Collapsible tubular container

© Start of patent duration: 19 80 06 15 Longest possible duration:

t Issued on: 1933 09 26

Inventor:

© dependence:

© Pamphlets considered to delineate the prior art:

AT 372 349

FR-PS 2052074 OE-AS 1486193

CH-PS 45 7251 OE-AS 2154602

US-PS 3874558 OE-AS 1786574

U.S. Patent 3,356,263

Nr.372349

The invention relates to a packaging tube with a multilayer tube tube having a metallic intermediate layer and thermoplastic cover layers, the upper edge of which engages over the shoulder part of a tube head made of thermoplastic material independently of this, the shoulder part being covered by a barrier layer extending to the neck of the tube head. Such a packaging tube is known from FR-PS No. 2,052,074.

Packaging tubes, the tube tube and tube head are manufactured separately and welded together as prefabricated parts are known. The processes required for this are suitable for the production of pure plastic tubes or those with a metallic barrier layer. Compared with those methods in which the tube head to the tube tube, eg by injection molding during forming, the former methods have the advantage that they can be carried out on less demanding machines. Waiting periods which cause sufficient solidification of accumulations of plasticized plastic are eliminated in these processes.

However, both of the above-mentioned known methods liable for the lack of that they are only applicable to such tubes in which the immediately adjacent parts of tube tube and tube head made of thermoplastically bondable plastics. Accordingly, these methods can not be used, for example, for the production of packaging tubes in which the upper edge of the tube surrounds the shoulder of the tube head made of plastic and the inside of the tube tube is not made of a thermoplastically connectable plastic material at least at this upper edge. That is the case, for example, when the tubes are equipped with diffusion-inhibiting barrier layers.

A method is also known in which the connection between a tube tube made of composite material with metal layer and the tube head is produced by induction welding. The inductive welding heat is generated in the metallic layer of the tube tube, which extends to this end to the shoulder and there overlaps the headboard. It can not be prevented that heat generated in this layer in the shoulder region is also dissipated in areas in which no heat is needed or this may even be detrimental, for example, by deformations, discoloration or even bubbles may arise in the composite film. Although in connection with the aforementioned known method measures, such as Cooling of the welds immediately adjacent areas of the tube body are known during the welding process, the fact remains that comparatively much more heat must be generated than would be required for the welding process.

In many cases, the generation of the heat loss, ie the heat dissipated by the metal layer is not possible without lengthening the piece time. In a thin-walled metal insert can not be generated as much heat for a short time, without damaging the composite film or even destroy.

According to another known solution, either the tube end is divided into different lobes, which can then fold over the shoulder section or it is the tube end so constricted with folds that so that the shoulder of the head part can be covered. Both of these known solutions are rationally difficult to produce. In addition, there is a risk that the currents induced in the individual lobes pierce each other and thereby burn the metal foil, while the formed by folding shoulder cover tends to the folded metal foil breaks under the pressure necessary for the connection of the head and body part, so that the diffusion barrier effect is no longer sufficiently guaranteed. Similar disadvantages are also to be expected in the solution according to the aforementioned FR-PS No. 2,052,074, in which the upper edge of the tube tube over the full radial extent of the shoulder to the neck is placed inwardly and thus also the barrier layer, which contains the tubular body made of composite material, extending to that point.

As already said, the taper of the tube head engaging over the upper end of the tube tube is difficult, these difficulties are the greater the stronger the diameter reduction. The necessary tools and the processing time make the shoe manufacturing process considerably more expensive. In addition, the tube shoulder would hardly get an attractive appearance.

- 3 Nr.372349

Other known solutions (cf., for example, CH-PS No. 457251) propose to prevent the diffusion by means of an injected in the headboard or by an inserted in the headboard barrier layer. However, the effectiveness of these measures depends essentially on how small the distance of the barrier layers of the shoulder portion or the tubular body can be kept to each other.

