WO2003029103A1

WO2003029103A1 - Multi-compartment container and a method for producing the same

Info

Publication number: WO2003029103A1
Application number: PCT/EP2002/009978
Authority: WO
Inventors: Johann KÜNZ
Original assignee: Alpla-Werke Alwin Lehner Gmbh & Co. Kg
Priority date: 2001-09-26
Filing date: 2002-09-06
Publication date: 2003-04-10

Abstract

The invention relates to a multi-compartment container, in particular a dual-compartment bottle (40), consisting of at least two container parts (41, 42) with pouring necks (43, 44) that are formed in one-piece from plastic. The container parts (41, 42) are interconnected via a connecting strut (49), which runs approximately parallel to the axial extension of the container parts (41, 42). Each container part (41, 42) is connected to the adjacent container part or parts on both sides of the axial connecting strut (49) by means of at least one strut-type reinforcement (33, 35), which essentially runs in a radial direction. The invention also relates to a method for producing an inventive multi-compartment container in a continuous or discontinuous extrusion blow-moulding process.

Description

Multi-chamber container and method for its production

The invention relates to an integral multi-chamber container, in particular a two-chamber bottle, according to the preamble of claim 1. The invention also relates to a method for producing such a multi-chamber container in a blow molding process.

Liquid substances consisting of separate components are often used in the home and in commercial and industrial applications. For example, the substances are cleaning agents or agents for use in garden maintenance or also in agriculture, which consist of at least two liquid individual components which must be kept separate from one another and only come into contact with one another when poured out. There is a need to accommodate the individual components in a unitary container that has multiple chambers. For this purpose, multi-chamber bottles made of plastic are known from the prior art, which are made in one piece.

The known multi-chamber bottles usually have two or more bottle parts with a corresponding number of chambers. Often there are multi-chamber bottles with just two bottle parts and two chambers. For applications in which the individual components are mixed in approximately the same quantitative ratio, multi-chamber bottles are known which have two bottle halves of essentially the same design with two separate chambers. The bottle halves are connected to each other by a thin connecting web that extends in the axial direction. Each bottle half has a separate pouring spout with a pouring opening, which can usually be closed separately. Most of the closures are screw closures. Variants of multi-chamber bottles of this type are also known, in which the pouring openings are connected by a common seal. closing part are closable, which is pushed over the pouring spout and positively attached to the bottle halves. The multi-chamber bottles are produced, for example, in the injection molding process or in a blow molding process. A disadvantage of the known multi-chamber bottles is that they deform during use. In particular, there is a pivoting of the bottle parts around the axial connecting web. This complicates the handling of the multi-chamber bottle, gives the user an unsafe feeling during use and can even cause the bottle to slip out of his hand.

From DE-A-1 657 199 a two-chamber bottle is known which consists of two largely identical bottle halves which are in turn connected to one another by a thin connecting web which extends in the axial direction over the entire bottle height. Each of the two bottle halves of the two-chamber bottle has its own pouring spout with a separate opening. The two pouring spouts are arranged mirror-symmetrically to one another in such a way that they together form a bottle neck of the two-chamber bottle, which can be closed with a common screw cap. In this case, threaded segments are formed on the outer surfaces of the two pouring spouts, which complement one another on the bottle neck to form a screw thread for the screw cap. The problem with this known two-chamber bottle is that the pouring parts of the bottle neck can pivot around the axial connecting web when it is pressed. As a result, the threaded sections on the outer surfaces of the two pouring spouts move towards one another and the threaded closure is overtightened. This means that the Zeikammer bottle is not closed properly and the contents of the chambers can flow out.

Apart from the mentioned disadvantages of the known multi-chamber bottles, there is often also the desire to provide such plastic bottles with a handle in order to facilitate the handling of the bottles. However, attaching a handle to plastic bottles, in particular in the case of multi-chamber bottles, can only be accomplished with a relatively large amount of production effort. Multi-chamber bottles made of plastic are also used in cosmetics and sanitary areas. There is often a desire and the need to apply the bottle upside down to the user. Special holders are often provided, into which the bottle is inserted by the user. However, these holders set relatively narrow limits for the design options for the bottle, since it must be ensured that the bottle does not slide through the mostly ring-shaped holder.

