WO1997012811A1

WO1997012811A1 - Blow-moulded plastics container, in particular lightweight bottle

Info

Publication number: WO1997012811A1
Application number: PCT/CH1996/000339
Authority: WO
Inventors: Günther HERBURGER
Original assignee: Soplar S.A.
Priority date: 1995-10-03
Filing date: 1996-10-01
Publication date: 1997-04-10
Also published as: EP0853584A1; ATE205150T1; DE59607637D1; DE19680847D2; AU6983396A; EP0853584B1

Abstract

The invention concerns a blow-moulded bottle inside which a connection (11) extends from one wall (13) to the other and prevents the walls (13) from bulging when the bottle is full. The risk of the bottle's being compressed so greatly when handled that fluid inside the bottle is unintentionally forced out and spilt is also counteracted. The connection (11) comprises two columnar recesses (19), the free ends (17) of the columns (15) being welded to one another. At the base of each column (15) undulations (25, 26, 27) are formed practically concentrically to the column (15), so providing a region (23) with increased flexibility. In this way, resilient deformation can occur in this region (23) if the bottle is dropped when full. The walls (13) can thus move inwards or outwards somewhat relative to the columns (15) without a great risk of cracking at the column base.

Description

Blow molded container, especially a light bottle, made of plastic

The present invention relates to a blow-molded container, in particular a light bottle, made of plastic, with at least one column that can be subjected to pressure and / or tension and extends from one wall in the direction of the opposite wall.

For environmental reasons, light bottles made of plastic have been propagated for a long time, which can be produced with a significantly lower consumption of plastic than the usual plastic bottles. A disadvantage of light bottles is that they are less dimensionally stable. Light bottles tend to bulge when filled. Furthermore, when holding a filled bottle there is a risk that it will be compressed so strongly that liquid will flow out.

In order to create a dimensionally stable container, it is proposed in GB-A-1 007 563 to provide one or more hollow columns in a container made of thermoplastic material, which protrude from one or more walls into the interior, so as to oppose opposite walls of the container keep your distance. Several embodiments of these spacing columns are proposed. For example, it is provided that pillar-shaped indentations protrude from one another into the interior of the container from two opposite walls and are welded to one another where they meet. Alternatively, an indentation is proposed as a connection of the walls, which extends from one wall to the opposite wall and is welded to it there. Furthermore, the possibility of providing a passage at the connection point is mentioned, so that a passage from one side to the other side of the container is created by the indentation or indentations.

FR-A-2, 110, 369 describes a plastic gasoline can, in which two mutually opposite walls are connected by welded column-like indentations. When the canister is filled, the pillars formed by the indentations are subjected to tensile stress and prevent the walls from bulging. EP-A-0 173 194 proposes a large-volume transport and storage container in which two mutually opposite walls are connected by an approximately tubular opening designed as a pass-through hole. This means that on the one hand it acts as a handle for one-handed handling and dosing, but on the other hand it counteracts bulging of the walls, as can be observed when filling products with a high liter weight. As an advantage, it is stated that even larger packs or packs with a smaller wall thickness than previously customary can be used without the risk of problems with lateral bulging.

However, all of the containers described have the disadvantage that they have insufficient case values. Even a case from a relatively low height can lead to a crack in the container, so that its contents can be measured. The fracture is usually located in the area of the column base, because there the material is severely stretched when the container, in which the column is also formed, is blown. The wall thickness is therefore relatively small, so that there is a particularly easy crack if the container falls down.

It is therefore an object of the present invention to provide a container of the type mentioned at the outset which, despite the low material requirement, has a better case value than the known containers, i.e. not easily damaged in a case and leaking.

This is achieved according to the invention in that the wall at the foot of the column has an area with increased flexibility in order to enable a limited relative movement of the column with respect to the wall. So it is a movement of the wall towards the column as well as towards possible away from the pillar. If a filled container designed in this way falls on the floor, an elastic deformation can take place in the area with increased flexibility without tearing. When the bottle is deformed by the impact, the wall can have different positions, ie

Shifts inwards or outwards, or also

Incline with respect to the column and then return to the original position. thanks to this

Spring action therefore greatly reduces the risk of tearing in the area of the column base.

A preferred embodiment provides that the area is corrugated with increased flexibility. When blowing the container, the material in the area of these waves is stretched more than in the rest of the wall, so that an area with increased flexibility is created. This flexibility is further enhanced by the surface enlargement caused by the waves. Preferably, the waves of the area with increased flexibility run practically concentrically to the column. This creates a springy structure similar to that of an aneroid can. This structure is therefore able to respond elastically to tensile and compressive forces. This also allows the column to bend sideways in any direction.