From US-PS no. 3,874,558 a compressible packaging tube is further known in which the shoulder of the tube head and an annular connecting body extend together over the shoulder area of ​​the tube. However, the connecting body is not multilayered in this case and also not welded to the neighboring parts.

The invention is therefore an object of the invention to provide a packaging tube, which meets with minimum effort in the production of high demands on the tightness, in particular with respect to diffusion. Furthermore, the Verpackungstube should also be suitable for chemically non-neutral products that attack, for example, a metal such as aluminum. In other words, therefore, in the case of a packaging tube which has a barrier layer extending to the neck, a structure is to be created which permits production to be as rational as possible.

This object is achieved according to the invention in the initially described packaging tube, that in known manner, the barrier layer by a metallic intermediate layer of a connecting body forming annular disc, which has thermoplastic on both sides, is formed, and that the annular disc the inwardly projecting edge of the tube tube engages and sits directly on the shoulder part, wherein the cover layers of the annular disc are welded to the inner thermoplastic cover layer of the tube tube or to the shoulder part of the tube head, wherein the cutting edge of the annular disc is covered by the material of the thermoplastic cover layers.

The stated object is achieved by the invention in an advanced manner. Since the continuation of the barrier in the shoulder region is effected by the annular disk forming a connecting body, a complicated deformation operation or machining of the upper tube tube end can be omitted. For the production of the connection between tube tube and annular disc, it is sufficient to crimp the corresponding tube tube end in a narrow edge region in order to allow the overlap with the annular disc. Such beading may possibly even occur when closing the mold, which is anyway necessary for the welding process. Crimping the edge or punching out spikes is definitely superfluous. The annular disc can be made on the other hand without much effort forth; it can be made of composite material, eg by punching with simultaneous embossing efficiently. In addition, it is possible to combine the annular disk with the tube head or to set this on the tube head even before the tube head has been staked on the mandrel of the welding mold and the tube tube has been supplied, thereby simplifying the automatic supply of such an annular disc. Finally, it is achieved with the embodiment according to the invention above all that an attractive tube is formed.

The drawings show in axial section the upper part of a tube tube -2- with a connecting body -60- and a tube head part -62-. The tube tube -60- is formed of a three-layer composite material, the inner layer -10- and outer layer -6- preferably made of polyethylene, the middle layer -34- made of metal, preferably made of aluminum. The connecting body -60- consists of a three-layer composite material, namely an outer layer -64- and an inner layer -66-, as well as a barrier layer -68-. The barrier layer is preferably an aluminum alloy. The layers -64 and 66- are heat-sealing layers which are preferably made of polyethylene or a copolymer well adhering to the aluminum layer. The headboard -62- is a molded article made of plastic, such as polyethylene, which is produced in a known manner by injection molding.

The threaded portion of the head portion -62- may have an annular groove -70-, whereby a sleeve -72- is formed, which prevents a rapid flow back of the contents immediately after removal. As a result, a tightening of harmful for the contents of air as far as possible

No.372349 avoided. Also, the annular groove -70- by a ring, not shown, from a

Material filled with diffusion-blocking properties.

The head part -62- further comprises a shoulder -74-, which serves as a stop and first sealing surface for a screw cap, not shown screwed. Another with the Ver⁵ Closure cap cooperating sealing surface can only be effective if it is elastic. For this purpose, the cap can be dimensioned so that it presses with its inner base on an arranged on the head part -62- annular sealing lip -76-. Another possibility for a further sealing surface provides a bevel -78- above the external thread on the head part -62-, which bevel must be adapted to the cap. The Dichtlip10 pe -76- or the chamfer -78- act in conjunction with a plastic cap as elastic seals that can compensate for manufacturing tolerance within certain limits.

A particular advantage is that the distance between the barrier layers -34, 68- of the tube tube -2- or of the shoulder portion forming connecting body -60- as small and ¹⁵ the overlap of the barrier layers -34, 68- can be kept as large as possible. As a result, the diffusion path is correspondingly large, so that a good diffusion-inhibiting effect is achieved.