The object of the invention is therefore to remedy these disadvantages of the multi-chamber containers of the prior art. A multi-chamber container, in particular a two-chamber bottle, is to be created which can be safely handled by the user. Another aspect of the present invention is to provide a multi-chamber container, in particular a two-chamber bottle, which enables a handle to be attached easily. At the same time, the prerequisites should be created for holding and storing the multi-chamber container in an upside-down position, without thereby excessively restricting the scope for design with regard to the shape of the multi-chamber container. A multi-chamber container, in particular a two-chamber bottle, is also to be created, in which a reliable sealing of the container with a single closure lid is ensured. The multi-chamber container should be able to be produced in an extrusion blow molding process.

The solution to these tasks of these partly contradictory tasks consists in a multi-chamber container which has the features stated in the characterizing section of patent claim 1. A manufacturing method according to the invention for the multi-chamber container is characterized by the features mentioned in the characterizing section of the independent method claim 10. Preferred embodiments and / or further developments of the invention are the subject of the dependent device and method claims.

The invention creates a multi-chamber container, in particular a two-chamber bottle, which consists of at least two container parts with pouring spouts, which are formed in one piece from plastic. The container parts are via a connecting web interconnected, which runs approximately parallel to the axial extent of the container parts. Each container part is connected to the adjacent container part (s) on both sides of the axial connecting web via at least one essentially radially extending, web-like stiffening.

The radial stiffening webs of the container parts give the multi-chamber container greater rigidity. In particular, this prevents the container parts from tilting or pivoting about the axial connecting web. Due to the design-related increase in container rigidity, the wall thickness of the container parts can be reduced, which has an advantageous effect on the manufacturing costs of the multi-chamber container. The multi-chamber container according to the invention can have one or a number of axially protruding pouring necks, which corresponds to the number of chambers. The pouring necks can also be arranged inclined to the axis of the container.

It proves to be expedient for the radial stiffening webs to run at the same axial height of the container parts on both sides of the axial connecting web. This measure means that each container part is connected in the same way to its neighboring container part (s). When handling the multi-chamber container, its radial orientation therefore plays no role in terms of rigidity.

For the rigidity of the additional connections of the container parts to one another and for manufacturing reasons, an axial wall thickness of the radial stiffening webs of approximately 0.5 mm to approximately 8 mm has proven to be advantageous.

A particularly tilt-resistant construction of the multi-chamber container, even with a reduced wall thickness of the container parts, results if the radial stiffening webs are connected to the axial connecting web.

By stiffening webs are provided in a gripping section of the multi-chamber container, each of which is arranged axially one after the other in pairs, the stiffening takes place precisely where the user grips the container. The stiffeners in the gripping section of the multi-chamber container significantly improve the stability of the container even in the partially emptied state. Even with relatively thin-walled multi-chamber containers, the multi-chamber container with stiffeners in the gripping section proves to be easier to handle for the user. Another advantage of the paired axial arrangement of radial stiffening webs one behind the other is that they can be designed to connect a handle part. For this purpose, undercuts or the like, for example, can be formed on an axial pair or also on axial pairs of stiffening webs, which enable a handle designed with correspondingly forked cross arms to be pushed on or slipped open. Such pairs of radial stiffening webs also allow the multi-chamber container to be connected to a correspondingly designed holder, for example in order to store the multi-chamber container upside down.

Multi-chamber containers are often used for the storage and dispensing of multi-component materials that are to be mixed and used in equal quantities. For this purpose and above all for manufacturing reasons, in order to keep the complexity of the molds low, the container parts are of the same design.

The multi-chamber container according to the invention is advantageously produced in one piece in the extrusion blow molding process. The extrusion blow molding process has been tried and tested and allows the mass-technical, cost-effective production of one-piece multi-chamber plastic containers in large quantities.

In a variant of the multi-chamber container, the pouring spouts complement one another to form a neck piece of the multi-chamber container. In the peripheral region of their mouth edges, the pouring spouts of the container parts are connected to one another essentially continuously to form a circular neck edge. A multi-chamber container designed in this way can be closed with a single closure, usually a screw closure. For this purpose, the pouring spouts are provided on their outer surfaces with threaded sections which complement one another to form a screw thread for the common screw cap. It proves proves to be particularly advantageous if the pouring spouts are connected below the circular neck rim with radial stiffening webs. The neck piece has a particularly high stability due to the radial stiffening webs. This reliably prevents overtightening of the screwed joint screw cap for the pouring spout of the container parts.

