

2nd

Fitting

3rd

edge

4th

Threaded connector

5

membrane

6

shoulder

7

Notches (the upper row of notches)

8th

sharpen

9

new notch

10th

wrinkles

11

Bottom of the fitting

12th

Area, unchanged when indenting

13

Rotating cap

14

sloping, conical shoulder of the cartridge

15

Folded edges

16

surface

17th

surface

18th

surface

19th

surface

20th

Folded edge

21

new notch row

22

Folded edges

23

Notches (the lower row of notches)

Claims (19)

1. A cylindrical, more particularly cartridge-like container having a plastically deformable peripheral wall (1), a closed base at the rear end of the container and an element designed to open the container at its front end, more particularly a screwthreaded spout (4) or a nozzle, the peripheral wall (1) being axially compressible and comprising at least one row of linear, circumferentially and colinearly extending notches (7) encircling the container at only one end or at both ends thereof at the peripheral wall (1), characterized in that only part of the peripheral wall (1) has rows of notches (7) encircling the container, the rest of the peripheral wall (1) being smooth, and in that the interval between adjacent notches (7) in one row is so narrow that the gap between adjacent notches (7) of one row disappears when the peripheral wall (1) is compressed longitudinally of the container and a new row of notches (9) is formed parallel to, and at an axial interval from, the previous row of notches (7).
2. A container as claimed in claim 1, characterized in that each row of notches contains at least 4 and preferably exactly 6 notches (7).
3. A container as claimed in claim 1 or 2, characterized in that the notches (7) are only provided at the rear end of the container.
4. A container as claimed in any of the preceding claims, characterized by at least two parallel rows of notches (7) encircling the peripheral wall (1), the notches of adjacent rows being circumferentially offset by about half the length of a notch.
5. A container as claimed in any of the preceding claims, characterized in that the length of a notch is about one sixth of the circumference of the container.
6. A container as claimed in claim 4 or 5, characterized in that the interval between adjacent rows of notches (7) is about half the length of a notch.
7. A container as claimed in any of the preceding claims, characterized in that the rear end of the container is closed by a cup-like moulding (2) of which the base projects into the interior of the peripheral wall (1) while its opening faces outwards.
8. A container as claimed in claim 7, characterized in that the height of the moulding (2) is gauged in such a way that the front end of the completely empty container adjoins the base of the cup-like moulding (2).
9. A container as claimed in claim 7 or 8, characterized by an encircling shoulder (6) on the peripheral wall of the moulding (2) which supports the first row of folds when the container is compressed.
10. A container as claimed in any of claims 7 to 9, characterized in that the base (11) of the moulding (2) is flexible.
11. A container as claimed in claim 10, characterized in that the base (1) of the moulding is corrugated and has a dome-like curvature, the corrugations forming in particular concentric circles.
12. A container as claimed in any of claims 7 to 11, characterized in that the moulding (2) has guide noses, more particularly 3 to 5 in number.
13. A container as claimed in any of claims 7 to 12, characterized in that the moulding (2) consists of the same material as the peripheral wall (1) and the front end of the container.
14. A container as claimed in any of claims 7 to 13, characterized in that the moulding (2) is welded onto the peripheral wall (1) of the container.
15. A container as claimed in any of the preceding claims, characterized in that the container is made of metal, more particularly tin plate or aluminium.
16. A container as claimed in any of the preceding claims, characterized in that the peripheral wall of the container consists of a sufficiently elastic material so that a peripheral wall with dents smooths out during compression.
17. A container as claimed in claim 16, characterized in that the peripheral wall (1) consists of tin plate.
18. A container as claimed in any of the preceding claims, characterized in that the container is a cartridge intended to hold a jointing compound.
19. A container as claimed in any of claims 1 to 17, characterized in that the container is a beverage can.

Images