The formation of the area with increased flexibility is preferably such that each wave protrudes further from the wall towards the foot of the column into the interior of the container. This has advantages in terms of blowing technology. The column is advantageously frustoconical. It is also possible for the column to have several frustoconical sections. Such a shape is recommended for blow molding reasons. Although it would be possible to form the column other than by blowing, it proves advantageous to design the column as an indentation of the wall in order to form the column or columns at the same time as the bottle is being blown.

The interior of the bottle expediently extends from two mutually opposite sides of the column. Compared to bridging the distance between the walls by means of a single column formed by an indentation, this has the advantage that excessive stretching of the material in the area of the column can be avoided.

If the risk of bulging the filled bottle is not great and merely to prevent the container from being compressed during handling, there is no need to connect the free end of the column to the opposite wall or to the free end of the opposite column. However, the free end of the column is expediently connected to the opposite wall or the free ends of the columns are connected to one another. This can easily be accomplished by corresponding contact of the still plastic material during the blowing process. For certain applications, it is expedient for the column or columns to form a tubular passage.

Exemplary embodiments of the invention will now be described with reference to the drawing. It shows:

Fig.l em first embodiment of the container according to the invention,

2 shows a section along the line II-II in FIG. 1,

3 em second exemplary embodiment of the bottle and

Fig. A is a side view of the bottle, partly in section along the line IV-IV.

The blow molded light bottle in FIGS. 1 and 2 consists in one piece of plastic, for example polyethylene or polypropylene. The invention is not limited to a specific bottle shape. Inside the bottle there is a connecting piece 11 which connects opposite sides of the bottle to one another. In the shown Exemplary embodiment, the connecting piece 11 consists essentially of two frustoconical columns 15, the free ends 17 of which are connected to one another. The connection is made by welding the material that is still hot during the blowing process. The columns 15 are formed during the blowing process by indentations 19 of the wall 13.

It is now important that the wall adjacent to the foot 21 of the column has increased flexibility. This increased flexibility allows a limited relative movement of the column 15 with respect to the wall 13. The area 23 with increased flexibility is corrugated. The waves 25, 26, 27 run practically concentrically to the column. This creates a structure similar to the wall of an aneroid can. From the wall 13 to the foot 21 of the column, each shaft 25, 26, 27 projects further into the inside of the bottle.

Instead of welding the free ends 17 of the columns 15 together, it is also possible to arrange them at a small distance from one another, for example, so that the bottle can practically not be pressed together or only to a small extent. However, if bulging of the bottle is to be prevented, the two columns 15 must be connected by welding or in some other way so that the columns 15 can also be subjected to tension. Bulging the walls 13 must be prevented, especially in the case of large bottles. In the grip bottle according to FIGS. 3 and 4, the columns 15 in particular have the task of avoiding bulging of the filled bottle. For this purpose, the free ends 17 of the columns 15 are welded together. For the rest, reference can be made to the preceding description of the bottle according to FIGS. 1 and 2.

Various configurations are possible without deviating from the inventive concept. For example, the free ends 17 of the columns 15 can be welded in such a way that a through hole is formed, that is to say that a tubular passage is formed by the two indentations 19.

Claims

1. Blow-molded container, in particular a light bottle, made of plastic, with at least one column that extends from one wall (13) in the direction of the opposite wall (13) and can be subjected to pressure and / or tension

(15), characterized in that the wall (13) is adjacent to the foot (21) of the column (15)

(23) with increased flexibility to a limited relative movement of the column (15) with respect to the wall

(13) to enable.

2. Container according to claim 1, characterized in that the area (23) is corrugated with increased flexibility.

3. Container according to claim 2, characterized in that the shafts (25, 26, 27) of the region (23) run with increased flexibility practically concentrically to the column (15).

4. Container according to claim 3, characterized in that from the wall (13) to the foot (21) of the column (15) hm each shaft (25, 26, 27) protrudes further into the interior of the container.

5. Container according to one of claims 1 to 4, characterized gekenn¬ characterized in that the column (15) is frustoconical.

6. A container according to claim 5, characterized in that the column (15) has a plurality of frustoconical sections (16, 18).

7. Container according to one of claims 1 to 6, characterized in that the column (15) by an indentation

(19) of the wall (13) is formed.

8. Container according to one of claims 1 to 7, characterized gekenn¬ characterized in that from two opposite walls (13) columns (15) to each other extend into the bottle inside.

9. Container according to one of claims 1 to 7, characterized gekenn¬ characterized in that the free end (17) of the column (15) is connected to the opposite wall (13), or that the free ends (17) of the columns ( 15) are interconnected.

10. A container according to claim 9, characterized in that the column (15) or the columns (15) form a tubular passage.