The method for producing the multi-chamber container according to the invention with at least two similar container parts with pouring spouts, which are connected to one another via an axial connecting web, and which together form a container neck, is an extrusion blow molding process. In this case, a preform is introduced into a blow mold which is equipped with separate mold chambers for the production and connection of the container parts and is inflated by means of a blow mandrel introduced into the blow mold by means of a gas blown in under excess pressure. In the case of two-chamber bottles, for example, a split blow mandrel is provided on a blow mandrel holder. Overflow channels are provided on the blow mold wherever essentially radial connecting webs are to be formed, via which the softened plastic can flow over during the blowing process and can connect to the plastic of the container parts. With this very simple trick, the process is modified in such a way that multi-chamber containers with higher rigidity can be produced. This also allows the use of preforms with smaller wall thicknesses. Material can be saved in this way, and the unit costs for the multi-chamber bottles, for example for two-chamber bottles, can be reduced even further.

In order to allow the softened plastic to overflow, overflow channels are provided in the molds, which are very simply designed as grooves in the mold sections separating the mold chambers. As a result, the existing molds can continue to be used after simple reworking. The grooves are advantageously created with a diameter of approximately 0.5 mm to approximately 8 mm. With the selected diameters, reliable overflow is guaranteed; on the other hand, an uncontrolled expansion of the softened plastic is prevented. The invention is explained in more detail below with reference to the schematic drawings. In a representation that is not to scale:

Fig. 1 is a schematic representation of an extrusion blow molding process;

2 shows an embodiment of a multi-chamber container according to the invention using the example of a two-chamber bottle with a common neck piece;

3 shows a plan view of the two-chamber bottle according to FIG. 2;

4 shows a detailed view according to detail Z in FIG. 2;

5 shows an axial section of the two-chamber bottle according to section line V-V in FIG. 3 and

Fig. 6 is a two-chamber bottle with two separate spouts.

The extrusion blow molding process is used for the mass production of thin-walled hollow bodies, such as bottles, canisters, drums, but also watering cans, tanks for motor vehicles and similar containers made of thermoplastic materials. For this purpose, the plastic, which is usually in the form of granules, is melted and a preform is produced from it. The preform can be in different forms. For example, it can be formed as a tube or have a long, cylindrical shape. The preform is then introduced into the cavity of a blow mold immediately after its production or only at a later point in time and is inflated in accordance with the mold cavity and thereby shaped into its final shape. 1 schematically shows the sequence of an extrusion blow molding process. An extrusion blow molding machine provided with the reference number 1 is composed of an extruder 2 with an extrusion head 4 for producing a preform 5 and a blow molding unit which immediately adjoins and which has a blow mandrel 7 which protrudes from a blow mandrel holder and which usually consists of two in the cavity 10 Halves existing blow mold 9 is retractable. In the extrusion blow molding process, the preform 5 is produced immediately before being introduced into the blow mold 9. This can be done in a continuous or batch process. In the continuous extrusion blow molding process, a plastic P, usually in the form of granules, is fed to the extruder 2 via a funnel 3, melted and conveyed to the extrusion head 4 in the molten state. At the exit of the extrusion head 4, a hose-like preform 5 is continuously extruded, which is introduced into the cavity 10 of the blow mold 9 essentially immediately after its production. The preform 5 can be extruded or co-extruded in one or more layers as required. After the preform 5 has been separated from the continuously extruded tube with the aid of a knife 6, the blow mandrel 7 is introduced in order to inflate the preform 5 to the shape predetermined by the cavity 10 in the blow mold 9. In the discontinuous extrusion blow molding process, the plastic melt is temporarily stored in the extruder head 4. The blow mold 9 is arranged directly below the extruder opening and is only opened and closed in the cycle cycle. When the blow mold 9 is open, the melt is expelled into the cavity 10 of the blow mold 9 at high speed as a tubular preform 5. When the blow mold 9 is welded, the preform 5 is separated. The blow mandrel 7 can then be inserted in order to inflate the preform 9. The preform 5, which is inflated into its final shape, cools down due to its contact with the wall of the blow mold 9 and through the blowing medium, for example air, and can be removed as a fully formed container 13. The slug pieces on the bottom and on the neck of the container 13 are separated by a punch indicated with the reference numeral 8. Thereafter, the container 13 is usually checked for leaks. Whether the container 13 produced is a container having one or more chambers ultimately depends on the blow mold 9 used. 2-5 show a first exemplary embodiment of a multi-chamber container designed according to the invention using the example of a two-chamber bottle, which bears the overall reference number 20. The two-chamber bottle 20 comprises two container parts 21, 22 with pouring spouts 23, 24. The two container parts 21, 22 are of the same design and are connected to one another via a connecting web 29 which extends over the axial length of the two container parts 21, 22. Distributed over the axial extent of the two container parts 21, 22 are radial, web-like stiffeners 31, 33, 35, which connect the two container parts 21, 22 to one another and give the two-chamber bottle 20 greater rigidity. The radial stiffening webs extend, preferably at the same height in each case, on both sides of the axial connecting web. In the side view of FIG. 2, however, only the radial stiffening webs 31, 33, 35 of one side of the bottle are shown.

The pouring spouts 23, 24 complement each other to form a neck piece 25 of the two-chamber bottles 20. As can be seen in particular from the top view in FIG. 3, the mouth edges of the pouring spouts 23, 24 are continuously connected to one another and form a circular neck rim 28. On the outer surfaces of the pouring spouts 23, 24 threaded sections are formed, which add up to a screw thread for a screw cap. As shown in Fig. 3, the mutually facing walls of the two container parts 21, 22 in the shark 25 form a partition 30 which divides the opening in the neck piece 25 of the two-chamber bottle into the two approximately semicircular partial openings of the pouring spouts 23, 24.

FIG. 4 shows the detail of the two-chamber bottle designated Z in FIG. 2. In particular, FIG. 4, representative of the radial stiffening webs, shows the radial stiffening web, designated 33, which is arranged approximately in the middle of the axial extent of the two-chamber bottle. The radial stiffening web 33 forms a cohesive connection between the two container parts 21, 22 and is preferably also cohesively connected to the axial connecting web 29. The axial wall thickness t of the radial stiffening web 33 is approximately 0.5 mm to approximately 8 mm. 5 shows the radial stiffening webs 31, 32 and 33, 34 and 35, 36 on both sides of the axial connecting web 29. The radial stiffening webs 31 - 66 are integrally connected to the container part 21 with the pouring spout 23. The threaded section 26 is indicated on the pouring spout 23. In particular, it is evident from the illustration that two stiffening webs 31, 32 are arranged in the region of the neck piece of the two-chamber bottle, below the neck rim 28 on both sides of the axial connecting web. Further radial stiffening webs 33, 35 and 34, 36 are arranged in pairs axially one behind the other, on both sides of the axial connecting web 29 in the gripping section of the two-chamber bottle. These stiffening bars give the two-chamber bottle increased rigidity, especially in the gripping section. There is also the possibility of connecting a handle to the stiffening webs 33, 35 and 34, 36 arranged axially one behind the other. For this purpose, at least two of the stiffening webs 33, 35 or 34, 36 arranged axially one behind the other are equipped with undercuts or similar connecting elements which interact with corresponding connecting parts on the handle. The radial stiffening webs arranged in pairs one behind the other can also be used for mounting the two-chamber bottle in a correspondingly designed holder, for example in order to store the two-chamber bottle upside down. The radial stiffening webs 31-36 each open into the axial connecting web 29 and are integrally connected to it.

The axial connecting web 29 and the radial connecting webs 31 - 36 consist of the same plastic material as the container parts and are produced during the blow molding process. For this purpose, overflow channels are provided on the blow mold wherever essentially radial connecting webs are to be formed on the two-chamber bottle. The plastic softened during the blowing process can flow through these channels and connect to the plastic of the container parts and the connecting web. This applies analogously to the design of the neck piece with a continuous, circular neck edge. The overflow channels are designed as bores or grooves in the walls of the molding chambers, in which the container parts are molded during the blowing process. The bores or grooves have a diameter of approximately 0.5 mm to approximately 8 mm. 6 schHessHch shows a further exemplary embodiment of a two-chamber bottle, provided with the reference number 40, which has two separate spouts 43, 44 for the two container parts 41, 42. The separate spouts have external threads 45, 46, each of which enables a screw cap to be screwed on. The two container parts 41, 42 are connected to one another via an axial connecting web 49. Radial stiffening webs are again provided in the gripping section of the two-chamber bottle, which are provided with the reference numerals 33 and 35 in analogy to the illustration in FIG. 2. The stiffening webs 33, 35 serve to stiffen the two-chamber bottle 40 and prevent tilting around the axial connecting web 49. The stiffening webs 33, 35 can also be used to fasten a handle or to mount the bottle in an appropriately designed holder.

The invention has been explained using the example of two-chamber bottles. Selbstver- ständHch can also be equipped gen three- or multi-chamber container with the novel radial Verbindungsste ^'. In the described exemplary embodiment according to FIGS. 2-5, three pairs of connecting webs are provided in addition to a continuous neck edge. Fewer or more radial connecting webs can also be arranged. However, it proves to be advantageous for the welding process with a common screw cap if at least radial connecting webs are arranged in the area of the neck piece or in the vicinity thereof on both sides of the axial connecting web. The connecting webs do not necessarily have to run in pairs at the same axial height; they can also be provided on both sides of the connecting web at different axial heights of the multi-chamber container. As was explained on the basis of the exemplary embodiments described, different types of multi-chamber containers, in particular multi-chamber bottles, can be equipped with radial connecting webs. This also applies in particular to so-called inclined-neck bottles, in which the pouring neck (s) are arranged inclined with respect to the bottle axis.

Claims

claims

1. Multi-chamber container, in particular two-chamber bottle (20; 40), comprising at least two container parts (21, 22; 41, 42) with sealable pouring spouts (23, 24; 43; 44), which container parts are integrally molded from plastic and have one in the axial direction extending connecting web (29; 49) are connected to each other, characterized in that each container part (21, 22; 41, 42) along its longitudinal extent, on both sides of the axial connecting web (29; 49), via at least one essentially radially extending web-like Stiffener (31 - 36; 33, 35) is connected to the adjacent container part (s) (22, 21; 41, 42).

Multi-chamber container according to claim 1, characterized in that the radial stiffening webs (31, 32, 33, 34, 35, 36) run on both sides of the axial connecting web (29) at the same axial height of the container parts (21, 22).

3. Multi-chamber container according to claim 1 or 2, characterized in that the radial stiffening webs (31-36) have an axial wall thickness (t) of approximately 0.5 mm to approximately 8 mm.

4. Multi-chamber container according to one of the preceding claims, characterized in that the radial stiffening webs (31-36) open into the axial connecting web (29).

5. Multi-chamber container according to one of the preceding claims, characterized in that the container parts (21, 22; 41, 42) in a gripping section of the multi-chamber container (20; 40) via two pairs of radial stiffening webs (33, 35 34, 36; 33, 35) are connected to one another, which are arranged axially one behind the other on both sides of the connecting web (29; 49).

6. Multi-chamber container according to claim 6, characterized in that at least two of the radial stiffening webs (33, 35) arranged in pairs one behind the other are designed as connecting parts for a clip-on or clip-on handle and / or for a holder for the container.

7. Multi-chamber container according to one of the preceding claims, characterized in that the container parts (21, 22; 41, 42) are essentially of the same design.

8. Multi-chamber container according to one of the preceding claims, characterized in that it is produced in one piece in a continuous or discontinuous extrusion blow molding process.

9. Multi-chamber container, in particular two-chamber bottle, according to one of the preceding claims, characterized in that the pouring spouts (23, 24) complement one another to form a neck piece (25) which in the circumferential area of the mouth edges of the pouring spouts (23, 24) is essentially one Continuous, circular neck edge (28), and that the pouring spouts (23, 24) below the circular neck edge (28) are connected to each other by stiffening webs (31, 32).

10. Method for producing a multi-chamber container (20) with at least two container parts (21, 22) connected to one another via an axial connecting web (29) with pouring spouts (23, 24), which together form a container neck (25), in a continuous or discontinuous manner Extrusion blow molding process, wherein a preform is introduced into a blow mold (9) which is equipped with separate mold chambers for the production and connection of the container parts and is inflated by means of blow mandrels (7) introduced into the mold chambers of the blow mold by means of a gas blown in under excess pressure, characterized in that on the blow mold (9) wherever essentially radial connecting webs are to be soldered, overflow channels are provided, through which the softened plastic can overflow during the blowing process and can connect to the plastic of the container parts (21, 22).

11. The method according to claim 10, characterized in that the overflow channels are grooved as grooves in the mold sections separating the mold chambers.

12. The method according to claim 11, characterized in that the grooves with a diameter of about 0.5 mm to about 8 mm are first Ut.